蓖麻蚕线粒体基因组中nd1及其侧翼tRNA基因的克隆与结构分析

Cloning and Analysis of Structure of nd1 and its Connected tRNA Genes of Mitochondrial Genome From Eri Silkworm Samia cynthia ricini

按KoichiroTamura等 (1988)的方法制备出蓖麻蚕线粒体DNA ,用EcoRⅠ和XbaⅠ双酶解后 ,以pSK(+)(Ampr)为载体进行克隆 ,获得 1个 3 3kb的克隆片段。测序结果表明 ,所测序列包括部分 16SrRNA、完整的tRNA Leu ,nd1和tRNA Ser基因。其中 16SrRNA(3’端部分 )、nd1基因与家蚕具有很高的同源性。同时以nd1基因为依据构建了 17种动物的分子进化树 ,显示出蓖麻蚕与家蚕、野蚕有最近的演化关系。根据tRNA Leu和tRNA Ser基因的一级结构 ,推定了可能的二级结构 ,并与家蚕进行了比较。

Mitochondrial DNA of eri silkworm Samia cynthia ricini (ScmtDNA) was prepared with the method of Koichiro Tamura et al (1988) and was doubly digested by EcoRⅠ and XbaⅠ.And a 3.3 kb restriction fragment was cloned into pSK(+) (Amp r) vector and sequenced.The results showed that the sequenced part of this clone contains partial 16S rRNA,complete genes of tRNA-Leu,nd1 and tRNA-Ser.Of which 16S rRNA and nd1 gene has high homology with those of Bombyx mori.A phylogentic tree of 17 animal species was constructed based on nd1 gene sequences.The tree indicated that Samia cynthia ricini has closest relationship with Bombyx mori.Meanwhile the possible secondary structures of tRNA-Leu and tRNA-Ser genes of Samia cynthia ricini were deduced according to these sequences and compared to Bombyx mori.