Uterine involution represents a crucial component of the reproductive process in animals, with the extent of involution being a key determinant of whether a female animal can achieve subsequent pregnancy. The completion of uterine involution in female animals postpartum is influenced by a variety of factors, including nutrition, postpartum care, and the season of parturition. In ruminants, this process is primarily regulated by the hypothalamic-pituitary-gonadal axis (HPGA). However, current research on the mechanisms underlying uterine involution in ewes remains fragmented, and the specific regulatory pathways of the HPGA in this context are not yet fully elucidated. This review aims to comprehensively examine the mechanisms of uterine involution in ewes, the factors influencing this process, and the role of the HPGA. It is intended to provide a foundational reference for a deeper understanding of the significance of the HPGA in uterine involution in ewes and to offer a theoretical basis for future research into the regulatory mechanisms of the HPGA in this area.

Despite the significant advancements in China's animal husbandry sector, enhancing the reproductive capacity of livestock and poultry still remains a relentless pursuit for breeding farms. Follicular atresia, which refers to the non-ovulatory follicles, is extremely common in livestock and poultry and has become a significant factor constraining their reproductive capabilities, thus attracting increasing attention. Granulosa cells, as a key factor affecting follicular atresia, play a crucial role in the process of follicular atresia. Currently, most research findings indicate that the proliferation of granulosa cells can influence the development of follicles, while apoptosis of granulosa cells can lead to follicular atresia. However, the underlying mechanisms still require further exploration. This paper discusses the roles of granulosa cells in apoptosis, autophagy, ferroptosis, pyroptosis, and necroptosis, providing new perspectives and insights into the complex mechanisms of follicular atresia.

Bile acids, as a natural substance that inhibits the growth of microorganisms in animals, is gaining increasing attention. Currently, there is still a lack of systematic analysis of the diversity of antibacterial mechanisms of bile acids. In this review, the latest progress in the study of the antibacterial mechanism of bile acids, including the direct antibacterial mechanism (surfactant mechanism, destroying cell membrane homeostasis mechanism and oxidative damage mechanism), and the indirect antibacterial mechanism (activating the expression of host antibacterial substances and affecting the expression of bacterial functional genes). On this basis, the structural modification strategies (dimerization/polymerization, introduction of positively charged groups and synthetic biology of secondary bile acids) to improve the antibacterial activity of bile acids were summarized, with a view to providing theoretical reference and basis for the application of bile acids in bacteriostasis.

The addition of antibiotics to animal feed has reduced the occurrence of animal diseases in livestock and poultry production and promoted growth. However, it also leads to a series of problem including antibiotic residues in animal-derived products and the environment, an increase in multi-drug resistant bacteria in animals, etc. And also has a serious impact on food safety and the development of animal husbandry, which threatening human health and the ecological environment. Against the backdrop of the national policy of "banning antibiotics in feed and reducing their use in breeding", the use of alternative products that can enhance the disease resistance of animals has become a research hotspot. Among them, traditional Chinese medicine has received widespread attention due to its wide sources, few side effects, and low likelihood of developing drug resistance. When used alone or in combination with antibacterial drugs, it shows good antibacterial effects. This article discusses the current situation of antibiotic resistance in animal-derived bacteria in China and reviews traditional Chinese medicines that can reduce antibiotic resistance in animal-derived bacteria and their mechanisms of action, with the aim of providing a scientific basis for in-depth research and control of antibiotic resistance in animal-derived bacteria.

Porcine epidemic diarrhea virus (PEDV) is a virus that causes acute diarrhea, vomiting, dehydration, and other symptoms in piglets. Due to its high incidence rate and high mortality, it has caused substantial economic losses to the global pig industry. Although vaccination is currently the most economical and effective measure for preventing porcine epidemic diarrhea (PED), the frequent emergence of PEDV variants has resulted in poor immune protection from existing vaccines, making the development of effective antiviral drugs particularly urgent. In recent years, researchers have been dedicated to screening and evaluating substances with potential anti-PEDV activity, which mainly exert their effects by targeting the invasion, replication, or assembly processes of the virus, or by enhancing the host's immune response. This article provides an overview of the anti-PEDV effects and mechanisms of chemical drugs, natural products, and other biological agents, in order to provide new directions and ideas for the screening and research of anti-PEDV drugs.

Porcine epidemic diarrhea (PED) is an acute, highly contagious intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV), characterized primarily by vomiting, dehydration, and diarrhea. In recent years, the emergence of variant PEDV strains has led to significant economic losses in the pig farming industry in many countries. Therefore, investigating the pathogenic mechanisms of PEDV and identifying effective prevention and control measures are essential to ensuring the health and productivity of pig farming. This review summarizes the mechanisms by which PEDV evades host immune responses, including the inhibition of interferon production and the regulation of apoptosis, autophagy, pyroptosis, and inflammatory responses. Additionally, it discusses the progress in vaccine development and nutritional interventions aimed at controlling PEDV, providing a theoretical foundation for the effective control of PED.

Porcine epidemic diarrhea (PED) is a highly contagious disease caused by the porcine epidemic diarrhea virus (PEDV), characterized by symptoms such as vomiting, watery diarrhea, dehydration and weight loss. The mortality rate of suckling piglets after infection can be as high as 100%, resulting in significant economic losses to the global pig industry. Currently, there are no effective therapeutic drugs available for PEDV, and vaccines have certain limitations. During viral infection, viral proteins interact with host proteins to evade host innate immunity while promoting replication on one hand and regulating the host immune response to inhibit viral infection on the other hand. Therefore, identifying viral proteins that interact with host proteins is crucial for understanding host defense against viral infections and pathogenesis of infectious diseases leading to novel antiviral targets discovery. This review elaborates on protein interactions between viruses and hosts during PEDV infections while summarizing its pathogenic mechanism to provide new ideas for designing effective vaccines or drugs aimed at preventing and controlling PEDV spread.

Rabies is an acute zoonotic infectious disease caused by the viruses of the genus Lyssavirus in the family Rhabdoviridae. According to the latest 10th report of the International Committee on Taxonomy of Viruses, the Lyssavirus is currently divided into 17 species. Serotype Ⅰ rabies virus (RABV), a member of the Lyssavirus family, is the most common cause of rabies. As sequencing technologies advance, more and more whole genomes of the Lyssaviruses are being sequenced, providing a deeper molecular-level understanding of the epidemiology and natural evolution of the virus. This review aims to summarize the distribution, transmission, origin and phylogeny of lyssaviruses, providing a theoretical reference for tracing the origin of lyssaviruses, mastering their transmission and genetic evolution, and formulating scientific strategies for rabies prevention and control.

Ehrlichia canis is a tick-borne pathogen transmitted by Rhipicephalus sanguineus s.l., primarily parasitizing the host's blood cells. It poses a significant threat to human and animal health worldwide, and has considerable zoonotic importance. Several studies have found that the transmission and distribution of Ehrlichia canis is closely related to a variety of factors, including vector abundance, natural environment, age, usage, and health status of dogs. This paper provides a comprehensive review, covering the etiology, clinical manifestations, global epidemiological characteristics, and risk factors affecting the transmission and distribution of Ehrlichia canis. Its objective is to offer new perspectives and strategies for ehrlichiosis prevention and control.

The purpose of this study was to analyze the whole genome copy number variation and its association with backfat thickness of Yunan black pigs, and to explore the key copy number variation (CNV) and candidate genes affecting the backfat thickness of Yunan black pigs, so as to provide new breeding ideas for the genetic improvement of Yunan black pigs.In this study, a genome-wide copy number variation (CNV) analysis was conducted on 120 Yunan black pigs from a core breeding population by SNP chip and PennCNV software. Backfat thickness was systematically measured at five anatomical landmarks (P2 point, maximum shoulder thickness, 6th-7th rib interface, last rib, and lumbosacral junction), and the average values were calculated for the association studies. After stringent quality control, 104 individuals were retained for downstream analysis. Using high-density SNP microarrays and PennCNV software, 252 CNVs were identified and further merged into 62 non-overlapping copy number variation regions (CNVRs) distributed across autosomes 1 to 18. Genome-wide association analysis using Plink revealed 4 loci on chromosomes 1, 8, and 16 that exhibited statistically significant correlations with backfat thickness (P < 0.05). Subsequent functional annotation using BioMart and GeneCards databases dentified 11 candidate genes located in proximity to these loci: SOCS6, PTTN, CD226, NR3C2, ARHGAP10, DCLK2, IQCM, CDH9, CDH10, U2 and U6. Functional characterization indicated that these genes are involved in diverse biological pathways: SOCS6, NR3C2 and CDH10 are associated with lipid metabolism and adipocyte differentiation; CD226, U2 and U6 are linked to meat quality attributes and reproductive performance; and ARHGAP10 plays a role in growth regulation and body weight modulation. These findings not only enhance the understanding of the genetic architecture underlying backfat deposition in Yunan black pigs but also provide actionable targets for precision breeding programs aimed at optimizing carcass traits through marker-assisted selection.

This study aimed to investigate the effects of Adipor2 gene interference on thermogenesis in subcutaneous inguinal adipocytes of Tibetan pigs and to elucidate the molecular mechanisms by which AdipoR2-AMPK pathway activity influences lipid synthesis and ATP production. Subcutaneous inguinal adipose tissues were collected from 20-day-old Tibetan pigs in winter (TW group, average environmental temperature -15 ℃), Tibetan pigs in summer (TS group, average environmental temperature 25 ℃), and Landrace pigs in summer (LS group, average environmental temperature 25 ℃), with 5 individuals per group. Small interfering RNA (siRNA) targeting AdipoR2 was used to post-transcriptionally silence Adipor2 expression. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was employed to measure mRNA levels of adiponectin receptor genes, siRNA-AdipoR2 interference efficiency, AMPK downstream signaling, lipid synthesis-related genes, thermogenesis-related genes, and mitochondrial complex Ⅰ-Ⅲ genes in adipose tissues. Cell proliferation capacity was analyzed using a cell counting kit-8 (CCK-8), while Western blot (WB) was used to detect the expression of AMPK and its downstream signaling. Oil Red O staining was performed to assess lipid deposition capacity, and JC-1 mitochondrial membrane potential and ATP production kits were used to evaluate thermogenesis in Tibetan pig adipocytes. In vivo, long-term cold exposure significantly increased the expression of Adipor1/2 in subcutaneous inguinal adipose tissues of Tibetan pigs (P < 0.01 or P < 0.000 1). In vitro, the expression of Adipor2 in induced mature adipocytes from Tibetan pigs was significantly higher than that in Landrace pigs on days 4, 8, and 12, while Adipor1 expression was significantly lower (P < 0.01 or P < 0.000 1). siRNA-AdipoR2 significantly inhibited the expression of Adipor2, promoted the expression of the lipid synthesis gene Fasn, and inhibited the expression of thermogenesis-related genes (Dio2 and Cidea) and mitochondrial complex I gene Ndufa (P < 0.05, P < 0.001, or P < 0.000 1). Additionally, Adipor2 interference significantly reduced cell expansion efficiency at 48 h, inhibited AMPK phosphorylation, and promoted lipid deposition (P < 0.05, P < 0.01, or P < 0.001). JC-1 aggregate mitochondrial membrane potential and ATP production analyses revealed that siRNA-AdipoR2 significantly suppressed mitochondrial membrane potential and ATP production (P < 0.01 or P < 0.001). This study demonstrates that Adipor2 interference inhibits AMPK signaling, promotes lipid deposition, and suppresses thermogenesis in Tibetan pig adipocytes, providing molecular insights and a theoretical basis for understanding the unique cold adaptation mechanisms of Tibetan pigs.

This study aimed to activate avian macrophages using a selective SIRT1 activator and identify relevant target genes and signaling pathways through transcriptomic analysis. Chicken macrophages were treated with a selective SIRT1 activator, SRT1720 HCl, at a concentration of 1 μmol·L^-1. The experiment was divided into a control group (treated with DMSO) and an experimental group (treated with SRT1720 HCl), with 5 biological replicates per group. After 24 hours of treatment, total cellular RNA was extracted and reverse transcribed. High-throughput sequencing was then performed using the Illumina Novaseq X Plus platform, and subsequent bioinformatics analyses were conducted. Differentially expressed genes (DEGs) were identified using thresholds of |log₂ FC|>1 and an adjusted P < 0.05. A total of 1 183 DEGs were detected (P < 0.05), of which 781 were upregulated and 402 were downregulated, including key genes such as CD14, TLR7, IL10RA, NFKBIA, and JUN. Five genes selected from the DEGs were validated by real-time quantitative PCR, and the results were consistent with the transcriptomic data. Gene Ontology (GO) enrichment analysis revealed significant enriched terms associated with metabolic processes, immune system processes, biological adhesion, and catalytic activity (P < 0.05). Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results showed significant enriched pathways including the MAPK signaling pathway, Toll-like receptor signaling pathway, and NOD-like receptor signaling pathway. Notably, enrichment of the Salmonella infection pathway was observed, suggesting that activation of SIRT1 in avian macrophages might influence Salmonella infection. Protein-protein interaction network analysis further indicated that SIRT1 was closely related to genes such as NFKBIA and JUN. The study utilized transcriptome analysis of chicken macrophages after SIRT1 gene activation to screen for immune-related genes and important pathways, provides a research foundation for exploring the role of SIRT1 in avian immunity.

The aim of this study was to investigate the incidence of myopathies in breast muscle of domestic broilers and the similarities and differences between spaghetti meat (SM) and wooden breast (WB) in terms of histological characteristics, meat quality indexes and processing attributes. A total of 1 900 post-slaughter breast muscle samples from 42-day-old broilers reared under the same feeding conditions were used to classify the severity grades of SM, WB, and white striping (WS) and to count the incidence. From these, 326 samples were selected and divided into 4 major groups, including 46 samples from normal group, 78 samples from SM group, 174 samples from WB group, and 28 from the co-occurrence group for the determination of pectoralis major weight, compression force, shear force, marinade uptake, drip loss and meat color; and another 131 samples were also selected and divided into 4 groups, including 20 samples from normal group, 35 samples from SM group, 70 samples from WB group and 6 samples from the co-occurrence group for the analysis of cooking loss and pH. The results showed that the total incidence of myopathies in the two groups was 48.88% and 48.67%, with 14.60% and 13.90% incidence of SM, and 9.20% and 8.40% incidence of moderate and severe WB, respectively. Histological analysis using hematoxylin-eosin and Picrosirius Red staining revealed that the connective tissues in the muscle bundles membranes of SM and WB were significantly different from those of normal muscle, presenting a heterogeneous arrangement of collagen fibers of type Ⅰ and type Ⅲ, whereas the muscle bundles of SM had a greater degree of dissociation and fewer and shorter collagen fibers, with type Ⅲ fibers predominating. Meat quality analyses showed that SM severity was significantly and negatively correlated with shear and compression forces; compression force and meat color brightness of WB significantly increased while redness significantly decreased, and were significantly and positively correlated with pectoralis major weight (P < 0.05). pH of SM and WB were significantly (P < 0.05) higher than those of normal meat. Analysis of processing attributes showed no significant changes (P>0.05) in marinade uptake and drip loss for SM, whereas marinade uptake significantly decreased (P < 0.05) for WB. In summary, the occurrence of SM and WB altered the collagen fiber type, meat quality, and processing attributes of the breast muscle, which provides necessary reference information for solving the problem of myopathies by genetic, breeding, or processing means in broilers.

This study started with long non-coding RNA (lncRNA) and aimed to explore the transcriptome characteristics of ancestral-like coarse (ALC) individuals in the Aohan fine wool sheep population. Skin samples were collected from 3 ALC lambs and 3 non ancestral modern fine (MF) wool lambs, all 30 days old. RNA sequencing (RNA-seq) was performed to identify mRNA and lncRNA potentially associated with the "ALC" phenomenon in fine wool sheep. Through bioinformatics analysis, we explored the role of lncRNA in the development of fine wool follicles and conducted joint analysis of lncRNA and mRNA. The total of 1 540 differentially expressed lncRNAs (DE-lncRNAs) and 513 differentially expressed genes (DEGs) were screened, which were enriched in multiple signaling pathways related to hair follicle development, such as WNT, PPAR, MAPK, and all showed significant downregulation. DE-lncRNAs with significant differences (P < 0.05) was analyzed, including lncRNAs closely related to early development of primary hair follicles, such as GTL2. GO and KEGG enrichment analysis was performed on DE-lncRNA target genes and DEGs. DE-lncRNA target genes and DEGs were enriched in multiple signaling pathways related to hair follicle development, such as WNT, PPAR, MAPK, as well as biological processes related to TGF-β negative regulation. In addition, DE-lncRNA and DEGs enrichment analysis showed that ALC lambs had multiple upregulated pathways for substance and energy metabolism. The correlation analysis between DEGs and DE-lncRNA identified 90 genes that might be regulated by DE-lncRNA, including ADIPOQ, BRCA1, CCAR2, KIF20B, SOAT1, which are involved in processes related to cell proliferation, cell fate determination, cell cycle regulation, substance binding, catalytic activity, etc. The results showed that ALC lambs had significant differences in hair follicle-associated lncRNAs compared to MF lambs, indicating that the primary hair follicles of ALC lambs might be in the initial stage of comprehensive degeneration. The MAPK and PI3K/AKT signaling pathways were potentially important for the phenomenon of juvenile atavism in ALC sheep. The metabolism of ALC lamb was more vigorous than that of MF lamb. GTL2 and other DE-lncRNAs might be associated with stronger adaptability in ALC sheep. This study aims to explore lncRNAs related to ALC traits in fine wool sheep, providing reference clues for further research on the development mechanism of fine wool sacs and having important reference value for stress resistant breeding of fine wool sheep.

The study aimed to clarify the expression of miRNA in bovine skeletal muscle tissues at different developmental stages and screen the key miRNAs affecting bovine skeletal muscle development. The present study conducted RNA sequencing analysis on muscle tissues from 3-month-old and 6-month-old embryos, as well as 9-month-old fetal muscle tissues obtained through embryo splitting and embryo transfer techniques, all originating from the same source with highly consistent genetic backgrounds. Bioinformatics approaches were applied to screen for differentially expressed miRNAs, followed by target gene prediction and functional enrichment analysis. Compared with muscle tissue at 3 months old, 262 differentially expressed miRNAs (130 up-regulated and 132 down-regulated) were screened in muscle tissue at 6 months old; Compared with muscle tissue at 6 months old, 397 differentially expressed miRNAs (199 up-regulated and 198 down-regulated) were screened in muscle tissue at 9 months old; And compared with muscle tissue at 3 months old, 448 differentially expressed miRNAs (224 up-regulated and 224 down-regulated) were screened in muscle tissue at 9 months old. Meanwhile, 3 854, 7 434 and 8 167 target genes were predicted, respectively. Functional annotation and pathway analysis of the target genes revealed that the differentially expressed miRNAs between the 6-month and 3-month stages were predominantly involved in 5 muscle development-related pathways, including cytoskeleton in muscle cells, focal adhesion, autophagy-animal, etc. Similarly, the differentially expressed miRNAs between the 9-month and 6-month stages were primarily associated with 4 muscle development-related pathways, such as cytoskeleton in muscle cells, focal adhesion and growth hormone synthesis, secretion and action, etc. Furthermore, the differentially expressed miRNAs between the 9-month and 3-month stages were significantly enriched in 6 muscle development-related pathways, including cytoskeleton in muscle cells, focal adhesion, regulation of the actin cytoskeleton, etc. A regulatory network of differentially expressed miRNAs and functional target genes associated with skeletal muscle development was constructed, identifying 38 miRNAs, including bta-miR-139, bta-miR-499, bta-miR-7, bta-miR-148a and bta-miR-204, which might play regulatory roles in the growth and development of bovine skeletal muscle at different stages. The results of this study provide an important theoretical basis for in depth understanding of the molecular mechanism of bovine skeletal muscle development, and also provide basic data for subsequent miRNA research on bovine skeletal muscle.

The objective was to construct a genome-wide CRISPR/Cas9 knockout library in bovine mammary epithelial cells, which would facilitate the identification of functional genes associated with milk production, stress responses, and disease susceptibility in cow. This study focused on the protein-coding genes of the cow whole genome. CRISPR/Cas9 technology was employed to design and synthesize a sgRNAs library, which was subsequently cloned into the LentiCRISPR-V2 lentiviral vector to construct a cow whole-genome CRISPR/Cas9 knockout plasmid library. The gEditing ScreeningTM library sequencing was performed for validation. Next, the knockout plasmid library was packaged into lentivirus particles, and the viral titer was determined. Following infection of bovine mammary epithelial cells (bMECs), the optimal infection efficiency was confirmed through puromycin resistance screening and validated using RT-qPCR and Western blot analyses. Finally, high-throughput sequencing was conducted to verify the quality of the cell library by assessing the coverage and distribution of sgRNAs in the knockout cell library. A total of 20 545 protein-coding genes were targeted in the whole-genome knockout plasmid library constructed in this study, including 61 237 sgRNAs, of which 3 062 were not previously annotated in the cow genome. Sequencing analysis of the gEditing ScreeningTM plasmid library revealed a 100% coverage rate, a homogeneity index of 2.35, and an average sequencing depth of 577×. The plasmid library was subsequently packaged into lentiviral vectors, yielding a viral stock with a titer of 7.01×10⁸ TU·mL^-1, which was used to infect bMECs. Following 14 days of puromycin selection, stable cell lines were established at multiplicities of infection (MOI) of 0.2, 0.3, 0.4, and 0.5, with an optimal MOI determined to be 0.2. High-throughput sequencing results indicated that the cell library achieved a coverage rate of 78.74%, with stable base composition and high-quality sequence reads. In conclusion, both the cow whole-genome plasmid library and the cow whole-genome knockout cell library have met the established quality standards and experimental requirements. These resources can serve as a critical platform for screening cells to investigate key genes that regulate cow lactation traits and mammary gland health.

This study aimed to investigate the regulatory role of Msh-homeobox 2 (MSX2) in the proliferation of dermal papilla cells (DPCs) in long-haired rabbits. Skin samples were collected from the backs of 12 healthy 6-month-old long-haired rabbits, and DPCs were isolated and cultured. The coding sequence (CDS) of the MSX2 gene was cloned, and its biological characteristics were preliminarily analyzed using bioinformatics tools. The effects of MSX2 overexpression and knockdown on DPCs proliferation were explored, along with the regulatory roles of related genes. The results showed that the CDS of the MSX2 gene was 807 bp in length, encoding 268 amino acids. Overexpression of MSX2 in DPCs significantly increased the mRNA expression levels of hair follicle development-related genes, including CCND1, EGF, Wnt2, and Hoxc13 (P < 0.01), while significantly or extremely significantly decreased the expression of STAT1, SFRP2, and Wnt5a (P < 0.05 or P < 0.01). Conversely, knockdown of MSX2 exhibited the opposite trend. Additionally, MSX2 significantly promoted DPC proliferation. These findings provide a theoretical foundation for further research on the role of MSX2 in hair follicle development in rabbits.

This study aimed to explore the application effect of low-density SNP chips in pig breeding, especially in terms of genotype imputation and breeding value estimation accuracy. This study designed a low-density SNP chip with a density of 5K based on the medium to high density SNP chip "KPS Porcine breeding chip v2", which can be used for detecting genetic marker typing in breeding pigs and imputed into the quality control panel of "KPS Porcine breeding chip v2)", ultimately applied to genome selection. Subsequently, this study used data from 3 239 purebred Large White pigs from a certain pig breeding farm to investigate the genotype imputation accuracy and genome breeding value estimation accuracy of the low-density chip through five fold cross validation method. The results showed that the allele accuracy of genotype imputation reached 99.46%, and the average accuracy of genetic evaluation for age adjusted to 100 kg weight and back-fat thickness adjusted to 100 kg weight were 0.374 2 and 0.402 1, respectively. Compared with the original genotype data, the accuracy loss was only 0.001 5 and 0.001 2. The results indicate that low-density SNP chips retain the vast majority of original information while reducing detection costs. This study provides a basis and reference for the design of low-density chips for the whole genome of livestock and poultry. This strategy significantly reduces the cost of genotype testing and promotes the popularization of genomic selection of pigs in China.

The purpose of this study was to analyze the changes of cecal flora in Taihang chickens infected with Salmonella Pullorum. The cecal contents of 19-day-old Taihang chickens in uninfected group (group C) and infected group (group B) were collected. A final library of the 16S rRNA gene V3-V4 region was constructed, and the composition, abundance, and diversity of microbial flora in the two groups were analyzed. Metastat and LEfSe analysis were used to identify the different species between groups. PICRUSt was used to predict gene function. STAMP software was used to analyze gene function differences. The results showed that the relative abundance of potential beneficial bacteria in Lachnospiraceae, Erysipelotrichaceae and Faecalitalea_sp_ in group C were significantly higher than those in group B (P < 0.05). The relative abundance of Clostridiales_bacterium in group B was significantly higher than that in group C (P < 0.05). The prediction of PICRUSt gene function showed that the two groups were significantly enriched in six major metabolic pathways (P < 0.05), and the microorganisms in group B were more involved in CMP-sialic acid synthetase, which may affect the infection of Salmonella Pullorum. This study investigated the characteristics of cecal microflora flora using a Taihang chicken infection model of Salmonella Pullorum. It was hypothesized that Salmonella Pullorum may influence the host intestinal microbial flora through Clostridiales_bacterium and CMP-sialic acid synthase, providing reference data for research on Salmonella Pullorum infection.

The aim of this experiment was to analyze the reproductive toxicity of zearalenone (ZEA) on Pengbo semi-fine wool sheep testicular sertoli cells and the antioxidant stress protection mechanism of N-acetylcysteine (NAC) on testicular sertoli cells. The testicular tissue of 3-month-old male Pengbo semi-fine wool sheep ((13.87±0.46) kg) were isolated from sertoli cells for in vitro infection test, and the doses of ZEA in the experimental group were 25, 50, 100 and 200 μmol· L^-1, control group (NC group) added only 0.1% DMSO, with 3 replicates in each group, screening ZEA test concentration. Combined enzymatic digestion, differential attachment and immunofluorescence staining (IF) were used to isolate and purify sertoli cells, and to identify specific antibodies GATA4 and Vimentin. CCK-8 and EdU were used to detect the viability and proliferation of sertoli cells. qRT-PCR and Western blot were used to detect the expression changes of genes and proteins related to cell proliferation (pcna), apoptosis (bax, caspase3, caspase9) and oxidative stress (cat, gsh-px, sod1) and the protective effect of NAC. The results showed that combined enzyme digestion and differential adhesion could obtain the SCs for the ZEA toxicity test, cell activity and proliferation number of SCs gradually decreased with the increase of ZEA toxicity concentration, those of 200 μmol·L^-1 ZEA treatment group were extremely significantly lower than that in NC group (P < 0.01); The mRNA and protein expression levels of cell proliferation gene pcna were extremely significantly lower in 200 μmol ·L^-1 ZEA treatment group than that in NC group (P < 0.01); The mRNA expression levels of pro-apoptosis genes bax, caspase3 and caspase9 were extremely significantly higher than NC group (P < 0.01), the protein expression levels of CASPASE3 were extremely significantly higher than NC group (P < 0.01), BAX and CASPASE9 were significantly higher than NC group (P < 0.05); The mRNA and protein expression of anti-apoptosis gene bcl-2 were significantly lower than NC group (P < 0.05). The mRNA expression levels of oxidative stress-related genes gsh-px and sod1 were extremely significantly higher than NC group (P < 0.01), and gene cat were significantly higher than NC group (P < 0.05), the protein expressions of CAT and SOD1 were extremely significantly higher than NC group (P < 0.01). After pretreatment with NAC, compared with NC group, the expression levels of cleaved-CASPASE-9 and cleaved-CASPASE-3 in experimental groups were extremely significantly decreased (P < 0.01), BAX protein was significantly decreased (P < 0.05), and BCL-2 protein was significantly increased (P < 0.05). To sum up, ZEA could cause reproductive toxicity to Pengbo semi-fine wool sheep, inhibit testicular SCs proliferation, promote SCs apoptosis, and lead to oxidative damage of SCs. NAC has a protective effect on ZEA induced testicular SCs oxidative damage in Pengbo semi-fine wool sheep.

This study aimed to analyze the molecular regulation mechanism of ncRNA (non-coding RNA) on the development process of sheep ovary, and screen the key genes for improving sheep fertility. In this study, 3 healthy adult ewes were selected from multiparous sheep (Small-tail Han sheep) and single-born sheep (Ujumuqin sheep) to construct ncRNA and mRNA expression profiles of ovarian tissue, the differentially expressed lncRNAs, circRNAs, miRNAs and mRNAs were screened, and their target genes were predicted and GO and KEGG enrichment analysis were performed. Reproductive related pathways were screened out to further construct the ceRNA (lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA) regulatory network, and finally the key miRNAs in the regulatory network were summarized. The results showed that a total of 1 579 lncRNAs, 561 circRNAs, 175 miRNAs and 3 095 mRNAs differentially expressed in the ovarian tissues of Ujumuqin sheep and small-tailed Han sheep were screened. The results of GO and KEGG enrichment analysis showed that the target genes were significantly enriched in biological processes such as embryonic morphogenesis, meiosis activation, and mucin type O-glycan biosynthesis, glycosphingolipid biosynthesis, D-arginine and D-ornithine metabolism and other signaling pathways. The differentially expressed genes enriched in reproductive pathways were screened, and a ceRNA network(contained 87 lncRNAs, 27 circiRNAs, 3 miRNAs and 3 mRNAs)was constructed to obtain three key miRNAs(miR-140, miR-338 and miR-423-5p)and corresponding targeted regulatory ceRNA networks. Real-time fluorescence quantification (qRT-PCR) detection results of 9 differentially expressed lncRNAs, circRNAs, miRNAs, mRNAs, randomly selected were consistent with the trend of high-throughput sequencing results, indicating the reliability of sequencing data. This study analyzed the coordinated regulatory mechanism of DE ncRNAs and corresponding target genes, which provided an effective theoretical basis for elucidating the key genes and molecular mechanisms regulating the development of sheep ovary, and further fully understood the reproductive biological characteristics of sheep, which has important guiding significance for improving the reproductive efficiency.

This study aimed to clarify the mechanism of FGF2, LIF and IGF1 (FLI) improving bovine oocyte maturation in vitro. The study used ovaries collected from slaughterhouses, cumulus oocyte complexes (COCs) extracted from ovaries were randomly divided into control group and FLI group for in vitro maturation, 30 COCs per group, each experiment was repeated 3 times. After 24 hours of in vitro maturation, first polar body excretion rate, cumulus expansion, mitochondrial membrane potential, cortical granule distribution, glucose consumption and pyruvate content in the medium, oocyte redox state, number of TZPs, reactive oxygen species content, expression of relevant genes were detected; the cleavage rate, blastocyst rate and blastocyst cell number of subsequent embryo development were counted. The results show that, the cumulus expansion index in FLI group was significantly higher than that in control group (3.16±0.04 and 2.43±0.02, respectively, P < 0.001). Compared with the control group, the expression of cumulus expansion related genes in oocytes of FLI group was increased (P < 0.05), increased migration of cortical granules to periovum (P < 0.05), however, the first polar body excretion rate and mitochondrial membrane potential of oocytes did not change significantly (P>0.05). Compared with the control group, the consumption of glucose and the content of pyruvate in the culture medium of FLI group were significantly increased (P < 0.05), NADPH in oocytes increased significantly (P < 0.001), and the expression of genes related to glucose metabolism showed significant up-regulation (P < 0.05). The addition of FLI could reduce the levels of redox, FAD++ and ROS in oocytes (P < 0.05). At IVM 8 h, the number of TZPs in FLI group was significantly higher than that in control group (106±6.91 and 78±8.76, respectively, P < 0.001). After in vitro fertilization, the cleavage rate and blastocyst rate in FLI group were significantly higher than those in control group ((86.49±0.80)%, (37.44±0.42)% and (74.08±0.91)%, (27.34±1.08)%, respectively, P < 0.05). The results show that, FLI can improve the quality of oocyte in vitro maturation and embryonic development by increasing glucose metabolism.

This experiment aimed to explore the correlations between hormones, oxidative stress indicators, trace elements, and other factors in the peripheral plasma and pregnancy status of cows during early pregnancy, providing references for the early pregnancy diagnosis of cows. In this experiment, 120 healthy multiparous Holstein cows (2-3 parities) with similar body condition scores were selected from a dairy farm in Ningxia. Following estrus synchronization treatment, plasma samples were collected on the 7^th day after timed artificial insemination (TAI). The recurrence of estrus was observed using the step-counting method from 18 to 24 days post-TAI, and pregnancy diagnosis was performed via B-ultrasound on the 35^th day. Based on the diagnosis results, the cows were categorized into 3 groups: pregnant (n=46), non-pregnant (n=34), and return (n=40). ELISA was utilized to measure the levels of total antioxidant capacity (T-AOC), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase 4 (GPX4), catalase (CAT), cortisol (COR), melatonin (MT), prostaglandin E2 (PGE2), prostaglandin F2α (PGF2α), progesterone (P4), estradiol (E2), copper (Cu), and zinc (Zn) in plasma samples from the 3 groups. The results indicated that: 1)Among the 120 cows, 46 were pregnant (pregnancy group, 38.33%), 40 returned to estrus (the returns group, 33.33%), and 34 were not pregnant (non-pregnancy group, 28.34%); 2)The concentrations of plasma PGE2, COR, T-AOC, GPX4, CAT, and Zn in pregnant cows and non-pregnant cows were significantly higher than those in the returns group (P < 0.05), the MDA concentration in non-pregnant cows was significantly higher than that in pregnant cows (P < 0.05), while no significant differences were observed in other indices among the groups (P>0.05); 3)Analyzing the relationship between the concentrations of each index and pregnancy rate, it was found that when the concentrations of E2, P4, PGE2, PGF2α, MT, COR, T-AOC, GPX4, CAT, MDA, SOD, Cu and Zn were 239.27-292.73 ng·L^-1, 4.71-6.95 ng·mL^-1, 767.36-941.70 ng·L^-1, 386.70-489.05 ng·L^-1, 1 664.34-2 271.51 ng·L^-1, 316.32-382.36 ng·mL^-1, 0.34-0.39 mmol·L^-1, 62.80-71.90 mg·mL^-1, 10.67-17.75 U·mL^-1, 1.15-1.80 nmol·mL^-1, 14.20-15.73 U·mL^-1, 12.00-24.00 μmol·L^-1 and 14.71-16.53 μmol·L^-1, respectively, the pregnancy rate of cows was the highest, which were 75%, 47%, 63%, 56%, 48%, 60%, 57%, 50%, 50%, 50%, 57%, 50% and 50%, respectively; 4)The ROC curve analysis indicated that the AUC values for Zn, COR, and PGE2 in the plasma of cows on the 7^th day after TAI were relatively high (AUC>0.6). In conclusion, low concentrations of T-AOC, CAT, GPX4, COR, PGE2, and Zn are associated with recurrence of estrus of dairy cows, while low concentrations of MDA are linked to pregnancy on the 7^th after TAI. The varying concentrations of these biomarkers correspond to differences in the pregnancy rates of dairy cows. Zn, COR, and PGE2 could serve as candidate biomarkers for early pregnancy diagnosis in estrus dairy cows.

This experiment was conducted to investigate the effects of dietary net energy (NE) and standard ileal digestible lysine (SID Lys) levels on reproductive performance, serum hormone, lactation performance and fecal flora diversity of Rongchang sows in late pregnancy. Seventy-two Rongchang sows (2 to 4 parities) were randomly divided into 9 groups of 8 replicates with 1 pig in each replicate. A 3×3 two-factor design was used, dietary NE levels were 8.75, 9.48 and 10.04 MJ·kg^－1, and dietary SID Lys levels were 0.52%, 0.62% and 0.72%. The experiment started at the 84^th day of gestation and finished after farrowing. The results showed as follows: Dietary NE level had significant effects on the changes of backfat thickness, estrus interval of sow and birth weight of piglets (P < 0.05). The changes of backfat thickness of sows and birth weight of piglets in 10.04 and 9.48 MJ·kg^－1 NE groups were significantly higher than those in 8.75 MJ·kg^－1 NE group, and the estrus interval was significantly lower than that in 8.75 MJ·kg^－1 NE group (P < 0.05). When the dietary NE level and SID Lys level were 10.04 MJ·kg^－1 and 0.52%, the number of live litters born and birth litter weight of piglets were the highest. Dietary NE level had significant effects on serum hormone of pregnant sows (P < 0.05). The contents of serum insulin, follicle-stimulating hormone(FSH) and luteinizing hormone(LH) in 10.04 MJ·kg^－1 NE group were significantly higher than those in 8.75 MJ·kg^－1 NE group, and the insulin-like growth factor-I(IGF-I) content was significantly higher than that in 9.48 MJ·kg^－1 NE group (P < 0.05). Dietary NE level significantly influenced the composition of colostrum (P < 0.05). Lactose content in 10.04 MJ·kg^－1 NE group was significantly higher than that in 8.75 MJ·kg^－1 NE group (P < 0.05), and the levels of milk protein and dry matter in 8.75 MJ·kg^－1 NE group were significantly higher than those in 9.48 MJ·kg^－1 NE group (P < 0.05). Dietary NE level significantly affected the relative abundance of fecal flora in sows (P < 0.05). The relative abundance of Firmicutes in 10.04 MJ·kg^－1 NE group was significantly higher than that in 8.75 and 9.48 MJ·kg^－1 NE groups, and the relative abundance of Lactobacillus in 10.04 MJ·kg^－1 NE group was significantly higher than that in 8.75 MJ·kg^－1 NE group (P < 0.05), while the relative abundance of Streptococcus was significantly lower than that of 8.75 MJ·kg^－1 NE and 9.48 MJ·kg^－1 NE groups (P < 0.05). Correlation analysis showed that the relative abundance of Lactobacillus was positively correlated with the content of serum Insulin in sows, and the relative abundance of unclassified_p_251_o5 was negatively correlated with the contents of Insulin and LH (P < 0.05). Dietary SID Lys level had no significant effects on all indexes of pregnant sows (P>0.05). In conclusion, the effects of dietary NE level on reproductive performance, serum hormone, colostrum composition and fecal microflora of sows are greater than those of SID Lys level. When the dietary NE level was 10.04 MJ·kg^－1 and SID Lys level was 0.52%, resulting in the largest number of live litters of Rongchang sows.

This study aimed to analyze the immunogenicity of recombinant adenoviruses and baculoviruses expressing African Swine Fever Virus (ASFV) genes B602L-B646L. Piglets were immunized with rAd-F-Hsp70, followed by a booster with rBac-F either 21 days later or 3 days after co-administration with the CpG adjuvant. Alternatively, the immunization strategy involved rBac-F as the initial vaccine, followed by a booster with rAd-F-Hsp70 after 21 days. Each piglet received a dose of 1×10⁸ PFU. Serum was collected on days 21 and 42 post-primary immunization to measure antibody levels against ASFV pB602L and p72 proteins. Additionally, the levels of interferon-γ (IFN-γ) and interleukin-4 (IL-4) in the supernatants of antigen-stimulated peripheral blood mononuclear cells (PBMCs) were assessed on day 42 post-primary immunization. Results were as follows: Specific IgG antibodies were detected in the serum of all immunized pigs from day 21 onwards, with antibody levels significantly increasing after the booster immunization. The CpG adjuvant combined with rAd-F-Hsp70/rBac-F group showed significantly higher levels of pB602L and p72 antibodies compared to both the rAd-F-Hsp70/rBac-F (P < 0.01) and rBac-F/rAd-F-Hsp70 groups (P < 0.01). Among these, the rAd-F-Hsp70/rBac-F group exhibited significantly higher specific antibody levels compared to the rBac-F/rAd-F-Hsp70 group (P < 0.01). After stimulation of PBMCs with ASFV pB602L and p72 recombinant antigens, the supernatants from the CpG adjuvant combined with the rAd-F-Hsp70/rBac-F group contained significantly higher levels of IFN-γ and IL-4 compared to the other immunized groups (P < 0.01). This indicates that using rAd-F-Hsp70 as the primary immunization vector, combined with CpG adjuvant, significantly enhances both humoral and cellular immune responses. Using rAd-F-Hsp70 as the primary vaccine and rBac-F as the booster, along with the CpG adjuvant, significantly enhances the levels of specific antibodies and cytokines against pB602L and p72. These findings provide data to optimize ASFV vaccine strategies for future development.

Tight junction proteins play a crucial role in various viral infections, with tight junction protein 4 (Claudin-4, CLDN4) being a major member of this family. The role of CLDN4 in porcine epidemic diarrhea virus (PEDV) infection remains unclear. To explore the impact of PEDV infection on CLDN4 expression and the role of CLDN4 in PEDV infection, we performed quantitative PCR (qPCR) and Western blot to assess the transcriptional and protein expression levels of CLDN4 following PEDV infection. Additionally, a eukaryotic expression plasmid for the CLDN4 gene was constructed, and specific interference RNA targeting CLDN4 was designed. The effects of overexpression and knockdown of CLDN4 on PEDV replication were analyzed using qPCR, Western blot, immunofluorescence assay (IFA), and PEDV viral titer measurements. Finally, we examined the effects of overexpression of CLDN4 on the adhesion and invasion phases of PEDV infection. Results showed that PEDV infection upregulates CLDN4 transcription and protein levels, while overexpression of CLDN4 significantly promotes PEDV replication, and interference with CLDN4 expression inhibits PEDV replication. Moreover, CLDN4 facilitates PEDV adhesion and invasion. This study suggests that CLDN4 plays a role in promoting PEDV infection and replication, providing a reference for investigating CLDN4 function and elucidating PEDV replication mechanisms.

The aim of this study was to investigate the antibacterial activity in vivo and in vitro of PBD-1 over-expressed by prokaryotes, and to provide material and theoretical basis for the treatment of clinical mastitis. In this study, prokaryotic expression vectors of PBD-1 were constructed, the induced expression conditions were optimized, the minimum inhibitory concentration (MIC) was determined after over-expression and purification, and the bactericidal dynamic curve was drawn. The mouse model of mastitis was established with E. coli13-1 and S. aureus 4-1, and the intramammary perfusion therapy was performed with different concentrations of PBD-1, and the therapeutic effect was observed through the pathological changes of breast tissue and its bacterial load. The results showed that the prokaryotic expression vector of PBD-1 was successfully constructed, the recombinant PBD-1 was soluble and yielded of 328.6 mg·mL^-1. The recombinant PBD-1 had antibacterial effect on E. coli 13-1, S. aureus 4-1 and S. epidermidis 25-1, and the MIC was 82.15 μg·mL^-1 in vitro. The results of intramammary perfusion test showed that PBD-1 with 1×MIC and 2×MIC had a certain therapeutic effect on S. aureus 4-1 andE. coli 13-1 mouse mastitis models. Prokaryotic expression of recombinant PBD-1 has inhibitory effects on all three detected bacteriain vitro, and has therapeutic effects on S. aureus4-1 and E. coli 13-1 mastitis models.

The purpose of this study was to investigate the effect of monocyte chemotactic protein-induced protein 3 (MCPIP3) on porcine epidemic diarrhea virus (PEDV) replication. The dynamic change of MCPIP3 transcription level after PEDV infection was determined by RT-qPCR. Then, using monkey kidney epithelial cell cDNA as template, ZC3H12C gene was amplified by PCR and cloned into P3×Flag-CMV-14 eukaryotic expression vector to construct MCPIP3 eukaryotic recombinant vector. MCPIP3 protein was overexpressed or interfered on African green monkey embryonic kidney cells (MARC-145), and the influence of MCPIP3 protein on PEDV replication was investigated by Western blot, quantitative PCR, and virus titer determination. The results showed that PEDV infection significantly up-regulated ZC3H12C transcription on MARC-145 cells. The MCPIP3 recombinant plasmid was successfully constructed, which could induce exogenous high expression of MCPIP3 protein after transfection, and the specific siRNA could significantly down-regulate the transcription level of ZC3H12C. Compared with the control group, high expression of MCPIP3 significantly inhibited PEDV N protein expression level, down-regulated PEDV N gene transcription levels and virus titer, while interfered with MCPIP3 expression had the opposite effect, indicating that MCPIP3 significantly inhibited PEDV proliferation on MARC-145 cells. Furthermore, the MCPIP3 expression negatively regulated PEDV induced transcription of IL-8, IL-12β and TNF-α. This study expanded the function of MCPIP3 protein, and provided a theoretical basis for the study of PEDV replication mechanism.

The aim of this study was to understand the molecular epidemiological characteristics and genetic variation of porcine circovirus type 3 (PCV3) in China in recent years. In this study, 168 domestic (collected from 2017 to 2023) and 9 foreign PCV3 genome sequences were selected from GenBank database, and their phylogenetic tree construction, nucleotide homology comparison, amino acid sequence comparison, epitope prediction and gene recombination were analyzed by bioinformatics software, in order to clarify the transmission and genetic evolution law of PCV3 in China. The results showed that the genotypes of PCV3 in China can be divided into two subtypes, namely, PCV3a and PCV3b, and both of them can be further divided into different gene clusters: PCV3a-1~PCV3a-3 and PCV3b-1~PCV3b-5, among which PCV3a-1 and PCV3b-2 have the largest number and the highest proportion. The whole genome sequence similarity of 177 PCV3 is between 98.3% and 100%, and there are three main point mutation regions in the amino acid sequence encoded by ORF2 gene, without base deletion and insertion. In addition, the analysis of gene recombination shows that there is only one possible recombination event between these whole genome sequences of PCV3, which indicates that the prevalent genotypes of PCV3 in China are in a relatively stable stage. This study found a genotyping method that is likely to be widely recognized in the future through strict standard definition, and based on this genotyping method, the results obtained when analyzing the genetic variation of PCV3 in China from 2017 to 2023 are reliable, which not only provides a unified framework for the future research on genetic variation of PCV3, but also provides basic data for further revealing the molecular epidemiological characteristics, genetic diversity, vaccine design and prevention and control strategies of PCV3.

This study aimed to study the immunogenicity and adhesive properties of the Dnak protein of Mycoplasma bovis (Mb). Primers were designed according to the Dnak gene of Mycoplasma bovis HB0801 strain in GenBank. The Dnak gene of Mycoplasma bovis was amplified by overlap PCR and the recombinant plasmid pET-Dnak was constructed. After double enzyme digestion and sequencing, the recombinant plasmid was transformed into E. coli BL21 (DE3) and induced by Isopropyl-β-D-thiogalactopyranoside (IPTG) for expression. Western blot, ELISA, and indirect immunofluorescence assay were used to detect the immunogenicity of Dnak protein and the distribution of Dnak protein in Mycoplasma bovis. The complement-mediated bactericidal assay detected the activity of rDnak antiserum mediatedantiserum-mediated activation of mycoplasma. Adhesion and adhesion inhibition tests were used to analyze the adhesion function of Dnak protein to host cells. The results showed that the recombinant protein rDnak was successfully expressed in E. coli, the main soluble form was pure, the relative molecular size was about 70 ku, and the recombinant protein had good immunogenicity. Its multi-antiserum can effectively activate complement to kill mycoplasma; Dnak protein exists in both the membrane and cytoplasm of Mycoplasma bovis and is an adherence-related protein of Mycoplasma bovis, involved in adhesion to EBL cells. Dnak protein is an adhesion-related protein with good immunogenicity in Mycoplasma bovis, which lays a foundation for exploring the pathogenic mechanism of Mycoplasma bovis.

The aim of this article was to understand the current status of patent development related to Listeria in China. This study analyzed data on the number of patent applications related to Listeria monocytogenes, technology lifecycle, technology patent fields, applicants, and research cores. The results showed that domestic patent applications related to Listeria monocytogenes reached a peak in 2016, with a significant increase in both the number of applications and the number of applicants in 2015-2016 and 2018-2019; The applicant's main body covers universities, enterprises, research institutes, individuals, etc; The research focuses on the detection of Listeria monocytogenes and the serotype detection methods of Listeria monocytogenes. In conclusion, this study hoping to provide reference for further exploring the technological development of Listeria and the prevention and control of Listeria monocytogenes.

This study aimed to understand the epidemiological characteristics, virulence genes, resistance genes, resistant phenotype and genetic diversity of Klebsiella pneumoniae in Gansu Province. In this study, K. pneumoniae was isolated and purified from 156 yak lung samples collected from a slaughterhouse in Gansu Province. Serotypes, virulence genes and drug resistance genes of the isolates were tested by molecular biology means, and resistance profiles of the isolates were tested by K-B method. The results showed that, a total of 84 K. pneumoniae strains were isolated from 156 lung samples, the separation rate was 53.85%; Eight capsular serotypes were not detected, indicated that the isolates might belong to other serotypes; The virulence genes detection results showed that, the detection rate of pilus biosynthesis-related genes fimH (84.52%) and mrkD (95.23%), kipopolysaccharide-related gene uge (94.05%), the urease-related gene ereA (88.10%), and the iron uptake system gene ybtA (97.62%) were high, the detection rate of other virulence genes was low or not detected. The results of drug-resistance gene testing showed that, the detection rate of the bla_TEM gene of the ESBLs class (85.71%), Carbapenem VIM genes (79.76%) and acc (6')-Ib of aminoglycosides (77.38%) were high, other drug resistance genes was low or not detected. The results of the drug susceptibility test showed that the isolates were highly resistant to co-trimoxazole (98.81%), erythromycin (97.62%), vancomycin (95.24%) and clindamycin (94.05%), and have different degrees of resistance to the rest of the drugs; ERIC-PCR results showed, similarity> 60% can be classified into a cluster, divided into E 1 to E 6, where E1 was the dominant cluster, accounting for 50.00%. This paper analyzed the prevalence, virulence genes, drug resistance genes and drug resistance phenotypes of K. pneumoniae in Gansu yak, which has certain reference significance for clinical and preventive guidance.

Clostridium perfringens (C. perfringens) secretes β toxin (CPB) that can cause enteritis and enterotoxemia in livestock and wild animals, as well as severe food poisoning in humans. Therefore, the development of effective detection method is crucial for inhibiting the infection with C. perfringens. Here, the specific nanobody (named as CPB-VHH) was obtained by establishing a CPB nanobody library and panning through phage display technology, and the half-life, affinity and temperature stability were evaluated. Using CPB-VHH as the capture antibody and alpaca anti-CPB polyclonal serum as the detection antibody, a double-antibody sandwich ELISA method was established and evaluated. The results showed that CPB-VHH was successfully obtained with a half-life of 2.152 h, an affinity constant of 0.961 2 and good stability within 37 ℃. Based on CPB-VHH, a specific double-antibody sandwich ELISA was established with the critical value of 0.183, the sensitivity of 0.977 ng·mL^-1, accuracy of 92%, and without cross reaction with CPA, CPB, ETX recombinant protein of Clostridium perfringens, L. monocytogenes, S. aureus, Salmonella and Escherichia coli, which showed the good specification. The results suggested that the double-antibody sandwich ELISA method established in this study provided a diagnostic method for C. perfringens type B and C infections, and also provided guidance for vaccine development involving CPB quantification and research on the pathogenicity of β toxin.

Type Ⅵ secretion systems (T6SS) are widely found in Gram-negative bacteria, and its effector protein Tse1 plays an important role in bacterial interspecies competition. The aim of this study was to investigate the inhibitory effect of Tse1 on Staphylococcus aureus (S. aureus), and to explore its expression and effect in drug-resistant bacteria. Tse1 protein expression was induced and purified using an E.coli prokaryotic expression system containing the recombinant plasmid pET-28a-Tse1. The disruptive effect of the recombinant protein Tse1 on the cell wall of S. aureus was observed by fluorescence microscopy and scanning electron microscopy. Finally, the antibacterial activity of recombinant protein Tse1 against S. aureus and its combined effect with antibiotics were determined by agar pore diffusion inhibition test and micro broth dilution method. The results showed that the expression of Tse1 protein reached the highest level and existed in soluble form in the supernatant at 16 ℃ and IPTG concentration of 0.5 mmol·L^-1 for 16 h. The relative molecular mass of the protein was about 22 ku. The co-culture of recombinant protein Tse1 with S. aureus revealed that the protein was bound to the surface of the bacterium and was able to disrupt the cell wall of the bacterium, and the extent of the disruption was shown in a dose. The degree of disruption was dose-dependent. The agar pore diffusion inhibition assay showed that the recombinant protein Tse1 had significant inhibitory effects on different strains of S. aureus, and the inhibitory effect of Tse1 protein could be significantly enhanced by the combination of penicillin (PG). In this experiment, the prokaryotic expression and purification method of Tse1 protein were established, and it was proved that Tse1 protein had an inhibitory effect on S. aureus, and its inhibitory effect could be enhanced by combining with penicillin, which provided the theoretical basis for the excavation of new antibiotic substitutes.

In order to systematically understand the tick-borne pathogens in the Tumen River Basin and to investigate the tick flora, the molecular epidemiology of tick-borne pathogens of Haemaphysalis and Dermacentor as well as the tick flora in the Tumen River Basin were investigated in the experiment. Dermacentor silvarum, Haemaphysalis japonica, Haemaphysalis concinna were collected at 5 sampling points in 3 cities and counties in the Tumen River basin. Tick-borne bacteria were investigated using high-throughput sequencing technology, and 147 ticks were analysed by second-generation sequencing of the V3-V4 variable region of the 16S gene of tick-borne bacteria. PCR was performed on 442 ticks carrying spotted fever groups Rickettsia, Anaplasma and Babesia. The results of the study showed that analyses of high-throughput sequencing results revealed the presence of at least two tick-borne pathogens and six potentially pathogenic genera with some pathogenic strains within the genus. There were differences in microflora carried by ticks of different genera and sexes in three cities and counties. One type of Rickettsia was detected in ticks in the region: Rickettsia raoulttii; One type of Anaplasma: Anaplasma capra; One species of Babesia: Babesia caballi. The obtained results provide basic data for tick borne pathogens and microbial communities in the region, and provide data support for the prevention and control of ticks and tick borne diseases.

Using the AmpR (ampicillin resistance) reporter gene expression system, we constructed Lactobacillus expression vector systems with different numbers of Lactobacillus constitutive promoter P_ldh in tandem, and different sequences of promoter P_ldh and AmpR reporter genes, and detected the AmpR reporter gene transcription level, protein expression and evaluated the AMPR enzyme activity, so as to screen out the constitutive multi-promoter that is stable and strongly expressed. This will provide a theoretical basis for the expression of exogenous antigens or functional proteins by Lactobacilli expression vectors. Bioinformatics analysis of P_ldh promoter was performed to construct recombinant Lactobacillus with different numbers of promoter P_ldh in tandem and recombinant Lactobacillus with different order of promoter and exogenous gene AmpR. The strength of exogenous gene expression in different expression systems was comprehensively evaluated by real-time fluorescence quantitative PCR, Western blot, indirect ELISA, and ampicillin live bacterial screening test. Results were as follows: PCR results showed that the recombinant Lactobacillus reuteri successfully amplified P_ldh-P_ldh, P_ldh-P_ldh-P_ldh, P_ldh-P_ldh-P_ldh, P_ldh-AmpR-P_ldh-AmpR, P_ldh-P_ldh-AmpR, and P_ldh-P_ldh-AmpR-AmpR target fragments of 600, 900, 2 300, and 2 300 bp, respectively; and the Western blot results showed that all recombinant bacteria could express the AmpR reporter gene at different amounts. The results showed that all the recombinant bacteria could express the AMPR protein, and the target proteins were all about 28 ku in size. Indirect ELISA, fluorescence quantitative PCR and AMPR enzyme activity assays all showed that the efficiency of the triple promoter to drive the expression of the AmpR reporter gene was significantly higher than that of the double promoter in the tandem Lactobacillus expression vector system with different numbers of promoter P_ldh(P < 0.05), and that the efficiency of triple promoter and dual promoter drove the efficiency of AmpR reporter gene expression were all highly significantly higher than that of single promoter (P < 0.01), and all of them were highly significantly higher than that of the control bacterium pPG-Ampr/HLJ-27 (P < 0.01); in the Lactobacillus expression vector system with different sequences of promoter P_ldh and AmpR reporter genes, the recombinant bacterium pPG-P_ldh-P_ldh-Ampr-Ampr/HLJ-27 drove the expression of the AmpR reporter gene very significantly more efficiently than recombinant bacterium pPG-P_ldh-Ampr-P_ldh-Ampr/HLJ-27 P < 0.01). This study successfully constructed five constitutive multi promoter P_ldh lactic acid bacteria expression systems using AmpR reporter genes. The results showed that in different numbers of promoter P_ldh cascade driven single exogenous protein vector systems, the promoter regulated transcription and thus drove the expression level of exogenous genes, which was positively correlated with the number of promoters; In the dual promoter driven dual exogenous protein vector system, the continuous cascade of two promoters regulates transcription and drives the expression efficiency of dual exogenous genes, which is significantly higher than the expression efficiency of dual exogenous genes driven by two promoters separately; The above data provides necessary basis for optimizing the expression efficiency of exogenous proteins in lactic acid bacteria expression vectors.

The purpose of this article is to report the pathologic and immunohistochemical features of a case of feline nasal malignant neuroendocrine neoplasm. A 4-year-old male British shorthair cat was referred to our hospital after being treated for pneumonia for one month. A nasal mass was found on examination, and a surgical biopsy was performed to remove the nasal mass for histopathological and immunohistochemical examination. A biopsy of the nasal mass was performed for histopathological and immunohistochemical examination. Histopathological findings indicate that the tumor cells exhibit significant variability in size and shape, with marked atypia. The nuclei are predominantly vesicular, and the tumor has invaded surrounding tissues. Immunohistochemical results show positive staining for neuron-specific enolase (NSE), synaptophysin (Syn), vasoactive intestinal peptide (VIP), and CD99 (cluster of differentiation 99, CD99). Based on laboratory tests, histopathology and immunohistochemistry, the final diagnosis was nasal malignant neuroendocrine neoplasm and more inclined to poorly differentiated neuroendocrine carcinoma (NEC). This case hoping to provide a reference for diagnosing this tumor and differentiating it from other nasal cavity tumors.

This study aimed to investigate the expression distribution and possible roles of the JAK2/STAT3 signaling pathway and its regulated PCNA, a key protein for cell proliferation, in the lungs of yaks of different ages. In this experiment, the lungs of newborn, juvenile, adult and aged healthy yaks were used to detect the expression of JAK2, STAT3 and PCNA mRNA in the lungs of yaks of different ages by quantitative real-time fluorescence PCR (qRT-PCR), and the expression of JAK2, STAT3, P-JAK2/STAT3 and PCNA proteins in the lungs of yaks of different ages was detected by Immunohistochemistry (IHC) and Western blot methods. The expression distribution of JAK2, STAT3, P-JAK2/STAT3 and PCNA were basically consistent, these are mainly distributed in the bronchial epithelium and vascular endothelium, the smooth muscle layer of the bronchial wall, vascular smooth muscle and alveolar cells. The expression of JAK2 mRNA in the lungs of yaks at different ages demonstrated a tendency of increasing and then decreasing, and the expression of JAK2 mRNA in the adult group was the highest. The expression of STAT3 mRNA in the lungs increased with the age of yaks, and the expression was highest in the old group. The expression of PCNA mRNA in the adult and old groups was significantly higher than that in the newborn and juvenile groups. Additionally, the expressions of JAK2, STAT3, P-JAK2/STAT3 and PCNA proteins were different in the lungs of yaks at different ages. The expression trend of P-JAK2/STAT3 was found to be essentially identical to that of JAK2/STAT3. The expression of JAK2/P-JAK2 proteins was the highest in the juvenile group, and the expression of STAT3/P-STAT3 proteins in the newborn and adult groups was significantly higher than that in the juvenile and old groups, and the newborn group was higher than that in the adult group. The expression of the PCNA protein in the newborn group was significantly higher than that in the juvenile, adult, and old groups. The findings of this study indicated that there were differences in the expression and distribution of JAK2/STAT3 signaling pathway and its regulated PCNA in yak lungs of different ages, suggesting that the JAK2/STAT3 signaling pathway plays a role in the development of yak lungs. This study provides a research foundation for further clarifying the role of the JAK2/STAT3 signaling pathway and its targeted regulation of PCNA in the adaptation of yak lungs to the plateau environment.

This study aimed to investigate the preventive effects of aspirin eugenol ester (AEE) on fatty liver hemorrhagic syndrome (FLHS) in laying hens. A total of seventy-eight 160-day-old Hy-Line Brown laying hens were randomly assigned to six groups, each containing 13 hens. Results were as follows: Group Ⅰ received a basal diet, while Groups Ⅱ to Ⅴ were fed a high-energy, low-protein diet supplemented with 0, 25, 50, and 100 mg·kg^-1 of AEE, respectively. Group Ⅵ was provided a diet containing 2 g·kg^-1 choline chloride. The experiment lasted for 90 days. The results are in the following fashion: ① Compared to Group Ⅰ, Group Ⅱ showed a significant decrease in egg production rate and average egg weight (P < 0.05), and a significant increase in the feed-to-egg ratio (P < 0.05). In comparison to Group Ⅱ, Groups Ⅲ to Ⅵ exhibited a significant increase in egg production rate and average egg weight at different time points (P < 0.05), and a significant decrease in the feed-to-egg ratio (P < 0.05). ② Compared to Group Ⅰ, the body weight of hens in Group Ⅱ significantly increased (P < 0.05). However, compared to Group Ⅱ, the body weights of hens in Groups Ⅲ to Ⅵ significantly decreased (P < 0.05). ③ Compared to Group Ⅰ, the hens in Group Ⅱ showed significantly enlarged livers with a yellowish color, punctate hemorrhages on the surface, and increased friability. HE staining revealed disordered hepatocyte arrangement and the presence of fat vacuoles of various sizes. In contrast, the liver structure of hens in Groups Ⅲ to Ⅵ returned to normal compared to Group Ⅱ. ④ Liver Index and Lipid Levels: Compared to Group Ⅰ, Group Ⅱ showed significantly increased liver index and elevated levels of triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) in serum and liver tissues, with significantly decreased high-density lipoprotein (HDL) levels (P < 0.05). However, compared to Group Ⅱ, Groups Ⅲ to Ⅵ exhibited significantly lower liver index, TG, TC, and LDL levels, and significantly increased HDL levels (P < 0.05). ⑤ Group Ⅱ exhibited significantly lower activities of liver superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT), along with significantly higher malondialdehyde (MDA) levels compared to Group Ⅰ (P < 0.05). In comparison, Groups Ⅲ to Ⅵ had significantly higher SOD, GSH, and CAT activities and lower MDA levels compared to Group Ⅱ (P < 0.05). The results indicate that feeding laying hens a high-energy, low-protein diet effectively induces fatty liver hemorrhagic syndrome. Supplementing this diet with varying doses of AEE demonstrates a protective effect against FLHS in laying hens.

The study aims to investigate the therapeutic effect of exosomes from canine adipose derived mesenchymal stem cells overexpressing Klotho (KL-Exos) on acute kidney injury (AKI) in canines. Construct a recombinant plasmid pCDH-EF1-copGFP-T2A-PURO-Klotho that overexpresses Klotho (EF1-KL recombinant plasmid), and transfect it into canine adipose derived mesenchymal stem cells (cADMSCs). Collect KL-Exos by ultracentrifugation of cell culture medium. Select 8 male Chinese field dogs around one year old with similar physical condition and randomly divide them into 4 groups: normal control group (NC), acute kidney injury group (AKI), Exos treatment group (Exo), and KL-Exos treatment group (KL-Exo). AKI group, Exo group, and KL-Exo group were injected with gentamicin sulfate at a dose of 60 mg·kg^-1, twice daily for 5 consecutive days; the Exo group and KL-Exo group were treated with 300 μg of Exos or KL-Exos injected on days 6, 9, and 12, respectively; the NC group and AKI group were injected with the same dose of physiological saline. After the treatment is completed, the treatment effect is comprehensively evaluated through imaging, serology, anatomy, histology and molecular biology testing in sequence. The sequencing results indicate the successful construction of the EF1-KL recombinant plasmid. Compared to the empty vector group, the Klotho expression level of cADMSCs transfected with EF1-KL recombinant plasmid was significantly upregulated (P < 0.001), indicating the successful establishment of cADMSCs overexpressing Klotho (KL-cADMSCs).The precipitate obtained by ultracentrifugation of the cell culture medium was detected to have a particle size of around 150 nm and a "tea tray like" appearance, which also express exosomes marker proteins CD63 and Alix, indicating that the precipitate belongs to exosomes. The treatment results showed that compared with AKI group canines, Exo group and KL-Exo group canines had significantly improved renal function, improved renal morphology, texture and tissue structure, and decreased renal oxidative stress. Compared to the Exo group canines, the serum creatinine (Cre) concentration (P < 0.000 1) and urea nitrogen (Bun) concentration (P < 0.000 1) of the KL-Exo group canines significantly decreased; B-ultrasound examination showed no obvious hydronephrosis; the kidneys are reddish brown in color and have a soft and smooth texture; the results of hematoxylin-eosin (HE) staining showed that the renal tubules were arranged neatly and no lesions such as congestion were observed; the concentration of superoxide dismutase (SOD) in the kidneys significantly increased (P < 0.000 1), while the concentrations of hydrogen peroxide (H₂O₂) (P < 0.000 1) and malondialdehyde (MDA) (P < 0.01) significantly decreased; the gene expression level of kelch-like ECH-associated protein 1 (Keap1) in the kidneys was significantly upregulated (P < 0.05), and the downward trend of nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression level was more pronounced. KL-Exos mainly treat AKI in canines by reducing oxidative stress in kidneys and enhancing the body's antioxidant capacity; the Keap1-Nrf2 signaling pathway may be a key pathway for KL-Exos to treat AKI.

Honokiol (HNK), an isomer of magnolol, is an effective antibacterial and anti-inflammatory component within Magnolia officinalis. In order to enhance the antimicrobial effect of Honokiol against methicillin resistant Staphylococcus aureus (MRSA), in this study, MOF material (HKUST-1) was synthesized from Cupric Acetate Monohydrate and Trimesic acid at room temperature, and HNK/HKUST-1 was prepared as HNK-loaded nanoparticles. The in vitro drug release test was used to assess the drug release performance in different media. FIC test was conducted to verify the effect of HKUST-1 in conjunction with HNK on the antibacterial efficacy of HNK. The minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), inhibition rate, cell membrane damage and reactive oxygen species (ROS) production of the antimicrobial agents against MRSA were evaluated. The results demonstrated that the nanoparticles exhibited a typical multi-faceted crystal structure, with a particle size of 496.93 nm±7.01 nm. Drug loading was 18.88%±0.11%. The drug release ability of HNK/HKUST-1 in acidic medium was significantly better than that in neutral medium. The combination of HKSUT-1 and HNK had an addition effect on FIC (5/8) of MRSA. The bactericidal effect of HNK/HKUST-1 nanoparticles on MRSA was superior to that of HNK, and the antibacterial effect of HNK/HKUST-1 nanoparticles was more enduring. A notable leakage of intracellular components, including β-galactosidase, proteins, and DNA, was observed in MRSA following treatment with HNK/HKUST-1. Additionally, a notable increase in intracellular reactive oxygen species concentration was evident, indicating that the nanoparticles could exert an antibacterial effect by disrupting the cell membrane integrity and stimulating the generation of intracellular reactive oxygen species. These effects were more pronounced than those observed with HNK alone. In conclusion, the encapsulation of HNK using HKUST-1 markedly enhanced the antimicrobial effect of HNK against MRSA. Furthermore, the nanoparticles have the potential for drug release in an acidic environment at the site of bacterial infection, which is anticipated to enhance the efficacy of HNK in clinical applications.

This study investigated the role and mechanism of Gambogenic acid (GNA) in inhibiting the malignant biological behavior of canine osteosarcoma (OS) cells based on tumor cell glycogen metabolism pathway. We used the Mckinely canine OS cell line to determine the dosage of GNA by CCK-8 assay; to investigate the inhibitory effect of GNA on the proliferation of canine OS cells by plate cloning assay; to investigate the inhibitory effect of GNA on the migration and invasion of canine OS cells by scratch healing assay, Transwell assay and Western blot assay; to investigate the effect of GNA on the pathway of glycogen metabolism of canine OS by Glycogen Metabolite Kit, Enzyme activity kit, RT-PCR and Western blot assays to investigate the effect of GNA on the glycogen metabolism pathway of canine OS. The CCK-8 assay was used to determine the doses required for subsequent cell experiments, with low dose of 0.24 μmol·L^-1, medium dose of 0.28 μmol·L^-1 and high dose of 0.32 μmol·L^-1; the results of the experiments related to the malignant biological behaviors of the cells showed that GNA significantly inhibited the proliferation, migration and invasive behaviors of the canine OS in a dose-dependent manner (P < 0.05); the results of the Western blot assay showed that GNA significantly inhibited Vimentin, MMP-9 and Snail protein expression in a dose-dependent manner (P < 0.05); Glycogen metabolism assay showed that GNA significantly promoted glucose uptake and increased intracellular glycogen content in canine OS cells, and significantly inhibited GPa enzyme activity; RT-PCR results showed that GNA significantly promoted the expression of GLUT1 in canine OS cells (P < 0.05); and the results of Western blot assay showed that GNA significantly inhibited GLUT1 expression in canine OS cells (P < 0.05), but had no significant effect on the expression of HK2 and PYGL in canine OS cells (P>0.05); the results of Western blot assay were basically the same as those of RT-PCR; the results of cellular immunofluorescence assay showed that GNA inhibited the entry of PYGL into the nucleus, and the average fluorescence intensity of PYGL was gradually decreased with the increase of the concentration of GNA (P < 0.05). GNA inhibited proliferation, migration and invasion of Mckinely canine OS cells and was associated with inhibition of the PYGL-mediated glycogenolysis pathway.

The aim of this study was to investigate the effects of herbal feed additives on bile acids metabolism and immune function in Hu sheep liver tissues by a transcriptomic methods. Eighteen healthy male lambs of Hu sheep with similar body weight ((19.57±1.56) kg) at 3 months of age were selected and randomly divided into three groups of six sheep each. The control group was fed a basal ration, and the herbal feed additives in test groups Ⅰ and Ⅱ were added at 0.5% and 1% of the concentrate supplement in the ration for a pre-test period of 10 d and a formal test period of 90 d. At the end of the experiment, 6 sheep in each group were slaughtered, liver tissue samples were collected, and RNA was extracted from the liver tissue for transcriptomic sequencing, and differentially expressed genes were obtained based on the screening criteria of |log2Fold Change|>1 and FDR < 0.05, and GO function and KEGG pathway enrichment analysis of differentially expressed genes were carried out, as well as fluorescence quantification for detecting the genes related to bile acids metabolism and immune function in the liver tissue. Corresponding kits were used to detect the content of immune indicators (IgA, IgG, IgM, C3, C4) in the liver. The results of immunological indexes showed that the liver IgA, IgG, C3 levels in test group Ⅰ were significantly higher than those in the control group (P < 0.05). Sequencing results showed that 915 differentially expressed genes (DEGs) were obtained by two-by-two comparison between the groups. There were 237 and 270 up-regulated genes and 78 and 106 down-regulated genes in test Ⅰ and test Ⅱ groups, respectively, compared with the control group. Among them, the results of GO functional annotation showed that the differentially expressed genes were mainly associated with GO terms including viral defence regulation, immunity and hormone regulation and biosynthesis. The results of KEGG enrichment analysis showed that compared with the control group, DEGs in test group Ⅰ was mainly enriched in the pathways of cholesterol synthesis, arachidonic acid metabolism which were related to the biological processes and metabolic pathways, and most of the genes in the pathways were significantly up-regulated. As the dose of the herbal feed additive was further increased, DEGs in test group Ⅱ were more enriched in metabolism-related pathways such as glutathione and caffeine metabolism. This was confirmed by RT-qPCR of bile acid-related genes (FXR, UGT2B18, ABCC4, UGT1A6, CYP7A1, HMGCR, SHP, FGFR4, GPBAR1, HSL) and immune-related genes (LOC101119773, MAPK4, XAF1, AHR, TLR2, TLR4, IL-16), which showed that the expression of SHP and FXR genes in test group Ⅰ was significantly higher than that in control group (P < 0.05), while the expression of FGFR4, CYP7A1, GPBAR1, ABCB11 and HSL genes showed an increasing trend in test group Ⅰ, but the difference with the control group was not significant (P>0.05). LOC101119773, MAPK4, XAF1, AHR, TLR4, TLR2 and IL-16 genes were significantly higher in the test Ⅰ group than in the control group (P < 0.05). The results suggest that herbal feed additives can promote the synthesis and secretion of bile acids in the liver of Hu sheep, enhance immunity, and the addition of 0.5% has the best effect under the current condition.

The aim of this study was to develop a recombinant adenovirus vaccine against African swine fever virus (ASFV) to provide a scientific basis for the clinical application and development of ASFV vaccines. We constructed a recombinant adenovirus (rAd-CP530R-Hsp70) expressing the fusion of ASFV CP530R gene and Mycobacterium tuberculosis heat shock protein 70 (Hsp70) using the pAdEasy-1 system. The expression of the target protein was verified by indirect immunofluorescence and Western blot. Mice were immunized with the rAd-CP530R-Hsp70 recombinant adenovirus, and the levels of antibodies and cytokines produced in the mice were detected. Results were as follows: The recombinant adenovirus successfully induced mice to produce specific antibodies against pp62, with antibody titers reaching 1.33 at 35 days post-immunization. The levels of IL-2, IL-4, and IFN-γ in the supernatant of mouse splenocyte cultures were significantly increased after immunization, indicating that the vaccine could effectively activate both humoral and cellular immune responses. The constructed recombinant adenovirus vaccine can effectively induce an immune response in mice, providing data support for the development of African swine fever vaccines.

Porcine circovirus type 2 (PCV2) is the primary pathogen causing porcine circovirus-associated diseases (PCVAD), which manifest in pigs as poor growth, respiratory difficulties, reproductive disorders, and other symptoms. These diseases have caused significant economic losses to the global pig industry. Currently, multiple subtypes of PCV are prevalent in China, resulting in tremendous economic losses to the pig industry. To identify the tissue sample of a pig suspected of dying from a novel PCV2 infection, we collected tissue samples from pigs suspected of PCV infection and isolated and cultured the virus. The virus was identified through PCR, immunofluorescence staining, and sequencing analysis. Six week old BALB/c mice were used to observe the pathological sections of different tissues after infection with the virus strain. The positive samples underwent whole-genome amplification and sequencing. Homology, phylogenetic trees, and recombination characteristics were analyzed with 28 PCV strains from different countries and regions in GenBank. The fifth-generation virus solution was used to infect healthy 14-week-old pigs through nasal drop administration and intramuscular injection into the neck. The pathogenicity of the virus strain was evaluated by observing and analyzing the pigs' body temperature, weight gain, viremia, and viral load in various tissues. The results showed that a PCV2d subtype strain, named SD02, was isolated in this experiment. The whole genome size of this strain was 1 767 bp (GenBank accession number OQ730503), of which the ORF2 size was 705 bp, encoding a total of 234 amino acids. Compared to other reported PCV2d strains, SD02 has an additional lysine at the carboxyl terminus of the Cap protein encoded by ORF2. The nucleotide homology of the entire gene sequence between SD02 strain and the reference strain ranges from 94.2% to 99.1%, with the highest homology of 99.1% with the 22625-33 strain (PCV2d). The mice infected with this strain showed obvious symptoms such as interstitial pneumonia and necrotizing hepatitis. After infection with this strain, it can cause symptoms such as emaciation and slow growth in pigs. Viremia lasts for more than 21 days and has a wide range of tissue tropism, with higher viral loads in various lymph nodes, which can cause immune suppression in the body. This study provides new references for PCV epidemiological research and vaccine development.

A blister-like disease was found on a pig farm which was immunized against foot-and-mouth disease in Henan province, it was suspected infected with Seneca virus type A. The purpose of this study was to isolate, identify the virus and analyze its genetic evolution. The samples' nucleic acid tested positive by RT-PCR and FQ-PCR were inoculated into BHK-21 cells and cultured by passage. The virus was identified by indirect immunofluorescence assay, electron microscope observation, whole genome sequence and evolutionary analysis. The results indicate that the strain was SVA, which was named HeNXX/swine/2017; electron microscopy showed that the virion was a typical icosahedron with a diameter of about 30nm; this SVA strain has a high breeding efficiency in BHK-21 cells, the highest virus titer was 10^9.5 TCID₅₀·mL^-1; the total genome length is 7 288 bp (without PolyA), and it has the highest homology with 2 USA strains. A strain of SVA was successfully isolated in this study, which will provide further study basis for the related disease.