Following the discovery of siRNA and miRNA, a new class of small noncoding RNA, called piRNA, was found. piRNA can interact with Piwi subfamily proteins and they involve in piRNA pathways,which can protect genetic information of animal germ cells from the harmful effects of molecular parasites such as transposon. In recent years,piRNA biogenesis-related proteins and their biological effects were studied. It was found that a variety of Piwi subfamily proteins could bind to piRNA to form Piwi-piRNA complex. These complexes were involved in germ cells formation and development, germline stem cells differentiation, sex determination and other biological functions through the way of epigenetic regulation. In the present paper,we reviewed the research progress on the biogenesis and characteristics of piRNA,the ways of Piwi-piRNA complexes playing the biological roles and biological functions of piRNA in female animals, which will provide a reference for further research on regulatory mechanism of piRNA in female animal reproduction.

CD4 molecular is mainly expressed on mature CD4⁺T cells surface. It can direct T cells normal differentiation and maturation, recognize antigen, mediate immune response and involve in immune regulation. DNA methylation modification is critical to regulating differentiation of T cell subsets. Especially, the DNA methylation of CD4 gene can significantly affect the amount and function of CD4⁺T cells, influence the ability of immune response and disease resistance of livestock, then against or adapt environmental changes. Up to date, studies have reported that DNA methylation of porcine and bovine CD4 gene can regulate immune responses of the host cells, while that of sheep and horse are rarely reported. To understand the molecular basis of complex diseases and provide novel breeding strategies against livestock diseases via molecular marker assistant selection methods, the progress on regulation mechanism of DNA methylation of livestock CD4 gene, and its effects on immune responses during CD4⁺T cells differentiation, as well its possible application in disease resistance breeding of livestock were reviewed and discussed in this paper.

Hepatozoonosis is a kind of parasitic disease which is caused by the apicomplexan parasites Hepatozooon that widely distribute in the world. They are mainly transmitted by hemophagia insects (e.g. ticks), resulting in a series of symptoms including depression, anorexia, emaciation, anemia and ataxia. Focusing on the pathogen, pathogenicity and diagnosis of the disease, this paper aims to provide a reference for the prevention and related research on canine and feline hepatozoonosis in our country.

The aim of this study was to explore CpG islands methylation status of TNFRSF1A gene, and clarify the relationship of methylation level with its expression and T lymphocyte subpopulation traits. In the present study, Dapulian piglets, one indigenous breed with higher disease resistance in North China, and Landrace piglets, one commercial breed with lower disease resistance, were used. Methylation level of CpG islands of TNFRSF1A gene upstream was determined by bisulfite sequencing PCR (BSP), and correlation analyses of methylation frequency of CpG sites with its expression and T lymphocyte subpopulation traits were carried out. The results indicated that: 1) There were 2 CpG islands in the upstream of TNFRSF1A gene, which contained 25 CpG sites by BSP overlapping 2 islands. Nine CpG sites were in Island 1, nine CpG sites were in Island 2, and others located between 2 islands. Population methylation frequency between Dapulian and Landrace piglets had no significant difference in Island 1 at 0.05 level, whereas methylation frequency of Dapulian piglets was significantly higher than that of Landrace piglets in Island 2 at 0.05 level. 2) The methylation frequencies in Island 2 were negatively correlated with the expression of TNFRSF1A, especially 5 CpG sites (+126, +128, +159, +162 and +164). 3) We also found methylation frequencies of CpG sites +159 and +164 were positively correlated with CD4+CD8+CD3+ at 0.05 level in the 2 populations. The methylation frequencies of CpG sites +159 and +164 in Island 2 were negatively correlated with the expression of TNFRSF1A, and positively correlated with T lymphocyte subpopulation trait CD4+CD8+CD3+. Thus, we speculated that increased methylation frequencies of CpG sites +159 and +164 might lead to the decreased expression of TNFRSF1A, which may influence on T lymphocyte subpopulation traits and the immunity of Dapulian piglets.

The objective of the present study was to investigate the expression profile of CaN/NFAT-dependent pathway genes, and their correlation analysis in 2 phenotypically distinct skeletal muscles were studied in chicken during the early development. qRT-PCR was used to detect the mRNA expression of CnAα, CnB1, NFATc3, MEF2C and PPARGC1A genes in lateral gastrocnemius and extensor digitorum longus of Recessive White chicken at 0,1,3,5,7 and 9 week age, the correlation among expression of these genes was analyzed. The results showed that the expression trends of all the genes between 2 phenotypically distinct skeletal muscles were similar except CnB1, and the expression level of these genes in 2 phenotypically distinct skeletal muscles was all raised from 7 to 9 week age. Comparison among the expression of these genes in 2 phenotypically distinct skeletal muscle showed that the expression level of PPARGC1A in the lateral gastrocnemius was higher than that in the extensor digitorum longus at each detected age, and the expression level of other 4 genes in the lateral gastrocnemius was higher at 3 week age and lower at 7 and 9 week age than that in the extensor digitorum longus. Correlation analysis among the 5 genes expression levels in the 2 phenotypically distinct skeletal muscles showed that there was a negative correlation between the CnAα and 2 genes (NFATc3 and PPARGC1A), and positive correlations among the expression of other genes. Overall, the expression patterns of CnAα, CnB1, NFATc3, MEF2C and PPARGC1A genes in chicken skeletal muscle are age and phenotype specific, which may be related to the regulation of the myofiber growth and type transition.

The aim of this study was to further reveal the regulation mechanism of MSTN in sheep myoblasts, prepare the tool silencing MSTN, and provide the methods and theoretical basis for increasing the yield of muscle mass by using RNA interference technology. In this study, sheep myoblasts were used as experimental materials. The short hairpin RNA(shRNA) expression plasmid vector specific targeting to MSTN gene were constructed, then the plasmids with better interference effect were packaged for recombinant adenovirus, the expression of MSTN, myogenic regulatory factor and interferon response genes in myoblasts after infected by recombinant adenovirus were detected by qRT-PCR and Western blot. The result showed that the interference efficiency of plasmid ShR218, ShR511 were 35% and 48%,respectively,the interference efficiency of ShR3+4 was 85%.Recombinant adenovirus vector Sh511 and Sh3+4 were successfully packaged, the virus titer reached 1×10⁸ pfu·mL^-1, the infection rate to myoblasts reached more than 90%. The mRNA expression of MSTN gene had been decreased by 53% and 76%, and the protein level had been decreased by 55% and 64% through Sh511 and Sh3+4, respectively. The knockdown of MSTN gene was accompanied with expression downregulation of myogenic regulatory factor Myf5, MyoD, MyoG and Myf6 at mRNA level(P<0.01), but at protein level only MyoG was significantly increased(P<0.01), no significant changes in Myf5, MyoD and Myf6. Adenovirus infecting myoblasts did not cause significant changes at OAS1 mRNA level, but caused significant increase at IFNGR1 mRNA level (P<0.01), while had no significant effect on their protein levels. In this study, shRNA adenovirus vector targeting to MSTN gene was successfully constructed, which can effectively inhibit the mRNA and protein expression of MSTN in myoblasts, and affect the expression of Myf5, MyoD, MyoG, Myf6 and IFNGR1 genes.

This study was conducted to establish model for genetic analyses of adult body size and body weight in Sanhe cattle, and to estimate population genetic parameters, in order to provide foundational parameters for establishing breeding objective and forming selection index for Sanhe cattle. Body size and body weight data of 4 491 adult Sanhe cows were measured from 1997 to 2010, a total of 48 946 records were collected from Xiertala Cattle Farm of Inner Mongolia, where the nuclear herd for Sanhe cattle were located, and used for genetic analyses. The 15 body size and body weight traits included body height(BOH), body length (BL), chest girth (CG), cannon circumference(CC), body weight (BW), abdomen circumference (AC), back height(BAH), hip cross height(HCH), chest depth (CD), chest width (CW), hip width (HW), pin bone width (PBW), rump length (RL), head length (HL) and forehead width (FW). DMU package was used for genetic evaluation(AI-REML and EM algorithm) combined with multiple traits animal model, considering age of cow as fixed effect, farm-year-season and additive genetic effect as random effects. Heritabilities and genetic correlations were computed based on estimated variance components, and genetic trends of all traits were analyzed based on estimated breeding values. The results showed that the estimated heritabilities of BOH, BL, CG, CC, BW, AC, BAH, HCH, CD, CW, HW, PBW, RL, HL and FW in adult cows were 0.73±0.02, 0.58±0.02, 0.43±0.03, 0.51±0.02, 0.41±0.03, 0.51±0.03, 0.60±0.03, 0.69±0.03, 0.55±0.03, 0.26±0.02, 0.28±0.03, 0.17±0.02, 0.21±0.02, 0.69±0.03 and 0.55±0.03, respectively. The genetic correlation coefficient among body size and weight traits for adult cows were from-0.19 to 0.92, and their phenotypic correlation coefficient were from-0.30 to 0.93. The genetic correlation coefficient among BOH, BAH and HCH were 0.79-0.88, and their phenotypic correlation coefficient were 0.76-0.93. Genetic correlation among HW, PBW and RL were low (0.11-0.34), and their phenotypic correlation were medium (0.50-0.83). The heritabilities of body size and body weight in adult Sanhe cows are medium to high inheritable traits in general. In which, low genetic correlation exists among traits related to reproduction performance, while higher genetic correlation exists among traits related to body structure. It is suggested that selection system for Sanhe cattle should be strengthened, so that genetic level of economically important traits could be improved steadily.

The study aimed to analyze the effect of non-genetic factors on body measurements in Yili horse and estimate genetic parameters of body measurement traits. The 1 556 records about body measurement traits of 1-11 years old horse during 2005-2014 year were used to estimate effect of non-genetic factors on body measurement traits by least square variance analysis, the genetic parameters and heritabilities of body measurement traits and correlation among traits were estimated by REML by animal model. The results showed that the herd, age and birth year had significant effect on body height, body length, chest girth and cannon circumference(P<0.01), the sex had significant effect on body height, body length and cannon circumference(P<0.01) but had no significant effect on chest girth(P>0.05). The heritability of body height, body length, chest girth and cannon circumference were 0.87, 0.67, 0.40 and 0.52, respectively. Body length and chest girth had the highest genetic correlation, the correlation coefficient was 0.93. Body height and cannon circumference had the highest phenotypic correlation, the correlation coefficient was 0.65. Body height was significantly related in phenotype to body length, chest girth and cannon circumference(P<0.01), respectively. Body length was significantly related in phenotype to chest girth and cannon circumference(P<0.01), respectively. Cannon circumference was significantly related in phenotype to chest girth(P<0.01). The results will provide a theoretical basis for the genetic evaluation of body size traits in Yili horses.

The study aimed to analyze the histological structures at different ages of postnatal porcine ovary and rules of follicular atresia during ovarian development. Three pig ovary samples from 3,40,50,60,72,86,95 and 165 postnatal days were collected, respectively, and these samples were examined by using common paraffin sectioning method,HE staining and terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) technology. The results showed that the histological development process of pig ovary was divided into 3 periods:proliferation of oogonia, slow growth of follicles and rapid growth of follicles. Proliferation of oogonia period was characterized by the proliferation of oogonia. In slow growth of follicles period, the number of primordial follicles gradually declined with ages, while the number and the volume of primary follicles evidently increased. In rapid growth of follicles period, both the number and the volume of growing follicles continued to increase, and the number reached its maximum at 86 postnatal days. Tertiary follicles were first observed in ovary at 72 postnatal days, and nearly mature follicles appeared at 95 postnatal days, respectively. In all 3 periods, the phenomenon of follicular atresia could be observed both in oogonia and follicles. Eespecially, the atresia in primordial follicles were the most significant. TUNEL staining showed that, in proliferation of oogonia period, the atresia of a great number of primordial follicles and primary follicles could be observed, which were mainly caused by apoptosis on follicular oocytes. In slow growth of follicles period, phenomenon of atresia occured in all kinds of growing follicles. Primary follicular atresia was mainly caused by apoptosis on oocyte, some of them were caused by the apoptosis both on oocytes and follicular cells. Secondary follicular atresia was mainly due to apoptosis of layers of the granular cells. In rapid growth of follicles period, with the rapid growth of follicles, the phenomenon of atresia occured in all kinds of follicles became more evident. The atresia in tertiary follicles and secondary follicles were mainly caused by the apoptosis of granulosa cells.

This study was conducted to explore the molecular mechanism for vitrified-thawed damage of the cross-bred blastocysts of the yak by RNA-seq. The cross-bred blastocysts were derived from yak oocytes in vitro fertilized with cattle spermatozoa. Total RNA were extracted from these fresh blastocysts (FRB) and vitrified-thawed blastocysts (VTB) and cDNA was amplified via the Smart-seq2 method, and finally RNA libraries were constructed and sequenced. We obtained 51 099 116 and 54 192 358 clean reads from FRB and VTB, respectively, of which more than 80% were mapped to referenced genome. A total of 11 196 differentially expressed genes (DEGs) were detected, in which 7 570 were upregulated, and 3 626 were downregulated in VTB vs. FRB. The FRB and VTB had 49 016 and 64 352 alternative splicing, 16 681 and 224 750 putative SNPs, respectively. GO enrichment analysis of DEGs showed that they were enriched in molecular function, cellular component, and biological process. The KEGG analysis of DEGs showed that there were 318 pathways in VTB and FRB, of which 14 pathways were significantly enriched. We speculated that the coordination between Spliceosome, Ubiquitin mediated proteolysis and protein processing in endoplasmic reticulum pathway's etc. and the differential expression of Prp19, Prp4, CaM, PKA, Hsp70 and CCL2 might play an important role in the mechanism for vitrified-thawed damage. This is the first report to explore the mechanism for damage of VTB using high-throughput sequencing, which might serve as a key resource for improving embryo vitrification technology. The study also provided valuable information to study gene structure of cross-bred yak, and discover new genes related to vitrification damage of embryos.

The aim of this study was to investigate the mRNA expression profile of Smad 4 gene and to explore the possible miRNAs that target to Smad 4 gene in yak. The reverse transcription PCR(RT-PCR) was used to detect the expression of Smad 4 gene mRNA in the 12 yak tissues including hypothalamus,pituitary,liver,heart,spleen,lung,kidney,biceps femoris,lymph nodes,ovary,oviduct and uterus.The possible miRNAs that target to Smad 4 gene were predicted by TargentScan and miRBase softwares, and their tissue expression profiles in yak were also analyzed by RT-PCR. The results showed that Smad 4 mRNA was expressed in the 12 yak tissues, especially widely expressed in the ovary, oviduct and uterus of the reproductive system. It was predicted that there were 20 miRNAs that could target to the Smad 4 gene of yak, and 6 were selected for expression analysis. The results indicated that bta-miR-106a and bta-miR-377 were expressed in the 12 detected tissues, and bta-miR-146a, bta-miR-224 and bta-miR-1434-5p were expressed in other tissues except for the oviduct of yak, whereas bta-miR-212 was expressed only in the ovaries. The results suggest that Smad 4 gene may play important roles in the various tissues of yak, and bta-miR-212 may be a miRNA targeting to Smad 4 gene only in the ovary of yak, which possibly participates in reproductive physiological process in yak, needing further studies to clarify the mechanism.

Expression patterns of sex-related genes in early dairy cattle fetuses were detected in this study. Holstein dairy cattle fetuses at gestational ages ranging from 34 days postcoitum (dpc) to 80 dpc were obtained by artificial infertilization. Their urogenital crests and mesonephroi were incised to determine the expression levels of 4 genes and locations of 4 proteins by quantitative PCR and immunohistochemistry. The other tissues were used for sex identification of fetuses. Sex identification results showed that there were 10 male and 9 female fetuses in 19 fetuses totally with accurate gestation age. SRY mRNA was expressed only in male fetuses. FOXL2 mRNA was expressed obviously in female fetuses and expressed tracely in the male. SOX9 and DAX1 mRNA had similar expression patterns in male fetuses, while the level of SOX9 was lower than that of DAX1 from 44 to 56 dpc. In female crests from 38 to 80 dpc, SOX9 mRNA level was always lower than DAX1. In female crests after 53 dpc, the expression level of SOX9 was persistently low, while the DAX1 rose violently after that point. The time for sex determination in bovine was from 35 to 39 dpc for the males and from 39 to 41 dpc for the female. SRY and FOXL2 may be the sex determination genes for the male or female in bovine fetus, respectively. This study revealed preliminarily the expression patterns of sex related genes in early bovine fetuses and provided an important theoretical foundation for sex control in mammals.

This study was conducted to evaluate the effects of dietary Enterococcus faecium B₁₃ on growth performance, nutrient digestibility, serum immune parameters and fecal microbiota in weaned piglets. A total of 56 healthy crossbred “Duroc×Landrace× Yorkshire” weaned piglets at 28 days of age with an average body weight of (7.89 ± 1.37) kg were allotted to 4 treatments: group A (antibiotic group), group B (without antibiotic group), group C (compound bacteria group), group D (test group: Enterococcus faecium B₁₃), according to the complete randomized block design. The experiment lasted for 42 d. The result showed that: 1) The ADG and the apparent digestibility of Ca were improved in group C and D compared with group B(P<0.05). The level of IgG in group D was increased by 19.72%(P<0.05) compared with group B.2) Denaturing gradient gel electrophoresis (DGGE) showed that the application of E. faecium B₁₃ changed the bacterial community in fecal. 3) Real-time PCR results showed that, compared with group B, the number of Lactobacillus and E. faecium were increased (P<0.05) and the number of Escherichia coli had decreasing tendency (P = 0.07) in group C and D. Therefore, under the condition of this experiment, the dietary of E. faecium B₁₃ supplementation can improve the growth performance, digestibility of crude protein and calcium and enhance immune responses in weaned piglets. It can maintain the stability of digestive tract microflora of piglets and prevent the growth of pathogenic microorganisms.

This study aimed to elucidate the fatty acids content in muscles and fatty acid synthesis related gene expression profile in muscle of Wanxi White geese during fattening period. A total of 60 geese were selected at 70 d of age with similar body weight. The geese were divided into 3 replicates with 20 per replicate. Five geese were randomly selected from each replicate for breast muscle, leg muscle and liver sampling with 10 d interval during fattening till 100 d of age. Gas chromatography was used for fatty acid content determination and RT-PCR was used for PPARα, FADS2 and ME1 gene expression levels determination. The results showed that:1) Saturated fatty acid content in breast muscle was higher than that in leg muscle (P<0.000 1). Monounsaturated fatty acids and polyunsaturated fatty acids were lower in breast muscle than that in leg muscle (P=0.044, P=0.017). The content of C16:1 and C18:2 were increased, C18:0 was decreased during fattening. 2) The expression of PPARα was the highest on 20 d and the lowest on 30 d (P<0.000 1) in fattening period. The expression of FADS2 was the highest on 10 d (P=0.009) in fattening period. The expression of ME1 was lowest on 30 d (P=0.010) in fattening period. 3) The expression of PPARα increasing was associated with the increasing C16:1, C18:3 and UFA/SFA contents while the content of SFA decreased. The expression of FADS2 increasing was associated with the increasing C16:1, C18:1, C18:3, MUFA and UFA/SFA contents, while SFA and PUFA decreased. The expression of ME1 increasing was associated with the increasing C16:1, C18:1, C18:3, MUFA and UFA/SFA contents, while C18:0, C20:3 and SFA contents decreased. The expression levels of PPARα, FADS2 and ME1 were significantly associated with fatty acids content in Chinese Wanxi White geese, suggesting that these genes might be used as candidate genes for fatty acid selection in geese breeding.

The aim of this study was to develop a multiple PCR assay on a basis of Genome Lab Genetic Expression Analysis System (GeXP) for simultaneous detection of 8 pathogens of bovine infectious diseases, including food-and-mouth disease virus (FMDV), bluetongue virus (BTV) ,vesicular stomatitis virus (VSV), bovine viral diarrheal virus (BVDV), bovine rotavirus (BRV), enterotoxigenic E. coli (ETEC), bovine herpesvirus 1 (IBRV), Peste des petits ruminants virus (PPRV). The GeXP profilerutilisesgene-specific primers containing 5'-universal adaptor sequences. Eight gene-specific primers consist of a universal sequence fused to the 5'-end and a gene-specific sequence were designed according to the conserved sequence of each pathogen and used for amplification.The reaction system and condition were optimized. The specificity of GeXP were examined with samples of the single and mixture of 8 viruses' co-infection. The sensitivity was evaluated by performing the assay on serial 10-fold dilutions of cloned plasmids. And 305 clinical samples were detected by GeXP to further evaluate the reliability. The results showed that the corresponding specific fragments of genes were amplified respectively. The detection limit of GeXP was 100 copies·μL^-1 when all of 8 pre-mixed plasmids containing target genes of 8 bovine pathogens. In detection of 305 clinical samples, the results of GeXP were consistent with real-time PCR completely. Analysis of positive samples by sequencing demonstrated that the GeXP assay had no false positive samples of nonspecific amplification. In conclusion, this GeXP assay is a high throughput, specific, sensitive, rapid and simple method for the detection of 8 pathogens of bovine infectious diseases. It is an effective tool applied to differential diagnosis rapidly for clinical samples and epidemiological investigation.

Mycoplasma hyorhinis (M. hyorhinis) is a commensal inhabitant in swine. It can cause polyserositis, pneumonia, arthritis and pericarditis in pigs. Because of the high cross-reactivity among M. hyorhinis and other swine mycoplasmas, there is no specific serological diagnostic method reported. In this study, an indirect ELISA was established by using the variable lipoprotein (Vlp) as the coating antigen. By optimizing the reaction conditions, the optimal concentration of coating antigen was 0.312 5 μg·mL^-1 and the serum dilution was 1∶100, and serum reaction time was 30 min. The optimal dilution at 1∶20 000 for the goat anti-pig HRP-IgG was determined, and the reaction time was 30 min. The optimal substrate chromogenic time was 10 min. The cut-off value of the assay was 0.27. In the cross-reactivity experiment, the Vlp-ELISA showed no cross-reactivity with common swine pathogens or other swine mycoplasmas. The coefficients of variation of the inter-assay and intra-assay experiments were both below 10%. To investigate the specificity and sensitivity of this method, the positive and negative sera samples were detected by the Vlp-ELISA. After that, a total of 247 clinical samples and sera from the experimentally-infected pigs were tested by the Vlp-ELISA, and the results showed the same tendency with that of Tween 20 extracted membrane protein-ELISA method. In conclusion, the indirect ELISA established in this study was specificity and stability, which can be widely used in clinical detection.

Due to the deficiency of antibody detection methods in evaluation of immunity against swine pseudorabies virus, to fully evaluate the cell-mediated immunity of PRV vaccine in combination with humoral immunity, we try to develop an Enzyme Linked Immuno-spot Assay (ELISpot) method for the detection of PRV specific IFN-γ level. In this study, according to the basic protocol of ELISpot, we tried to optimize the best conditions of stimulant concentration, peripheral blood mononuclear cells (PBMC) density and incubation time. After that, an animal experiment was performed, twenty PRV gB antibody-free piglets were divided into four groups which were administered with attenuated live vaccine, inactivated vaccine, live vaccine plus inactivated vaccine and normal saline (as control group). The immune response was evaluated by our in-house IFN-γ ELISpot,gB-ELISA and neutralization test, together with the results of challenge test. After optimization, the PRV IFN-γ ELISpot protocol was determined. The optimal stimulant concentration, cells density/well and incubation time were 2 μg·well^-1, 10⁶ cell·well^-1, and 36 h. Results obtained from the animal experiment revealed that live plus inactivated vaccine group showed the high level of both humoral and cellular immunity, the serum neutralization (SN) antibody titer was 1∶14.48 and the ELISpot result was 151.8±26.61, while those of SN antibody and ELISpot in live vaccine group and inactivated vaccine group were 1∶32.36, 40.4±9.07 and 1∶1.36, 189.6±27.36, respectively. The challenge test showed that the protective effect of live vaccine plus inactivatel vaccine was best as body temperature, viral shedding and clinical signs are the slighter in this group than those in other groups. The inhouse IFN-γ ELISpot results had a good relation with challenge test, providing an effective method for the evaluation of both cell immune response and optimal immune procedures for porcine pseudorabies vaccination.

The purpose of this paper was to study the pathogenesis of Muscovy duck reovirus (MDRV) infected muscovy ducking. Forty-four healthy muscovy ducklings were divided into treatment group challenged with MDRV and control one injected with Hank's. Livers were collected at the 5^th day after challenge. Proteomics of the livers were determined by differential proteomic technology. Differential protein spots between both groups were performed and analyzed by two-dimensional gel electrophoresis and MALDI-TOF-TOF mass spectrometer, and then they were identified by protein search software, Mascot 2.3.02. Thirty-eight differential protein spots were separated and identified. Ten down-regulated protein spots and seventeen up-regulated protein spots were observed in the liver samples of the treatment after comparison between the two groups. Seven protein spots were appeared only in the livers of control and four protein spots were only emerged in the livers of treatment. The results indicate that differential proteomics in livers, which were impacted and damaged by MDRV may provide a new idea of pathogenesis of MDRV infected muscovy duckling.

In this study, a unique antigenic epitope ₈₇YAEYI₉₁ on E protein of duck Tembusu virus (DTMUV) was identified by phage display technology with purified monoclonal antibodies (MAb) 1A5 against DTMUV E protein. To determine whether the ₈₇YAEYI₉₁ sequence is conserved among the E proteins of flaviviruses, we aligned the E protein amino acid sequences of flaviviruses. The results revealed that YAEYI was highly conservative in DTMUV strain, but the epitope sequence wasn't conserved among the corresponding amino acid sequence of the E protein in other strains of flavivirus. Dot blotting assay showed that epitope ₈₇YAEYI₉₁ had a good affinity with positive sera to DTMUV, and there was not cross-reacting with JEV-, DENV-, WNV-positive sera, suggesting that ₈₇YAEYI₉₁ was DTMUV unique epitope. An Epitope-ELISA assay was established by using unique epitope (₈₇YAEYI₉₁) fused protein and used to test duck serum samples which were also detected by the Neutralization Test as the standard method. According to results, the specificity of this test was 100%. The sensitivity of this epitope-based peptide serologic test for DTMUV infection was 96%. So, Epitope-ELISA was a specific method for detecting antibodies against DTMUV.

To study the multilocus sequence types of Cryptosporidium andersoni from calves in Shaanxi Province, 36 fecal samples positive for C. andersoni were collected from 0-6 months calves in four regions of Shaanxi province and examined by the polymerase chain reaction (PCR). Sequence analysis was based on four genetic loci, namely CM-MS1, CM-MS2, CM-MS3 and CM-MS16. The results showed that a total of 15 C. andersoni isolates were successfully genotyped in all four loci and divided into 4 subtypes of MLST, namely A4, A4, A2, A1; A4, A4, A4, A1; A5, A4, A4, A1; A1, A4, A4, A1. Among them, the MLST (A4, A4, A4, A1), as the dominant subtype, was widely distributed in various farms and different breeds of calves. These findings indicated that genetic variation was presented in C. andersoni of calves in Shaanxi province and various MLST subtypes were found in these calves.

Toxoplasma gondii is an obligate protozoan parasite with only one species, but it has rich genetic diversity with very different virulence. We chose three strains of the only species: Pru, BJ, VEG strains to compare their pathogenicity after intraperitoneal injection in Kunming mouse. We evaluated their virulence by clinical symptoms, serum antibody level, organ distribution of parasites and brain burden. Our results showed that mice symptoms infected with type Ⅱ was more significant than type Ⅲ infected group. Mice specific Toxoplasma antibody in serum was detected from the 4th day in type Ⅱ infection group, and remained increase after that until the 64th day, while type Ⅲ group got the peak earlier at the 32nd day. Interestingly, the three strains showed similar distribution features in mice organs: in early stage (the 1st day), parasites were detected in lung, kidney and muscle, then appeared in heart, lung, muscle and brain in mid-term (the 8th day), at last (the 32nd day) brain was the only detected organ. During infection, parasites were not be detected in spleen and liver. Our work successfully built up a Toxoplasma infection mice model of three strains and demonstrated their pathogenicity in detail. In addition, there was a certain similar regularity on mice organ distribution at different time among different Toxoplasma genotypes infection, which means organ tropism along time. Our results give reference for Toxoplasma pathogenicity and establishment of its animal infection model.

The research was conducted to study the effects of reticuloendotheliosis virus (REV) on cell apoptosis, enzyme activities and expression of relevant factors in immune organs of chicks. Seventy one-day old SPF chicks were randomly selected into REV infection groups (I) and control groups (C). The methods of enzyme activities detection kit, RT-PCR, ELISA and TUNEL were applied to detect activities of Caspase-3 and Caspase-9, expression of Bcl-2 and cell apoptosis in central immune organs. The results showed that the detected indexes in thymus of SPF chicks infected with REV were significantly higher than control groups at 7 to 28 days after infection. The indexes in bursa of Fabricius of SPF chicks infected with REV were significantly increased than control groups at 7 to 35 days after infection. These data indicate that cell apoptosis caused by enhancement of Caspase-3 and Caspase-9 activities, up-regulated expression of the Bcl-2 mRNA and protein in central immune organs of SPF chicks infected with REV, are closely related to immune function suppression.

The experiment was conducted to study the effect of chicken spleen transfer factor (TF)on intestine antioxidant capacity and the mechanism on production and immunity ability of chicken. One hundred chickens of 1-day-old were selected and were divided into 5 groups. Four TF groups including 20 chickens each received TF treatment as follows: 0.05 mL (Minimum dose group), 0.10 mL (Low dose group), 0.25 mL (Medium dose group), 1 mL (High dose group) per chicken TF were given for one week by drinking water every day from 5-days-old to 12-days-old, respectively, and then fed without TF to 19-days-old. Group 5th was normal control group. Fifty chickens were killed at 12-days-old and 19-days-old, respectively. The chickens were weighted, and the antioxidant capacity of the duodenum, jejunum, ileum and rectum were measured. The results showed that one week' treatment of TF showed an increased tendency of body weight, yet the effect was not obvious. However, the high TF dose group significantly increased the activity of SOD (17.07%-31.54%), CAT (16.98%-25.77%), GSH-PX (13.99%-23.59%) and T-AOC (16.48%-43.16%) of duodenum, jejunum, ileum and rectum, but significantly reduced the activity of MDA (P<0.05) in intestine. The activities of T-AOC, SOD in the intestinal segments, CAT (except for ileum) and GSH-PX (except for duodenum) were significantly increased in the middle dose groups (P<0.05), but the content of MDA was decreased significantly in the low and middle dose groups (P<0.05). At 19 days old, the changes of T-AOC, CAT, GSH-PX, SOD and MDA in each intestinal group were decreased compared with 12 days old, but there was still significant in individual intestinal segment (P<0.05). The results indicate that the TF, as a new feed additive, has a significant role in improving anti-oxidative stress ability.

In order to learn the situation of parasitic virus in Culicoides in Yuli County, Xinjiang, a total of 18 000 Culicoides were collected from Yuli County and divided into 360 groups, with 50 Culicoides in each group. Then the Culicoides were ground and inoculated into BHK-21, C6/36 and Vero cells, respectively. After 5 generations of blind passage, one group of Culicoides made CPE arise in BHK-21. Then the isolated strain was firstly identified to be RNA viruses by drug sensitivity test (5-floxuridine). Secondly, the amplified primers were identified by arthropod-borne RNA viruses and the result showed that the strain belongs to alphaviruses and is suspected to be Getah viruses. Finally, the isolated strain was determined to be Getah viruses by neutralization test, immunoelectron microscopic observation, PCR amplification of Getah virus C gene-specific primer and other methods. In this study, Getah viruses were isolated from Xinjiang Culicoides for the first time and the virus strain presents a closest genetic relationship (98%) with the 2005 Japanese isolated strain, for which the reason might be the introduction of Japanese breeding sires with the disease or their seminal fluid, suggesting that in the import and export trade activities of animal husbandry, quarantine inspection on Getah virus should be strengthened.