Basic studies on physical mapping, transcript mapping, and functional analysis of the silkworm (Bombyx mori) genome

作为国际合作，我们组装了家蚕的基因组序列，并发表了结果。我们还根据全长cDNA文库和小RNA群体进行了转录组分析，并构建了它们的序列数据库。通过将家蚕基因组与其他后生动物的基因组进行比较，我们发现了许多家蚕特有的基因。部分特定基因与真细菌基因的同源性高于与真核生物序列的同源性，这表明基因水平从真细菌转移到鳞翅目昆虫的祖先。我们还将家蚕基因组与近缘野生种野桑蚕和蓖麻蚕进行了比较。另一方面，我们利用基因组信息对家蚕中可见突变体进行了定位克隆。结果，我们成功地分离了lem(柠檬)、Rb(红血)和许多其他基因。

We assembled the genome sequences of the silkworm Bombyx mori as international collaboration and published the results. We also performed transcriptome analysis based on the full-length cDNA libraries and small RNA populations, and constructed a database for their sequences. By comparing the B. mori genome with those of other metazoans, we found many Bombyx-specific genes. A part of the specific genes show higher homology to eubacterial genes than to eukaryotic sequences, suggesting horizontal gene transfers from eubacteria to an ancestral lepidopterans. We also compared the B. mori genome with closely-related wild species, Bombyx mandarina and Samia cynthia ricini. On the other hands, we utilized the genomic information for positional cloning of visible mutants in B. mori. As the results, we succeeded in isolations of lem (lemon), rb (red blood), and many other genes.