In order to investigate the effect of the Chinese Herbal Medicine formula Jadescreen (Yu Ping Feng San) on response to infectious bursal disease(IBD) vaccine in chickens, the birds vaccinated with IBD vaccine were feed with Jadescreen Powder at high (A) (1%), middle (B) (0.75%) and low (C) (0.5%) dosages. And some other birds were allocated to two control group, one was omitted for herbal treatment and the other was omitted for both vaccination and herbal treatment. Peripheral blood samples were taken on 21st, 28th, 35th, 42nd and 49th days from ten chickens in each group for detecting the level of antibody to IBDV. T cell subsets of CD4+ and CD8+ were determined by flow cytometry at the 21st and 35th days. Activity of phagocytosis of macrophages was determined with the experiment of carbon particles clearance at the 21st, 35th and 49th days. The results suggested that Jadescreen Powder can increase the level of antibody to IBDV. A manifests higher level of the antibody than other groups, and the difference was significant after the 28th day (P<0.05). B and C have the higher level than the controls after the 35th day (P<0.01). Jadescreen Powder can increase density of CD4+ T cell and the ratio of CD4+/ CD8+ significantly (P<0.05 or P<0.01). Jadescreen Powder can also increase the activity of phagocytosis of macrophage, and A has the better effect (P<0.05 or P<0.01). In conclusion, Jadescreen Powder can enhance both the humeral and cellular immunity in chickens challenged with IBD vaccine.

To detect the infection or immune state of Mycoplasma hyopneumoniae (Mhp) exactly, an indirect ELISA assay for antiMhp IgA detection was developed. In this study, P97 R1 protein of Mhp was chosen as coating antigen, goat anti pig IgA and rabbit anti pig IgGHRP were used as second and third antibody, respectively. The concentrations of coating antigen, second and third antibodies were optimized as well as their working time. As a result, a stable and specific indirect ELISA assay for antiMhp IgA detection was developed. And the developed method could be used for Mhp infection and immune state monitoring.

Mycoplasma hyopneumoniae; IgA; indirect ELISA

This study was conducted to analyze the effect of genotype combinations between the single nucleotide polymorphisms (SNPs) of adipocyte fatty acid binding protein (AFABP) gene and adenosine 5′monophosphate deaminase 1 (AMPD1) gene on the partial meat quality traits in BeijingYou chickens. 160 purebred BeijingYou male chickens were used. The SNPs of the base mutation C→T at position 51 (P4 site) for AFABP gene and mutation A→G at position 129 (PB site) for AMPD1 gene were detected by PCRSSCP. The results showed that BB genotype for AFABP gene and NN genotype for AMPD1 gene were acted on IMF and IMP contents respectively as the superior genotypes for their own polymorphic sites. Among nine different genotype combinations, BBNN and BBMN genotypes were the dominant combination. The content of IMF and percentage of abdominal fat (AFP) and width of fat strip (WFS) of individuals with BBMN genotype were 7.80%, 50.74% and 4.92% significant higher than the average value of individual BB and MN genotype respectively（P<0.05）, and 2.53% higher on IMP. However, there is no interacted effect between two sites (P>0.05). In conclusion, IMF and IMP contents could be improved by applying markerassisted selection (MAS) of combining P4 site for AFABP gene and PB site for AMPD1 gene in BeijingYou chicken.

In order to investigate the genetic diversity and origin of Chinese game chicken, a total of 535 bp of
mitochondrial DNA Cytb gene of five game chicken breeds (40 individuals) including Henan game, Luxi game, Tulufan game, Xishuangbanna game and Zhangzhou game chicken were sequenced by DNA sequencing method. The results showed that there were 6 haplotypes found in the five game chicken breeds. The haplotype diversity was arranged from 0.428 57 to 0785 71, and the nucleotide diversity was arranged from 0.000 80 to 0.006 54. The genetic distance between the Zhangzhou game chicken and other game chicken were farther. The analysis of phylogenetic trees for the chicken constructed based on the haplotypes indicated that the Chinese game chicken may originate from several subspecies of red jungle. The results indicated that there were richest genetic diversity in Zhangzhou game chicken and lowest genetic diversity in Tulufan game chicken and Xishuangbanna game chicken and the maternal origin of Chinese game chicken may originate from several subspecies of red jungle.

The test were designed to study biological characters of Haemaphysalis concinna under laboratory conditions. The life history of H. concinna was observed firstly in two groups according to hosts. Rabbits were taken as the host in experimental group, the completion of engorgement to next generation was (120.6±14.5) d. The prefeeding, feeding, premolting and molting periods of larva were (7.1±0.9), (5.6±1.1), (11.8±2.0) and (12.5±1.6) d respectively, and those of nymph were (5.9±1.1), (3.9±0.6), (9.8±2.3) and (12.3±0.4) d, the prefeeding, feeding, preoviposition, oviposition and death periods of adult were (7.6±1.2), (4.9±0.6), (9.2±1.7), (16.0±3.2) and (5.8±0.5) d respectively, and the incubation period were (24.2±0.9) d. In control group, the rabbit, dog and cattle respectively were taken as the host of larva, nymph and adult, and the completion of engorgement to next generation was (130.2±12.8) d. The prefeeding, feeding, premolting and molting periods of larva were (7.1±1.2), (5.8±0.8), (12.1±2.5) and (12.3±1.7) d respectively, and those of nymph were (6.2±0.7), (4.6±0.3), (12.4±2.1) and (12.9±0.3)d, the prefeeding, feeding, preoviposition, oviposition and death periods of adult were (7.6±1.1), (6.1±0.4), (10.7±0.8), (15.7±2.4) and (8.1±0.7) d respectively, and the incubation period were (23.3±1.6) d. The engorged weight of larva and nymph ticks were different from those of the control group (P<0.05), the weight of engorged female adult was extremely different from that of the control group(P<0.01). There was a highly significant correlation between the engorgement body weight of female and the number of egg product r=0.912(P<0.01). The reproductive efficiency index (RE1) and reproductive fitness index(RFI)in female of the experimental group was 10.48 and 6.82 respectively，and it was different from that of the control group(P<0.05). These results indicated that rabbit was the suitable host for this tick.

This study was conducted to analyze the polymorphisms of SLADQB gene in native and exotic pig breeds and aimed to provide a theoretical foundation for further research on correlation between SLADQB gene and disease resistance. The polymorphisms of exon 2 of SLADQB gene were detected in wild boar, 14 native pig breeds and 4 exotic pig breeds by the PCRRFLP with the restrictive enzyme HaeⅢ digestion, there were 9 genotypes and 5 alleles. The wild boar only appeared A and B alleles. The domestic pigs appeared 6 genotypes and 3 alleles which did not detected in the wild boar. The native pig breeds appeared higher levels of polymorphism than exotic pig breeds, Wuzhishan pigs and Huai pigs showed highest level of polymorphism with eight kinds of genotypes. The allele A was the dominant gene in the population of wild boar, while allele B and C were the dominant gene in all other populations. The allele D was only detected in Lingao pigs, which showed that Lingao pig maybe has some special characters. The results indicated that genetic diversity of exon 2 of SLADQB gene may be influenced
by environment and the genetic purity of breeds, on the whole, genotype distribution in SLADQB gene exon 2 was not obviously different between exotic pig breeds, developed pig breeds and Chinese native pig breeds, while band patterns were significantly different between particular population pairs.

The transportation of piglets results in stress that is associated with increased susceptibility to diseases, presumably due to alteration of immune function and antioxidative ability. The objective of present study was to determine if a 2 h transportation of piglets by road induced changes in antioxidative ability and proinflammatory cytokines. Thirty piglets weighting about 20 kg were divided into experimental and control group on the average. The animals in experimental group were transported by truck on road for 2 h. Then hearts and livers were collected, blood was harvested from all piglets. The antioxidative capacity of hearts and livers and serum concentration of
IL1β and IL2 were assayed. The result were as follows, the antioxidative ability was not obviously changed in hearts after transportation, although production of reactive oxygen species (ROS) in hearts of transported animals was greater than that of control group(P>0.05). In livers, the activities of total antioxidative capacity (TAOC) and catalase (CAT) were obviously decreased (P<0.05) following transportation, and the decrease was accompanied with significant rise of the maleic dialdehyde (MDA) concentration (P<0.05). CuZn superoxide dismutase (CuZn SOD), a important antioxidative enzyme, was downregulated in hearts and livers following transportation in mRNA level (P>0.05 ). The serum contents of proinflammatory cytokines IL1β and IL2 were risen slightly. It was concluded that 2 h transportation of piglets induces decrease of antioxidative capacity only in the liver and increase of proinflammatory cytokines of IL1β and IL2 concentration in sera slightly. It was indicated that the decreased antioxidative capacity and increased proinflammatory cytokine concentration lead to tissue lesion of piglets following transportation.

Based on the antigenic analysis of Reticuloendotheliosis virus (REV) env protein, we designed a pair of primers to amplify the gene fragment encoding high antigenic domain of REV Cterminal env protein. The cloned gene was inserted into pGEX4T3 vector to obtain the recombinant pGEX4T3env plasmid. The recombinant plasmid was transformed into E. coli BL21, and expressed in very high level after induction with IPTG. SDSPAGE and Western blot showed that the fusion protein was a 66.5 kD protein with immunogenicity. The recombinant env protein was purified with GST·Bind resin protein purification procedure. Then an indirect ELISA was established to detect antibody against REV by using the purified env protein as the coating antigen. The detection results revealed that the ienvELISA had good diagnostic sensitivity and specificity. The accuracy was over 90% when compared with IFA and iREVELISA. The IenvELISA is simple to produce and perform and suitable for large scale surveys of REV antibodies.

In order to explore the changes of physiology of Escherichia coli(E. coli) under the pressure of enrofloxacin, and to provide references for further study on resistance and response mechanisms to drug pressure of bacteria, E. coli ATCC25922 were inoculated in liquid LB medium containing enrofloxacin (the concentration was 1/2 MIC), shaking cultured at 37 ℃. The growth curve of E. coli was drawn, and then light microscope and electron microscope were used respectively for morphological observation. The changes of expression profiles of the bacteria after shaking culture for 5 h at 37 ℃ were analyzed by the microarray. The results showed that the growth rate of E. coli obviously decreased and morphology was filamentous after addition of enrofloxacin. The microarray analysis showed that, fluorescence intensity of 519 hybridization dots were obviously changed comparing with control group, in which 239 upregulated and 280 downregulated. There were 34 genes with a ≥3fold upregulation and 32 genes with a ≥3fold downregulation. These genes were involved in many biological processes such as SOS response, cell division, stress response, biosynthesis, metabolism, transport and regulation of transcription. All results suggest that under the pressure of enrofloxacin, the SOS response of the bacteria was started, cell division was inhibited, and the physiological mechanism may undergo extensive and complex changes.

The depressing effects of trans10, cis12 CLA on milk fat synthesis and its mechanism in lactating goats were observed in the study. Four lactating Laoshan dairy goats fitted with permanent abomasal fistulae and elevated carotid artery were used in a 4×4 Latin square experiment. The CLA levels of abomasal infusion were 0, 2, 4, and 8 g·d1, respectively containing trans10, cis12CLA per goat in four treatments. The results indicated that: (1) Abomasal CLA infusion had no effect on milk yield, and DMI. 4 and 8 g·d1 CLA infusion decreased milk fat content and yield sharply（P<0.01）, increased the content of milk protein（ P<0.01）, but decreased milk protein yield. CLA infusion had no effect on the contents and yields of lactose and SNF. (2) CLA infusion decreased mammary uptake efficiency of circulating NEFA (P<0.05). Mammary uptake efficiency of circulating acetate tended to increase at first and then decrease with elevated CLA infusion (P=0.07). Mammary uptake efficiency of circulating butyrate tended to decrease with abomasal CLA infusion (P=0.07). (3) CLA infusion increased the content of C16 fatty acids in milk fat (P<0.05), and had no effect on the contents of those de novo synthesized (C4C14:1) and fatty acids (>C16) absorbed by plasma. The contents of c9, t11 CLA (P<001), t10, c12CLA (P<0.05), c9, c11CLA (P<0.05), and t9, t11CLA (P<0.01) in milk fat were increased by CLA infusion. (4) CLA infusion decreased the yields of C14:1, C16:1, and >C16 fatty acids (P<0.05), had no effect on the yield of C16:0 although the apparent yields tended to be decreased with elevated infusion (P=0.19). Compared with the control, 8 g·d1 CLA infusion decreased the yields of C4C14:1, C16+C16:1, and >C16 fatty acids by 4268%, 3615%, and 55.59%, respectively. (5) CLA infusion increased the ratios of C14:0/C14:1, C16:0/C16:1, and trans11C18:1/cis9, trans11CLA, which indicated that the activity of △9desaturase enzyme was depressed. (6) Compared with the control, CLA infusion depressed the level of acetyl CoA carboxylase mRNA in biopsied mammary tissue. It was concluded that trans10, cis12 CLA depressed both the incorporation of fatty acids in plasma into milk and the de novo synthesis of fatty acids in the mammary gland of lactating goats.

A DNA fragment, which encodes the glycoprotein of Rabies virus (RV) CVS strain, was amplified by RTPCR. The ectodomain and complete glycoprotein genes were cloned into pET32a respectively. Of two recombinant plasmids, only the ectodomain protein was expressed in very high level after the recombinant pET32aPG plasmid transformed into BL21(DE3) when induced with 1.0 mmol·L1 IPTG. The reactiongenicity of the expressed product was demonstrated by Westernblot and ELISA. By coating plates with purified recombinant protein as antigen, an indirect ELISA for the detection of neutralizing antibodies against RV was established, and was standardized further with titerknown OIE reference serum. The results obtained indicated that the amount of optimum coated antigen was 3.74 μg, and optimum serum dilution was 1100. The cutoff value was determined as 0.50. By parallel detecting a total of 418 serum samples with developed ELISA and fluorescent antibody virus neutralization (FAVN), the calculated coincidence rate was 98.61%.

To study the effect of glutamine on immunity of the 13 week′s broilers, three hundred healthy Avian 1day old broilers were randomly divided into four groups (three replicates each) fed with cornsoybean meal diet containing different glutamine levels: 0%，05%, 10% and 15%, respectively. On 7, 14 and 21 days, six chicks per treatment (2 chicks/pen) were slaughtered for sampling thymus，spleen and serum. Immune organ index, complement3(C3), immunoglobulin and interleukin(IL) were detected. The results indicated that glutamine significantly increased the level of thymus and spleen index, IgA, IgM, and IL2, IL6 in thymus and bursa of 13 week broilers, and the C3,IgG of 1 week broilers(P<0.05). However, there were no significant effects on IL2 in serum of 1 week broilers and bursal index of 13 week broilers(P>0.05). The results showed that supplementation of glutamine improved the immunity of the broilers.

In order to identify the linear Bcell epitope of structural protein VP2 of footandmouth disease virus(FMDV) serotype Asia1, the VP2 protein was dissected into seven overlapping fragments, and expressed in Escherichia coli, respectively. Western blot analysis of the seven fused proteins was carried out with sera from FMD infected cattle. The results showed that the linear Bcell epitope of VP2 protein is located in the 144 aa of Nterminal region. We also found that serotype O, serotype A, serotype C FMD standard serum and infected serotype SAT2 FMD rehabilitation period bovine serum could also identify the epitope fusion protein. Based on these, the short peptide protein F1 was dissected into six overlapping fragments further. Finally, we identified that the linear B cell epitope on VP2 is located in the 615 amino acid of Nterminal region.

The experiment was conducted to study the effects of GLP2 on proliferation, metabolism and apoptosis of intestinal epithelial cells after injury by βconglycinin in 28dayold weaned piglets and GLP2′s possible action mechanism. According to singlefactor design principle, different βconglycinin concentrations of 1.2 and 2.4 mg·mL1 were used for conteracting toxic substances to primary culture epithelial cells of weaned piglets. The cell damage model was established on the investigation of the cell proliferation, metabolism and apoptosis. Then the experiment of 2×3 factorial design was adopted to study the impacts of the sensitized cultured cell with different GLP2 concentrations of 1×109, 1×108 and 1×107mol·L1. The results were as follows: when βconglycinin were used for counteracting toxic substances, the MTT OD significantly decreased (P<0.05); the protein retention and total protein content in cell significantly decreased (P<0.01); LDH activity significantly increased (P<0.01); Na+K+ATP enzyme activity significantly decreased (P<0.05); caspase3 activity significantly increased (P<0.01). When βconglycinin were used for conteracting toxic substances after addition of GLP2, the MTT OD, the protein retention, total protein content and Na+K+ATP enzyme activity significantly increased (P<0.05). LDH activity gradually decreased (P<0.05 or P<0.01) and caspase3 activity significantly decreased (P<0.01) along with the increase of GLP2 concentration. The results indicated that βconglycinin had adverse effects on intestinal epithelial cells proliferation and cell integrality in vitro. GLP2 could relieve or avoid the adverse effects on intestinal epithelial cells proliferation and cell integrality by regulating Na+K+ATP enzyme activity and caspase3 activity, and consequently affecting cell metabolism.

In order to study the effect of overfeeding on gene expression of MTP, the gene expression level of MTP mRNA in intestine and liver tissues of Landes geese was detected by RTPCR, which were collected from the control and overfeeding treatment groups. The relevant 6 body composition parameters and 4 serum parameters were studied. The results showed that the detected parameters increased significantly. The MTP mRNA was expressed in intestine and liver tissues. Compared the control group, after overfeeding, the level of MTP gene mRNA had no significant change in liver (P>0.05), and the level of MTP gene mRNA increased significantly (P<0.05) in small intestine. In conclusion, the change difference of the MTP mRNA level induced by overfeeding might be related to the lipids level which could be used in hepatocytes, other regulating factors in vivo and the high fat diets.

The present study is aimed to construct a hairfolliclecellspecific expression vector of ovine insulin like growth factor 1 (IGF1), transfect it into caprine fetal fibroblast cells (CFFCs), and further to obtain CFFCs cell lines stably expressing red fluorescence, which can be used in nuclear transfer. IGF1 cDNA was synthesized by reverse transcription polymerase chain reaction. Then pCDsRKI (7.4 kb), a hairfolliclecellspecific expression vector of IGF1, was constructed by connecting with KAP61 promoter, as well as a pCDsRed2 expression unit. The CFFCs were successfully isolated by attachment of tissue pieces from a fetus of cashmere goat. The 2nd passage of CFFCs were transfected with the expression vector mediated by lipofectamineTM 2000. After screening the transfected cells by genetycin in DMEM/F12 media supplemented with 10% FBS for 12 to 15 days at 37 ℃ in a humidified 5% CO2 condition, cell clones stably expressing red fluorescence were obtained. Identification of the transgene in cell clones by ploymerase chain reaction proved that the exogenous DNA has been integrated into genome. The growth curves of transgenic cells were drawn and the analyses of the cells chromosome were performed. The result showed that growth of the transgenic cells was prosperous and the parameters of genetics were normal. So this study was a preparation of donor cells to obtain transgenic cashmere goats by nuclear transfer.

This experiment is aimed to analyze mitochondrial DNA ND4 gene genetic polymorphism of Southwest horse in China. A partial fragment of mitochondrial DNA ND4 gene was sequenced and analyzed by PCRSSCP for 142 individuals from 6 Southwest horse breeds in China. The results showed that the spliced sequence of mtDNA ND4 gene of Southwest horse was 679 bp, and the content of A+T(55.7%) was higher than that of G+C (44.3%). 11 mutational sites were detected and all of these sequence polymorphic sites were sorted into 6 haplotypes. The average nucleotide diversity was 0.638%, and the genetic polymorphism of mtDNA of tested Southwest horse was not abundant. The cluster analysis of these haplotypes suggested that Southwest horse in China originated from two maternal ancestors.

The objective of this study was to evaluate the effects of different level 53Cr(pic)3 injected in vein on piglet hepatocytes DNA. Thirty （15.0±1.0） kg body weight male crossbred (D×L×Y) piglets were divided into five treatments with six replication each treatment，each was raised in one cage. In the 14 days experimental period, piglets in each treatment were respectively injected with 0，8，200，400，800 μg Cr·d1 at 08：0010：00 every morning. The antioxidant enzymes activity in liver, the level of 8OHdG in urine, the content of chromic in liver, and comet figure were measured. About the antioxidant enzymes activity in liver and the level of 8OHdG in urine, no significant difference was detected among all groups (P>0.05).The content of chromium in liver was increased by increasing 53Cr(pic)3. Compared to control, the concentration of chromium in liver was markedly increased while the chromium injected was more than 200 μg Cr (53Cr(pic)3)（P<0.05）. In comparison with control，no significant difference was discerned in comet figure, except the tail length of 8 and 200 μg group decreased significantly (P<0.05). Compared to 8 μg group, the indicators of comet assay in 400 and 800 μg group increased significantly (P<0.05). Chromium picolinate below 800 μg Cr·d1 injected in vein for 14 day, does not induce the change of antioxidant enzymes activity in liver and DNA oxidative damage, but the content of chromium in liver
was increased with 53Cr(pic)3 increasing, it has doseeffect relationship between the content of chromium in liver and DNA integrity in hepatocytes of piglet.

In order to understand the molecular mechanism and the candidate genes for high fecundity in Hu sheep, sixteen adult Hu ewes, grouped into single lambling (S) and multiple lambling (M) groups, were treated for synchronized estrous and sacrificed for tissue sampling and recording ovulation number. The tissue distributions and expression levels in the ovary for BMPRIA and BMPRII mRNA in Hu sheep were investigated by RTPCR and realtime PCR. The results showed that both the BMPRIA and BMPRII mRNA expressed in the ovary and other tissues, including hypothalamus, pituitary, uterus, heart, liver, spleen, lung, kidney, muscle and oviduct. There was no significant difference in the BMPRIA mRNA abundance in the ovary between S and M groups（P>0.05）and no correlation with ovulation number（P>0.05）, but the BMPRII mRNA abundance in the ovary was higher in M group than that in S group（P<0.05）and positively correlated with ovulation number (r=0.722, P<0.05). The results suggested that BMPRII might play an important role on ovulation number and might be a candidate gene for high fecundity in Hu sheep.

The aim of the present study was to clone Capra hircus Sox2 gene, and to construct its recombinant prokaryotic expressing plasmid (pGEXSox2), and finally to obtain the purified GSTSox2 fusion protein in E．coli. The complete coding sequences (CDS) of Sox2 was amplified from the genital ridges of a Capra hircus fetus at the age of six weeks, and inserted into pMD18T vector, and then subcloned into vector pGEXKG. The recombinant plasmid pGEXSox2 was transformed into E．coli BL21(DE3), and the soluble GSTSox2 protein was expressed by induction of IPTG; SDSPAGE analysis and Western blotting was performed to detect the GSTSox2 protein which was isolated and purified by glutathione Sepharose 4B. The results showed that the CDS of Capra hircus Sox2 was 960 bp, recombinant plasmid pGEXSox2 was expressed efficiently in the E. coli BL21(DE3) under the optimized induction condition(1 mmol·L1 IPTG for 16 hours at 22 ℃); the rightsized GSTSox2 fusion protein(60 ku) was purified with glutathione Sepharose 4B.In summary, Capra hircus Sox2 gene was cloned, and the purified GSTSox2 fusion protein was obtained in the present study, which laid a foundation for preparing antiSox2 polyclonal antibody, and deriving Capra hircus iPS cells（induced pluripotent stem cells）.

To detect the QTL for ham weight (HW), a total of 1 028 F2 animals at 240 days of age from a White Duroc × Erhualian resource population were measured for phenotypic data. All F2 individuals and their parents and grandparents were genotyped for 183 informative microsatellite markers on 19 pairs of porcine chromosomes. Quantitative trait loci (QTL) for ham weight were identified by using an interval mapping method based on leastsquares regression. The threshold values of significance were determined empirically by a permutation test. In total, 10 QTLs were detected including five 1% genomewide significant QTLs on pig chromosomes (SSC) 2, 4, 7, 8 and 18 and two QTLs at the 5% genomewide significant level on SSC5 and SSC7. The most significant QTL was found at 58 cM on SSC7 with a confidence interval of 5 cM. The results provide a start point to refine the QTLs for the interest traits and isolate positional candidate genes.

GPAT，AIRC and PURH genes are involved in the de novo purine biosynthesis, they all have significant effect on muscle IMP content. This study was designed to investigate the effect of GPAT，AIRC and PURH genes on muscle IMP content in Baier chickens, single genotype effects as well as the combined genotype effects were all studied. PCRSSCP and DNA sequencing were applied to detect SNPs in three genes. The results showed that GPAT，AIRC and PURH genes had significant effect on the muscle IMP content in Baier chickens (P<0.05), they are candidate loci or linked to major genes that affect muscle IMP content; The combined genotype effects were higher than the single genotype effects. It was concluded that combined genotypes are superior to single genotypes as potential molecular markers for meat quality traits in chicken.

In order to clone the sequence of porcine MyD88 gene and explore the expression levels of pMyD88 in different tissues. cDNA of MyD88 gene was cloned from total RNA of mesenteric lymph nodes(MLN) in Taihu pig by RTPCR. The structure and function of MyD88 gene were predicted with some software tools, and the expression profile of MyD88 gene in 11 different porcine tissues was analyzed with Realtime PCR. Sequence analysis indicated that the cloned porcine MyD88 cDNA was 897 bp in length (EF198416) containing a complete ORF encoding a deduced protein of 293 amino acid residues. The deduced amino acid sequence has a DD domain and a TIR domain (the common structural features of Toll/IL1Rs). The alignment of the deduced amino acid sequence of porcine MyD88 with those of cattle, human, rat and mouse showed that the sequence similarities were 88.4%, 85.7%, 78.8% and 78.2%, respectively and the MyD88 was highly conserved among the studied mammal species. Realtime PCR analysis showed that the MyD88 gene was expressed in various tissues with different levels. Higher expression levels in Peyer′s patches and mesenteric lymph nodes (MLN) and lower expressions in musle and heart. This work laid a foundation for the further study on function of MyD88.