中文摘要：

为了探讨家蚕氨酰－tRNA合成酶（BmaaRS）基因的数目、种类、结构及起源，利用家蚕基因组数据和EST数据进行了BmaaRS基因的电子克隆，结果表明，家蚕核基因组中含有2套不同的aaRS核基因，分别编码线粒体和细胞质BmaaRS，但编码线粒体BmSerRS的基因有2个，可能缺少编码细胞质的BmHisRS基因和编码线粒体的BmGInRS、BmLysRS、BmGIyRS和BmThrRS基因，这些基因的功能可能由具有相似功能的其他蛋白完成，或通过某个BmaaRS基因的可变剪接分别形成不同功能的BmaaRS。EST证据表明，BmaaRS基因存在不同形式的可变剪接；BmaaRS氨基酸序列的相似性及二、三级结构分析表明部分BmaaRS存在结构域的扩增，有些不同的BmaaRS具有相同结构域，相同功能的BmaaRS具有相似的三级结构；进化分析表明，BmaaRS为2套不同来源的BmaaRS基因编码，细胞质和线粒体BmaaRS的起源不同。

英文摘要：

For further research on number, type, composition and origin of Bombyx mori aminoacyl-tRNA synthetase （BmaaRS） genes, in silico cloning was performed with Bombyx mori genomic and EST databases. There might be two different sets of aaRS nuclear gene in Bombay nori genome, which encode mitochondrial BmaaRS and cytoplasmic BmaaRS, respectively. Among BmaaRS genes, there were 2 genes encoding mitochondrial BmSerRS, but no genes encoding cytoplasmic BmHisRS and mitochondrial BmGlnRS, BmLysRS, BmGlyRS, and BmThrRS. The functions of these absent genes could be directly replaced by other proteins with similar functions, or might undergo their distinct BmaaRS functions based on the alternative splice of one certain BmaaRS mRNA. Evidence of EST indicated that BmaaRS performed different alternative splicing patterns. The homology comparison and advanced structural analysis of BmaaRS demonstrated the existence of extended domains of BmaaRS. This is because some different BmaaRSs contained similar domain. Moreover, BmaaRSs with similar functions possessed the similar tertiary structure. Phylogenetic analysis revealed that BmaaRS encoded by two various sources of BmaaRS genes. Mitochondrial and cytoplasmic BrnaaRS had different origin.