野桑蚕漆酶基因克隆、序列分析及转录表达谱研究

Cloning,sequence analysis and transcriptional expression profiles of Bombyx mandarina Laccase gene

利用RT-PCR方法,克隆了野桑蚕Bombyx mandarina漆酶基因,获得了其cDNA序列.该序列长2 317bp,含有一个2 295bp的完整开放阅读框,有8个外显子,7个内含子,编码一个由764个氨基酸残基组成的蛋白质,其蛋白质的分子量和等电点分别为84 340.91和6.61.推导的氨基酸序列与其它鳞翅目昆虫(Laccase)基因相应氨基酸序列有较高的同源性,该序列具有它们的漆酶基因所共有的典型特征.组织特异性表达分析表明了该基因仅在野桑蚕的表皮、头部、中肠和血液中有表达.这些结果为进一步研究野桑蚕漆酶基因的功能提供了分子基础.

The complemental deoxyribonucleic acid（cDNA）of Bombyx rnandarina Laccase gene was cloned by reverse transcription-polymerase chain reaction（RT-PCR）. The results showed that the cDNA with 2 317 bp in length contained an open reading frame （ORF） of 2 295 bp which encoded 764 amino acid residues, contains 8 exons and 7 introns, and a predicted molecular weight of 84340.91 and isoelectric point of 6.61. The deduced amino acid sequence had a high identity to the reported sequence of laccase2 from other lepidopterous insects and shared the typical structural features of laccase from other insects. The Laccase was only expressed in epidermis, head, midgut, and blood of B. mandarina by RT-PCR analysis. These results provide molecular basis for further studying the function of Laccase gene in B. mandarina.