Animal cognition refers to the ability of animals to make relevant learning and memory, make appropriate decisions and respond to environmental changes when exposed to stimulus or stress. Research shows that the cognitive function of livestock is closely related to its reproductive performance and livestock production. This paper summarizes the domestic and foreign research on livestock cognition in recent years and the impact of cognition on livestock reproduction and production performances, and also systematically elaborates the regulation mechanisms of "neurovascular unit", epigenetic modification and mitochondria on cognitive function. It provides important referential values for the in-depth study of cognitive behaviors and cognitive function of livestock.

Sheep is one of the important agricultural economic animals and their characteristics vary in different sheep breeds. Major putative regions and gene loci affecting economic traits can be mapped by genome-wide analysis in sheep breeds with phenotypic variation. These identified gene loci may be utilized as molecular markers to benefit sheep breeding and speed up the process of genetic selection. In this paper, genes related to reproduction, growth, disease resistance and stress tolerance identified from different sheep breeds were extensively reviewed. Furtherly, discovery process, regulatory mechanism and application progress in molecular breeding in sheep were also reviewed. These studies may contribute to further molecular mechanisms exploration of these major genes and provide new insights into molecular breeding of sheep.

Breeder roosters play an essential role in breeder production, and the semen quality directly affects the reproductive efficiency of breeder farms. Several bioactive substances have regulatory effects on sperm quality, oxidative damage, reproductive hormones, and related molecular networks in breeder roosters. This paper briefly describes the effects of different bioactive substances on the reproductive performance of breeder roosters and their action mechanism, in order to provide theoretical reference for a comprehensive understanding of the regulatory effect of bioactive substances on the reproductive performance of breeder roosters and their application in breeder production.

Meat flavor is the sensory impression of taste and smell perception, which is fundamentally determined by the content of meat metabolites and complex chemical processes. With the continuous progress of metabolite determination technology, the effect of the content of metabolites in meat on meat quality has attracted more and more attention. The content of metabolites in meat has gradually become a hot spot in research and breeding. Thus digging out candidate genes for metabolic regulation. This paper reviews the types of metabolites in livestock and poultry meat, chemical reactions of flavor-forming metabolites, effects of metabolites on meat quality, and genetic regulation of metabolites. This overview aims to clarify the regulatory mechanism of meat metabolites on meat flavor formation, and provide theoretical basis and research ideas for the improvement of meat flavor in livestock and poultry.

Fatty liver hemorrhagic syndrome (FLHS) is one of the main causes of noninfectious death in cage chickens. It is characterized by fragile liver, rupture bleeding and sudden death. Chicken is easier to form FLHS than mammals because of its physiological characteristics,but the pathogenesis of chicken FLHS is not clear. This paper will elaborate the multiple influencing factors of FLHS disease, such as genetics, nutrition, hormones, environment and intestinal microorganisms. Enumerating and comparing the way of structuring FLHS model by changing diet composition or hormones, and putting forward the pathogenesis of "the multiple-hit" pathogenesis in order to provide a reference for further study of chicken FLHS.

Feline lower urinary tract diseases (FLUTD) is one of the most common diseases in cats. Because of its high incidence, complex etiology, difficulty in diagnosis, easy recurrence after treatment and other characteristics, it has been progressively becoming a hot topic in the research of feline diseases. Due to the wide types of FLUTD, precision treatment and reasonable prevention have emerged as the key of scientific measures in FLUTD prevention and control. In order to drive in depth investigation and diagnosis and treatment of FLUTD, the classification, epidemiology and risk factors, pathogenesis, clinical symptoms, diagnosis and control of FLUTD were reviewed.

The cryopreservation of gametes (sperm and oocytes) is the freezing of gametes under ultra-low temperature conditions, which can be used for long-term preservation of excellent individual livestock and rare and endangered animal germplasm resources. Gamete freezing is an important part of the protection, preservation and utilization of rare and endangered animal germplasm resources, and it is also a key technology for the construction of animal germplasm resources. This article discusses in detail the current research status of domestic and foreign sperm and oocyte cryopreservation and utilization. At the same time, it introduces the research on the damage assessment of gametes after freezing and thawing. The application strategies and recommendations for preservation of gametes of endangered and rare animals are expected to provide references for the construction of my country's livestock biological germplasm resource bank, the protection and development and utilization of livestock germplasm resources, and the protection of rare and endangered animals.

The abuse of antibiotics has led to the problem of bacterial resistance more and more serious in the world, which has posed a great threat to the health of human beings and livestock as well as the development of animal husbandry. Antimicrobial peptides (AMPs), which have diverse functions and are not tend to cause bacterial resistance, have gradually developed into potential substitutes of antibiotics. β-sheet structure is a major secondary element constituting the classification of AMPs, which usually maintains the structural stability through one or more disulfide bonds. Compared with the widely studied α-helical AMP, they are believed to have stronger resistance to enzymolysis and higher cell selectivity. This review briefly introduces the natural sources and antibacterial mechanism of β-sheet AMPs, and sorts out some common molecular design methods and application strategies. The content obtained here can provide novel ideas for the research and application of β-sheet AMPs.

The purpose of this study was to better understand the genetic diversity, relationship and family structure of Hang pigs conserved population, protect and utilize the genetic resources of Hang pigs efficiently. The 50K SNP chip was used to detect the single nucleotide polymorphism (SNP) in 30 Hang pigs (4 male and 26 female). And the quality control of SNP genotyping results was conducted by Plink software to calculated the minor allele frequency, observed heterozygosity, expected heterozygosity and polymorphism information content so as to analyze the genetic diversity of Hang pigs conserved population. The runs of homozygosity (ROH) was calculated and identity by state (IBS) distance matrix was constructed by Plink software, the inbreeding coefficient was then calculated based on ROH. The genetic relationship was analyzed according to the G matrix result constructed by Gmatrix software. The boar phylogenetic tree which constructed by Mega X software was used to analyze the family structure of Hang pigs conserved population. The results showed that, 57 466 SNPs were detected in 30 Hang pigs, the average genotyping rate was 0.988 3±0.000 4, there were 34 156 SNPs passing quality control. The average minor allele frequency, polymorphism information content, average observed heterozygosity and average expected heterozygosity were 0.228±0.137, 0.255±0.098, 0.359±0.181 and 0.314±0.140, respectively. The average IBS genetic distance of Hang pigs conserved population and boar were 0.241 7±0.033 6 and 0.178 3±0.025 5, respectively, and the result of G matrix was consistent with IBS genetic distance, the IBS genetic distance and G matrix results showed that some individuals in Hang pigs conserved population were closer to each other. A total of 828 ROHs were detected in 30 Hang pigs, and the length of 83.33% of these ROHs was less than 10 Mb, and the average length was (6.96±9.62) Mb, and the average total length of individual ROH was (191.95±201.56) Mb. The average inbreeding coefficient based on ROH of Hang pigs conserved population and boar were 0.078±0.082 and 0.219±0.082, respectively, indicated that the inbreeding degree of Hang pigs conserved population was not serious, but there was inbreeding in boar. The phylogenetic tree result showed that, there were only two families in Hang pigs conserved population, and one family contained all 4 boars and the other family only contained sows. In summary, the blood number of the boar of conserved population in the Hang pigs conserved farm was few, the inbreeding degree of sow was low, but there was inbreeding in boar, it was necessary to introduce new blood or create new blood to maintain the balance of family structure, so as to facilitate the long-term preservation of Hang pigs genetic resources and prevent the loss of genetic diversity.

This study aimed to analyze the population structure and genetic diversity of Tongcheng pig conservation population based on SNP chip information and to monitor the conservation effect. In this study, "Zhongxin No.1" 50K SNP chip was used to scan the whole genome SNPs of 68 Tongcheng pigs, and the population conservation effect was evaluated from two aspects:1) Population structure. Based on the analysis of population stratification, genetic distance, kinship, and boar genome family, the population structure among Tongcheng pigs were studied; 2) Genetic diversity. Allele frequency, effective number of alleles, polymorphism information content, proportion of polymorphic loci, heterozygosity, nucleotide diversity, and other polymorphism and heterozygosity-related parameters were employed to estimate genetic diversity and to analyze effective population size and runs of homozygosity (ROH). Based on these parameters, comprehensive evaluation of population conservation effects was conducted. The results showed that:1) The conservation population exhibited no obvious stratification with the genetic distance of 0.27, and they had a medium kinship 0.17; 2) The genome allele frequency was 0.77; the effective number of alleles was 1.52; the mean polymorphism information content was 0.31; the proportion of polymorphic markers was 88.28%; the observed heterozygosity was 0.32; and the expected heterozygosity was 0.31. The effective population size of Tongcheng pigs before the 20th generation was 105, and the effective population size of the current generation was 94. There were 184 ROHs in total. The average ROH length was 23.71 Mb, of which 28.80% was between 15 and 20 Mb in length. The genomic inbreeding coefficient was 0.04%, indicating a low level of inbreeding. Taken together, the results show that the conservation population of Tongcheng pigs is a pure breed without stratification, and Tongcheng pigs had rich genetic diversity with remarkable population conservation effect.

The study aimed to explore the genetic mechanism of Min pigs excellent germplasm characteristics, and analyze their low temperature adaptation mechanism.In this experiment, 6 female Min pigs at the age of 6 months with similar body weight were randomly divided into 2 groups with 3 individuals in each group. Individuals in the control group were raised in a pig house whose temperature was controlled at (18±2)℃, and individuals in the experimental group were raised in a semi-open house outside. The ambient temperature dropped from 5℃/-5℃ on the first day to -15℃/-24℃ on the last day. The experiment lasted 58 days. Both groups of individuals were guaranteed free access to food and water. At the end of the experiment, all individuals were slaughtered, and the longissimus dorsi was taken for RNA-seq. The genes and lncRNAs induced by low temperature in Min pig skeletal muscle were screened, and their functions were annotated and their regulatory relationships were analyzed. The RNA sequencing analysis showed that 86 genes in skeletal muscle were significantly up-regulated and 16 genes were significantly down-regulated after 58 days of low temperature stress, 112 lncRNAs were significantly up-regulated and 74 lncRNAs were significantly down-regulated. Among the genes that were significantly up-regulated, 4 nervous system-related genes NTSR2, ARC, FOSL1 and RCAN1 were significantly up-regulated, and 7 solute transport related genes SLC2A4, SLC2A5, SLC4A10, SLC19A2, SLC20A1, SLC28A1 and SLC38A2, 6 genes AREG, CISH, OTUD1, TRIB1, GPA33 and ITPKC related to inflammation and immunity were significantly up-regulated. The circadian rhythm-related ARNTL gene and the RASL11A gene inhibiting cell proliferation, were significantly down-regulated. Under low temperature stress, differentially expressed genes were significantly enriched in apoptosis pathway, colorectal cancer pathway and transcriptional misregu-lation in cancer pathway, indicating that cell proliferation and apoptosis were affected. Significantly changed lncRNAs mainly regulated target genes in trans, and have complex interactions with target genes. The target genes regulated by lncRNAs were enriched in Herpes simplex virus 1 infection pathway, MAPK signaling pathway and Fanconi anemia pathway. In addition, no other pathways were affected. Low temperature stress affects the nervous and immune systems of Min pigs, changes the transport of substances in the cells, and affects the growth and differentiation of cells. However, because the fold of gene changes is small (mainly 1-2 times) and fewer pathways (only 3) are affected, it is speculated that low temperature stress does not cause serious damage to the skeletal muscle of Min pig.

The objective of this study was to investigate the effects of nutritious diet on alternative splicing (AS) and splicing factors (SFs) in key tissues of metabolic disease susceptible pigs. Twelve metabolic disease susceptible male pigs with the same health status, age and body weight were randomly divided into 2 groups. Eight pigs were fed a high fat and energy diet for 2 months as the nutrient-rich diet group (TG-HFHSD), and 4 pigs were fed a normal diet for 2 months as the control diet group (TG-CD).The adipose, liver, muscle, and hypothalamus tissues of TG-HFHSD and TG-CD were sequenced by RNA-seq, and the differential AS between the groups was identified by rMATS software, GO and KEGG enrichment analysis of differential splicing genes (DSGs), and SFs in liver was analyzed by DESeq2 software and pearson correlation coefficient. The results showed that 48 279, 39 536, 47 888 and 52 210 AS events were identified in adipose, liver, muscle, and hypothalamus, respectively, all of which were mainly of SE type, accounting for 77.09%-78.29%. The number of DSGs in adipose, liver, muscle, and hypothalamus were 528, 1 070, 570, and 600, respectively. The increased DSGs in the liver mainly came from RI and MXE with 177 and 471, respectively, while only 12-28 and 99-110 for other tissues. The enrichment of GO and KEGG showed that, in addition to the processes related to cell structure, the DSGs in liver was also significantly enriched in processes such as alternative splicing and mRNA metabolism, lipid metabolism, DNA damage and repair, complement and coagulation cascades. Fifty-six differentially expressed SFs were screened from liver, among which CLK1, PGC-1ɑ, USP4 and others were closely related to glucolipid metabolism and metabolic diseases. The results of this study showed that nutritious diet significantly increased DSGs in liver and affected the occurrence of liver metabolic diseases through splicing regulation, glucolipid metabolism and DNA damage, which will provide reference for the study of the early pathogenesis of liver metabolic diseases.

The purpose of this study was to explore the effects of SMAD7 on the proliferation and apoptosis of follicular granulosa cells in goat. In this study, follicular granulosa cells were collected from 3-to 4-month-old Dazu black goats. The overexpression, siRNA interference, ELISA, qRT-PCR, Western blot and flow cytometry were used to investigate the effects of SMAD7 on proliferation, apoptosis and steroid secretion of granulosa cells. The results showed that overexpression of SMAD7 significantly reduced the proliferation activity and promoted the apoptosis of granulosa cells, inhibited the expression of PCNA (P<0.05) and decreased the ratio of BCL2/BAX(P<0.01). Oppositely, SMAD7 interference significantly promoted the proliferation activity of granulosa cells, significantly up-regulated the expression of PCNA and the ratio of BCL2/BAX (P<0.05).SMAD7 overexpression significantly increased progesterone secretion of granulated cells, and reduced estradiol expression levels (P<0.01). Meanwhile,SMAD7 interference significantly down-regulated the secretion of progesterone and up-regulated the secretion of estradiol (P<0.01). Further studies showed that SMAD7 overexpression significantly inhibited SMAD2,SMAD3 mRNA and protein expression (P<0.05), but did not affect SMAD4 expression. SMAD7 interference significantly promoted the mRNA and protein levels of SMAD2,SMAD3 (P<0.05). The results suggested that SMAD7 inhibits the proliferation and estradiol secretion, promotes apoptosis and progesterone synthesis, and inhibits the expression of SMAD2,SMAD3 in follicular granulosa cells, thereby regulating the development and atresia of follicles.

The aim of this study was to analyze the molecular mechanism of VPS28 gene regulating milk protein synthesis and to lay a theoretical foundation for molecular breeding of lactation traits in dairy cows. In this study, the expression level of VPS28 gene in primary mammary epithelial cells (BMECs) of dairy cows was knocked down by RNAi technology, and the expression level of 11 genes, ubiquitin proteins, and the proteasome activity involved in milk protein synthesis, ubiquitin-lysosome, and ubiquitin-proteasome pathways were detected. Then, the activity of proteasome and lysosome in BMECs were inhibited, and the expression levels of casein-related genes and ribosomal proteins were detected. Finally, iTRAQ comparative proteomics was used to analyze the differentially expressed proteins in BMECs before and after knocking down. After VPS28 knockdown, the CSN1S1, CSN2, CSN3, RPS8, UBC, PSMC3, and PSMC5 genes were significantly up-regulated, while PSMD12 was significantly down-regulated. After proteasome inhibition, the CSN1S1, CSN2, and CSN3 genes were significantly up-regulated, while RPL13 was significantly down-regulated. The expression of casein-related genes was not significant after lysosome inhibition. iTRAQ results showed that there were 129 differentially expressed proteins, the down-regulated proteins were mainly enriched in ribosomes, lysosomes, spliceosomes,and other related pathways, while the up-regulated proteins were mainly enriched in the protein processing in the endoplasmic reticulation, vasopressin-regulated water reabsorption process, RNA transport, and other pathways. The results indicate that VPS28 gene can affect milk protein synthesis through ubiquitination signaling pathways in BMECs.

The aim of the study was to predict heterosis of different crosses for growth and carcass traits by single nucleotide polymorphism (SNP) markers at the whole genome level in Simmental, Wagyu, and Holstein. The Illumina Bovine HD 770 K and GGP Bovine 100 K chips were used to detect genotypes of 1 222 Simmental, 464 Wagyu and 43 Holstein, respectively. The trait-associated SNP markers were obtained by blasting Illumina Bovine HD 770 K and GGP Bovine 100K chips with QTLs database of birth weight, yearling weight, and carcass weight in NCBI. The genetic distance (GD) was used to predict heterosis of different crosses based on genomic SNPs and trait-associated SNP markers. The combining ability was estimated to verify heterosis effect of Simmental and Holstein in practice. The results showed that the genetic distances were no significant difference between genome-wide and trait-associated SNPs in two hybrid groups. At the genome-wide level, the genetic distances of Simmental(♂)×Holstein(♀) and Wagyu(♂)×Holstein (♀) were 0.346 1 and 0.338 9, respectively. For trait-associated SNPs with birth weight, yearling weight and carcass weight, the genetic distances of Simmental(♂)×Holstein(♀) were 0.343 1, 0.348 7 and 0.336 7, it was 0.337 6, 0.340 7 and 0.329 2 in Wagyu(♂)×Holstein (♀), respectively. In short, Simmental(♂)×Holstein(♀) had the larger GD than Wagyu(♂)×Holstein (♀). Therefore, Simmental(♂)×Holstein(♀) would obtain greater heterosis in birth weight, yearling weight and carcass weight. According to combining ability test of German Simmental×Holstein, it was found that general and specific combining ability of 10 German Simmental sires had positive effect on birth weight, and the highest value were 3.760 9, 8.931 2, respectively. Hybridization of Simmental and Holstein would obtain greater heterosis for birth weight, yearling weight, and carcass weight.

The purpose of this study was to investigate the effect of PLCγ1 on the development of sheep early embryo in vitro, and to lay a foundation for revealing the action mechanism of PLCγ1 in the development of sheep early embryo. In this study, sheep oocytes with more than 3 layers of granulosa cells were selected as experimental materials, and they were divided into two groups after mature in vitro culture. PLCγ1 was introduced into MⅡ oocytes (n=127) by microinjection as experimental group. Microinjection of empty vector pcDNA3.1-EGFP was used as the control group (n=120), and after 48 h the cleavage rate were measured. The Ca²⁺ probe Rhod 2-AM was used to monitor the Ca²⁺ fluctuation of MⅡ oocytes and early embryos at 16, 48, 72, 96 and 120 h after microinjection. The results showed that the cleavage rate was ((19.67±0.2)%, P<0.01)) and morula development rate was ((9.00±0.17)%,P<0.05)) after microinjection of PLCγ1. After injection of PLCγ1, Ca²⁺ concentration in oocytes and early embryos varied at different developmental stages.It was observed that Ca²⁺ was mainly distributed in the cytoplasm and reached the peak at 48 h after injection (P<0.01). The results showed that PLCγ1 gene could induce Ca²⁺ oscillation during ovine oocyte development, initiate cleavage, and promote the development of early embryo.

The purpose of this experiment was to explore the effects of dietary supplementation of different levels of rutin on alleviating testicular tissue damage in heat-stressed mice. Thirty 5-week-old male mice of ICR strain with similar body weight (20-22 g) were randomly divided into 5 groups. Mice in each group were fed basal diet supplemented with 0 (CON group), 0 (HS group), 250 (HS+R250), 500 (HS+R500) and 1 000 (HS+R1000) mg·kg^-1 rutin for 10 days, respectively. Except for control group (CON), all mice were treated in an incubator at 42℃ between 10:00 and 14:00 every day for 8 consecutive days, and then slaughtered for sampling and analysis. The results showed as follows:1) Compared with CON group, the testis index of mice in HS group had no significant change (P>0.05), but dietary 250 mg·kg^-1 rutin significantly increased the testis index of mice under heat stress (P<0.05). The results of mouse testicular tissue sections showed that compared with the CON group, the cross-sectional area and diameter of the seminiferous tubules in the HS group were significantly reduced (P<0.05), and the rate of spermatogenic cell shedding was significantly increased (P<0.05). Compared with the HS group, the cross-sectional area of the seminiferous tubules in the HS+R250 group was significantly increased (P<0.05), the rate of spermatogenic cells shedding was significantly reduced (P<0.05), while the rate of spermatogenic cell shedding in the HS+R500 group was significantly reduced (P<0.05), and the diameter of the seminiferous tubules in the HS+R1000 group was significantly increased (P<0.05); There was no significant difference in testis index, seminiferous tubule diameter and seminiferous tubule shedding ratio between the rutin-treated groups and the CON group (P>0.05), however, the cross-sectional area of the seminiferous tubules in the HS+R250 group was significantly higher than that in the CON group (P<0.05). 2) Compared with CON group, malondialdehyde (MDA) content in testis tissue of HS group increased significantly (P<0.05), while total antioxidant capacity (T-AOC), glutathione (GSH) content and the mRNA expression of hemolytic enzyme 1 (HO-1) in testis tissue of mice were significantly decreased (P<0.05). The supplementation of 250 mg·kg^-1 rutin significantly decreased the MDA content (P<0.05), increased the T-AOC and GSH content in testis of heat-stressed mice (P<0.05), and enhanced nuclear factor E2 related factors 2 (Nrf2), HO-1 and glutathione peroxidase (GSH-Px) mRNA expression (P<0.05), while the supplementation of 500 and 1 000 mg·kg^-1 rutin also significantly increased the GSH content (P<0.05); Compared with the CON group, except that the Nrf2 mRNA expression in the HS+R250 group was significantly higher than that in the CON group (P<0.05), there were no significant changes in the antioxidant genes and enzyme activity indexes in the testis tissue of the heat-stressed mice in the rutin groups. (P>0.05). 3) The mRNA expression levels of nuclear factor -κB (NF-κB), Toll-like receptor 4 (TLR-4) and Bax in testis of heat-stressed mice were significantly increased (P<0.05), while the expression level of Bcl-2 was significantly decreased (P<0.05). Dietary supplementation of 250 mg·kg^-1 rutin significantly reduced the mRNA expression of NF-κB, TLR-4, myeloid differentiation factor 88 (MyD88), interleukin-Iβ (IL-1β) and Bax (P<0.05), enhanced the expression level of Bcl-2 (P<0.05); Adding 500 mg·kg^-1 rutin to the diet significantly reduced the expression of NF-κB and TLR-4 (P<0.05), while adding 1 000 mg·kg^-1 rutin significantly increased the expression of Bcl-2 (P<0.05). There was no significant difference in the expression of immune and proliferation apoptosis-related genes in mouse testis between the rutin groups and the CON group (P>0.05). These results suggest that dietary supplementation with appropriate dose of rutin can improve the morphology and function of testis in heat-stress mice, and the mechanism may be closely related to the relief of oxidative stress through Nrf2 signaling pathway, the inhibition of inflammatory response through TLR-4/NF-κB signaling pathway and the regulation of Bax/Bcl-2 mRNA expression. The effect of dietary 250 mg·kg^-1 rutin was better under the experimental conditions.

Hyla meat rabbits were taken in this experiment to study the effects of fasting and non-fasting on the stress level, meat quality and behaviors, and to explore a reasonable post-treatment method for meat rabbits after transportation. Eighty male Hyla rabbits with weight of (2.5±0.5) kg were chosed and randomly divided into 8 groups:control group, 0 h after transportation group, non-fasting 6 h group, non-fasting 24 h, fasting 6 h group, fasting 24 h group, fasting behavior observation group and non-fasting behavior observation group (behavior observation without slaughter). The pre-trial period was 7 days, and the transportation in formal experiment lasted for 2 hours. The results were as follows:Compared with the control group, the serum levels of ALT, AST, TG, Glu, CK and LDH had no significant changes at 0 h after transportation (P>0.05), but the serum TP concentration decreased and the cortisol concentration increased significantly after transportation (P<0.05). The levels of serum glucose were higher, but CK activities were lower in non-fasting 24 h group than in fasting 24 h group (P<0.05), and the levels of LDH activities in non-fasting 6 h group were lower than those in fasting 6 h group (P<0.05). In the determination of meat quality, the muscle pH increased significantly at 0 h after transportation (P<0.05), and the muscle L^* and a^* levels decreased significantly (P<0.05). The L^*, a^* and b^* values of non-fasting 24 h group were significantly higher than those of fasting 24 h group. There was no significant difference in muscle pH, water loss rate, cooking loss rate or shear force between fasting group and non-fasting group (P>0.05). In terms of gene expression, JNK and Caspase-3 levels increased significantly at 0 h after transportation (P<0.05). Compared with fasting, non-fasting decreased the relative expression of JNK mRNA (P<0.05), but had no significant effect on Caspase-3 level (P>0.05). In the aspect of behaviors, compared with fasting, non-fasting only reduced the caecotrophy behavior (P<0.05), but did not change the stereotyped behaviors of meat rabbits significantly (P>0.05). Non-fasting for 24 hours during lairage period after transportation can improve the meat quality to a certain extent, reduce stress and body damage, and improve the welfare levels of meat rabbits.

Coccidiosis is a serious intestinal parasitic disease caused by Eimeria spp., which causes huge economic losses to poultry industry all over the world every year. At present, coccidiosis is mainly controlled by anti-coccidial drugs. Drug resistance of Eimeria to all of used drugs has been developed due to the long-term and unreasonable use of drugs. To study the molecular mechanism of the resistance of Eimeria to drugs, differentially expressed genes between two drug-resistant strains (diclazuril-resistant strains, maduramicin-resistant strains) and drug-sensitive strain of Eimeria tenella were obtained by using RNA sequncing in our lab. We found that E.tenella contained HD domain protein (EtHDCP) up-regulated in two drug-resistant strains. In this paper, EtHDCP gene was successfully cloned from the first cDNA strand of E.tenella drug sensitive strain sporulated oocysts (SO) as template, and the recombinant plasmid pGEX-4T-EtHDCP was constructed, and the recombinant protein rEtHDCP was induced successfully. qRT-PCR and Western blot were used to analyze the transcription and translation levels of EtHDCP in the four different developmental stages of E. tenella drug sensitive strains. At the same time, the translation levels of two drug-resistant strains and drug sensitive of E.tenella were detected. The results showed that the transcription and translation level of EtHDCP in second-generation merozoites stage were the highest, the protein translation level of EtHDCP in drug-resistant strains were significantly higher than those in drug sensitive strains. Indirect immunofluorescence localization showed that the protein was mainly located on the surface of sporozoites and merozoites and in the cytoplasm of merozoites. Invasion inhibition test showed that rabbit anti-rEtHDCP polyclonal antibody could effectively inhibit invasion of sporozoites to host cells. These results showed that the protein may be involved in the growth and development of parasite in host cells, the development of drug resistance and the invasion of sporozoites into host cells.

The aim of this study was to explore the regulation of C5a/C5aR signal in the immune response of host CD4⁺ T cell during Cryptosporidium parvum infection. We have utilized C. parvum as the research object, and selected BALB/c suckling mice and C5aR inhibited BALB/c suckling mice as infection models. The expression level of C5aR in the ileum tissues of BALB/c suckling mice was detected by using real-time PCR and immunohistochemistry. The expression patterns of C. parvum HSP70 gene and main effector cytokines (IFN-γ, IL-4, IL-17 and TGF-β) of CD4⁺ T cell subsets (Th1, Th2, Th17 cells and Treg cells) were analyzed by real-time PCR. The injury of ileal mucosa in suckling mice was observed by histopathology analysis. Compared with mice in the control group, C. parvum infection could significantly increase the expression levels of C5aR mRNA and protein (P<0.05), as well as IFN-γ in the ileum tissues of suckling mice (P<0.05). Compared with mice infected with C. parvum, the expression levels of main effector cytokines of Th1, Th2 and Treg cells, namely IFN-γ, IL-4 and TGF-β, significantly reduced in C5aR inhibited BALB/C suckling mice infected with C. parvum (P<0.05), and the expression level of IL-17, the main effector cytokine of Th17 cells, significantly increased in suckling mice treated with C5aR inhibitor (P<0.05). Histopathology analysis of ileal mucosa in suckling mice indicated inhibition of C5aR could significantly improve the changes of villus diameter and mucosal thickness of ileum caused by C. parvum infection (P<0.05), but not for the villus length and the ratio of villus length to crypt depth. Analysis of the mRNA level for Cryptosporidium HSP70 gene showed that inhibition of C5aR could significantly affect the proliferation of C. parvum in ileum (P<0.05). C5a/C5aR signal may participate in the process of interaction between host and Cryptosporidium by dynamically regulating the expression of major effector cytokines for CD4⁺ T cell subsets, providing reference basis for further understanding the interaction mechanism between Cryptosporidium spp. and host.

To explore the influence of Staphylococcus aureus on IFN-α production and IFN-α mRNA expression in microglia cells. IFN-α released into the culture medium and TBK1/IRF3 signaling of BV2 cells were detected after BV2 cells were infected with S. aureus. TBK1/IRF3 pathway activation and IFN-α levels were detected after S. aureus infected BV2 cells which were treated by BX-795, amlexanox, IMD-0354 inhibitors, respectively. The results showed that IFN-α transcriptional levels increased from 3 to 12 hours post infection, and IFN-α release was enhanced from 6 to 12 hours post infection in a dose-dependent manner. TBK1 and IRF3 were not affected at both the mRNA and protein levels, but their phosphorylation was triggered from 1 to 12 hours, indicating that S. aureus infection activated TBK1/IRF3 pathway. IRF3 phosphorylation and IFN-α were attenuated in the presence of BX-795, amlexanox or IMD-0354, indicating that TBK1 and NF-κB were involved in S. aureus-induced IFN-α release. Collectively, S. aureus infection leads to TBK1-and NF-κB-dependent IFN-α production. It provides potential targets and theoretical basis for clinical prevention and treatment of S. aureus infection in the central nervous system.

The purpose of this study was to study the effect of Brucella outer membrane protein 16 on apoptosis and immune activity of mouse macrophage RAW264.7 cell, and to explore its mechanism. In this study, OMP16 treated RAW264.7 cells were used as a model to detect the effects of OMP16 on cell viability by MTT and Hoechst assay. The expressions of Caspase-3, GRP78 and CHOP level were detected by Western blot. The apoptosis of OMP16 treated RAW264.7 was detected by flow cytometry. The changes of IL-1β, IL-6 and TNF-α were detected by RT-PCR. The results showed that OMP16 could affect the activity of RAW264.7 cells in a concentration-dependent manner. OMP16 significantly increased the expression of caspase-3 (P<0.001) and promoted apoptosis of OMP16 treated RAW264.7 cells. The expression of ER stress marker protein GRP78 and CHOP was significantly increased in RAW264.7 cells after OMP16 treated 24 and 36 h. The mRNA expression levels of IL-1β, IL-6, TNF-α were significantly up-regulated. Brucella OMP16 can induce RAW264.7 apoptosis, and OMP16 significantly causes ER stress through CHOP pathway.

To further explore the changes of transcription level of tracheal genome after Mycoplasma gallisepticum (MG) infection in SPF chickens, the differentially expressed genes and regulatory pathways involved in inflammatory injury of tracheal mucosa after MG infection were screened; The infection model was established by infusing SPF chickens with MG-HY strain at 0.2 mL per feather through nasal and eye drops. Tracheal tissues were collected and then using RNA-Seq technology for sequencing analysis. The results of transcriptome analysis showed that a total of 3 112 significantly (P<0.01) differentially expressed genes (DEGs) were selected by RNA-seq during MG infection, including 1 646 up-regulated genes and 1 466 down-regulated genes. GO functional analysis found that differential genes mainly involve biological processes such as biological regulation, stimulus response, multicellular biological processes, cell component organization or biogenesis. KEGG-Pathway analysis showed that differential genes are involved in mucosal immune signaling pathways, such as:cytokine-cytokine receptor interactions, cell adhesion molecules (CAMs), extracellular matrix (ECM) receptor interactions, tight junctions, PPAR signaling pathways and MAPK signaling pathway, etc., overall, these results showed that these genes may be involved in MG-induced tracheal inflammatory response and injury in chicks. Using qRT-PCR to verify 13 differentially expressed genes related to mucosal immunity, the results are consistent with transcriptome analysis. This study provides a basis for further elucidating the host tracheal mucosal epithelial damage and mucosal immune mechanism caused by MG infection.

Mycoplasma synoviae (MS) can cause respiratory diseases, infectious synovitis, abnormal eggshell top and growth retardation in poultry, and bring huge economic losses to the global poultry industry. However, there are differences in drug resistance and pathogenicity of MS in different countries and regions. Therefore, this study aims to explore the characteristics of MS strains in Fujian. The contents of the articular cavity of chickens suspected of suffering from MS in Fujian were collected, the strains were isolated and identified, and the whole genome was sequenced by third-generation combined with second-generation sequencing technology. The results showed that the pathogenic characteristics of the isolate were stable and had been deposited in China center for type culture collection. The preservation number was CCTCC No.:M 2021210 and named MS-FJ01. The total length of MS-FJ01 genome was 795 381 bp and the content of GC was 28.39%; The predicted number of coding genes was 704, accounting for 90.48% of the whole genome; 476, 382 and 425 genes were annotated in COG, GO and KEGG databases respectively. Through the analysis of each data, 40 drug resistance related genes, 4 carbohydrate related enzyme genes, 136 pathogen host interaction related genes, 47 virulence factor related genes, 106 membrane transporter related genes and 25 restriction modification related genes were annotated. Through further comparison with MS HN01 and MS 5-9 genomes, it was found that MS-FJ01 had a good collinear relationship with both Chinese strains, and was closer to MS 5-9. This study clarified the genomic structure of Fujian MS strain, predicted and annotated the function of its gene through the analysis of relevant databases, to provide a reference basis for the further study of MS.

The current study aims to provide experimental data and references for the development of Salmonella specific antibacterial agents. Here, we isolated a Salmonella phage from chicken farm sewage and studied its biological characteristics and genomics. The results showed that Salmonella phage S5 was isolated. Transmission electron microscopy showed that the phage was a long-tailed phage with a head diameter of about 50 nm and a tail length of about 200 nm. Its head was icosahedral symmetrical, belonging to Caudovirales, Siphoviridae. The phage has a lysis rate of 75% against 20 strains of Salmonella, with a titer of 8×10⁹ PFU·mL^-1. The phage titer remained basically unchanged at the temperature from 30 to 60℃ for 30 min or 1 h, with little effect on phage activity at pH4.0-11.0. The optimal MOI of phage was 0.000 1. The one-step growth curve showed that its titer remained basically unchanged within 5 min incubation period after infection with the host bacteria. The outbreak period was about 95 min, and the average lysate was 50 PFU·cell^-1. Phage S5 was a double-stranded DNA virus. The genome was 72 519 bp in length, and the GC content was 39.45%. It contained 9 types of tRNAs and 109 predicted ORFs. No harmful factors such as bacterial virulence factors had been found. Salmonella virulent phage S5 has good lysis effect, strong adaptability to the environment and clear genetic background. It is expected to become an alternative product of antibiotics for the prevention and control of Salmonella.

In order to construct the UL41 gene deletion strain of duck enteritis virus (DEV), the recombinant fosmid D1 dUL41 with UL41 gene deletion was constructed by using Red/ET recombinant technique with the recombinant fosmid D1 containing UL41 gene as the backbone. The UL41 gene deletion fosmid D1 dUL41 was co-transfected into duck embryo fibroblasts (DEF) with four other parent fosmids containing DEV genomic fragments, and the UL41 gene deletion strain rDEV-SD19/dUL41 was obtained. After the UL41 deletion virus was inoculated on DEF, the virus genome was extracted for PCR identification and sequencing, and the expression of UL41 gene in the infected cells was detected by indirect immunofluorescence assay. The growth curve of the rescued gene deletion virus was tested and its replication characteristics in vitro were analyzed. The PCR and sequencing results showed that the recombinant fosmid D1 dUL41 with UL41 deletion was obtained in this study. Typical plaque lesions can be produced after co-transfection of the UL41-deletion fosmid with other parent fosmids containing DEV genomic fragments. The results of PCR and sequencing showed that UL41 gene was successfully deleted from the DEV genome, and indirect immunofluorescence assay showed that there was no expression of UL41 protein after the inoculation of rDEV-SD19/dUL41 in DEFs. The growth curve in vitro showed that the replication ability of rDEV-SD19/dUL41 in DEF was significantly lower than that of the parent virus, indicating that UL41 gene plays important roles in DEV replication. The construction of DEV UL41 gene deletion strain lays a foundation for the study of the function of UL41 gene in DEV infection and pathogenesis.

Staphylococcus aureus is the main cause of bacterial mastitis in dairy cows, and the formation of biofilm is the key factor of S. aureus persistence under adverse environmental conditions. Exploring the correlation between drug resistance and growth state of the same strain in biofilm and planktonic growth state can lay a foundation for further exploring the drug resistance mechanism of S. aureus. In this study, the biofilm of S. aureus was cultured and its formation was observed by optical microscope and scanning electron microscope. The minimum inhibitory concentrations of 9 kinds of antibiotics against 32 strains of S. aureus in biofilm and planktonic states were measured and compared. Transcriptome sequencing was performed on S. aureus under the two states to screen out cell signaling pathways and expressed genes with significant differences. At the same time, the main differentially expressed genes were verified by RT-qPCR. The results showed that in the early stage of biofilm formation, with the extension of culture time, the aggregation area of biofilm state bacteria observed under the microscope became larger and larger, and the structure was more and more compact. After 72 hours of culture, the biofilm gradually began to disperse. MIC results showed that the inhibitory concentration of planktonic bacteria was lower than that of biofilm bacteria. Transcriptome results showed that there were 1512 differentially expressed genes in the two states, among which 760 genes were up-regulated and 752 genes were down-regulated in the biofilm state. GO and KEGG enrichment analysis showed that, compared with plankplankton, metabolization-related pathways were significantly enriched in biofilm bacteria, followed by amino acid biosynthesis and ABC transporter pathways.Genes associated with biofilm formation, such as those encoding ABC transportersare up-regulated, while genes associated with metabolic pathways are down-regulated.Ten major differentially expressed genes were verified by RT-qPCR, and the differentially expressed trends were consistent with transcriptome sequencing results. These differences may be helpful to study the high drug resistance and virulence of S.aureus in biofilm state.

The aim of this study was to clone goat SERBP1, and to reveal the role of interfering with SERBP1 gene on the proliferation, cell cycle and apoptosis of goat turbinate bone primary cells. These data may provide important experimental data for further mechanism study underlying cell apoptosis induced by Orf virus (ORFV). With the Jianzhou goats as the experimental animal, the SERBP1 gene sequence was cloned by RT-PCR and analyzed by bioinformatics. Real-time fluorescent quantitative PCR(RT-qPCR) was performed to determine the expression of SERBP1 in different tissues, and screening the most effective interference sequence. The MTT method was used to detect the effects of siRNA interference SERBP1 on cell proliferation of goat turbinate bone cells, and the effects of siRNA interference with SERBP1 on the cell cycle and apoptosis were detected by flow cytometry, and the effects on apoptosis-related genes P53, Caspase7 and Caspase3 were detected by RT-qPCR. A total length of 1 293 bp SERBP1 gene sequence was cloned successfully, including 44 bp of 5'UTR, 1 179 bp of CDS region, and 70 bp of 3'UTR,encoding 392 amino acids, with no signal peptide and mainly located in the nucleus. It was predicted that SERBP1 might interact with 10 proteins including RPL31 and RPS3. The expression mRNA of SERBP1 gene was the highest in goat pancreas, and an effective interference sequence with an interference efficiency of 70% was selected. siRNA interference of SERBP1 gene inhibited the proliferation and apoptosis of goat turbinate primary cells, and the cells were arrested in G₀/G₁ phase. The mRNA expression of Caspase3, Caspase7, BCL2L11 and Bax gene was down-regulated but no significant difference was determined in the mRNA expression of Bcl-2, P53, and PARP1 gene. Interference with goat SERBP1 gene could inhibit the proliferation and apoptosis of goat turbinate bone cells and induce cell cycle arrest. These data may lay a foundation for further study of SERBP1 gene function, and also facilitate the mechanism research underlying cell apoptosis inhibited by ORFV125 gene.

The aim of this study was to investigate the cytotoxicity effect of amyloid fibrils of hen egg-white lysozyme (HEWL) on SH-SY5Y cells. The 100 μmol·L^-1 HEWL protein was incubated with agitation at 57℃ in glycine solution of pH 2.0. The ultrastructure of HEWL amyloid fibrils was observed under transmission electron microscopy, the hydrophobicity was detected by ANS fluorescence, the secondary structural contents were measured and analyzed by circular dichroism. After SH-SY5Y cells were treated by the formed HEWL fibrils, the cell viability was determined by MTT assay and the apoptosis features were detected by nuclear staining. The transmission electron microscopy results showed that HEWL protein formed short and rod-shaped amyloid fibrils after 4 days of incubation. Meanwhile, compared with the native HEWL protein, the surface hydrophobicity and β-sheet structure of aggregates were both greatly increased. Furthermore, 1-3 μmol·L^-1 HEWL fibrils all produced significant cytotoxicity in SH-SY5Y cells after 12, 24 and 48 h treatments(P<0.01). For different concentrations of 1, 2 and 3 μmol·L^-1 HEWL fibrils, the cell viability were 75.16%±15.51%, 67.54%±12.13% and 67.89%±10.26% for 12 h treatment,respectively; 75.78±13.01%, 58.41%±5.55% and 61.90%±8.94% for 24 h treatment,respectively; 71.59%±14.75%, 55.65%±5.78% and 46.45%±6.23% for 48 h treatment,and the decreased cell viability displayed time-dependent and concentration-dependent manner. Nuclear staining results further confirmed the apoptosis features. These results suggest that HEWL protein could form into toxic amyloid fibrils under certain physicochemical conditions, which could provide basis for understanding the mechanisms of amyloid fibrils forming of prion protein and other amyloid proteins.

In this study, 3T3-L1 preadipocytes were induced to transdifferentiate into 3T3-L1 adipocytes to explore the inhibitory effect and mechanism of diminazene aceturate (DIZE) endogenous activation of angiotensin converting enzyme 2 (ACE2) on cell lipid deposition. 3T3-L1 preadipocytes were transdifferentiated. The successfully differentiated 3T3-L1 adipocytes were divided into control group and DIZE group (12.5, 25 μmol·L^-1 treatment), siACE2 group and siACE2 + DIZE group (after siACE2 interference + 25 μmol·L^-1 (dice) for 48 h, supernatant and cells were taken for the following experiments. Results:1) 3T3-L1 adipocytes were successfully induced. Fat droplets appeared in more than 95% of preadipocytes on the 14th day; 2) The action concentrations of DIZE were determined to be 12.5 and 25 μmol·L^-1 When 3T3-L1 adipocytes were treated with the drug concentration and time for 48 hours, the content of triglyceride in cell supernatant decreased significantly (P<0.05) and the content of glucose increased significantly (P<0.05); The lipid droplets of cells in the 25 μmol·L^-1 DIZE treatment group decreased, but the siACE2 group had no significant change. The accumulation of lipid droplets in the siACE2+DIZE group was between the control group and the DIZE group; the ACE2 protein level was significantly higher in the 25 μmol·L^-1 DIZE group. Compared with the control group (P<0.05); the siACE2 group was significantly down-regulated (P<0.05), and the siACE2+DIZE group had no significant change compared with the siACE2 group; 3) Compared with the control group, the expressions of FAS, ACC and SREBP-1c proteins in the 25 μmol·L^-1 DIZE group were down-regulated, while those in the siACE2 group and siACE2+DIZE group were all up-regulated.; 4) Compared with the control group, the expression levels of GLUT4 and CS proteins in the 25 μmol·L^-1 DIZE group were significantly up-regulated (P<0.05), while those in the siACE2 group and siACE2+DIZE group were significantly down-regulated (P<0.05). DIZE treatment improved adipocyte fat deposition by mediating endogenous activation of adipocyte ACE2. Its mechanism:on the one hand, it inhibits lipid synthesis; on the other hand, it promotes glucose uptake and oxidative metabolism, which synergistically reduces fat deposition. The results suggest that ACE2 or DIZE can be used as potential targets or drugs to prevent and control the occurrence and development of fat deposition.

This study aimed to screen differential methylation genes and analyze the differential methylation regions specific to the Gene Ontology (GO) by comparing the distribution characteristics of differential methylation peaks in the whole genome of PK15 cells transfected by Poly I:C and Aza-CdR. Firstly, the pig 385 K whole genome promoter and CpG Island methylation chip were used based on MeDIP-chip technology. Three groups of experimental materials (porcine PK15 cells transfected with Poly I:C virus mimic, PK15 cells transfected with methylase inhibitor Aza-CdR, and mock cells without treatment) were analyzed to obtain significantly enriched differential methylation peaks between two experimental groups based on Peak DM Value and Peak Score. Secondly, Gene Ontology (GO) annotation of differential methylation genes was performed to screen for differential methylation regions and differential methylation genes. Finally, the differential methylated region DMR was verified by Bisulfite clone sequencing and mRNA fluorescence quantitative expression test. DNA methylation in the whole genome of porcine kidney cells was mainly distributed in the 5' regulatory region. After comparison between groups, especially P vs. C and A vs. C comparisons, it was found that the distribution characteristics of DNA methylation on the genome were related to the density of CpG island and the location of distance from TSS. DNA methylation in the near promoter region (0-+200 bp) significantly affected gene expression. The effect of Poly I:C on PK15 increased the number of hypomethylation promotors at 200 bp (-200-+500 bp) near TSS, indicating that Poly I:C and Aza-CdR have similar potential demethylation effects. Especially, 669 bp Peak Length CG sites were demethylated in the 10459946-10460615 bp region of the BNIP3L gene on pig chromosome 14. It was revealed that Poly I:C and Aza-CdR did not demethylate in all pig genes, but mainly targeted specific promoters of specific genes, demonstrating that CpG islands of these specific promoters were particularly sensitive to Poly I:C and Aza-CdR.

Plasma cells secreting IgA and IgG are two important effector cells in mucosal immune system. This study aimed to explore the distribution characteristics of plasma cells secreting IgA and IgG in the nasal cavities of rabbits. Twenty healthy adult rabbits were selected as the research objects. According to the characteristics of the hard palate folds and teeth, the nasal cavities of rabbits were divided into five segments,including Ⅰ Ⅱ Ⅲ Ⅳ and Ⅴ segments. Histology, immunohistochemistry, image analysis and statistical methods were used to carefully investigate the distribution characteristics of plasma cells secreting IgA and IgG in nasal cavities of rabbits. Immunohistochemical results showed that plasma cells secreting IgA and IgG were located in every segment of the nasal cavities of rabbits, diffusedly distributed in the lamina propria of nasal mucosa. The morphology was round or oval, and the nucleus was usually located at the side of the cells. Abundant cytoplasm was positive. Statistical results showed that the distribution density of plasma cells secreting IgA and IgG in different segments of nasal cavities from high to low was Ⅳ segment, Ⅴ segment, Ⅲ segment, Ⅱ segment and Ⅰ segment of nasal cavities. The distribution density of plasma cells secreting IgA in Ⅲ, Ⅳ and Ⅴ segments of the nasal cavities was significantly higher than that in Ⅰ and Ⅱ segments (P<0.05). The distribution density of plasma cells secreting IgA in maxilloturbinate, ethmoid turbinate and nasal septum was significantly higher than that in the superior tuibinate (P<0.05). Compared with plasma cells secreting IgA, plasma cells secreting IgG have similar distribution trend except that distribution density of plasma cells secreting IgG in the Ⅳ segment of the nasal cavities was significantly higher than that in Ⅲ and Ⅴ segments(P<0.05). The results confirmed that plasma cells secreting IgA and IgG were distributed diffusedly in the nasal mucosa propria of each segment of the rabbit nasal cavity, which would be conducive to SIgA and IgG molecule formation complete protective barrier in the whole nasal mucosa. Plasma cells secreting IgA and IgG were mainly distributed in Ⅲ, Ⅳ, Ⅴ segments of the nasal cavities, maxilloturbinate, ethmoid turbinate and nasal septum, indicating that these areas are important effective sites of intranasal immunization in rabbits. This study will provide an important theoretical basis for the prevention of rabbit's respiratory diseases and further exploration of the mechanism of nasal immune response in rabbits.

The study aimed to investigate the mRNA transcription levels of inflammation related cytokine genes in mammary tissues of dairy cows with S. aureus or E. coli type mastitis. S. aureus or E. coli (10⁵ CFU·mL^-1) were respectively injected into the cow's udder through its duct. On the 7th day of infection, the mammary tissues were collected by aseptic operation in vivo. Then the mastitis models were identified by HE staining and immunofluorescence of mammary tissues. qPCR was used to detect the mRNA transcription levels of nine genes in cow mammary tissues of two induced groups and control group, including chemokine family (CCL2, CCL8, CXCR1, CXCL2 and CXCL13), complement factor (CFI and CFB), autophagy factor DEPP1 and interleukin receptor IL21R. Compared with the control group, the protein expressions of the key molecules (TLR4, NF-κB and TNF α) in TLR4/NF-κB signaling pathway related inflammation were extremely significantly up-regulated in the mammary tissues of the two induced groups (P<0.01), indicating that two types of mastitis in vivo models were successfully constructed combined with the results of HE staining. The results of mRNA transcription levels detection showed that, compared with the control group, the mRNA transcription levels of seven genes (CCL2, CCL8, CXCR1, CXCL2, CFI, CFB and IL21R) were extremely significantly up-regulated in mammary tissues of the two induced groups (P<0.001), the mRNA transcription levels of CXCL13 were extremely significantly up-regulated only in mammary tissues of the S. aureus induced group (P<0.01), while the expression of DEPP1 was extremely significantly down-regulated in mammary tissues of the both induced groups (P<0.01). In addition, the mRNA transcription levels of five genes including CCL2, CCL8, CXCR1, CFI and IL21R in E. coli induced group were significantly higher than those in S. aureus induced group (P<0.01). S. aureus or E. coli infection can cause serious clinical mastitis symptoms in dairy cows, and promote the abnormal expression of the above inflammation related genes in mammary tissues, to response to the occurrence and development process of mammary inflammation. The mRNA transcription levels of five genes including chemokine CCL2 in E. coli induced group were significantly higher than that in S. aureus induced group, which explained that E. coli often caused acute mastitis, while S. aureus caused chronic mastitis. The above results will provide the reference for further research on the molecular regulation mechanism of different type mastitis in dairy cow.

The purpose of this study was to study the alleviating effect of dandelion extract on lipopolysaccharide (LPS) induced mastitis in mice and its mechanism. The mice were divided into blank group, model group, positive group (DEX) and dandelion extract high, medium and low dose groups. Dandelion extract was administered at high, medium and low doses according to 10.0, 5.0, 2.5 g·kg^-1 gastric lavage, continuous gastric lavage for 6 days, 2 times per day, and the blank group was gastrically filled with equal volume of normal saline. One hour after the last administration, 50 μL of 0.2 mg·mL^-1 LPS was perfused in the basal part of the breast of mice to establish LPS-induced model of mastitis in mice, and the positive group was injected 5 mg·kg^-1 of dexamethasone intraperitoneally 6 and 12 h after modeling. Twenty-four hours later, blood was collected and serum was separated, and breast tissue was stripped. The contents of serum tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were determined by ELISA, the content of myeloperoxidase (MPO) was measured by MPO kit, the pathological change was observed by HE staining, the expressions of TLR4 protein and related proteins of NF-κB and MAPKs signaling pathways in mouse mammary glands were measured by Western blot. The results showed that dandelion extract at high and medium dose groups significantly inhibited the secretion of serum TNF-α, IL-1β and IL-6 (P<0.01), reduced MPO content in LPS-induced mastitis mice (P<0.01), and dandelion at high and medium dose groups extract improved pathological changes of mastitis induced by LPS, significantly down-regulated the expression of TLR4, p-IκB, p-p65, p-p38, p-JNK, p-ERK proteins in LPS-induced mastitis (P<0.01). The results showed that dandelion extract can significantly alleviate LPS induced mastitis by regulating NF-κB and MAPKs signaling pathways in mice, which lays a foundation for the clinical development and application of dandelion.

The main antibacterial active ingredients and mechanism of Isatis indigotica were predicted based on network pharmacology. The active ingredients and targets of Isatis indigotica were screened by using TCMSP database; The related targets were searched by OMIM and GeneCards databases with the keyword of "antibacterial"; The intersection target of Isatis indigotica and bacteriostasis were collected through the Venny platform; STRING database combined with Cytoscape software were used to construct the PPI network and screen the key targets; GO function enrichment analysis and KEGG pathway enrichment analysis were carried out by using DAVID database; The key pharmacodynamic ingredients with the antibacterial targets were connected through Autodock Tools 1.5.7 software; The bacteriostatic effects against Escherichia coli(CVCC1515) and targets of the key ingredients were verified by colony counting and SDS-PAGE. A total of 33 active components of Isatis indigotica, 61 potential drug targets, 2 192 bacteriostatic targets, and 32 intersection targets of Isatis indigotica and bacteriostatic action were screened. Protein interaction network analysis revealed that 30 proteins, including TNF, TP53, CASP3, JUN, ESR1 and PTGS2 and so on, might be the key targets of antibacterial activity of Isatis indigotica. The GO functional enrichment analysis yielded 126 entries, including 86 biological process items (e.g. response to estradiol apoptotic signaling pathway, positive regulation of neuron apoptotic process), 11 cell composition items (e.g. cytoplasm, nucleus), and 29 molecular function items (e.g protein homodimerization activity, enzyme binding). KEGG pathway enrichment analysis yielded 20 related signal pathways. Molecular docking result showed that the binding energies of the key active components (beta-sitosterol, stigmasterol and acacetin) with the coding proteins of key antibacterial targets were all less than 0 kJ·mol^-1. Antibacterial experiments showed that stigmasterol was the key active component of Isatis indigotica which might down-regulated the expression of intracellular CASP3 and PTGS2 proteins. Stigmasterol of the active components of Isatis indigotica exerts antibacterial effect through the targets of CASP3 and PTGS2 which involved in TNF signaling pathway and pathways in cancer.

The aim of this study was to screen the best dosage of Radix Hedysari polysaccharide-1-1 (RHPS-1-1) regulating intestinal flora imbalance in mice. The single polysaccharide RHPS-1-1 was isolated and purified from the crude RHPS by DEAE-52 and Sephadex G-100, respectively. The monosaccharide composition of RHPS-1-1 was determined by high-performance anion-exchange chromatography (HPAEC), and the structure of the polysaccharide was identified by methylation and infrared spectroscopy. Ninety C57BL/6 mice were randomly divided into normal control group, model group, self-healing group, and different doses of RHPS-1-1 groups (12.5, 25, 50, 100, 200 and 400 mg·kg^-1) with 10 mice in each group. The intestinal flora imbalance mouse model was established by intragastric administration of antibiotic cocktail (ampicillin, neomycin, metronidazole and vancomycin) for 14 consecutive days. At the end of model establishing, the mice in model group were killed and sampled. Each drug administration group was gavaged with different doses of RHPS-1-1, and normal control and self-healing groups were gavaged with equal volume of normal saline for 14 consecutive days. Finally, 16S rDNA high-throughput sequencing method was used to analyze the changes of intestinal flora of cecal contents in each group, and the organ indices and histopathological changes of major organs in normal control, self-healing and 25 mg·kg^-1 RHPS-1-1 groups were calculated and observed. The results showed that the purified RHPS-1-1 was a single polysaccharide with a weight average molecular weight of 19.420 ku. RHPS-1-1 was mainly composed of glucose, the main chain of which was connected by 1,4-D-Glcp, and had a special absorption peak of plant polysaccharides. Gavaging with antibiotic cocktail caused a serious intestinal flora imbalance in mice. The abundance of Bacteroidetes, Firmicutes and Actinomycetes were extremely reduced, while Proteobacteria were relatively increased. And this alteration could not recover naturally. The diversity and richness of intestinal flora were changed after RHPS-1-1 administration, and the Chao 1 index of 25 mg·kg^-1 RHPS-1-1 group was significantly increased (P<0.05). The principal components analysis (PCA) and unweighted pair-group method with arithmetic averages (UPGMA) showed that the intestinal flora structure of 25 mg·kg^-1 RHPS-1-1 group was the closest to that of the normal control group. The abundance of harmful bacteria Muribaculaceae_unclassified was decreased, while the abundance of beneficial bacteria Ruminococcaceae_UCG-014 and Clostridiales_unclassified were increased. Compared with normal control group, liver index in self-healing group was significantly decreased (P<0.05), and significantly increased after 25 mg·kg^-1 RHPS-1-1 treatment (P<0.05). However, there were no obvious pathological changes in heart, liver, spleen, lung, kidney and brain in normal control group, self-healing group and 25 mg·kg^-1 RHPS-1-1 treatment group. The results demonstrated that RHPS-1-1 was a plant glucan with a molecular weight of 19.420 ku. At the dose of 25 mg·kg^-1, RHPS-1-1 had the best effect on promoting the recovery of intestinal flora disorder caused by antibiotics in mice, and could improve the decline of liver index. The present study provided evidences for the clinical application of RHPS regulating intestinal flora.

The aim of this experiment was to study the characteristics of a novel goose astrovirus strain causing gosling gout. In this experiment, the virus was isolated from goose astrovirus positive goslings in Anhui Province, and the whole genome of the isolated virus strain was sequenced, followed by genetic evolution analysis. The results showed that the virus which named as GASTV-ZM strain was successfully isolated from goose embryos at 9-11 days of age after inoculation, and was identified as postive by indirect immunofluorescence assay(IFA). The length of the genome of ZM strain was 7 175 nt. The nucleotide and amino acid homology of ORF2 gene were 96.7%-98.9% and 96.9%-99.0%with the strains isolated from 2014 to 2020, respectively. And the ORF2-encoded amino acid sequence showed that the three amino acid mutation sites were significantly different from the previous ones. ZM strain is in the same evolutionary branch with the novel goose astrovirus that has been circulating in China since 2016, and its homology with HNSQ-6 strain and XT1 strain isolated in 2020 is high. This study laid a foundation for further study of the pathogenicity and pathogenicity mechanism of this virus.