Breeding of Anti-diarrhea Gene in Local and Exotic Pig Breeds in Guizhou Province

[Objectives]This study was conducted to breed special pig breeds resistant to diarrhea by using modern biotechnology.[Methods]From Guizhou local breeds,such as Nuogu pigs,Kele pig,Yorkshire pigs and Duroc pigs,190 samples were collected for the analysis of anti-diarrhea gene.[Results]The anti-diarrhea genotype frequency of Kele pigs was 70.00%,which was higher than that of Nuogu pigs(67.37%)and Yorkshire pigs(Yorkshire pigs and Duroc pigs)(50.59%).The favorable anti-diarrhea gene of all Nuogu pigs,Kele pigs,and Yorkshire pigs and Duroc pigs was G,with gene frequencies of 0.7355,0.8368 and 0.8500,respectively,and the frequencies of allele A were 0.2645,0.1632 and 0.1500,respectively.In the process of generation selection,combination selection of GG♂×GG♀,GG♂×GA♀,GA♂×GG♀and GA♂×GA♀was conducted,and GG individuals were selected while gradually phasing out GA and AA individuals.The anti-diarrhea genotypes of 98 pigs in the offspring were tested,and it was found that the frequency of genotype GG was greatly improved,and the frequencies in Nuogu pigs,Kele pigs,Yorkshire pigs and Duroc pigs were increased to 73.91%,81.82%,85.25%and 66.67%respectively,thus forming a special anti-diarrhea breed.[Conclusions]This study provides a basis for selecting excellent breeding pigs,establishing core populations and screening resistance genes in the core populations and their offspring.

Core and variable antimicrobial resistance genes in the gut microbiomes of Chinese and European pigs

Monitoring the prevalence of antimicrobial resistance genes(ARGs)is vital for addressing the global crisis of antibiotic-resistant bacterial infections.Despite its importance,the characterization of ARGs and microbiome structures,as well as the identification of indicators for routine ARG monitoring in pig farms,are still lacking,particularly concerning variations in antimicrobial exposure in different countries or regions.Here,metagenomics and random forest machine learning were used to elucidate the ARG profiles,microbiome structures,and ARG contamination indicators in pig manure under different antimicrobial pressures between China and Europe.Results showed that Chinese pigs exposed to high-level antimicrobials exhibited higher total and plasmid-mediated ARG abundances compared to those in European pigs(P<0.05).ANT(6)-Ib,APH(3')-IIIa,and tet(40)were identified as shared core ARGs between the two pig populations.Furthermore,the core ARGs identified in pig populations were correlated with those found in human populations within the same geographical regions.Lactobacillus and Prevotella were identified as the dominant genera in the core microbiomes of Chinese and European pigs,respectively.Forty ARG markers and 43 biomarkers were able to differentiate between the Chinese and European pig manure samples with accuracies of 100%and 98.7%,respectively.Indicators for assessing ARG contamination in Chinese and European pigs also achieved high accuracy(r=0.72-0.88).Escherichia flexneri in both Chinese and European pig populations carried between 21 and 37 ARGs.The results of this study emphasize the importance of global collaboration in reducing antimicrobial resistance risk and provide validated indicators for evaluating the risk of ARG contamination in pig farms.

Identification of immune feature genes and intercellular profiles in diabetic cardiomyopathy

BACKGROUND Diabetic cardiomyopathy(DCM)is a multifaceted cardiovascular disorder in which immune dysregulation plays a pivotal role.The immunological molecular mechanisms underlying DCM are poorly understood.AIM To examine the immunological molecular mechanisms of DCM and construct diagnostic and prognostic models of DCM based on immune feature genes(IFGs).METHODS Weighted gene co-expression network analysis along with machine learning methods were employed to pinpoint IFGs within bulk RNA sequencing(RNA-seq)datasets.Single-sample gene set enrichment analysis(ssGSEA)facilitated the analysis of immune cell infiltration.Diagnostic and prognostic models for these IFGs were developed and assessed in a validation cohort.Gene expression in the DCM cell model was confirmed through real time-quantitative polymerase chain reaction and western blotting techniques.Additionally,single-cell RNA-seq data provided deeper insights into cellular profiles and interactions.RESULTS The overlap between 69 differentially expressed genes in the DCM-associated module and 2483 immune genes yielded 7 differentially expressed immune-related genes.Four IFGs showed good diagnostic and prognostic values in the validation cohort:Proenkephalin(Penk)and retinol binding protein 7(Rbp7),which were highly expressed,and glucagon receptor and inhibin subunit alpha,which were expressed at low levels in DCM patients(all area under the curves>0.9).SsGSEA revealed that IFG-related immune cell infiltration primarily involved type 2 T helper cells.High expression of Penk(P<0.0001)and Rbp7(P=0.001)was detected in cardiomyocytes and interstitial cells and further confirmed in a DCM cell model in vitro.Intercellular events and communication analysis revealed abnormal cellular phenotype transformation and signaling communication in DCM,especially between mesenchymal cells and macrophages.CONCLUSION The present study identified Penk and Rbp7 as potential DCM biomarkers,and aberrant mesenchymal-immune cell phenotype communication may be an important aspect of DCM pathogenesis.

An Investigation of the Effects of B7-H4 Gene rs10754339 and miR-125a Gene rs12976445 on Cancer Susceptibility

Objective To investigate the effects of the B7-H4 gene rs10754339 and miR-125a gene rs12976445 on cancer susceptibility through a case-control study and meta-analysis.Methods A total of 1,490 cancer patients(lung/gastric/liver/:550/460/480)and 800 controls were recruited in this case-control study.The meta-analysis was performed by pooling the data from previous related studies and the present study.Results The results of this study showed that in the Hubei Han Chinese population,the rs10754339gene was significantly associated with the risk of lung and gastric cancer but not liver cancer,and the rs12976445 gene was significantly associated with the risk of lung cancer but not liver or gastric cancer.The meta-analysis results indicated that rs10754339 and rs12976445 contributed to cancer susceptibility in the Chinese population and also revealed a significant association between rs10754339and breast cancer risk,as well as between rs12976445 and lung cancer risk.Conclusion The B7-H4 gene rs10754339 and miR-125a gene rs12976445 may be the potential genetic markers for cancer susceptibility in the Chinese population,which should be validated in future studies with larger sample sizes in other ethnic populations.

Prediction of Tumor Microenvironment Characteristics and Treatment Response in Lung Squamous Cell Carcinoma by Pseudogene OR7E47P-related Immune Genes

Objective Pseudogenes are initially regarded as nonfunctional genomic sequences,but some pseudogenes regulate tumor initiation and progression by interacting with other genes to modulate their transcriptional activities.Olfactory receptor family 7 subfamily E member 47 pseudogene(OR7E47P)is expressed broadly in lung tissues and has been identified as a positive regulator in the tumor microenvironment(TME)of lung adenocarcinoma(LUAD).This study aimed to elucidate the correlation between OR7E47P and tumor immunity in lung squamous cell carcinoma(LUSC).Methods Clinical and molecular information from The Cancer Genome Atlas(TCGA)LUSC cohort was used to identify OR7E47P-related immune genes(ORIGs)by weighted gene correlation network analysis(WGCNA).Based on the ORIGs,2 OR7E47P clusters were identified using non-negative matrix factorization(NMF)clustering,and the stability of the clustering was tested by an extreme gradient boosting classifier(XGBoost).LASSO-Cox and stepwise regressions were applied to further select prognostic ORIGs and to construct a predictive model(ORPScore)for immunotherapy.The Botling cohorts and 8 immunotherapy cohorts(the Samstein,Braun,Jung,Gide,IMvigor210,Lauss,Van Allen,and Cho cohorts)were included as independent validation cohorts.Results OR7E47P expression was positively correlated with immune cell infiltration and enrichment of immune-related pathways in LUSC.A total of 57 ORIGs were identified to classify the patients into 2 OR7E47P clusters(Cluster 1 and Cluster 2)with distinct immune,mutation,and stromal programs.Compared to Cluster 1,Cluster 2 had more infiltration by immune and stromal cells,lower mutation rates of driver genes,and higher expression of immune-related proteins.The clustering performed well in the internal and 5 external validation cohorts.Based on the 7 ORIGs(HOPX,STX2,WFS,DUSP22,SLFN13,GGCT,and CCSER2),the ORPScore was constructed to predict the prognosis and the treatment response.In addition,the ORPScore was a better prognostic factor and correlated positively with the immunotherapeutic response in cancer patients.The area under the curve values ranged from 0.584 to 0.805 in the 6 independent immunotherapy cohorts.Conclusion Our study suggests a significant correlation between OR7E47P and TME modulation in LUSC.ORIGs can be applied to molecularly stratify patients,and the ORPScore may serve as a biomarker for clinical decision-making regarding individualized prognostication and immunotherapy.

A Novel Genetic Polymorphism and Its Genetic Effects of Porcine Heart Fatty Acid-Binding(H-FABP)Gene in Intron 1

[Objective] The aim was to provide basic reference for the use of H-FABP gene in marker-assisted selection of the breeding process of pig.[Method] Single-nucleotide polymorphisms of the H-FABP gene in Shanxi White pig,Mashen pig,Large White pig,Landrace and Duroc were tested by PCR-SSCP,and the correlation between genotype and intramuscular fat content in pigs were analyzed.[Result] One polymorphism was found in the amplified region of intron 1 of porcine H-FABP gene,in which two alleles（A and B）and three genotypes（AA,AB,and BB）were examined.C→T transition was detected by sequencing the homozygotes.The multiple comparison of the distribution of genotype in different pig varieties revealed that Mashen pig showed extremely significant difference（P0.01）in genotype distribution with Shanxi White,Landrace,Large White and Duroc breeds;whereas no significant differences（P0.05）were found in genotype distribution between other breeds.Based on the fixed effect model,extremely significant differences（P 0.01）were found in the intramuscular fat content among different H-FABP genotypes.Using least square analysis,it was found that there was significant differences（P 0.05）in the intramuscular fat content between the individuals of the BB genotypes and those of the AA genotypes.[Conclusion] The H-FABP genotype had significant effects on the meat quality.

The collagen type Ⅰ alpha 1 chain gene is an alternative safe harbor locus in the porcine genome

Efficient and stable expression of foreign genes in cells and transgenic animals is important for gain-of-function studies and the establishment of bioreactors.Safe harbor loci in the animal genome enable consistent overexpression of foreign genes,without side effects.However,relatively few safe harbor loci are available in pigs,a fact which has impeded the development of multi-transgenic pig research.We report a strategy for efficient transgene knock-in in the endogenous collagen type I alpha 1 chain(COL1A1)gene using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9(CRISPR/Cas9)system.After the knock-in of a 2A peptide-green fluorescence protein(2A-GFP)transgene in the last codon of COL1A1 in multiple porcine cells,including porcine kidney epithelial(PK15),porcine embryonic fibroblast(PEF)and porcine intestinal epithelial(IPI-2I)cells,quantitative PCR(qPCR),Western blotting,RNA-seq and CCK8 assay were performed to assess the safety of COL1A1 locus.The qPCR results showed that the GFP knock-in had no effect(P=0.29,P=0.66 and P=0.20 for PK15,PEF and IPI-2I cells,respectively)on the mRNA expression of COL1A1 gene.Similarly,no significant differences(P=0.64,P=0.48 and P=0.80 for PK15,PEF and IPI-2I cells,respectively)were found between the GFP knock-in and wild type cells by Western blotting.RNA-seq results revealed that the transcriptome of GFP knock-in PEF cells had a significant positive correlation(P<2.2e–16)with that of the wild type cells,indicating that the GFP knock-in did not alter the global expression of endogenous genes.Furthermore,the CCK8 assay showed that the GFP knock-in events had no adverse effects(P_(24)h=0.31,P_(48)h=0.96,P_(72)h=0.24,P_(96)h=0.17,and P_(120)h=0.38)on cell proliferation of PK15 cells.These results indicate that the COL1A1 locus can be used as a safe harbor for foreign genes knock-in into the pig genome and can be broadly applied to farm animal breeding and biomedical model establishment.

Genetic Screening of Halothane Gene on Selected Philippine Native Pig Herds

The establishment of nucleus herds (NHs) of Native Pigs (NPs) at various R&D stations in the Philippines is currently being undertaken for food security and genetic conservation advocacy. Marker-assisted selection (MAS) is being utilized to identify individuals carrying favorable alleles of genes associated with production traits and screen out genetic defects (GD) for breeding purposes. Porcine Stress Syndrome (PSS) caused by a mutation in Halothane (HAL) gene is a GD frequently found in commercial breeds that when expressed, causes pale, soft, exudative (PSE) meat. PSE is inferior quality meat undesirable in the market causing economic losses to the swine industry. Thus, this study was conducted to screen the HAL gene through mutagenically separated-polymerase chain reaction (MSPCR) in selected NP herds and assessed its repeatability in local breeds. Results showed that out of 577 screened individuals, 543 (94.11%) were normal (NN), 0 (0%) were homozygous mutant (nn) and 34 (5.89%) were heterozygous carriers (Nn). Therefore, the optimized PSS screening protocol using MSPCR is also applicable to local breeds. As such, the availability of genetic tests for PSS could be useful in improving the Philippine NPs breeding selection and inhibiting or eliminating PSS mutant incidence within its nucleus herd.

Codominance Functional Marker of Bacterial Blight Resistance Gene Xa7 in Rice

[Objectives]A codominance functional marker of the broad-spectrum bacterial blight resistance gene,Xa7,of rice was identified for accurate detection,generation tracking,and differentiation between homozygous and hemizygous genotypes of the gene.[Methods]A potential functional marker containing four primers was designed using Premier 5 software and based on the differences on the sequences of Xa7,xa7,and allele-free genomes.The molecular distinctness of the marker in different materials was verified by PCR.Three crossbreed lines of Xa7 and their parents were inoculated with seven bacterial blight strains at the booting stage to examine the affected agronomic traits at maturation.[Results]The homozygous R084 of Xa7 could be amplified into a 91 bp band and the Nip free of allele with a 153 bp band,while the heterozygote Nip/R084,91 bp and 153 bp bands.The candidate codominance marker,Xa7fun,amplified fragments that matched the predicted target bands.No 91 bp fragment was amplified from 18 germplasms of varied types,indicating a lack of Xa7 in them.Whereas Ry1,Ry2 and Ry3 had a 91 bp band,suggesting the inclusion of homozygous Xa7.Under an elevated temperature,Huazhan responded to the seven bacterial blight pathogens as highly susceptible(HS),intermediate susceptible(MS),or susceptible(S);R084 to six of the seven pathogens(HNA1-4,FuJ,GDA2,GD1358,PX086,and YN24)as highly resistant(HR),intermediate resistant(MR)or resistant(R);Ry-1 to five pathogens(GDA2,HNA1-4,FuJ,GD1358,and YN24)as HR or MR;Ry-2 to five pathogens(GDA2,GD1358,HNA1-4,PXO86,and YN24)as HR or R;and Ry-3 to 6 pathogens(HNA1-4,FuJ,GDA2,GD1358,PXO86,and YN24)as HR or MR.Therefore,the infiltration of Xa7 in the improved crossbred lines RY-1,RY-2,and RY-3 significantly accentuated the blight resistance of Huazhan.[Conclusions]Homozygous or hemizygous Xa7 could be accurately differentiated by the currently identified codominance functional marker Xa7 fun.The Xa7 introgression did not significantly alter the critical agronomic traits in the hybridization from generation to generation and could be safely applied in breeding rice varieties with bacterial blight resistance.

Novel gene mutation in maturity-onset diabetes of the young:A case report

BACKGROUND Maturity-onset diabetes of the young(MODY)is the most common monogenic type of diabetes.Recently,14 gene mutations have been found to be associated with MODY.In addition,the KLF11 gene mutation is the pathogenic gene of MODY7.To date,the clinical and functional characteristics of the novel KLF11mutation c.G31A have not yet been reported.CASE SUMMARY We report of a 30-year-old male patient with a one-year history of nonketosisprone diabetes and a 3-generation family history of diabetes.The patient was found to carry a KLF11 gene mutation.Therefore,the clinical data of family members were collected and investigated.A total of four members of the family were found to have heterozygous mutations in the KLF11 gene c.G31A,which resulted in a change in the corresponding amino acid p.D11N.Three patients had diabetes mellitus,and one patient had impaired glucose tolerance.CONCLUSION The heterozygous mutation of the KLF11 gene c.G31A(p.D11N)is a new mutation site of MODY7.Subsequently,the main treatment included dietary interventions and oral drugs.

Effects of Rosiglitazone and Serum on the Expressions of PPARα and PPARγ Genes in the Induced Differentiation Process of Pig Preadipocyte

[Objective] The research aimed to discuss the effects of rosiglitazone and serum on the expressions of PPARα and PPARγ genes in the induced differentiation process of pig preadipocyte.[Method] The pig preadipocyte was separated by using the collagenase digestion method.Three kinds of different differentiation culture solutions were used to induce the differentiation of pig preadipocyte.The oil red O staining extraction method was used to contrast the influences of different differentiation culture solutions on the variation of cellular fat content in the differentiation process.Moreover,the variation trends of PPARα and PPARγ expressions in the cellular differentiation process in the different differentiation culture solutions were detected by the real-time quantification PCR.[Result] The cellular fat accumulation was the fastest in MII which contained rosiglitazone and was the slowest in MI which didn＇t contain rosiglitazone.Rosiglitazone could significantly increase the expression of PPARγ gene（P0.01）,but had the certain inhibition effect on the expression of PPARα gene,which wasn＇t significant.The serum had the extremely significant up-regulation effect on the expression of PPARγ gene（P0.01）,but had the extremely significant down-regulation effect on the expression of PPARα gene（P0.01）.[Conclusion] Rosiglitazone could greatly promote the expression of PPARγ gene,which increased the cellular fat deposition.Maybe the activator of PPARγ gene existed in the serum,and the inhibitor of PPARα gene existed simultaneously.

Roles and regulation of bone morphogenetic protein-7 in kidney development and diseases

The gene encoding bone morphogenetic protein-7(BMP7) is expressed in the developing kidney in embryos and also in the mature organ in adults. During kidney development, expression of BMP7 is essential to determine the final number of nephrons in and proper size of the organ. The secreted BMP7 acts on the nephron progenitor cells to exert its dual functions: To maintain and expand the progenitor population and to provide them with competence to respond to differentiation cues, each relying on distinct signaling pathways. Intriguingly, in the adult organ, BMP7 has been implicated in protection against and regeneration from injury. Exogenous administration of recombinant BMP7 to animal models of kidney diseases has shown promising effects in counteracting inflammation, apoptosis and fibrosis evoked upon injury. Although the expression pattern of BMP7 has been well described, the mechanisms by which it is regulated have remained elusive and the processes by which the secretion sites of BMP7 impinge upon its functions in kidney development and diseases have not yet been assessed. Understanding the regulatory mechanisms will pave the way towards gaining better insight into the roles of BMP7, and to achieving desired control of the gene expression as a therapeutic strategy for kidney diseases.

Anti-gastric cancer active immunity induced by FasL/B7-1 gene-modified tumor cells

AIM: To study the activation of cytotoxic T lymphocytes (CTLs) against gastric cancer cells induced by FasL/B7-1 (FB-11) gene-modified tumor cells, and to explore whether co-expression of FasL and B7-1 in SGC-7901 tumor cells could initiate synergistic antitumor effect. METHODS: FasL and B7-1 genes were transfected into human SGC-7901 gastric cancer cells with adenovirus vectors. The positive clones were selected by G418. FasL and B7-1 genes were detected by flow cytometry and RT-PCR. Abdominal infiltrating lymphocytes and sensitized spleen cells were obtained from mice that were immunized with SGC-7901/FB-11 or wild type SGC-7901 cells intraperitoneally, and cytotoxicity of these CTLs against tumor cells was determined by MTT assay. RESULTS: Flow cytometry and RT-PCR showed that FasL and B7-1 genes were highly expressed. FasL and B7-1 transfected cancer cells had a high apoptosis index. DNA laddering suggested that FasL and B7-1 genes induced gastric cancer cell apoptosis. FasL+/B7-1+SGC-7901 cells (SGC-7901/FB-11) were inoculated subcutaneously in the dorsal skin of C57BL/6 mice and then decreased their tumorigenicity greatly (z = 2.15-46.10, P＜0.01). SGC- 7901/FB-11 cell-sensitized mice obtained protective immune activity against the rechallenge of wild type SGC 7901 cells (z = 2.06-44.30, P＜0.05). The cytotoxicity of CTLs induced by SGC-7901/FB-11 cells against SGC-7901 was significantly higher than that of CTLs activated by wild-type SGC-7901 cells (84.1±2.4% vs30.5±2.3%,P＜0.05).CONCLUSION: FasL and B7-1 genes can effectively promote the activity of CTLs against gastric cancer cells. FasL/B7-1 molecules play an important role in CTL cytotoxicity.

Let-7a gene knockdown protects against cerebral ischemia/reperfusion injury

The micro RNA（mi RNA） let-7 was one of the first mi RNAs to be discovered, and is highly conserved and widely expressed among species. let-7 expression increases in brain tissue after cerebral ischemia/reperfusion injury; however, no studies have reported let-7 effects on nerve injury after cerebral ischemia/reperfusion injury. To investigate the effects of let-7 gene knockdown on cerebral ischemia/reperfusion injury, we established a rat model of cerebral ischemia/reperfusion injury. Quantitative reverse transcription-polymerase chain reaction demonstrated that 12 hours after cerebral ischemia/reperfusion injury, let-7 expression was up-regulated, peaked at 24 hours, and was still higher than that in control rats after 72 hours. Let-7 gene knockdown in rats suppressed microglial activation and inflammatory factor release, reduced neuronal apoptosis and infarct volume in brain tissue after cerebral ischemia/reperfusion injury. Western blot assays and luciferase assays revealed that mitogen-activated protein kinase phosphatase-1（MKP1） is a direct target of let-7. Let-7 enhanced phosphorylated p38 mitogen-activated protein kinase（MAPK） and c-Jun N-terminal kinase（JNK） expression by down-regulating MKP1. These findings suggest that knockdown of let-7 inhibited the activation of p38 MAPK and JNK signaling pathways by up-regulating MKP1 expression, reduced apoptosis and the inflammatory reaction, and exerted a neuroprotective effect following cerebral ischemia/reperfusion injury.

Lentivirus carrying the Atoh1 gene infects normal rat cochlea

Lentivirus carrying the Atohl gene can infect Corti＇s organ and express a hair-like cell surface marker in the supporting cell area. However, expression of the gene carried by adenovirus is instantaneous, which undoubtedly limits its clinical application. Lentivirus acts as a carrier that can stably and continuously express genes. In this study, the cochlear structure and hearing level were not affected, and Atohl gene carried by lentivirus promoted the production of hair-like cells in the cochlear supporting cell area. This led to expression of the hair-like cell surface marker myosin 7a 30 days after lentivirus carrying Atohl was microinjected into the cochlear round window of rats.

Sequence Analysis of Type III Effector tccP and tccP2 Genes in Escherichia coli O157:H7 from Chinese Water-chestnut

[Objective] This study aimed to analyze the type III effector tccP and tccP2 genes in Escherichia coli O157：H7 from Chinese water-chestnut. [Method] Gene-specific and locus-specific primers were utilized to amplify tccP/tccP2 and their flanking regions for sequence analysis. [Result] E. coli O157：H7 CWN11 harbored intact tccP and tccP2 genes, however, the number of proline-rich repeats in tccP gene was only one that probably resulted in biological incapability, whereas, the tccP2 gene consisted of five and half proline-rich repeats and could encode functional protein. [Conclusion] Here, we reported the first sequence of tccP gene that consisted of only one proline-rich repeat and tccP2 was assumed to play a crucial role in colonization and subsequent signaling cascades.

Variations of Melanocortin Receptor 1 (MC1R) Gene in Three Pig Breeds

Variations of Melanocortin Receptor 1 （MC1R） were investigated using sequencing, PCR-RFLP and PCR-SSCP, in three pig breeds, Landrace, Yorkshire, and Duroc. Five polymorphic sites were found, in which 668G→C occurred within 5＇ UTR, nt894insCC in coding region resulting in a premature stop at codon 56, and 1318C→T, 1554G→A, l197G→A in coding region resulting in Ala164Val, Ala243Thr, and Asp124Asn respectively. All individuals in Landrace and Yorkshire present homozygous 668GG, 1197AA, 1318CC, and 1554GG, and have CC insertions at the 894 site, whereas the individuals in Duroc present a contrast homozygous 668CC, 1197GG, 1318TT, and 1554AA, and have no CC insertions at the corresponding site. No heterozygote has been found at these mutation sites. Presumably, 668G→C, 1318C→T, and 1554G→A may be associated with the recessive red color in the Duroc breed, and nt894insCC making 1197G→A nonsense may be associated with the white color in Landrace and Yorkshire breeds.

Expression of Porcine Reproductive and Respiratory Syndrome Virus ORF7 Gene and Purification and Immunological Activity Analysis of the Recombinant Protein

[Objective] The aim of this study was to realize efficient expression of the porcine reproductive and respiratory syndrome virus （PRRSV） ORF7 gene in genetic engineering bacteria and analYze the immunological activity of the recombinant protein after purification. [ Method] The constructed recombinant expression vector pET-ORF7 was transformed into Escherichia co1BL21 （DE3） and induced by IPTG under the optimal condition. After analysis of SDS-PAGE and Western Blot, the expression products were purified by Ni-NTA His · Bind Resin chrom- atographic column under denaturing condition and renatured by gradient dialysis. Subsequently, the immunological activity of the renatured recombinant protein was detected by Westem Blot and indirect ELISA. [ Result] The recombinant plasmid pET-ORF7 expressed in E. coli successfully, and the fusion protein was in the form of inclusion body. By SDS-PAGE detection, the molecular weight of the expression protein was approximate 33 kD, according with the expectation. Analysis by Bandscan software showed that the expressed fusion protein was about 50% of total bacterial protein of BL21 （DE3）. Wastem Blot and indirect ELISA detection showed that the renatured protein could react with PRRSV positive serum specifically, indicating its good immunological activity. [ Conclusion] This study lays a foundation for the preparation of PRRSV monoclonal antibody and diagnostic kit.

Polymorphisms of CMYA3 Gene in 13/17 Robertsonian Translocation Pigs

[Objective] The aim was to study the polymorphism of CMYA3 gene in the 148 pigs of hybrid offspring of 13/17 Robertsonian translocation pigs [2n = 37,rob （13;17）] intercrossing.[Method] PCR-RFLP method was adopted.[Result] A 507 bp fragment of CMYA3 gene was obtained by PCR amplification,and then amplification product by using restriction nuclease Bsh1236Ⅰ was detected by agarose gel electrophoresis.As a result,both alleles （A and B） of the loci were found in the population.The frequencies of allele A and B were 0.699 and 0.301.The genotype frequencies of AA,AB and BB were 0.615,0.169 and 0.216.The frequencies of allele A and genotype AA were significantly higher than allele B and genotype BB in populations.[Conclusion] The study will provide theoretical basis for molecular breeding and marker-assisted selection of 13/17 Robertsonian translocation pigs.

Polymorphism of FUT1 Gene and Its Relationship with Litter Size in Northeast Hebao Pigs

[ Objective] To analyze the FUT1 gene polymorphism of Hebao pigs and its relationship with litter size and provide reference for conservation, breeding, development and utilization of Hebao pigs. [Method] The DNA was extracted from Hebao pigs＇ ears, and the polymorphism of FUT1 gene was detected by PCR-RFLP. Then the relationship between genotype and litter size was analyzed. [Result] The FUT1 gene had three kinds of genotypes, GG, AG and AA, as indicated by digestion with Hin6 I. The genotype frequency of AA was 0.115 9, and the allele frequency of A was 0.275 4. The average litter size from the 1 = parity to the 5th parity was higher in the individuals with the genotype AA than in those with the genotype AG or GG. And this difference was significant in average litter size of the 3th parity and the 4th parity （ P 〈 0.05）. [ Conclusion ] The FUT-1 gene is polymorphic in Hebao pigs, and the allele frequency is similar to that of foreign Duroc pigs but greatly different from that of other breeds such as Landrace, Large white, and Landrace x Large white pigs. The genotype AA is a prevalent genotype for litter trait.