A pair of primer were designed according to the sequence of porcine IFN-γ,then the gene was cloned into pET-30 a prokaryotic expression vector,recombinant expression vector pET-30 a-pIFN-γ was constructed.The recombinant plasmid was transformed into E.coli BL21(DE3) and then identified by PCR,double enzyme digesting and sequencing,and induced by IPTG.The soluble expressed product was purified through Nickel-affinity chromatography column,the protein was further purified by Sephadex-G100.The inclusion body was washed by DOC,then dissolved with SKL and subsequently renatured by dialysis,and the expressed protein was analyzed by SDS-PAGE and Western-blot.It was confirmed that the highly purified pET-30a-IFN-γ was harvested.Antiviral effect of the purified product was tested by cytopathogenic effect inhibition assay,the results indicated that the purified product had a higher activity of interferencing virus replication,the activity of IFN-γ against PRV was about 2.0×103 U·mg-1,the activity of IFN-γ against FMDV serotype O was about 2.56×105 U·mg-1.

Genomic DNA was extracted from the skin tissue of suspected capripox sheep in Jingtai,Gansu Province,and the membrane-protein encoding ORF23 gene was cloned by PCR and sequenced.The results showed that the length of open reading frame of membrane protein encoding ORF23 gene was 1113 bp,coding a 370-amino acid protein.Its nucleotide component was imbalance with 69.90% of A+T content and 30.10% of G+C.The homology of nucleotide and deduced amino acid sequence between sheeppox virus Gansu strain,sheeppox virus A train and NISKHI strain was 99.6%,99.5% and 98.7%,98.4% respectively.ORF23 gene of the sheeppox virus Gansu strain shared 96.5% and 94.8% identity with that of Lumpy skin disease virus Neethling Warmbaths LW strain and goatpox virus Pellor strain.Structural analysis of the deduced ORF23 protein indicated that the ORF23 antigen was not a secretory protein with one O-linked glycosylation sites and one phospholipase domain.It suggested that the ORF23 membrane protein is conserved among sheeppox field strains and has potential value in development of vaccine or/and diagnosis.

This experiment examined the virulence of 6 Eimeria spp.Lanzhou strain by infecting Jiahehuang female broilers at various dosages.Nine trial groups,including negative control group(NC) and 8 challenge infection groups(1-8) were tested.The average relative growth ratio(RGR) of 8 groups was 100 %,77.23 %,77.02 %,76.42 %,72.86 %,63.91 %,67.19 % and 42.06 %,respectively.The RGR of NC group was significantlg higher than other groups(p0.01).The RGRs of the 1st and the 2nd group were significant higher than the 5th and the 6th groups(p0.01) and the 7th group(p0.01).The feed conversion ratio(FCR) in the 7th group was significantlg higher than other groups.The OPG of the 7th group(150.11×104) was significantly higher than the 1st(3.05×104),the 2nd(2.35×104),the 3rd(32.20×104),the 4th(62.23×104) and the 5th group(60.45×104)(p0.01) after challenge.The mortality rate of 9 groups was 0,5.0 %,5.0 %,15 %,25 %,40.0 %,45.0 %,95 % and 100 %,respectively.These results indicated that the Eimeria spp.strains isolated from Lanzhou are highly virulent.Chickens infected with 6×104 oocysts suffered significant suppression in growth and 50 % mortality.The best challenge dosage was 1×104-1×105(each Eimeria spp.).

从甘肃景泰疑似羊痘绵羊的皮肤组织中提取基因组DNA,PCR扩增糖蛋白0RF121基因.序列分析表明,该基因由519个核苷酸组成,编码172个氨基酸,分子量为19.9 kua,序列中A+T含量占74.95%,G+C含量仅占25.05%.甘肃景泰株ORF121基因同绵羊痘病毒参考株之间的核苷酸同源性高达99%;与疙瘩皮肤病病毒和山羊痘病毒参考株之间的同源性分别为97%和95.6%.结构预测结果显示,0RF121蛋白具有两个N-糖基化位点和一个跨膜区,且具有极强的亲水性.以上结果表明,ORF121蛋白在不同的绵羊痘病毒流行株之间非常保守,具有潜在的疫苗或/和诊断价值.

In the process of SL(spliced leader) trans-splicing,with the help of spliceosome,SL as a mini-exon is added to the 5'-end of pre-mRNA to mature mRNA through the sites SD in SL RNA and SA in pre-mRNA.This modification pattern of pre-mRNA is completely retained in evolutionarily conservative molecules.Sometimes,the size of SL from different organisms is greatly different,and,in some creature,there are two different SLs that play different roles in the process of pre-mRNA.Although the nucleotide constituent of different SL RNAs varies significantly,their structures show high similarity,such as a TMG cap at the 5'-terminal,conservative sites SD and Sm,the secondary structure of SL RNA.The phenomenon of SL trans-splicing has crucially evolutionary significance.Because of the loss of SA site or the gain of SD site in the transcriptional process of pre-mRNA,the SL trans-splicing way is discarded in evolution in most vertebrates.The lack may be one of the reasons that give rise to the increase of C value.

Taenia solium 45W proteins are good candidates for development of anti-cysticercosis vaccines. However, the genetic characteristics of the 45 gene family are still unclear between different isolates. We investigated the polymorphism of the 45 gene family between Chinese and Mexican T. solium. Alignment showed that TSO45-4B and TSO45-1C antigens were conserved absolutely, whereas other TSO45 proteins varied between these two isolates. It is informative to guide using of recombinant 45W vaccines to control porcine cysticercosis caused by Asiatic or African/Latin American T. solium.

Genomic DNA was extracted from the skin tissue of suspected capripox sheep in Jingtai, Gansu Province, and the glycoprotein-encoding orf118 gene was cloned by PCR. Comparison shows that the length of open reading frame of glycoprotein-encoding orf118 gene is 516 bp, coding for a 171-amino acid protein with molecular weight of approximate 19 500, and its nucleotide component showed a serious imbalance with 72.48% of A+T and 27.52%of G+C. The homology of nucleotide and deduced amino acid sequence between sheeppox virus ,Gansu strain and sheeppox virus TU-V02127 strain is 99.8% and 100%, respectively. orf118 of the sheeppox virus, Gansu strain shares 96.5% and 94.8% of identity with Lumpy skin disease virus and goatpox virus G20-LKV strain at a nucleotide level. Structural prediction of the deduced orf118 protein indicates that the orf118 antigen is a secretory glycoprotein with two N-linked glycosylation sites and one trans-membrane domain. Together with above results suggest that the orf118 glycoprotein is completely conserved among sheeppox field strains and has potential value for vaccine and diagnosis.

To evaluate the mechanism of immune enhancement of β-lentinan(LTN) in chickens,both in vitro and in vivo trials were carried out to study the effect of LTN on NO productive capacity of the splenic and thymus lymphocytes and abdominal macrophage.One-hundred-twenty 21day-old chickens were randomly divided into 4 groups which were injected abdominally with 2 mL of 1 g/L LTN,10 g/L LTN,20 g/L sodium thioglycolate and normal saline solution,respectively.The NO production of the splenic and thymus lymphocytes and abdominal macrophage were measured on day 3 post-injection.And the macrophage activated by sodium thioglycolate were stimulated with LTN at level of 50 mg/L,100 mg/L,200 mg/L and 400 mg/L respectively and the NO production by macrophages were measured.In consequence,1 g/L and 10 g/L LTN stimulated the splenic and thymus lymphocytes and macrophages to produce NO.Different concentrations of LTN were able to stimulate macrophages to increase the production of NO.Moderate stimulation of immunocytes to produce NO may be one of the most important immunoactive mechanisms by LTN in chickens.