The genome of a lepidopteran model insect, the silkworm Bombyx mori
The genome of a lepidopteran model insect, the silkworm Bombyx mori
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DOI：
10.1016/j.ibmb.2008.11.004
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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年获得基因组序列草案的鳞翅目昆虫。将来自全基因组鸟枪测序的两个独立数据集与新获得的fosmid和BAC末端序列合并并组装在一起。本文介绍了改进后的新装置。将估计的432 Mb基因组的8.5倍序列覆盖率组装成具有类似于3.7 Mb的N50大小的支架;最大支架为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。一个特别的特点是高重复序列含量估计为43.6%，主要由转座因子。我们基于CLEAN算法预测了14，623个基因模型，这比该物种以前的基因模型更准确。超过3000个家蚕基因在其他昆虫或脊椎动物基因组中没有同源物。一些见解基因进化和特征的生物过程中提出了在这里和其他文件在这个问题上。大量的蚕丝生产与特定的IRNA簇的存在相关，并且与聚集在簇中的几个丝胶蛋白基因相关。这种蚕对桑葚的适应性进食，其中含有有毒的生物碱，可能与新型蔗糖酶基因的存在有关，显然是从细菌中获得的。家蚕基因组还揭示了保幼激素生物合成途径中涉及的级联基因，以及大量的表皮蛋白基因。(C)2008爱思唯尔有限公司保留所有权利。
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.