The Cloning And Sequence Analysis Of GP64 Genen Of BMNPV Isolates From Guangxi

Guangxi is the first large production base of sericulture industry in China, it is located in subtropical zone, where the climate condition is perfect for silkworm husbandry, but the hot and humid environment also easy to cause the prevalence and transmission of pathogenic bacteria and viruses, especially the Bombyx mori Nucleopolyhedrosis virus (BmNPV). The BmNPV epidemic almost can’t be controled when it outbreak, and bring serious damage to sericulture production. BmNPV is the pathogen of BmNPV epidemic, the viral envelope protein GP64 coded by gp64 gene of BmNPV plays a key role in the dissemination of the silkworm. The master sequence information of gp64 gene is advantageous to understand the situation and development of BmNPV system from the molecular level, and help to understand the infection mechanism of BmNPV, which can provide scientific basis for the prevention and control of Guangxi silkworm BmNPV epidemic, In this study, the gp64 gene of BmNPV isolates from different sericulture area of Guangxi were cloned and sequenced, the main contents and results as follows:1. The gp64 gene of 19 strains BmNPV isolates from Guangxi were cloned and sequenced, the complete gp64 gene ORF has three kinds of length. The gp64 gene ORF of 7 strains isolates are 1590bp,5 strains isolates are 1593bp and 7 strains isolates are 1599bp.2. Gp64 gene ORF nucleotide homology analysis showed that, only 1 strain isolate has 100%homology with the T3 strain, the nucleotide homology with T3 strain of the remaining 18 strains was between 98.5%～99.2%, the amino acid homology was between 98.5～99.6%. The nucleotide homology of the 19 strains isolates from Guangxi was between 98.4～100%, the amino acid homology was between 98.3～100%.3. Phylogenetic analysis of gp64 gene showed that,19 strains BmNPV isolates from Guangxi can be divided into two subsets of clade I and clade II,11 strains isolates belong to clade I and 8 strains isolates belong to clade II.4. Analysis of single nucleotide polymorphisms of BmNPV gp64 gene ORF showed that, the gp64 gene ORF of most isolates were requently harboring point mutations, the codon usage was changeable and without obvious codon bias.