中国棉铃虫单粒包埋核型多角体病毒多角体蛋白基因的序列分析

Nucleotide Sequence Analysis of the Polyhedrin Gene of Heliothis armigera Single Nucleocapsid Nucleopolyhedrovirus

以AcMNPV的多角体蛋白基因为探针，定位了中国棉铃虫单粒包理核型多角体病毒（HaSNPV）的多用体蛋白基因。序列测定表明，HaSNPV的多角体蛋白基因编码区为738个核苷酸，编码246个氨基酸，预计蛋白质分子量为29kDa。同源性分析表明，HaSNPV与美洲棉铃虫单粒包理核型多角体病毒（HzSNPV）具有最高的同源性，在整个阅读框架中只有4个碱基的差异，其中第179位碱基的变化导致唯一的氨基酸变化，这种变化并未导致其二级结构的改变。此外，两种病毒该基因的启动子结构也完全一样。HaSNPV与其它的SNPV和MNPV的同源性明显要低。结果预示HaSNPV与HzSNPV可能为同种病毒的不同变种。

The polyhedrin gene of the Heliothis armigera single nucleocapsid nucleopolyhedrovirus (HaSNPV) was localized by Southern blot hybridization with a probe from the Autographa cali-fornica MNPV (AcMNPV) polyhedrin gene. Nucleotide sequencing showed the open reading frame of the HaSNPV polyhedrin gene was 738 nt, encoded 246 amino acids with a predicted size of 29 kDa. Alignment with polyhedrin sequences in GENE Band indicated the highest homology with the polyhedrin gene of H. zea SNPV(HzSNPV). There were four different nucleotides and only one change (nt 197 C→A)resulted in an amino acid change in HzSNPV (Thr→Lys). Thischange did not alter the secondary structure of the molecule. The promoter regions of both poly-hedrins were identical including the location of the ATAAG core element, where the transcription starts. The amino acid homology with other SNPVs and with MNPVs polyhedrins was much low-er. The results indicate that HaSNPV and HzSNPV are probably variants of a single baculovirus genotype.