Retinoid X receptors (RXRs) are members of the ligand-dependent nuclear receptor family. Many studies in the past have revealed the importance of RXRs in animal's seasonal estrus and estrous cycles, but RXRs must form dimers with themselves or other nuclear receptors to work. Different dimers play different roles, therefore their molecular mechanism of playing role in reproduction is difficult to study. Some studies have shown that RXRs expressed at different levels in the hypothalamic-pituitary-gonadal (HPG) axis tissues of seasonal estrus animals. Dimers of THRs/RXRs, RARs/RXRs and PPARs/RXRs can stimulate the release of GnRH in the hypothalamus to regulate seasonal estrus and proliferation of ovarian granulosa cells, remodeling of ovarian vascular tissue, and steroid production, which affect the animal estrous cycle conversion. This paper summarizes the role of RXRs and their dimers in the different reproductive activities related to seasonal estrus and estrous cycle of animals, and provides a reference for future research.

Anthocyanins are a kind of water-soluble natural pigments rich in plants, which are favored by scholars because of their high safety and strong ability to scavenge free radicals. This paper mainly reviews the structure and safety of anthocyanins, their possible digestive and metabolic pathways in ruminants, and the mechanism of enhancing the body's antioxidant capacity and relieving oxidative stress, and discusses its feasibility as a new feed additive for ruminants. This review will provide theoretical references for related research.

The aim of this study was to investigate the effect of porcine SERPINC1 gene on PCV2 replication and to explore the transcriptional regulation of SERPINC1 gene. In this study, 15 purebred Laiwu pigs (LW) and 15 commercial Yorkshire×Landrace hybrid pigs (YL) were used. There were 2 groups in each breed, one for the challenged group (10) and one for the control group (5). Pigs in the challenged group were intramuscularly injected with 3 mL of 6.3×10^-3TCID₅₀ PCV2-SD strain, and pigs in control group were intramuscularly injected with 3 mL of phosphate buffer. Based on the previous transcriptome sequencing, the effect of SERPINC1 gene on PCV2 replication was analyzed, and the promoter and transcriptional activity of SERPINC1 gene were detected. The results indicated that over-expression of SERPINC1 could significantly inhibit the replication of PCV2 in PAM cells. The 3 854 bp sequence of the 5' regulatory region of the SERPINC1 gene in LW and YL pigs was cloned respectively, and the promoter activity was analyzed. It was found that the promoter activity of SERPINC1 gene in LW pigs significantly increased after PCV2 infection(P<0.05), while that of YL pig didn't significantly change. Four critical regulatory regions were found in the 5' regulatory region of the SERPINC1 gene. Four polymorphic sites were identified in the critical regulatory regions in LW and YL pigs. By site-directed mutation and dual luciferase reporter gene assay, we found that the activity of the SERPINC1 promoter was not affected by any one of the polymorphic sites in the above regions. The results laid a foundation for finding the gene and molecular markers related to the resistance of PCV2.

The aim of this study was to evaluate inbreeding among different sheep populations and detect genes related to economic traits of sheep based on the information of runs of homozygosity (ROH). Based on Illumina Ovine SNP50 BeadChip, we performed genome-wide ROH scan for 440 individuals from 10 sheep populations. The number, length and frequency of ROH were counted in each population and the genomic inbreeding coefficient(F_ROH) was calculated based on ROH. The genomic regions with high frequency in ROH were annotated. A total of 25 920 ROH fragments were identified in the 10 sheep populations. The number, length, frequency and distribution of ROH varied among these sheep populations. The average number of ROH per population ranged from 10.17 (Sunite) to 95.99 (Dorper), the average length of ROH per population ranged from 2.04 Mb (Tibetan sheep from Sichuan) to 4.71 Mb (Lop), and the average genomic inbreeding coefficients (F_ROH) ranged from 0.010 (Sunite) to 0.172 (Dorper) in sheep populations. The average F_ROH in commercial sheep breeds from abroad (Dorper and German Mutton Merino sheep) were higher than that in the indigenous sheep populations in China. Among Chinese indigenous sheep populations, Tibetan sheep from Tibet (0.085) had the highest average genomic inbreeding coefficient. Moreover, twenty-six genes related to economic traits of sheep located in the genomic regions with high frequency in ROH were identified. Among these genes, NCAPG, LCORL, PRKAA2, FAIM2 and HYDIN were associated with growth and development traits, LEPR, WNT10B and NCKAP5L were related to fat metabolism, and CDIPT, CAPN3 and FGF9 involved in meat quality and carcass traits. The inbreeding coefficients calculated based on ROH would provide reference for breeding and preservation of the 10 sheep populations and the candidate genes identified could be used for marker-assisted selection in sheep breeding.

The aim of this study was to explore the regulation mechanism of MSTN on muscle growth and development by analysis of the interaction regulation between the MSTN promoter and MEF2C in cattle. Firstly, the 2 267 bp upstream promoter region of MSTN and 1 425 bp coding region of MEF2C were amplified by PCR. Secondly, pGL3-Basic-MSTN and pcDNA3.1(+)-MEF2C dual luciferase reporter vectors were constructed and co-transfected into C2C12 myoblasts by liposome transfection method. The dual luciferase activity were measured after 24 hours. Finally, the core fragment with high activity of MSTN promoter was amplified by PCR. The recombinant expression vector pEGFP-N3-MSTN-P1-MEF2C which replaced (CMV) area with MSTN-P1 fragment was reconstructed, and it was transiently transfected into C2C12 myoblasts and rat mandibular gland epithelial cells, respectively, the expression of green fluorescent protein in cells was observed after 24 hours. Total RNA was extracted from cells after 48 hours. The expression levels of MEF2C in different cells were detected by qRT-PCR.The results showed that the activity of MSTN promoter was enhanced significantly by co-transfected of pcDNA3.1(+)-MEF2C(P<0.05), and it was enhanced extremely significantly compared with pGL3-Basic in C2C12 myoblasts(P<0.01); MSTN-P1 promoter core fragment could drive the expression of MEF2C, and the mRNA expression levels were extremely significantly up-regulated(P<0.01) in C2C12 myoblasts, and significantly up-regulated(P<0.05) in rat mandibular gland epithelial cells. The results indicated that both MSTN promoter and MEF2C could be involved in the regulation of growth and differentiation of muscle at the transcriptional level.

The aim of this study was to investigate the tissue expression profiles of yak Nramp1 gene mRNA and the possible miRNAs targeting to Nramp1. The mRNA expression profile of yak Nramp1 gene was analyzed by RT-PCR, and the possible miRNAs targeting to Nramp1 were predicted by TargentScan and miRBase softwares, and the relative expression levels for these miRNAs were analyzed in the 10 yak tissues including liver, spleen, lung, kidney, hind leg skeletal muscle, ovary, small intestine, submandibular lymph node, large intestine and intestinal lymph nodes by adding PloyA tail RT-PCR method. The results showed that the Nramp1 gene mRNA was expressed in the 10 examined tissues, and the expression levels in the yak spleen, submandibular lymph node and lung were extremely significantly higher than that in the liver, kidney, large intestine and intestinal lymph node(P<0.01), and significantly higher than that in small intestine tissue (P<0.05). A total of 201 miRNAs that might target to the yak Nramp1 gene were predicted, and 6 of them were selected for expression profiling analysis. It was found that Nramp1 mRNA and bta-miR-106a, bta-miR-20b, bta-miR-17-5p were co-expressed in the yak immune tissues such as the spleen, submandibular lymph node and intestinal lymph node, and were co-expressed with bta-miR-93, bta-miR-106b and bta-miR-20a in yak submandibular lymph nodes and intestinal lymph nodes. There were no significant differences in the expression of bta-miR-93,bta-miR-20a,bta-miR-106a,bta-miR-17-5p and bta-miR-20b between submandibular lymph nodes and intestinal lymph nodes(P>0.05), but the expression of bta-miR-106a and bta-miR-20b in submandibular lymph nodes and intestinal lymph nodes were extremely significantly higher than those in spleen tissues(P<0.01),and the expression of bta-miR-106b in submandibular lymph nodes was extremely significantly higher than that in intestinal lymph nodes(P<0.01). The extensive expression of Nramp1 mRNA in various tissues of yak suggested that it might have a wide range of immunomodulatory effects, and the co-expression of bta-miR-93, bta-miR-20b, bta-miR-106a, bta-miR-106b, bta-miR-20a, bta-miR-17-5p and Nramp1 mRNA in immune tissues indicated that they might have targeted regulatory relationship in immune regulation, but whether there is targeting regulation and their regulation mechanism remains to be further studied.

This work aimed to compare the effects of different target regions on the editing outcomes of CRISPR/Cas9 technology by using next generation targeted sequence, and provide a technical reference for target screening during application of this technology. This work was carried out as follows:1) Mouse Pyk2 gene was used in this study, and 3 target regions were designed in the first exon of this gene, through plasmid construction, cell transfection and next generation targeted sequencing of the cell DNA, we found that the total gene editing (Indels) efficiency of different target regions was different(site1:32.0%;site2:7.9%;site3:69.5%), and the preference for gene repair were also different among different groups. For the same target region, the editing efficiency was more stable in 2 experimental replicates(31.8% vs 32.3% for site1;7.4% vs 8.4% for site2;71.3% vs 67.8% for site3), and the preference of gene editing was relatively conservative; 2) Through Pyk2 site1 sgRNA and Cas9 in vitro transcription, mouse embryos microinjection, embryo transfer and genotyping, we found that the gene editing preference of the above target region was reproducible in gene editing animals production; 3) The mutant mouse with a single base inserted in site1 target region was used, sgRNA with a different base from site1 in orginal target was desigend. For the Pyk2 site1 target region, we found that single base inserts on Cas9 cleavage site had a significant impact on the efficiency of gene editing in the target region (49.2% vs 0%) by mutated mouse genomic PCR and Cas9 enzyme digestion in vitro cleavage test. In conclusion, target selection has a significant impact on the outcome of CRISPR/Cas9 gene editing. The next generation targeted sequence can effectively screen the CRISPR/Cas9 gene editing target region, and also obtain optimal results in the model animal production. In addition, inserting single base to the target region has a significant effect on gene editing efficiency.

This study aimed to select biomarkers featuring sperm motility in Simmental bull. Twenty four Simmental bulls semen were collected, eleven of which were viewed as abnormal group, and 13 as normal group according to their sperm motility. UPLC-Q-TOF MS metabolomics was used to study change in metabolic profile and metabolites of seminal plasma in the 2 groups. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that, compared to the normal group, seminal plasma metabolic profiles obviously altered, six metabolites levels significantly decreased(P<0.05), and 19 metabolites levels significantly increased(P<0.05) in abnormal group. These metabolites were further analyzed by ROC curve to observe their discriminating ability to classification. As a result, only 6 metabolites(including sphingosine, N6, N6, N6-Trimethyl-L-lysine, cyclohexylamine, 5'-Deoxyadenosine, pentadecanoic acid and alloxan) had an obviously distinguishing capacity for seminal plasma in the 2 groups. In conclusion, sphingosine, N6, N6, N6-Trimethyl-L-lysine, cyclohexylamine, 5'-Deoxyadenosine, pentadecanoic acid and alloxan in seminal plasma could be better potential biomarkers to evaluate sperm motility in Simmental bull, which could provide new methods and ideas for the study of semen quality determination technology.

The purpose of this study was to reveal the morphological characteristics and developmental regularity of various components in the mature follicle wall layer of goose, and to provide a new perspective for the grading of dynamic development of mature follicles in poultry. The 5 healthy female geese from maternal line of Tianfu geese in high-yielding period were selected, and their mature follicles at each stage (diameter 0-2, 2-4, 4-6, 6-8, 8-10 mm and F5-F1) were fixed. At least 3 follicles were randomly selected in each stage during 0-10 mm, and more than 3 different regions were randomly selected for HE slicing in each follicle (except 0-2 mm stage); While more than 3 different regions were randomly selected for HE slicing in each follicle during F5-F1 stage. More than 3 areas were randomly selected from each slice for image acquisition, and 3 areas were randomly selected from each image to measure. We counted and analyzed the thickness of follicular wall, granulosa layer, theca layer and connective layer, and observed and compared their morphological characteristics. The results showed that:1) There was no complete internal theca layer in some follicles less than 2 mm in diameter. 2) There was no significant difference in follicle size and follicular wall morphology between 2-10 mm and F5 follicles. 3) In stage F4-F2 follicles, the granulosa layer cells were flat, while the thickness of theca and connective layer increased significantly (P<0.05), and the morphology of follicular wall layer changed greatly. 4) The granulosa layer of F1 follicle became loose cubes, and the thickness of each component of follicular wall changed significantly (P<0.05). These results indicate that the development process of goose mature follicle can be divided into 5 stages:0-2 mm, 2-10 mm, F5, F4-F2 and F1. These follicles at different stages have unique morphological and structural characteristics, which may be closely related to their functional differences.

This study was conducted to investigate the effects of water volume, sample weight and sieving time on the mean particle size of pelleted diet, digesta and feces during wet-sieving, and to provide a reference for the determination of particle size for pelleted diet, digesta and feces of pig. The mean particle size was assayed with wet-sieving using a set of 6 sieves sized 2.0, 1.0, 0.5, 0.25, 0.106 and 0.072 mm. The water volume of 1,1.25 or 1.5 L, sample weight of 7.5 or 10 g for pelleted diet, 15 or 30 g for ileal digesta, 10 or 20 g for feces and sieving time of 4 or 5 min were used in a 3×2×2 factorial completely randomized arrangement. There were 12 treatments for each type of sample. The effect of wet-sieving conditions on the measurement of geometric mean particle size of samples was investigated. The results showed that:1) Increment of water volume significantly decreased the proportion of the mass content of the particles more than 1 mm in size(P<0.05), but significantly increased the proportion of the mass content of soluble matter in pelleted diet, ileal digesta and feces (P<0.05); Increment of the sample weight significantly increased the proportion of the mass content of the particles more than 1 mm in size(P<0.05), but significantly decreased the proportion of the mass content of soluble matter or particles less than 0.072 mm (P<0.05). However, there was no significant effect of sieving time on the proportion of the mass content on each sieves. 2) Water volume and sample weight extremely significantly affected the determination of mean particle size for pelleted diet, ileal digesta and feces (P<0.01), but significant effect of the sieving time was only observed on the determination of ileal digesta(P<0.05). The determined value of mean particle size was significantly higher in 1 L of water volume than 1.25 or 1.5 L (P<0.05). Moreover, particle size was significantly different between 1.25 and 1.5 L of water volume for feces (P<0.05), but there was no significant differences between 1.25 and 1.5 L of water volume for ileal digesta and pelleted diet. The sample weight of pelleted diet ranged from 7.5 to 10 g, ileal digesta from 15 to 30 g, and feces from 10 to 20 g led to the difference of less than 12 μm in determined particle size. In summary, in the determination of particle size for pelleted diet, digesta and feces of pig using wet-sieving method, the sample weight of pelleted diet ranged from 7.5 to 10 g, ileal digesta from 15 to 30 g, feces from 10 to 20 g, 1.25 L of water volume and 4 min of sieving time are the optimized condition to obtain a relatively stable result.

This experiment was conducted to explore the effect of acute cold stress on immune function and expression of HSP70 family genes in different tissues in sheep. Eight (12±0.5)-month-old healthy female sheep (F₁ of Small Tail Han sheep×Hu sheep) were selected and raised separately in cage in heat-preserved sheep house (wind chill temperature:(-7.14±2.53)℃). The adaptation period lasted for 7 d. At the 8th day, female sheep were treated with acute cold stress for 12 h in outdoor (wind chill temperature:(-27.40±3.12)℃), and then blood and tissue samples were collected before and after cold stress. Serum immune indexes (cytokine and immunoglobulin G content), the expression of HSP70 family genes (HSPA1A, HSPA6 and HSPA8) and heat shock transcription factor 1 (HSF1) in different tissues (liver, kidney, spleen, heart, longissimus dorsi muscle and duodenum) were measured by ELISA and RT-PCR method, respectively. The results showed as the follows:1) Compared with before acute cold stress, the serum levels of TNF-α, IL-1β, IL-2 and IL-6 increased significantly after acute cold stress(P<0.05), while the serum levels of IL-4 and IgG decreased significantly (P<0.05). 2) The mRNA expression of HSPA1A increased significantly in liver, kidney, heart and longissimus dorsi muscle after acute cold stress(P<0.05). HSPA6 expression level increased significantly in the longissimus dorsi muscle and heart (P<0.05). HSPA8 expression level increased significantly in longissimus dorsi muscle(P<0.05), and decreased significantly in spleen and duodenum(P<0.05). HSF1 expression level increased significantly in liver, heart and longissimus dorsi muscle (P<0.05), and decreased significantly in spleen and duodenum(P<0.05). In this experiment, acute cold stress could inhibit the immune function, and the expression levels of HSP70 family genes (HSPA1A, HSPA6 and HSPA8) were different in different tissues. The HSPA1A was more sensitive to temperature and could be suitable to as a biomarker for cold stress. The increased expression of HSP70 family genes in liver, heart and longissimus dorsi muscle might be related to keeping the normal heat production for tissue cells.

This study aimed to construct a defective recombinant adenovirus capable of expressing the P72 protein of African swine fever virus (ASFV). The ASFV B646L gene based on relevant China-SY18 isolate was synthesized. The synthetic B646L gene was cloned into transfer vector pENTR/D-TOPO. In order to construct a recombinant adenovirus, the recombination between the transfer vector pENTR/D-TOPO-ASFV-P72 and the backbone vector pAd/CMV/