Exosomes widely exist in various body fluids, which including a variety of bioactive substances such as proteins, lipids, mRNA and miRNA. As one kind of "mediator", it transmits signals between cells, and it is associated with many kinds of physiological process. Recently, exosomes were found in uterine fluid, fallopian tube fluid and placenta, which showed that exosomes might take part in regulating gametogenesis, fertilization, placenta, embryo implantation and fetal development. Through the study of exosomes, many valuable results were obtained, which increased people's understanding for the process of mammalian pregnancy, and provided new ideas for the research of reproductive regulation mechanisms. Therefore, this review describes the development of exosomes, their role in mammalian pregnancy and the relationship between exosomes and pregnancy diseases, which will provide a reference for further revealing the regulatory role of exosomes in mammalian pregnancy.

Silence information regulator (Sirtuins) are nicotinamide adenine dinucleotide-dependent histone deacetylase, which can bind to histones and various transcription factors and play important roles in regulating ovarian reserve, follicular development, oocyte maturation, granulosa cell function and embryonic development. In this paper, the effects of Sirtuins on female reproduction were reviewed in order to provide basis for further study of Sirtuins.

The purpose of this study was to obtain and compare partial sequences of mtDNA D-Loop high variable region of Tibetan pig in Ruoergai area,so as to provide reference for the protection and utilization of Tibetan pig genetic resources. In this experiment,the ear samples of 80 Tibetan pig from 9 towns in Ruoergai area were collected. The primers were designed based on the sequence of mtDNA D-Loop region of Tibetan pig in Gannan. Eighty nucleotide sequences were obtained by PCR amplification and sequencing technology,and the data processing method of bioinformatics were used to analyze the sequences. The results showed that the A+T content (56.46%) of mtDNA D-Loop high variable region (435 bp) was obviously higher than G+C content (43.54%) of Tibetan pig in Ruoergai area,and representing base bias. Among the 80 sequences of 435 bp length,14 mutation sites and 17 haplotypes were identified. Haplotype diversity (Hd),nucleotide diversity (Pi) and average number of nucleotide difference (k) were 0.881,0.004 66 and 2.028,respectively. Hd,Pi and k were the highest in Tibetan pig populations from Jiangzha, and Pi and k were the lowest in Tibetan pig population from Zhanwa. There were 8 shared haplotypes and 9 specific haplotypes,and there was big difference in specific haplotype number among different Tibetan pig populations in Ruoergai area. The highest number of specific haplotypes were found in Tibetan pig population from Jiangzha,accounting for 17.65% (3/17) of the total haplotype number. The haplotypes of Hap_1 and Hap_15 were shared haplotypes by Tibetan pig populations from 4 townships (Jiangzha,Yiwa,Re'er and Donglie),indicating that there were two common maternal ancestry haplotypes in Tibetan pig populations from the 4 towns. The average genetic distance of Tibetan pigs in Ruoergai area was 0.004 66. The genetic distance between Tibetan pig populations from Jiangzha and Donglie was the highest of 0.006 90,and the genetic distance between Tibetan pig populations from Baozuo and Yiwa was the lowest of 0.002 16. The NJ molecular phylogenetic tree was constructed to divide the Tibetan pigs into two branches. After Chinese domestic pigs, wild boars and introduced pig breeds were introduced,the Tibetan pigs in Ruoergai area were more dispersed in the evolutionary tree,indicating that the maternal lineage of Tibetan pigs in this area was genetically complex and had many genetic exchanges. This study further confirmed that the Tibetan pigs in Ruoergai area had higher genetic diversity than that in Tibet Nyingchi,Shannan,Shigatse,Ganzi and A'ba Prefecture,and the intensity of artificial selection was lower, and the protection and utilization of Tibetan pig genetic resources should be strengthened in Ruoergai area.

The objectives of this study were to investigate the regulation mechanism and particularity of muscle development in Tibetan chicken by RNA-sequencing and miRNA-sequencing. mRNA and small RNA in muscle tissues of Tibetan chicken on 120-and 150-day-old were sequenced. The differentially expressed genes (DEGs) and miRNAs were screened between two stages. The sequencing results were verified by qRT-PCR. A total of 1 691 DEGs were screened, of which 330 genes were up-regulated and 1 361 genes were down-regulated. Twenty two differentially expressed miRNAs were screened, of which 9 miRNAs were up-regulated and 13 miRNAs were down-regulated. qPCR verification results of 5 randomly selected genes and miRNAs showed that the expression trend was consistent with the sequencing results. GO enrichment analysis showed that the terms related to immunization accounted for a large proportion in the top 10 enrichment terms. The KEGG analysis showed that the immune-related pathways accounted for a large proportion in the 19 significant enriched pathways, and 83 miRNA target genes were in the significant enriched pathways. The integrated analysis of transcriptome and small RNA sequencing data indicated that 343 pairs of miRNA-mRNA were in the negatively correlated regulation pattern. This study provides a theoretical basis for further understanding the muscle development of Tibetan chicken from the multi-omics.

The study aimed to screen out the siRNA of cAMP response element binding protein (CREB) gene in dairy goats, and reveal the effect of interfering with CREB on the expression of milk fat synthesis related genes and triglyceride synthesis in mammary epithelial cells. The complete CDS region of CREB gene was amplified from the mammary gland tissue of Xinong Saanen dairy goat by qRT-PCR. Sequence and CREB expression analysis in different lactation periods were performed. The siRNA targeting the CREB gene was synthesized. The effective siRNA was screened by fluorescent quantitative PCR, at the same time, the expression of genes related to lipid synthesis was detected. The intracellular triglyceride content was detected using a kit. The results showed that:1) The CDS region of the CREB gene with 984 bp in dairy goat was cloned (GenBank accession number:MK158073) and analyzed by bioinformatics. 2) The expression level of CREB gene in the mammary gland of goats in lactating period was 1.93 times higher than that of goat in the dry period(P<0.05). 3) The effective siRNA targeting CREB gene was successfully screened, the interference efficiency was 72% (P<0.01),meanwhile transfecting it into the mammary gland epithelial cells of dairy goats. The expression of lipid synthesis-related genes were detected by qRT-PCR. Compared with the control group, the expression of FASN, ACACA, SCD1, FABP3,LPL, CPT1B,GPAM and DGAT2 genes was significantly inhibited after interfering with CREB gene (P<0.05), and the expression level of HSL was significantly increased(P<0.05),as well as the content of intracellular triglyceride was significantly inhibited(P<0.05). In summary, CREB gene maybe play an important role in goat milk fat synthesis by regulating the expression of lipid metabolism related genes and the content of triglyceride in primary mammary epithelial cells of dairy goats.

The purpose of this study was to analyze the genomic SNP characteristics of sika deer, red deer and their hybrid progenies (F1, F2) based on GBS(genotyping by sequencing) technology. In this experiment, the genomic DNA from 226 blood samples was sequenced by GBS. All samples were consisted of 63 sika deer, 12 red deer, 112 F1 generation individuals, 38 F2 generation individuals and 1 unknown individual. Furthermore, the previous sequencing data contained 110 sika deer, 197 red deer and 1 F1 generation individual. All the sequencing data was mapped to the reference genome of the sika deer which assembled at the chromosomal level. The sequence results produced 322.683 Gb Clean data for 226 individuals, averaging of 1 427.802 Mb for per sample. All samples were used as a population to detect SNP variation, and a total of 23 943 582 SNP loci were identified, while 31 630 SNP loci were remained after screening and filtering. A phylogenetic tree was constructed with 31 630 SNP loci by the maximum likelihood(ML) method, sika deer, red deer, F1, and F2 individuals were significantly distinguished in the phylogenetic. The SNPs of sika deer and red deer were compared and analyzed, and 1 032 specific SNPs were screened out for identifying red deer, sika deer, F1 and F2 generation (474 specific SNP loci for red deer, 558 specific SNP loci for sika deer). The calculation results showed that the proportion of F1 generation individuals containing red deer specific SNPs was mainly between 40% to 60%, and the proportion of F2 generation individuals containing red deer specific SNPs was mainly between 10% to 30%. The red deer did not contain the specific SNPs for sika deer; 55.49% of the individuals in the sika deer did not contain the specific SNPs for red deer,17.34% of the individuals contained less than 1% specific SNPs for red deer, and 13.29% of the individuals contained the 1%-10% specific SNPs for red deer, the rest individuals contained the 10%-20% specific SNPs for red deer except one individual who contained 33.3% specific SNPs for red deer. This study had established reliable markers for identifying hybrid progenies of sika deer and red deer, and the proportion of red deer's specific SNPs in F1 and F2 generation individuals was estimated. The red deer doesn't contain any specific SNPs for sika deer. The result of this study is of great significance to the identification of sika deer, red deer and their hybrid progenies (F1, F2).

This research was conducted to clone the sirtuin 3 (SIRT3) gene in yak and to identify its expression pattern in various tissues and testis at different development ages, respectively. This research might provide reliable basis for studying the mechanism of SIRT3 in testis development of yak. A total of 12 healthy male yaks (3 in each group) in fetal (5-6 months), calve (1-2 years old), sexual maturity (3-5 years old) and old (7-9 years old) stages were selected. Three samples from the same age were considered as biological duplications. The samples of liver, heart, spleen, lung, brain, kidney, muscle, small intestine, testicle and large intestine were collected from yaks during sexual maturity stage, and testicles were collected from yaks at 4 different development stages, respectively. Total RNAs in different samples were extracted respectively and the coding sequence of yak SIRT3 gene was cloned by reverse transcription PCR(RT-PCR). The structure and function of the protein encoded by SIRT3 gene were predicted by related bioinformatics softwares. The expressions of SIRT3 mRNA in different tissues and testis at 4 different development stages were determined by quantitative real-time PCR (qRT-PCR). The results showed that the ORF(open reading frame) of SIRT3 was 1 002 bp, which encoded 333 amino acids. The sequence of SIRT3 showed 99.9% and 96.7% homology with that of cattle and sheep, respectively. The mRNA of SIRT3 was widely expressed in various tissues of yak, and its expression was relatively higher in spleen, testis, lung and muscle. The expression of SIRT3 mRNA in the testis of yak increased firstly and then decreased with age, with the highest expression in sexual maturity stage. This study provides basic data for revealing the regulation of SIRT3 in yak growth and development, especially in testicular development.

The purpose of this study was to explore the role of SIRT1 on the in vitro maturation and aging of yak oocytes. The SIRT1 specific agonist (SRT2104, SRT group) and inhibitor (Inauhzin, INZ group) were added to the in vitro maturation medium of yak oocytes, respectively. After 24 h in vitro culture of yak cumulus-oocyte complexes (COCs), the expansion of cumulus cells and the excretion of the first polar body were observed. The ROS level in oocyte was measured by immunofluorescence after 24 and 36 h in vitro culture. The expression levels of SIRT1, FOXO3a, SOD2 and Bax in oocytes were detected by RT-qPCR method. Then, yak oocytes were fertilized after 24 and 36 h in vitro culture, and the cleavage and blastocyst formation rates were observed, respectively. The results showed that, after 24 h culture, the cumulus cells expansion degree in SRT group was significantly higher than those in the control group (P<0.05), while the cumulus cells expansion degree and the first polar body excretion rate in INZ group were significantly lower than those in the control group (P<0.05). With the increasing of culture time, the ROS level in oocyte increased significantly (P<0.05); SRT2104 addition significantly inhibited the ROS accumulation in oocytes (P<0.05), while Inauhzin addition significantly increased the ROS level in oocytes (P<0.05). After 24 h culture, the expressions of SIRT1, FOXO3a and SOD2 in SRT group were significantly higher than those in the control group (P<0.05), but the expression of Bax was significantly lower (P<0.05); the expressions of SIRT1, FOXO3a and SOD2 in INZ group were significantly lower than those in the control group (P<0.05), but the expression of Bax was significantly increased (P<0.05). After 24 h culture, the cleavage rate and blastocyst formation rate of oocytes in SRT group were significantly higher than those in INZ group and control group (P<0.05). While after 36 h culture, the cleavage rate and blastocyst formation rate of oocytes in INZ group were significantly lower than those in other groups (P<0.05). In conclusion, SIRT1 is involved in regulating in vitro maturation of yak oocytes. Adding SIRT1 agonist properly in in vitro culture medium can promote in vitro maturation and alleviate aging of yak oocytes, simultaneously improve the developmental capacity of early embryos.

This study aimed to establish the prediction equation of AME and AMEn of rapeseed meal for broiler chicken in 6 different areas from Hunan Province. Seven hundred 1-day-old AA broilers were divided into two test stages according to their age. The 420 broilers were randomly divided into 7 groups with 10 replicates per group and 6 broilers per replicate in the first stage(7-14 days old), the 280 broilers were randomly divided into 7 groups with 10 replicates per group and 4 broilers per replicate in the second stage(21-28 days old). The 7 treatment groups in two stages were made up of 6 experimental diet groups designed by full substitute for rapeseed meal from 6 different areas and 1 nitrogen-free diet group. The AME and AMEn of rapeseed meal from 6 different areas for broiler chicken on 14 and 28 days old were determined by total feces collection method and the prediction equation were established by stepwise regression method. The results showed as follows, the AME and AMEn of rapeseed meal for broiler on 14 days old were 7.44 and 7.35 MJ·kg^-1 respectively, the prediction equation of AME and AMEn were AME=24.98-0.39NDF and AMEn=25.04-0.39NDF; the AME and AMEn of rapeseed meal for broiler on 28 days old were 8.01 and 7.91 MJ·kg^-1 respectively, the prediction equation of AME and AMEn were AME=23.08-0.34NDF and AMEn=23.06-0.34NDF. The results of the study improved the database of the metabolism energy of rapeseed meal for broiler chickens, and provided support for the application of rapeseed meal in livestock and poultry diet.

The purpose of this study was to examine the effects of oregano essential oil (OEO) and monensin (MON) on serum biochemical parameters, digestive enzyme activities and ruminal microflora of Holstein calves. Eighty Holstein calves ((41.31±2.23)kg) were randomly divided into 4 treatments and with 20 calves each. The calves in control treatment were fed with whole milk and pellet feed. The calves in other treatments were fed with whole milk and pellet feed, and supplementation with 4 g·kg^-1 OEO, 3.6 g·kg^-1 MON and a mixture of 7.6 g·kg^-1 OEO and MON, respectively. At 56 and 70 days of age, six male calves were selected from each treatment with similar body weight, blood samples from the jugular vein were collected from each calf to determine serum biochemical parameters and rumen fluid was collected by oral catheter to determine digestive enzyme activities and ruminal microflora. The results showed that:1) OEO had significantly increased the concentration of TP, SOD, GSH and GSH-Px in calf serum at 56 days of age(P ≤ 0.05); MON had a tendency to decrease BUN concentration in calf serum at 56 and 70 days of age(P<0.10). 2) OEO had significantly decreased the number of F. succinogenes in the rumen of calves at 56 and 70 days of age (P<0.05), and had significantly increased the number of R. albus(P ≤ 0.05); MON had significantly decreased the number of protozoa in the rumen of calves at 56 and 70 days of age (P ≤ 0.05), and had a tendency to decrease the number of R. albus (P<0.10), at 56 days of age, MON had decreased the number of R. flavefaciens in the rumen of calf(P<0.10); There was significant interaction between OEO and MON on B. fibrisolvens in the rumen of calves at 56 and 70 days of age (P ≤ 0.05), OEO and MON had a tendency of interaction on P. ruminicola at 56 days of age (P<0.10), however, there was significant interaction between OEO and MON on P. ruminicola at 70 days of age (P ≤ 0.05). 3) OEO and MON had a significant interaction on the concentration of pepsase in rumen of calves at 56 and 70 days of age (P ≤ 0.05). These results indicated that dietary supplementation with OEO could enhance immunity and antioxidant capacity of calves. MON was better than OEO in inhibiting the number of protozoa in the rumen. The effect of OEO of increasing the number of protein-degrading bacteria was better than MON. In conclusion, supplementation with OEO in diet can improve the health status of calves, modify rumen microflora activity and population. OEO can be used as a natural plant antibiotic to replace other antibiotic growth promoters for preventive treatment of calves.

To explore whether the N-protein phosphorylation of porcine reproductive and respiratory syndrome virus (PRRSV) affects viral replication, the ser-105 and ser-120 of the PRRSV N-protein were mutated into alanine alone or simultaneously. The rescued viruses were named as A105, A120 and A105-120, and their growth curve and subgenomic transcription level were determined respectively. The viral replication rate and titer of the mutant virus in MARC-145 were significantly lower than that of parental strain PRRSV XH-GD (P<0.01 or P<0.05). While in the primary PAM cells, the replication rate of the mutant virus decreased (P<0.01), but the final virus titer was not affected. The genomic (g) RNA transcription level of the mutant virulence group was significantly decreased (P<0.01 or P<0.05), and the phosphorylation site mutation significantly reduced the transcription of the longer subgenomic mRNA (sgmRNA)2/3 (P<0.01 or P<0.05), but increased the expression levels of the shorter sgmRNA 4/5 with time. Based on the gRNA expression level, the expression of sgmRNAs expression was analyzed. Our current work showed that the N-protein phosphorylation significantly affects the expression of sgmRNA4/5(P<0.01 or P<0.05). Mutation of N protein phosphorylation site affects PRRSV replication and subgenomic transcription.

This study was conducted to further understand the viral community in diarrheal feces of Tibetan pig. The 146 diarrheal fecal samples were collected from 16 Tibetan pig farms in Qinghai-Tibet Plateau. The samples were mixed into a pool sample, then RNAs were purified and synthesized into cDNAs. TruSeq Illumina sequencing was used to analyze the sequences and molecular characteristics of the diarrhea-associated viruses. The results showed that the virus species in the fecal samples of diarrheal Tibetan pigs included 19 viruses from 11 families. They were mainly linear and cyclic small DNA viruses, such as porcine stool-associated circular virus type 7, porcine adenovirus and porcine bocavirus(PBoV). There are three diarrheal viral pathogens, such as porcine epidemic diarrhea virus (PEDV), porcine circovirus type 2 (PCV-2) and bovine viral diarrhea virus type 1 (BVDV-1), as well as three new pathogens, such as porcine bufavirus, rabovirus and pasivirus. The complete or nearly full-length genome of porcine parvovirus type 6(PPV-6), PCV-2, PBoV-2 and complete ORF2 gene sequence of hepatitis E virus (HEV) were assembled by SOAP software. The phylogenetic results showed that PPV-6 and PCV-2 had a relatively close genetic and evolutionary relationship with the reference strain, while PBoV-2 had a relatively distant genetic and evolutionary relationship with the reference strain, which were gathered into a single cluster, and may be a completely new genotype. In order to further investigate the detection rate of PCV-2 in diarrheal feces of Tibetan pigs, 146 samples were collected and the detection rate was 10.96% (16/146, 95% CI:6.4%-17.2%), and it was closely related to the epidemic strain of PCV-2 in Sichuan region. In this study, it was found that the viruses in diarrheal feces of Tibetan pigs are complex and varied, and may be cross-infected with other animals and humans, which has important public health significance, and also provides theoretical basis for prevention and control of diarrhea in Tibetan pigs.

Biofilm is one of the main cause of bacterial resistance. In this study, the effects of type Ⅲ secretion system 2 (ETT2) transcription regulator YqeI on the biofilm formation of avian pathogenic Escherichia coli and its influencing mechanism were investigated. Red homologous recombination method was used to construct yqeI gene deletion strains, and the effect of transcription regulator YqeI on the biofilm formation ability of avian pathogenic E. coli was explored by detecting the biofilm formation ability of wild strains and deletion strains, combining transcriptome sequencing and fluorescence quantitative detection of biofilm gene transription. The yqeI gene deletion strain was successfully constructed, and the deletion of yqeI does not affect the growth curve, but the biofilm formation ability was significantly decreased and the transription of the relevant biofilm gene was significantly down-regulated. The avian pathogenic E. coli ETT2 transcriptional regulator YqeI significantly affected the biofilm formation ability of avian pathogenic E.coli, providing a possibility to find new drug targets from the perspective of yqeI and related genes.

This experiment was conducted to investigate the apparent characteristics and molecular characteristics of Escherichia coli isolates from the feces of a mink farm in Zhucheng. Mink feces from the mink farm were collected for isolating E. coli strains, then the isolates were identified, and their serotypes and drug resistance phenotypes to 14 common antibacterial drugs were determined. The drug resistance genes and the carrying status of the Ⅰ integron gene cassette of these E. coli isolates were detected by using PCR. Multi-locus sequence typing (MLST) was used to analyze the clonal relationship of these strains,and a phylogenetic tree was constructed to analyze the genetic similarity of the same clonal strains. The results showed that 62 strains of E. coli were isolated from 82 samples of mink feces, with a separation rate of 75.61%, and the resistance rate of E. coli isolates to AMP and TET exceeded 90%, and the multidrug-resistant strain (MDR) accounted for 85.48%. Five drug-resistant genes were detected by PCR, and the detection rate of qnrS was the highest (61.29%,38/62). The aaC2, aaC4, sul1 and aac(6')-Ib-cr resistance genes were consistent with the corresponding resistance of these strains (P<0.01). The dominant structure of the class Ⅰ integron variable region in the isolated strain was dfrA27-aadA2-qnrA. The pathogenic serotype was identified and the corresponding strains had multiple drug resistance. The dominant serotype was O104:H4. There were 33 STs in the isolates, and ST46 was the dominant ST (16.13%). There were 3 main clones, CC10, CC46 and CC176, respectively. The STs strains associated with pathogenicity share a common genetic background with human E. coli. The results showed that the mink of the farm were contaminated by pathogenic and multi-drug resistant E. coli. The distribution of drug resistance genes in the same clonal strains showed significant differences in polymorphism and epigenetic characteristics.

The aim of this study was to understand the prevalence, drug resistance and drug resistance genes carried by Salmonella Kentucky in the chickens from the retail markets in Guangdong province. The chicken samples collected from five prefecture-level cities of Guangdong in 2016 were selected to isolate Salmonella strains.Then the Salmonella serotypes were identified. Drug sensitivity test, drug resistance gene detection and molecular typing of the isolated S. Kentucky were carried out. As a result, 152 strains of Salmonella were isolated from 245 chicken samples, with the positive rate of 62.04% (152/245). Nineteen serotypes were identified, of which the main serotypes were S. Agona (29/152, 19.08%), S. Corvallis (25/152, 16.45%) and S. Kentucky (20/152, 13.16%). The drug sensitivity test of S. Kentucky showed that they were highly resistant to sulfafurazole (100%), nalidixic acid (90%), tetracycline (75%), ampicillin (65%), ceftazidime (55%), and ciprofloxacin (55%). Eighty-five percent (17/20) of the strains were resistant to three or more antimicrobial agents. The detection of quinolone resistance genes presented gyrA mutations (Ser83Phe, Asp87Asn and Asp87Gly) in 95% (19/20) of the strains, including double mutations in gyrA (Ser83Phe and Asp87Asr, Ser83Phe and Asp87Gly) in 57.89% (11/19) of the strains and triple mutation in gyrA in 5.26% (1/19) of the strains. In addition, parC mutations occurred in 100% (20/20) of the strains (Tyr62Ser and Ser85Ile). Forty-five percent of the isolates (9/20) carried plasmid-mediated quinolone resistance (PMQR) genes (aac(6')-Ib-cr, qnrB, qnrS, oqxAB), with aac(6')-Ib-cr resistance gene as the most common one. The detection rates of β-lactam resistance genes, encompassing bla_TEM-1, bla_OXA-1 and bla_CTX-M-55, were 25%, 10% and 5%, respectively. The results of cluster analysis of pulsed field gel electrophoresis (PFGE) map unveiled the genetic relationship between the serotypes of S. Kentucky, their genetic diversity, and high homology in some strains. It was found that S. Kentucky was one of the major epidemics in the retail chicken meat in Guangdong. It was more resistant to traditional drugs such as sulfisoxazole, nalidixic acid, tetracycline and ampicillin, and was particularly resistant to ciprofloxacin and ceftazidime, featuring multiple and multi-drug resistant phenotypes. S. Kentucky characterized high mutation rates in the quinolone resistance-determining regions of gyrA and parC. Molecular typing revealed the possibility of cross-regional transmission between strains, underpinning the studies on the traceability of S. Kentucky.

The purpose of the study was to investigate the effect of photoperiods on the distribution and expression patterns of melatonin receptor in the "hypothalamic-pituitary-gonadal axis" of female rabbits, and to further analyze the mechanism of melatonin regulating estrus in female rabbits under different photoperiods. A total of 48 5-month-old nulliparous female New Zealand rabbits, 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 were reared in long light group (LD, L:D=16:8), short light group (SD, L:D=8:16) or control group (L:D=12:12) for the last 6 days separately. Light intensity was 80 lx, the total trial period was 16 days. The hypothalamus, pituitary and ovary samples were collected after the test. The effects of photoperiod on the distribution and expression of melatonin receptor subtypes in hypothalamus, pituitary and ovaries of female rabbits were investigated by real-time PCR, Western blot and immunohistochemical staining. The results showed that the expression of MT1 mRNA in the SD group was 88.8% higher than that in the LD group (P<0.05), and 54.9% higher than that in the control group (P<0.05), but there was no significant difference between the LD group and the control group. The expression of MT2 mRNA was not significantly different between different photoperiod groups (P>0.05). Immunohistochemical staining showed that the number of MT1 positive cells in the periventricular nucleus of the hypothalamus in the LD group was significantly lower than that in the SD group (69.4%, P<0.05) and the control group (37.3%, P<0.05), and that of SD group was 104.8% higher (P<0.05) than the control group. Meanwhile, the number of MT1 positive cells in the paraventricular nucleus of the LD group was 52.9% lower than that in the SD group (P<0.05), and that of the control group was 55.8% lower than that of the SD group (P<0.05), while there was no difference between the LD group and the control group (P>0.05). In the pituitary, the expression of MT1 mRNA in the SD group was 164% higher than that in the LD group (P<0.05) and 49.5% higher than that in the control group (P<0.05), and the LD group was significantly lower than the control group by 43.5% (P<0.05), while there was no significant difference in MT2 mRNA expression between different photoperiods (P>0.05). The expression of MT1 mRNA in the ovary of the LD group was 33.3% lower than that of the control group (P<0.05) and 53.6% lower than that of the SD group (P<0.05), and there was no significant difference between the SD group and the control group (P>0.05). However, the relative mRNA expression of MT2 of the ovary in the SD group was significantly higher than that of the control group by 90.0% (P<0.05) and the LD group by 100% (P<0.05), and there was no difference between the LD group and the control group (P>0.05). Short light photoperiod increased the expression of melatonin receptor MT1 subtype in hypothalamus, pituitary gland and ovary, rather than the MT2 receptor. These results suggest that the regulation mechanism of photoperiod on estrus in female rabbits may be realized by MT1 receptor pathway.

This paper will focus on the relationship between HSP60 expression and the tumor induced by the Marek's disease(MD) virus. The animal tumor model was established using MD virus and chickens were timely killed post artificial infection. The relationship between pathological lesion and distribution of HSP60 were studied using histopathology and immunohistochemistry methods. Three small interfering RNA sequences of HSP60 were designed and recombinant lentivirus were constructed. Flow cytometry were used to study the effect of down-regulation of HSP60 to the apoptosis ratio of MSB-1 cells. Results showed that HSP60 was mainly located in the cytoplasm of tumor cells. Recombinant RNA interference lentiviruses targeting HSP60 were successfully constructed and the interference effect of 5147 sequence lentivirus was the best. At 48 h post transfection, the transcription, expression of HSP60 were significantly reduced (P<0.01), and the apoptosis ratio of MSB-1 cells was significantly induced (P<0.01) in lentivirus transfected group than those in control cell group and control sequence lentivirus transfected group. HSP60 is mainly expressed in the cytoplasm of tumor cells induced by the MDV and down-regulation of HSP60 is able to induce the apoptosis ratio of MSB-1 cells.

This paper will focus on the mechanism of palmitic acid-induced BRL 3A cell steatosis. BRL 3A cells were treated with different concentrations of PA (0, 0.2, 0.4, 0.6 mmol·L^-1) for 24 h. The cell proliferation was detected by using CCK-8 method and RTCA technique, the cell lipid droplet formation was observed by using oil red O staining, the nucleus and cytoskeleton morphology were observed by using DAPI/F-actin double staining, the TG content was determined by colorimetry. The transcriptional levels of Acaca, Fasn and Dgat2 were detected by RT-PCR. The expressions of ACC, FAS, SCD1, GPAM and DGAT2 were detected by Western Blot. In result, compared with the control group, the 0.2, 0.4 mmol·L^-1 PA group had no effect on cell proliferation and 0.6 mmol·L^-1 PA inhibited cell proliferation. Oil red O staining showed that a large amount of lipid droplets accumulated in the 0.4 mmol·L^-1 PA group, and obvious fatty degeneration occurred. With the increase of PA concentration, the nucleus shrinks, deforms and fragments; the cytoskeleton was destroyed and the microfilament breaks. With the increase of PA concentration, the TG content increased significantly (P<0.01). The transcriptional levels of Acaca, Fasn and Dgat2 mRNA in the lipid synthesis genes of different concentrations of PA (0.2, 0.4, 0.6 mmol·L^-1) were significantly increased (P<0.05). The protein expression levels of ACC, FAS, SCD1, GPAM and DGAT2 were significantly increased (P<0.05). SCD1 protein expression was significantly lower in the 0.6 mmol·L^-1 PA group compared with the 0.4 mmol·L^-1 PA group (P<0.05). High concentration of palmitic acid inhibited the proliferation of BRL 3A cells and damaged the nucleus and skeleton. Palmitic acid induced the accumulation of lipid droplets and the increase of TG, and induced steatosis by up-regulating the transcription levels of Acaca, Fasn, Dgat2 mRNA and the expression of ACC/FAS/DGAT2 pathway proteins.

To study the effects of different beak-trimming methods on chicks' growth performance and immune function, 720 1-day-old Jingfen-1 chicks were randomly divided into 3 treatments:non-treated group (control group, CG), 1-day-old infrared beak trimming group (infrared beak trimming group, IBT) and 8-day-old hot-blade beak trimming group (hot-blade beak trimming group, HBT). The beak length, body weight, feed intake and feed wasted of birds in each cage were measured. Heterophils and lymphocytes were counted from one chick per cage. Protein and cytokine levels in plasma were detected by biochemical analysis and ELISA. After humanely sacrifice chicks, the spleen and cloacal bursa of each sampled chick were weighted, the spleen samples were collected for histological examination and Real-time PCR. The results indicated that the treatments of beak trimming could significantly reduce beak length, and the method of infrared beak trimming was better than hot-blade. The food waste of birds was reduced by different beak-trimming methods; however, the feed intake of chicks was not affected. Compared with CG group, the weight of birds in the IBT group decreased significantly on the day 4 of experiment. IBDV Ab titer of 29-day-old chicks in the IBT group was lower than other two treatments. Heterophils and lymphocytes in blood, protein, sCD and cell cytokine in plasma, organ index of spleen and cloacal bursa, and microstructure of spleen, the gene expression of inflammatory and apoptosis factors in spleen were not affected by different beak-trimming methods. Our results indicate that beak-trimming treatments can significantly reduce the rate of feed wasted, which are beneficial to reduce production cost, and 1-day-old infrared beak trimming is more convenient and effective than hot-blade trimming. 1-day infrared beak trimming temporarily be not conducive weight gain of chicks, but this effect gradually disappears with age. The protection time of vaccine may be shortened for combination of infrared beak trimming and vaccination at the age of 1-day chicks.

The purpose of this study was to explore the protective effect of mitochondria-targeted antioxidant Mitoquinone (MitoQ) on frozen sperm of Hu sheep. The semen of healthy adult rams was equally divided into 6 groups. M0, M1, M2, M3, M4 and M5 were the groups containing 0, 50, 100, 150, 200 and 400 nmol·L^-1 MitoQ in semen,respectively. After freezing and thawing, the sperm quality indexes, such as motility, viability, plasma integrity, acrosome integrity and mitochondrial activity, and antioxidative parameters, such as SOD, GSH-Px, ROS and MDA were detected. The results showed that the thawed 150 nmol·L^-1 MitoQ addition group (M3 group) got the highest motility, viability, plasma integrity, acrosome integrity and mitochondrial activity of thawed sperm, which were 55.00%, 52.34%, 48.32%, 54.51% and 51.28%, respectively. And the mitochondrial activity in M3 group was significantly higher than those in the other groups(P<0.05). The SOD and GSH-Px values of thawed sperm in M3 group were 203.90 U·mL^-1 and 123.62 U·L^-1, which were higher than those in M0, M1,M4 and M5 groups(P<0.05). The ROS and MDA values of thawed sperm in M3 group were 298.34 U·mL^-1 and 4.99 nmol·L^-1, which were significantly lower than those in the other groups(P<0.05). When the MitoQ concentration was 200 (M4 group) and 400 nmol·L^-1 (M5 group), the quality of frozen sperm began to decline and showed oxidative damage to sperm. In conclusion, during the freezing of Hu sheep sperm, 150 nmol·L^-1 MitoQ addition in the diluent could reduce sperm oxidative damage and improve frozen sperm quality. Further increasing the MitoQ concentration to more than 200 nmol·L^-1 had no protective effect on frozen semen of Hu sheep.

This study was carried out to establish geometric model and finite element model of goat rumen, three dimensional reconstruction and finite element simulation model were used based on CT images of rumen of Xiangdong black goats. Firstly, the three dimensional reconstruction software (Mimics) was used to reconstruct the geometric model of rumen, and then Solidworks was used to convert the geometric model into IGES format and import it into the finite element mesh model in the finite element analysis software Hyperworks. Finally, Hyperworks and Ls_dyna combined simulation were used to analyze the mechanical properties of the in vitro reconstructed finite element model of rumen. The results indicated that in vitro reconstructed rumen model was similar to the rumen of living animals geometrically, and this model can clearly reflect the lumen structure of the rumen. After the mechanical analysis of the rumen model, the stress, strain and displacement nephograms of the rumen model were obtained. Geometric model and finite element model of visual rumen were established to reflect the appearance structure and biomechanical characteristics of rumen in natural state. These results indicated that the feasibility of three dimensional reconstruction and finite element method in goat rumen modeling were also verified, which built up a new method for rumen reconstruction and construction researching.

In order to develop the method of induction and cultivation chicken bone marrow-derived dendritic cells (BMDCs) in vitro, and analyze the main characteristics of DCs,the bone marrow precursors were collected by differential adherence method after separating the chicken bone marrow cells using Lymphoprep. Then induction and differentiation of the bone marrow precursors were conducted by using granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). On day 7 of culture, the cells were stimulated with lipopolysaccharide (LPS) for 48 h, then the DCs were identified by morphologic and phenotypic characteristics using inverted phase-contrast microscope, scanning electron microscope and flow cytometry. The results showed that the cells volume enlarged, and the surface of the cells were dendritically shaped, phenotypic analyses of non-stimulated cells showed high expression of MHC class Ⅱ and CD11c. After stimulating by LPS, the veils became larger, these cells appeared a typical morphological feature of BMDCs under electron microscope, and the expression of MHC class Ⅱ was significantly increased. These data indicated that we succesfully obtained a large quantity of BMDCs with higher purity according to this method. This study laid a foundation for further research on the biological function of BMDCs in poultry and the role of BMDCs in the occurrence of certain diseases.

This study aimed to analyze the adaptation to environmental changes and bacterial secretion pathways in transcriptome sequencing of hfq gene deletion strains of Salmonella typhimurium and screen related genes. Real-time fluorescence quantitative PCR was used to verify the transcriptome sequencing results of hfq gene deletion strains of S. typhimurium, so as to conduct in-depth analysis on the bacterial chemotactic pathways, bicomponent pathways and secretion pathways of the hfq gene deleted strain of S. typhimurium, and screen the relevant important regulatory genes. Results were as follows:Four co-expressed genes, including yiaD, STM3138, STM3216 and malE, were screened out in the bacterial chemotaxis pathways. Seven co-expressed genes, including spaP, invA, prgH, invE, spaS, invG and ssaV, were screened from the bacterial secretion pathways. Sixteen co-expressed genes, including ybfM, htrA, pagO, STM3138, STm3031, ttrB, hilD, pstS, STM1530, hilA, pgtC, hydH, pocR, STM3216, ttrR and fljB, were screened in the bacterial two-component pathways. Differentially expressed genes were screened out from bacterial chemotactic pathways,two-component pathways and secretion pathways in hfg gene deleted S.typhimurium strain.And hfg could regulate these genes to affect related functions such as motility and virulence. The results laid a certain foundation for the prevention and cure of Salmonella and further study of sRNA and hfg in Salmonella.