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/V5-DEST was done. The PacⅠ-linearized recombinant vector was transfected into 293A cell to produce recombinant adenovirus by serial passage. The results showed that the titers of the recombinant adenovirus Ad5-ASFV-P72 were 2.53×10⁹ IFU·mL^-1; the ASFV-P72 protein was expressed successfully in Vero cells by identification of the Indirect immunofluorescence assay and Western blot, and the expressed protein could reacted with ASFV standard positive serum specifically. Ad5-ASFV-P72 recombinant adenovirus was constructed successfully in the study. These findings not only lay the solid foundation for developing ASFV multi-gene recombinant adenoviral vector vaccine, but also provide a safe and effective antigen for the establishment serological diagnostic methods.

This study was conducted to understand porcine deltacoronavirus (PDCoV) epidemic situation, and provide a tool for PDCoV serum antibody detection and the epidemiological investigation. Prokaryotic expression of recombinant PDCoV partial spike (S) protein was used as detection antigen, and an indirect ELISA antibody detection method based on PDCoV S1 protein was established. The method was used to detect 570 serum samples collected from some pig farms in Hebei from January to December 2017. The results showed that the established ELISA method of PDCoV IgG antibody in this study could specifically detect PDCoV antibody; no cross-reaction with antisera against porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever (CSF) and pseudorabies virus (PRV) was found. The coefficients of variation (CV) of repeated in-batch test was 1.9%-5.4%, CV of batch-to-batch test was 2.3%-5.1%. In 570 blood samples, 105 were positive, and the positive rate was 18.4% (105/570), which was higher than the positive rate of PDCoV IgG antibody (11%) in Hebei from January 2016 to October 2016. It is suggested that the infection rate of PDCoV in Hebei is on the rise. The ELISA method established in this study had the advantages of high sensitivity, strong specificity and good reproducibility, and can be used for the detection of clinical PDCoV serum antibodies.

In order to investigate the prevalence of Haemophilus parasuis (HPS) and its serotype in Henan province during 2014-2017, 813 suspected HPS samples were collected from different areas, such as Shangqiu, Luoyang, Zhoukou, etc. Firstly, pathogens were isolated by TSA medium, then, the isolates were identified based on 16S rDNA sequences and were serotyped by type-specific primers. Three different serotype isolates were selected as representative strains, which outer membrane proteins (OMP) were cloned and analyzed. The results showed that the total isolation rate of HPS was 7.75%(63/813), and the isolation rate was from 5.49% (13/237) to 11.31% (19/168) in different years. In these isolates, the serotype 4, 5, 14 and nontypeable strains were 38.10% (24/63), 33.33% (21/63), 7.94% (5/63), 20.63% (13/63), respectively. Serotype 4 and serotype 5 were the most predominant serotypes, followed by serotype 14 and non-typeable strains. Based on OMP sequence analysis, it showed that the homology of nucleotides and amino acids were 98.6%-99.9% and 99.0%-100.0%, respectively. Phylogenetic analysis indicated that all the strains were divided into two groups, Henan-HPS-KF4 and Henan-HPS-LY14 lied in the same branch, Henan-HPS-ZK5 was located in another branch. The comparison of amino acid sequence showed that the 57^th amino acid of Henan-HPS-ZK5 was mutated from T⁵⁷ (Thr) to A⁵⁷ (Ala). The 89^th,115^th,233^th and 239^th amino acid of serotype 4,serotype 5 and serotype 14 HPS were Gln (Q), Glu (E), Arg (R) and Gly (G), respectively, while the other serotypes HPS were Arg (R), Lys (K), Gly (G) and Arg (R), except for the nontypeable strains. These data could respond the epidemiological situation of HPS and its serotypes in Henan province, which will contribute to vaccine research and provides a scientific and objective basis for prevention and control HPS disease.

In order to detect Bacillus anthracis rapidly and accurately, two sets of specific primers and TaqMan probes were designed according to the chromosomal sequence BA5345 gene and virulent plasmid sequence PA gene to establish a duplex real-time PCR assay for detection of Bacillus anthracis. The specificity, sensitivity and repeatability were tested, respectively. Then the duplex real-time PCR was used to detect clinical samples and compared with conventional PCR. Results showed that the Bacillus anthracis could be identified specifically and without any cross reaction with other bacillus of Bacillus cereus group. Besides, the detection limits were 8.0 and 7.8 copies·μL^-1 for BA5345 gene and PA gene, respectively. The coefficients of variations were less than 1.5% for both intra-assay and inter-assay. Thirty-five samples contaminated by Bacillus anthracis were detected by the established assay, BA5345 positive rate was 80.0% and PA positive rate was 82.9%. The sensitivity of duplex real-time PCR was significantly higher than that of conventional PCR. The results indicate that the detection assay could be applied for rapid and high through-put detection of Bacillus anthracis.

This study aimed to comprehensively identify a strain of Brucella (B. abortus), tentatively designated BJ1, to provide a reference strain for the research of deer brucellosis. B. abortus BJ1 was diluted and cultivated on TSA plate, and single colony was inoculated into thiopurine and basic fuchsin medium for dye sensitivity test; The TSA plates inoculated with B. abortus BJ1 were placed in a common biochemical incubator and CO₂ incubator for 72 h at 37℃ to observe its dependence on CO₂; B. abortus BJ1 was inoculated into lead acetate medium for H₂S release test; Bacterial S/R type was identified by crystal violet staining and thermal agglutination test; mono-specific serum reactivity was determined by plate agglutination test; bacterial species were identified by AMOS-PCR. Guinea pigs were infected with 1×10⁹ CFU of BJ1 for 14 days to determine the virulence of BJ1 by measuring the number of B. abortus in one gram of spleen of the infected guinea pig. The entire genome was sequenced by next-generation sequencing approach, and phylogenetic analysis was performed using Mauve software to compare with B. abortus 2308. Results were as follows:B. abortus BJ1 was demonstrated to grow independent of CO₂, and produced H₂S. BJ1 was able to grow on medium containing thiopurine and basic fuchsin, and it was confirmed to be smooth phenotype with capability of agglutination with M factor serum. A number of 1.17×10⁶- 2.05×10⁶ CFU of the strain could be obtained from one gram of spleen 14 days post infection. The genome size of BJ1 was 3 270 584 bp, and a total of 46 Indel difference were found in the coding region of BJ1 genome, compared to the B. abortus 2308 strain. Phylogenetic analysis showed that BJ1 exhibited high homology with B. abortus 8416. B. abortus BJ1 was identified to be a bovine species type 9 and enriched the Brucella species. Our findings provide a reference for in-depth understanding of the epidemiology of brucellosis in wild animals of China.

This study was conducted to explore the correlation among the angiotensin-converting enzyme (ACE2), the neutral amino acid transporter B⁰AT1 and the glucose transporters SGLT-1 and GLUT-2 by studying their distribution and expression in the intestines of piglets of different ages. Weaning piglets were used as the experiment animals. The middle jejunum tissues of piglets at 21 and 35 days of age were collected. The distribution and expression of ACE2 in the jejunum of piglets, and the expression of B⁰ AT1, SGLT-1 and GLUT-2 mRNA in jejunal tissues of piglets at different days were determined by Immunohistochemistry, Western blot, real-time PCR and HPLC. By detecting the types and content of free amino acids in plasma, the relationship between these indexes was analyzed. The results showed that ACE2 was mainly located in the folds and villi of the small intestine, and was expressed significantly in the brush border, serosal layer and muscle layer of jejunal epithelial cells; As the piglets grew older, the mRNA expressions of ACE2, B⁰AT1 and SGLT-1 and the content of serum neutral amino acids all increased, while the mRNA expression of GLUT-2 showed no significant change. These results indicated that ACE2 existed in jejunum of piglets, and ACE2 was related to the transport of amino acids and other substances in intestine. This fact provides the basis for the exploration of the unknown new functions of ACE2.

Fibroblast growth factor 4(FGF4) is the first FGF molecule that discovered during the mammalian embryo development, which plays a key role in promoting proliferation of trophoblast cells. Abnormal expression of FGF4 affects development of early embryos and affects the growth and function of mouse placenta as well. Until now, FGF4 is not identified in bovine placenta at early pregnancy. In this study, paraffin sections were prepared and stained with HE, PAS to study the structure in bovine placenta at early pregnancy. In addition, immunofluorescence staining and qRT-PCR were used to study the cell location and expression of FGF4 in bovine placenta at early pregnancy. The results showed that Fgf4 mRNA was detected in amnion, cotyledon and caruncle at every detected age, and the expression of every part varied according to region and gestational age. FGF4 was detected in the cytoplasm of mononuclear trophoblast, trophoblast giant cell, caruncle epithelia, endometrium epithelia, and uterine gland, and was strongly stained in trophoblast giant cell and uterine glandular epithelia. FGF4 and its mRNA were exist in bovine placenta at early pregnancy. With the growth of gestational age, the relative expression of FGF4 mRNA was plunged at first, and then increased in fetal placenta (cotyledon); and in maternal placenta (caruncle), the expression was firstly increased and then decreased.

In this study, we investigated the effects and mechanisms of estrus rate, estrus and gonadal axis on female rabbits. A total of 48 5-month-old female New Zealand rabbits, not multiparous, were reared in artificial illumination. They were randomly assigned to 3 groups of 16 each. All groups were reared in 12-h L/12-h D photoperiod for the first 10 days, then the 3 groups were reared in long light group (LD, L:D 16:8), control group (L:D 12:12) or short light group (SD, L:D 8:16) for the last 6 days separately. Light intensity is 80 lx. The blood, hypethalamus, pituitary and ovary were collected, and estrus ratio was recorded. Effects of photoperiod on secretion of development of follicular and gonadotropic hormone were investigated by HE staining, ELISA, real-time PCR methods. Our results revealed that the serum melatonin level in LD was significantly decreased by 34.8%, 47.8% compared to control and SD groups (P<0.05). Meanwhile,the serum melatonin level in SD was 25% higher than that of control group (P<0.05). The GnRH mRNA expression of the hypothalamus in the rabbit exposed to LD was increased. The GnRH mRNA level of hypothalamic significantly increased by 453%, 250% compared to SD and control groups (P<0.05), while there was no significant difference between SD group and control group (P>0.05). Similarly, the GnRH mRNA level of the pituitary exposed to LD significantly was increased by 70%, 41.7% compared to SD group and control group (P<0.05), while there was no significant difference between SD group and control group (P>0.05). The level of serum follicle stimulating hormone(FSH) in the LD group was 33.7% and 25.1% higher than those of SD group and control group significantly (P<0.05, respectively). Serum luteinizing hormone(LH) level in the LD group was significantly increased by 54.2% as compared to SD group (P<0.05). The level of serum estradiol in the LD group was significantly increased by 34.8%, 47.8% compared to control group and SD group (P<0.05). The number of primary follicles per unit area in long photoperiod group was 120% and 68.3% higher than those of short photoperiod group and the control group (P<0.05). There were no significant differences in the number of antral follicles per unit area of the ovary among groups (P>0.05). Compared to control group (31.25%), estrus ratio of long photoperiod group increased to 81.25%, while that of short photoperiod group reduced to 12.5%. Melatonin plays a critical role in the mechanism by which photoperiod affects estrus of female rabbit. Long photoperiod reduces the secretion of melatonin, which promotes the secretion of GnRH in hypothalamus and the expression of GnRH in pituitary. Furthermore, the serum LH, FSH level were elevated, which increasing estradiol secretion, and promoting the development mature of follicles. Finally, it induces the estrus of the female rabbit.

The aims of this study were to find the reason of the arginine spots lag in the thin layer chromatography (TLC) identification of Ban Qing granules, and to improve this identification method. The TLC identification test was carried out as described in the current version of ChVP2015 Part Ⅱ - Ban Qing granules. Sucrose hydrolysis during TLC sample preparation process was tested by Fehling's solution. TLC sample preparation process was modified by changing the dissolution and heating steam drying methods. The results showed that the arginine spots lag in the Ban Qing granules TLC identification test was due to the Maillard reaction between arginine and the sugar reduced from sucrose during the TLC sample preparation process, and this could be eliminated by modifying TLC sample preparation process:replacing the homeopathic alcohol with 95% alcohol, and replacing the steam drying by natural volatilization drying. These results indicated that, the Maillard reaction between arginine and the reduced sugar from the sucrose in the Ban Qing granules during the TLC sample preparation, is the key reason for the arginine spots lag in TLC test. Modification of TLC sample preparation could eliminate the effect of sucrose on the TLC identification of Ban Qing granules and resolve the spot lag problem. This provides a necessary scientific basis to revise the quality standard of Ban Qing granules.

Encephalomyocarditis virus (EMCV) can infect humans and many animals. This genome-wide expression profile could contribute to exploring the association between gene expression and pathogenicity, and revealing the molecular mechanism after infection. N2a cells were infected usingEMCV BD2 strain. The cells were collected 7 hours after infection, total RNA was extracted from EMCV infected group and normal control group, respectively. Microarrays were hybridized with labeled ds-cDNA in a NimbleGen Hybridization System. Following hybridization, washing was performed. After being washed, the slides were scanned. The data of the differentially expressed genes obtained from scanning were identified and analyzed by applying bioinformatics method. Real-time FQ-PCR was performed to corroborate the results obtained with the microarray analysis. The results showed that a total of 21 143 genes were identified as differentially expressed genes at 7 hours after EMCV infection. These genes are involved in many vital functional classes, including immune response, inflammatory response, apoptosis, defense response, signal transduction. And the differentially expressed genes associated with interferon were significantly up-regulated, suggesting that interferon plays an important role in host antiviral infection. The pathway analysis demonstrated that the most significant pathways were associated with PI3K-Akt signaling pathway, MAPK signaling pathway, chemokine signaling pathway, cytokine, TLR, TCR, RLR and Jak-STAT signaling pathway. These results indicate that the host initiates a different strategy to activate immunological and inflammatory reaction to fight infection after EMCV infection. The changes of 10 differentially expressed genes detected by Real-time FQ-PCR were consistent with those predicted by microarray analysis.

To investigate the epidemic distribution of Chuzan disease in China, a total of 8 232 cattle, goat and sheep sera derived from 13 provinces in China between 2016 and 2018 were detected for the antibodies against Chuzan virus (CHUV) by C-ELISA test. The results showed that the CHUV antibodies were observed in 12 provinces, the positive rate of CHUV increases from north to south (0-74.03%), and the infection rate in autumn (September to November) was the highest (2.50%-60.00%), which was significantly higher than that in spring (0-10.00%) and summer (2.22%-35.00%). Detection of sera from cattle, goat sand sheep in Ulanchab, Hami, Hechi and Qujing were conducted, the results showed that the positive rate of cattle sera was higher than that of goat and sheep serum. On the one hand our findings showed that the Chuzan disease was prevalent and provide the reliable reference regarding CHUV surveillance in China, on the other hand it was verified that the prevalence of CHUV was closely related to the activities of its media insects and has obvious regional and seasonal characteristics.