Tylosin (TYL) is one of the veterinary antibiotics which were widely used in animal husbandry in China.After absorbed by animal，the prototype and metabolites of TYL were excreted with urine and manure，which resulted in negative effect on the environmental microorganism.Firstly this article introduced the residue of TYL and its metabolites in the environmental medium as animal waste，soil and water.TYL was a mixture of Tylosin A (TYLA)，Tylosin B (TYLB)，Tylosin C (TYLC)，and Tylosin D (TYLD)，with TYLA been the major component accounting up to 80% to 90% of TYL，so TYLA was the main form of tylosin residues in the environment.But TYLA could be converted into TYLB，TYLC and TYLD in the different environmental conditions.Secondly this article summarized the interaction effects of tylosin residues with soil microorganism，including the impact of the TYL residues on the number，structure，and function of soil microorganism，and the adaption of soil microorganism to the TYL residues as the degradation of TYL residues，and the generation and transmission of antibiotic resistance genes.Finally the shortage of present research and direction of future research were also prospected.

This study aimed to analyze the genetic and physiological and biological factors impacting meat quality traits from the point of glycolysis metabolism.The pH，L value and metabolisms (lactate acid，glycogen and free glucose) content were detected at 5 time-points during the process of aging in two kinds of muscles，and the level of mRNA expression of glycolysis genes were investigated by qRT-PCR.The results showed that， during the process of aging，the lactate acid content kept same change trend with pH.At the beginning of aging，the quickly decrease of pH and increase of lactate acid content lasted for 48 hours，and then gradually keep stable.The suggestion was to measure the terminal pH at 48 h after slaughter.The glycolysis genes detected took part in the metabolism in a coordination way，the mRNA levels correlated with lactate acid content and pH.Glycolysis is important to the meat quality，especially the HK-2 and PKM，ACL and ATP5B genes are the controlling factors for the meat quanlity.

 In the present study，expression of IGF-I，IGF type-I receptor (IGF-IR)，and IGF binding protein (IGFBP)-3 genes was quantified by RT-PCR in the liver and muscle tissues on days 13，17，21，25，27 of embryonic development，as well as at 7 days post-hatching (pH) in Gaoyou and Jinding ducks differing in growth rates.The results showed that IGF-I, IGF-IR and IGFBP3 mRNA could be detected as early as on E 13 d in ducks，and showed an extremely significant breed and development differential diathesis.The expression level of IGF-I was very low throughout embryonic development before increasing dramatically by E 27 d and 7 days pH in both duck breeds.In contrast，IGF-I was expressed in muscle at much higher levels than liver throughout development.Expression of liver IGF-IR was higher than that in muscle，and differed between breeds in breast muscle.IGFBP-3 mRNA expression in liver was relatively low in both duck breeds，while in breast muscle increased gradually from the late of the embryonic period to the early post-hatching.Inverse relationships were observed for the expression of IGF-I and IGF-IR，and IGF-I and IGFBP-3，while positive relationship was observed for the expression of IGF-IR and IGFBP-3，meanwhile varying degrees of linear correlation was found between insulin-like growth factor system genes mRNA expression and body weight，liver weight and breast weight in duck.The data indicates differential expression of selected genes that comprise the IGF system in the duck liver tissue during embryonic and early pH growth and development，and provide some data for further study on the mutual regulation mechanism of genes in IGFs system.

This experiment was conducted to observe the expression of PepT1 mRNA in Chongren Spotty chicken intestine in order to support the study on the mechanism of transporting small peptide through small intestine and the distribution of peptide transporters.Samples were obtained from intestine of 120-day-old Chongren Spotty chicken and real-time fluorescent quantitative PCR was used to study the differential expression of peptide transporter 1 (PepT1) mRNA in different intestinal segments and breeds with different feed conversion rate.The results showed that the abundance of PepT1 mRNA gradually decreased from duodenum to jejunum and ileum，the expression of PepT1 mRNA in duodenum was significantly higher than that in ileum (P<0.01)，but there was no significant difference in the abundance of PepT1 mRNA between duodenum and jejunum or between jejunum and ileum (P>0.05).The abundance of PepT1 mRNA from breed with high feed conversion rate was higher than that from breed with low feed conversion rate (P>0.05).The results indicate that the anterior small intestine is the primary site for the expression of PepT1 mRNA and the abundance of PepT1 mRNA is the highest in the duodenum，meanwhile，Chongren Spotty chicken with high feed conversion rate has higher PepT1 mRNA abundance compared with those with low feed conversion rate.

To investigate the effect of 17β-E₂ on osteoblasts induced by chicken bone marrow mesenchymal stem cells(BMSCs) ，the method of in vitro culture of BMSCs and its inducement of osteoblasts were established in this experiment.Chicken BMSCs were purified with whole marrow adherent culture and subculture in vitro.The third generation of cells of BMSCs were selected for inducing osteoblastic culture.The growth and morphology，the cell proliferation rate and the cell cycle of osteoblasts induced-BMSCs were detected with inverted phase contrast microscope，methyl-thiazol-tetrazolium (MTT) and flow cytometry，respectively.Induced-BMSCs obsteoblasts were identified by alkaline phosphates (ALP)，Van-Gieson staining and Alizarin red staining，respectively.The induced osteoblasts were divided into 5 experimental groups and cultured with osteogenic differentiated medium containing different 17β-E₂ concentrations of 10^-7，10^-8，10^-9，10^-10，10^-11 mol·L^-1 for each group，respectively.Cells cultured without 17β-E₂ as a blank control group.Effects of different concentrations of 17β-E₂ on the proliferation and differentiation of induced-BMSCs osteoblasts were measured by MTT and PNPP for finding the most effective concentration.Then this effective concentration of 17β-E₂ was used for culturing induced-BMSCs osteoblasts，and the percentages of apoptotic cells were measured by flow cytometry.The results showed that BMSCs could be purified with whole marrow adherent culture.Osteoblasts could be induced from purified BMSCs using classic differentiated medium and were typically characteristic of the osteoblastic biology.The induced-BMSCs osteoblasts’ ALP，collagen typeⅠand calcified nodules’ staining were strongly positive compared with control group.10^-9 mol·L^-1 17β-E₂ concentration represented the most action of promoting proliferation and differentiation and inhibiting apoptosis of induced-BMSCs osteoblasts among the other concentration groups.Thus，it is shown that osteoblasts can be induced from purified chicken BMSCs and estrogen can enhance the function of induced-BMSCs osteobalsts.

The aim of the present study was to clone myogenin (MyoG) gene of Jiulong yak，to carry out bioinformatics analysis and to assay gene expression profiling in different tissues and developmental stages，in order to lay the foundation for studing meat quality formation and muscle development of Jiulong yak.Based on the published nucleotide sequence of bovine MyoG gene in GenBank，a pair of primer was designed.The Jiulong yak MyoG gene was amplified by RT-PCR，the tissue specificity of MyoG gene were analyzed by semi-quantitative RT-PCR，and different development stages expression specificity of MyoG gene were analyzed by fluorescence quantitative PCR．The results showed that Jiulong yak MyoG gene cDNA was 700 bp (GenBank accession number：KC184120)，with an ORF of 675 bp encoding 224 amino acids.Compared with cattle，human，mouse，rat，pigs，sheep，rabbit，the homology of amino acid sequences were 92%-99%.The MyoG gene expression was only observed in longissimus muscle，and not detected in heart，liver，kidney，spleen and fat.The MyoG mRNA expression level increased with Jiulong yak growth，showing higher mRNA level in longissimus muscle of 3.5-5.5 and over 9 years old Jiulong yaks than that in 0.5 years old Jiulong yaks (P<0.05).These results suggest that MyoG may play an important role in the development of muscle tissue of Jiulong yak.

To investigate the underlying relationship between amino acid transportation and lactation in dairy cow mammary gland，LAT1 and 4F2hc expression were detected by laser confocal microscope.The results showed that LAT1 and 4F2hc expression were higher in mammary gland with high quality milk than mammary gland with low quality milk and mammary gland in dry period.In lactation，LAT1 and 4F2hc were detected on the basolateral of acinar epithelial cells and myoepithelial cells.In dry period，LAT1 and 4F2hc were detected on the plasma membrane of ductal epithelial cells.Correlation analysis showed LAT1 expression was highly correlated with 4F2hc.All these results revealed that LAT1 was the major amino acid transporter in mammary gland of dairy cow.LAT1/4F2hc coordinated expression was closely related to milk protein synthesis and mammary gland reconstruction.

To study the effect of RNAi on MC1R expression in mouse embryo fibroblasts(MEF). MC1R gene was taken as candidate gene affecting the formation of mammal’s hair color. The aim of the study was to inhibit the expression of MC1R by RNA interference in the MEF. Three pairs of specific siRNA for MC1R gene were designed for RNA interference and transferred into the MEF by reverse transfection. After 48 h, the total RNA and protein were extracted from the MEF, and the relative expression of MC1R mRNA and protein was detected by using QRT-PCR technology and Western bolt. The results showed that the relative expression of MC1R mRNA and MC1R protein in the siRNA1 and siRNA2 groups were significantly lower (P<0.05) than those in the blank control group, but the expression of siRNA3 group was unconspicuous. These tests were successfully inhibited the expression of MC1R in the MEF by RNA interference (reverse transfection) with LipofectamineTM RNAiMate. The expression trendency of MC1R gene and protein are consistent. The results showed that the inhibition effect of siRNA1 and siRNA2 groups were effective, the effective siRNA were screened from three specific siRNAs, can be served as a scientific foundation for the further study of regulation mechanism of MC1R in the process of coat development.

 aP2-cre-PU.1^fl/fl mice were generated and identified using gene engineering，homologous recombination，PCR and Western blotting technologies in this study.The results showed that，compared with PU.1^fl/fl mice,PU.1 protein was down-regulated to the level of that of aP2-cre-PU.1^fl/fl.The body weight and body composition were analyzed in PU.1^fl/fl and aP2-cre-PU.1^fl/fl mice with 1-6 month old.Moreover，the body weight of aP2-cre-PU.1^fl/fl mice was significantly higher than that of PU.1^fl/fl mice at month 5 and month 6 (P<0.05).There was no significant difference in muscle weight but fat weight was significantly higher in aP2-cre-PU.1f^l/fl mice than that in PU.1^fl/fl mice (P<0.05).The results suggest that increase of adipose tissue of aP2-cre-PU.1^fl/fl mice results in the increase of their body weight.Therefore，aP2-cre-PU.1^fl/fl mice is the better animal model to explore PU.1 physiological functions in adipose tissue，which provide the theorical basis for exploring the effect of PU.1 gene on fat deposition in animals.

This experiment was conducted to study the effects of different choline levels on cholesterol and crude fat in liver，muscle and egg，fatty acids in liver，muscle，biochemical indicators in blood of Shaoxing ducks，and to explore the optimal choline level in the diet of laying ducks．The single factor randomly group design was used in this study.540 (during the initial egg-laying period) Shaoxing ducks were randomly assigned to 5 dietary trearments.Each treatment consisted of 6 replicates with 18 birds per replicate.The experiment lasted for 20 weeks． Five groups were supplemented with 0,250,500,750 and 1 000 mg·kg^-1 choline chloride in the basal diets，respectively．The results showed as follows：1) Compared to the control group，supplemental choline significantly reduced cholesterol and crude fat in liver and muscle (P<0.05)；diets with choline did not affect the liver weight/duck weight and muscle weight/duck weight (P>0.05).2) Compared to the control，with the increase of choline levels in diet cholesterol in egg significantly decreased (P<0.05)，crude fat in egg significantly increased(P<0.05).3)Supplemental choline significantly decreased content of saturated fatty acids(SFA) in liver and breast muscle(P<0.01)；significantly improved content of monounsaturated fatty acids(MUFA) and polyunsaturated fatty acids(PUFA) in liver，breast muscle(P<0.01).4)Choline had no significant effects on LPS，Ch，VLDL，LDL-C，HDL-C，TG，PL，NEFA，T-CHO，AKP in blood.The results suggest that supplementing the diet with choline reduces cholesterol and crude fat content in liver，muscle and egg，decrease SFA content in liver and muscle，and improve MUFA，PUFA content in liver，muscle.

In order to study the effects of freezing-thawing on mutton quality，nutrition components and ultrastructures, longissimus dorsi were collected from 1.0-1.5 year-old Lanzhou Fat-tailed sheep，vacuum packed and repetitively frozen-thawed for different times，and then meat qualities，nutrition components and ultrastructures were studied.The results showed that，compared with fresh mutton，the thawing loss (TL)，cooking loss (CL)，dry matter (DM) content and ash content were significantly increased (P<0.05) while the shear force (SF) and crude protein (CP) content were significantly decreased (P<0.05) with the increase of times of freezingthawing.Water loss (WL) and crude fat (CF) were significantly increased after frozing-thawing for two and three times (P<0.05)，respectively.Freezing-thawing had no significant effect on pH (P>0.05).In the same time，freezing-thawing vacuolated structure formation in the mitochondria，confused fiber bundles，increased the space between muscle fiber，and shortened sarcomere，blurred even disappeared Z disc.The results demonstrate that repetitive freezing-thawing damage the structure of myofibril seriously，change the nutrition components and decline the mutton quality of Lanzhou Fat-tailed sheep.

This experiment was conducted to measure the NH3 emission rate and investigate emission characteristics using respiratory chamber. Three hundred and 1-day-old healthy Arbor Acres broilers with similar body weight were randomly allotted into three respiratory chambers.The broilers were reared on the net and manure was not cleaned until 42 d.A continual monitoring system for monitoring ventilation rate and the NH3 concentration was used in this research to determine ammonia emission.The results showed as follows：total ammonia emissions during 1 to 42 d were estimated to (2 777.78±55.58)mg per bird，and mean ER was (66.14±1.32)(mg·bird^-1)·d^-1 with body weight (2 530.95±57.74)g.The daily ER during 1 to 18 d remains stable，and then showed a increasing trend with age of broiler.

 The genome and pathogenicity of pigeon NDV isolate were characterized for better understanding the evolution of NDV.A strain of Newcastle disease virus，named Pigeon/China/SDLC/2011，was isolated and identified from diseased pigeon flock.The full-length genome of Pigeon/China/SDLC/2011 was sequenced and compared with reference strains.Besides，the pathogenicity of Pigeon/China/SDLC/2011 was evaluated in pigeons and SPF chickens.Sequence analysis showed that the complete genome of Pigeon/China/SDLC/2011 contained 15 192 nucleotides(nt).The cleavage site of the fusion protein was¹¹²RRQKRF¹¹⁷，a feature generally associated with virulent NDV strains.Phylogenetic analysis，based on the genomic sequences and sequences of the fusion gene，revealed that Pigeon/China/SDLC/2011 should be classified as genotype Ⅵ NDV.Mutations were observed in the six structural proteins of Pigeon/China/SDLC/2011 compared with reference NDV strains of genotype Ⅶ.More mutations were localized in the P and HN protein than the other proteins and the amino acid sequence identities of P and HN proteins between Pigeon/China/SDLC/2011 and genotype Ⅶ NDVs was 84.6%-84.8%，90.0%-91.1%，respectively.In the challenge test，70%-80% of pigeons inoculated with Pigeon/China/SDLC/2011 showed a series of nervous disorders：bilateral or unilateral locomotor disturbances of wings or legs，torticollis，and watery green diarrhea and died in 6-14 days.However，chickens remained clinically normal throughout the study.Viruses were detected more frequently in the swabs of pigeons than chickens.The results showed that marked differences in molecular characterization and pathogenicity in chickens were recorded between Pigeon/China/SDLC/2011 and the virulent NDVs of genotype Ⅶ.Although Pigeon/China/SDLC/2011 was nopathogenic for chickens，some measures should be taken to prevent virus transmission between pigeions and chickens as viruses were detected in swabs of infected chickens.

 Protein P65，the immunodominance protein of Mycoplasma hyopneumoniae (Mhp)，and shows no cross reaction with other Mycoplasmas，is usually used as the target protein or gene for Mhp detection.In this study，the front 922 bp fragment containing three rare codons in P65 gene was obtained by gene synthesis，and the other fragment of P65 gene was amplified by PCR from Mhp 168 strain，then the mutated P65 gene was obtained through the Splicing by overhang extension (SOE-PCR) with the surplus segment connection，finally the recombinant plasmid pET-32a(+)/P65 was constructed by inserting the mutated P65 gene into expression vector pET-32a(+).Under IPTG induction，E.coli BL21(DE3)/pET-32a(+)/P65 expressed the recombinant P65 protein with 87 kD.The result of Western blot analysis showed that the recombinant protein has satisfactory immunoreactivity.High level of antibody was obtained in BALB/c mice after inoculating the recombinant P65 protein，which indicated the recombinant P65 protein has a good immunogenicity.We had successfully obtained the recombinant P65 protein of Mhp by expressing in the E.coli，it provide the support for Mhp detection and subunit vaccine，and also offers the help for the further study of the pathogenic mechanism of this disease.

Based on the sequences of the hut gene specific for Salmonella and the SdfⅠ, Spy，glgC，and Spec genes specific for Salmonella serotypes，five pairs of primers were designed and synthesized.A multiplex PCR (mPCR) method was developed and uses for detection of clinical Salmonella isolates.The results showed that the strains of S.enteritidis，S.typhimurium，S.pullorum and S.gallinarum were identified specifically by the mPCR，the sensitivities of mPCR for all bacteria were 3×10³ CFU，and the sensitivities of mPCR for chromosomal DNA of S.enteritidis，S.typhimurium，S.pullorum and S.gallinarum were 162，202，214 and 178 pg·μL^－1，respectively.Compared to the traditional serological assay，the sensitivities of the PCR for 55 Salmonella clinical isolates were 100%，and the minimal coincidence rate of the mPCR assay were 96.4%.The results indicated that the mPCR assay is a rapid，sensitive and specific method for identification of the four serotypes Salmonella.

 Phenotypic and genetic characteristics of two Listeria monocytogenes strains H4 and 54006 with naturally low pathogenicity were carried out to elucidate the possible molecular mechanisms.The two strains，together with other 3 L.monocytogenes strains representing different serovars，were investigated by serotype and lineage identification，virulence to mice，phospholipase activity，adhesion and cytotoxicity assay against HeLa cells，detection of virulence associated genes as well as their transcription levels via real-time PCR.Result were as follows：Strains H4 and 54006 belonged to serovar 4a and lineage Ⅲ，with notable phospholipase activity and increased adhesion to HeLa cells.However，these two strains had decreased pathogenicity to mice，but exhibited significantly higher cytotoxicity against HeLa cells （P<0.05）.The virulence associated genes in the two strains were quite homologous to other test strains，with PrfA depicting G145S mutation in strains H4 and 54006.The transcription levels of main virulence genes in strain H4 were significantly higher than those of other strains.Mutant strain H4-ΔprfA (substitution at position 145 from serine to glycine) was constructed by sitedirected mutagenesis and homologous recombination，with abolished phospholipase C activity and increased virulence to mice as compared with its parent strain H4 (10^5.00 vs 10^7.18) .The transcription levels of main virulence genes in mutant strain H4-ΔprfA were lower than those of the wild type strain.The study presents some clues that the low virulence of strains H4 and 54006 maybe result from PrfA G145S mutation，and leading to over-expression of PrfA regulated proteins.Hence，the strains might be exposed to the host immune responses with their stronger cytotoxicity.

 The aim of this study was to investigate the role of p38MAPK in acute lung injury (ALI) induced by H9N2 influenza virus isolated from swine (H9N2-SIV) in mouse model.BALB/c mice were divided into H9N2 infected group，H9N2 + p38MAPK inhibitor (SB203580) group and mock infected group.The lungs were observed for lesion of pathological change and the lung wet weight/dry weight (W/D) were investigated; The quantity of MAP kinases protein were detected by Western blot analysis; The cell count and the contents of TNF-α and IL-1β in bronchial alveolar lavaged fluid (BALF) were measured.The results were as follows：the result of western blot showed that the quantity of MAP kinases protein in lung of H9N2 group higher significantly compared with H9N2 + SB203580 group (P<0.01); Furthermore，depression，dyspnea and weight loss appeared on H9N2 infected mice markedly; Histopathologically，the similar histopathological changes such as alveolar and interstitial edema，hemorrhage，inflammation cell infiltration were also observed in lung in H9N2 + SB203580 group mice，but the degree of lung lesions was not as serious as those in H9N2 group; Moreover，the interventions of SB203580 decreased the morality of infected mice (P<0.01)，and prolonged the survival time of infected mice significantly.Meanwhile，it also decreased markedly W/D（wet weight/dry weight of lung），the number of inflammatory cell and levels of TNF-α and IL-1β in BALF (P<0.01).The results indicated that p38MAPK had an important role in the process of H9N2-SIV-induced ALI，and its inhibors SB203580 may block effectively expression of p38MAPK，and ameliorate lung injuries by inhibiting excessive discharging of TNF-α and IL-1β，which suggesting that SB203580 have benefit role to intervene the ALI induced by H9N2-SIV influenza virus in future.

In order to study cellular localization,tissue profile and regulation of signalling lymphocyte activation molecule （SLAM),a receptor of canine distemper virus （CDV),indirect immunofluorescence assay （IFA) was conducted to detect SLAM expression in Vero cells,IFA was also used to detect CDV-antigen in liver,lung,spleen,kidney and brain of CDV-infected minks; semiquantitive PCR and Indirect Immunohistochemical assay （IHA) was selected to detect SLAM expression in referred tissues of minks with and without Distemper.The results showed that viridis fluorescence was appeared in cell membrane and cytoplasm of Vero-SLAM cells,CDV and SLAM positive reaction was appeared in cell membrane and cytoplasm of liver,lung,spleen,kidney and brain of CDV-infected minks; In minks with early distemper lesions characterized by presence of the virus,higher numbers of SLAM-expressing cells were found in multiple tissues recognized as targets of CDV compared with those in control minks,more CDV-positive cells were observed than SLAM-expressing cells.These findings suggest that SLAM is expressed in cell membrane and cytoplasm of minks,especially in lung.Virus infection is associated with up-regulation of SLAM,and there is other receptor for CDV in minks.

The aim of the study was to investigate the distribution of superantigen genes and the profile of antimicrobial resistance in staphylococcal strains isolated from dairy cows with clinical endomitritis in Inner Mongolia.A total of 260 purulent secretions collected from bovine with clinical endomitritis were used for the isolation of Staphylococci and subsequently，the suspected strains were molecularly identified to species level.The distribution of staphylococcal superantigen toxin genes (SEs and TSST-1) was investigated by PCR.The MICs of 16 antimicrobial agents and 3 pairs of antimicrobial agents combinations to the isolates were determined by broth micro-dilution method.PCR was conducted to detect the presence of genes conferring resistance to erythromycin and tetracycline.A total of 127 Staphylococcus isolates belonging to 10 varied species，including 53 SA (41.7%) and 74 CNS (58.3%)，were isolated from 260 clinical samples.Eighty isolates (63.0%) were found to harbor at least one staphylococcal superantigen toxin gene and the prevailing of 17 different combinations of superantigen toxins genes was observed.Sej (38.6%) was the most frequently found and the “sec+sej+sen”(33.3%) was the most commonly encountered combination.The highest resistance was observed in penicillin (79.5%) and ampicillin (71.7%).The resistance rate of the isolates to cephalosporins，macrolide and tetracycline，fluoroquinolones and 3 antibiotic combinations were approximately 60%，40% 20%，and 10% respectively.None of isolates were resistant to vancomycin.The resistance to erythromycin of the isolates was mainly contributed by the ermC (46.4%) and ermB (37.5%) gene and ermA gene was not found in any isolates.TetK (70.0%) and tetM (10.0%) gene conferred the resistance of the isolates to tetracycline.Twenty-two CNS isolates were phenotypic and molecularly identified as MRS.The resistance rate of MRS isolates to penicillin (P<0.01)，ampicillin (P<0.01)，clarithromycin (P<0.01)，erythromycin (P<0.01) and cefotaxime (P<0.05) were significantly higher than MSS.The results indicated that the prevalence of the superantigen genes in staphylococci isolated from bovine with clinical endometritis in Inner Mongolia was complicated and the antimicrobial resistance of the isolates was serious，meanwhile，the prevalence of MRCNS was observed in bovine originated staphylococcal isolates，suggesting that the resistance of the isolates to antimicrobial agents was one of the crucial reasons causing the failure of treatment for bovine clinical endomitritis in Inner Mongolia.

This experiment was conducted to study the age-related changes in the lymphocyte proliferation and apoptosis during the embryonic and post embryonic development of the Tianfu duck thymus.Sixty five Tianfu ducks were divided into 13 groups as follows: 22，24 and 26 days embryonic stage，and 0 （neonatal stage)，3，5，8，14，17，20，26，29 and 32 weeks after hatching.Proliferating cell nuclear antigen (PCNA) and Caspase-3 immunohistochemisty and light，electron microscopy techniques were used in this study.The results showed that PCNA and Caspase-3 positive lymphocytes were distributed in the thymus.The proliferative rates of thymic lymphocytes in the cortex and medulla decreased significantly from 2226 days embryonic stage，and kept stable from 03，817 and 2632 weeks after hatching，but markedly decreased on 5，8，20 and 26 weeks after hatching.In the same age group，the proliferative rate of lymphocyte in the cortex was higher than that in the medulla.The apoptosis rates of thymic lymphocytes in the cortex and medulla kept unchanged from 22-26 days embryonic stage，then increased from 0-8 weeks after hatching，and kept stable from 8-17 weeks，but rose continually from 20-32 weeks.In the same age group，the apoptosis rate of lymphocytes in the cortex was higher than that in the medulla.The nuclei of apoptotic lymphocytes with swollen mitochondria and broken cristae mitochondriales presented different features.The apoptotic bodies were phagocytized by the macrophages.The proliferation and apoptosis of lymphocytes exist universally during the normal embryonic and post embryonic development of the Tianfu duck thymus which undergoes obvious agerelated changes，and then supervises and controls the development and regression of this organ cooperatively.

This experiment was conducted to study the effect of the bacterial enriched-selenium polysaccharide enterobacter cloacaeZ0206 on the renal disease of the Type Ⅱ diabetic KKAy mice.Six to eight week-old male KKAy mice were allocated in diabetes group (Model)，Z0206 bacterial enriched-selenium polysaccharide group (CEPS) and Z0206 purified enriched-selenium polysaccharide group (PEPS) based on the blood glucose concentration after two weeks pre-feeding，8 mice in each group.The groups received 0.5 mL distilled water，10 mg·mL^－1 CEPS，10 mg·mL^－1 PEPS respectively.Eight 7-week-old C57/BL mice were used as normal control group (Control).The feeding trial lasted for 42 days.Compared with the control group，the activity of Glutathione Peroxidase (GSH-Px) and Superoxide Dismutase (SOD) in Model group were significantly decreased (P<0.05)，the mRNA transcription of interleukin-1 (IL-1)，interleukin-6 (IL-6)，monocyte chemotactic protein 1 (MCP-1)，nuclear factor-κB (NF-κB)，transforming growth factor-β (TGF-β)，plasminogen activator inhibitor 1 (PAI-1)，plateletderived growth factor β (PDGF-β) and Collagen Type Ⅳ (Col-Ⅳ) were significantly increased (P<0.05).The level of MDA were significantly increased (P<0.05).Compared with the Model group，the enriched-selenium polysaccharide groups resulted in significant repair effect，the activity of GSH-Px and SOD in both polysaccharide groups were significantly increased (P<0.05)，the mRNA transcription of IL-1，IL-6，MCP-1，NF-κB，TGF-β，PAI-1，PDGF-β and Col-Ⅳ were significantly decreased (P<0.05)，the level of MDA were significantly decreased (P<0.05)，matrix proliferation was significantly reduced.It is suggested that the polysaccharide can enhance the antioxidant function of the Type Ⅱ diabetic KKAy mice and repair the damage caused by diabetes to it.

This study aimed to detect expression of genes related to early embryonic development and sexual differentiation in the chicken-quail hybrids.First，the whole embryos were collected during the hybrid early embryonic development at different times(72，78，84，90，96，102，108，114，120，144，168 and 192 h).Then，based on the identification of early hybrid embryo sexes，Real-time PCR method was used to detect the expressions of sex differentiation associated genes (3β-HSD，P-450c17，P-450arom and ER) during the embryonic development of male and female hybrids at different times.The results showed that in chicken-quail hybrid embryos，both of 3β-HSD and ER genes expression in females were generally significantly higher than that in males.The lowest expression of 3β-HSD occured at 72 h in male，while the highest expression occurred at 96 h in female and male embryos.Within 90 h，the gene expression level of the male and female hybrid embryos P-450c17 was higher，peaking at 78 h，and there were significantly differences(P<0.01) in females and males at each time point within 90 h.P-450arom hybrid embryo gene expression could be detected in females，but the expression of the males could not be detected.There were two peaks，respectively，at 72 and 108 h expression of ER gene in early hybrid embryonic development.

To study the function of APC gene in alpaca coat color formation，the expression and localization of APC in different alpaca coat color were investigated.Quantitative real-time PCR (QRT-PCR) and immunohistochemistry were used to detected the mRNA expression level and the location of APC protein in brown and white alpaca skin.The gene expression quantity of APC in brown alpaca skin was 5.042 2 times than white one.The results of immunohischemistry revealed that the APC positive signals were found in hair bulb，hair root and epidermis in alpacas.Moreover，the average protein expression of APC in brown alpaca skin was higher than that in white one based on the average optical density (P<0.05).Based on the results，it indicated that APC may involve in alpaca coat color formation.

The indirect ELISA and the competitive ELISA method were compared in the detection of serum antibody against Peste des Petits Ruminants Virus (PPRV).The PPRV N protein to be used as a coating antigen was expressed in BL21 and purified by Ni Sepharose FF column.Ninety-four sheep and twenty-five goats serum samples were detected by the ELISA methods based on the recombinant N protein.The coincidence rate of the indirect ELISA and the competitive ELISA kit was 74.8%，the coincidence rate of the competitive ELISA and the competitive ELISA kit was 96.6%.The detection results showed that the competitive ELISA is more reliable than the indirect ELISA method， and the competitive ELISA is suitable for clinical application.