The genome of a lepidopteran model insect, the silkworm Bombyx mori
The genome of a lepidopteran model insect, the silkworm Bombyx mori
复制标题
鳞翅目模式昆虫——家蚕 Bombyx mori 的基因组
DOI：
10.1016/j.ibmb.2009.01.004
复制
发表时间：
2008-12-01
影响因子：
3.8
通讯作者：
Morishita, Shinichi
中科院分区：
文献类型：
--
作者：
Xia, Qingyou;Wang, Jun;Morishita, Shinichi
家蚕（Bombyx mori）是一种主要的昆虫研究模型，也是第一个在 2004 年获得基因组草图序列的鳞翅目昆虫。来自全基因组鸟枪法测序的两个独立数据集被合并并与新获得的 fosmid 和 BAC 末端序列组装在一起。这里展示了经过显着改进的新组件。估计 432 Mb 基因组的 8.5 倍序列覆盖率被组装成 N50 大小类似于 3.7 Mb 的支架；最大的支架有 1450 万个碱基对。在高密度 SNP 连锁图的帮助下，我们将 87% 的支架序列锚定到所有 28 条染色体上。一个特别的特征是重复序列含量高，估计为 43.6%，并且主要由转座元件组成。我们基于基于 CLEAN 的算法预测了 14,623 个基因模型，比该物种之前的基因模型预测更准确。超过三千个蚕基因在其他昆虫或脊椎动物基因组中没有同源物。本文以及本期其他论文中介绍了对基因进化和特征生物过程的一些见解。大量的丝产量与特定 IRNA 簇的存在以及簇中组装的多个丝胶基因的存在相关。蚕适应以含有有毒生物碱的桑叶为食，可能与新型蔗糖酶基因的存在有关，该基因显然是从细菌中获得的。家蚕基因组还揭示了参与保幼激素生物合成途径的基因级联，以及大量的角质层蛋白基因。 (C) 2008 Elsevier Ltd. 保留所有权利。
Bombyx mori, the domesticated silkworm, is a major insect model for research, and the first lepidopteran for which draft genome sequences became available in 2004. Two independent data sets from whole-genome shotgun sequencing were merged and assembled together with newly obtained fosmid- and BAC-end sequences. The remarkably improved new assembly is presented here. The 8.5-fold sequence coverage of an estimated 432 Mb genome was assembled into scaffolds with an N50 size of similar to 3.7 Mb; the largest scaffold was 14.5 million base pairs. With help of a high-density SNP linkage map, we anchored 87% of the scaffold sequences to all 28 chromosomes. A particular feature was the high repetitive sequence content estimated to be 43.6% and that consisted mainly of transposable elements. We predicted 14,623 gene models based on a CLEAN-based algorithm, a more accurate prediction than the previous gene models for this species. Over three thousand silkworm genes have no homologs in other insect or vertebrate genomes. Some insights into gene evolution and into characteristic biological processes are presented here and in other papers in this issue. The massive silk production correlates with the existence of specific IRNA clusters, and of several sericin genes assembled in a cluster. The silkworm's adaptation to feeding on mulberry leaves, which contain toxic alkaloids, is likely linked to the presence of new-type sucrase genes, apparently acquired from bacteria. The silkworm genome also revealed the cascade of genes involved in the juvenile hormone biosynthesis pathway, and a large number of cuticular protein genes. (C) 2008 Elsevier Ltd. All rights reserved.