家蚕核型多角体病毒四方形多角体突变株多角体蛋白基因的DNA序列分析

DNA SEQUENCE OF THE POLYHEDRIN GENE OF A CUBIC POLYHEDRA MUTANT OF BOMBYX MORI NUCLEAR POLYHEDROSIS VIRUS

核型多角体病毒(Nuclear polyhedrosis virus,NPV)属于杆状病毒科,其特征是在感染后期的宿主细胞核内大量形成多角体包含体,即多角体。多角体具有保护病毒免受不良环境影响的作用。人们对它的理化性质,结构功能等已进行了一系列研究。多角体的形态是由病毒基因组决定的,形态变异往往是病毒基因组结构发生变化的结果。

The nucleotide sequence of a 1.5kb fragment of Bombyx mori nuclear polyhedrosis virus containing the entire polyhedrin gene and its 5' and 3' flanking region was determined. Comparison with the nucleotide sequence with BmNPV T3 isolate revealed that a single point mutation occured within the polyhedrin coding region. Two other mutations were found upstream of the coding region. Amino acide sequence comparison revealed that the cubic mutant differs from BmNPV T3 isolate, Zhenjiang isolate, Canadian isolate and AcNPV E2 strain by 1,2,8 and 34 amino acids res pectively. The results showed that the Met of the 156th amino acid posi-tion substituted by Val was found not only in the cubic polyhedrin mutant, but also in Zhenjiang isolate and AcNPV E2 strain.