家蚕浓核病毒(镇江)株主要结构蛋白基因的克隆及表达

家蚕浓核病毒(Bombyx mori densovirus,BmDNV)是一种昆虫细小病毒.与其它昆虫细小病毒感染昆虫体内多种组织不同,家蚕浓核病毒只感染家蚕中肠上皮组织的圆筒型细胞,感染该病毒细胞的细胞核可以被孚尔根和甲基绿浓染,在病毒感染的早期中肠上皮组织细胞数量增加,形成褶皱,最后感染细胞脱落到肠腔中1-3].自从20世纪70年代末日本学者证实家蚕浓核病是由于家蚕浓核病毒感染引起的以来4],已经分离得到了多个病毒株系5-8].根据它们在血清学、理化特性、品种感受性和病理特征等方面的差异,分为BmDNV-1(伊那株)和BmDNV-2(以山梨株为代表)8-11].

Cloning of the Major Structural Protein Gene of Densovirus (Zhenjiang Isolate)in Silkworm, Bombyx mori,and Its Expression in Escherichia coli

The major structural protein gene was cloned from Bombyx mori densovirus,Zhenjiang strain (BmDNV-ZJ),sequenced and expressed in Escherichia coli.The gene consists of 1500 nucleotides and is predicted to code a protein of 499 amino acids.An identity of 98.1% in nucleotide sequence and 98.6% of the predicted amino acid sequence are shared with its homologue,Bombyx mori densovirus (Yamanashi isolate) VD_1-ORF_2,respectively.The gene was inserted into expression plasmid vector pET-28a and expressed in Escherichia coli BL21(DE3) strain under the inducible promoter Lac.The expressed 53kD product could be detected by Western blotting with viral antiserum.It suggests that the gene we cloned is a structural protein gene.