Extensive synteny conservation of holocentric chromosomes in Lepidoptera despite high rates of local genome rearrangements
Extensive synteny conservation of holocentric chromosomes in Lepidoptera despite high rates of local genome rearrangements
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DOI：
10.1073/pnas.0910413107
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发表时间：
2010-04-27
影响因子：
11.1
通讯作者：
Feyereisen, R.
中科院分区：
文献类型：
--
作者：
d'Alencon, E.;Sezutsu, H.;Feyereisen, R.
家蚕28条全着丝粒染色体上432 Mb基因组的最新组装已成为鳞翅目非常多样化的基因组分析的参考。我们对棉铃虫和草地贪夜蛾两种主要害虫的BAC序列进行了测定，对应于分布在11个B上的15个区域。mori染色体，每个BAC/区域由已知的正向同源基因锚定，以分析三个物种之间的同线关系和基因组重排。近300个基因和大量的转座因子被确定，与长散布核元件和末端反向重复序列的最丰富的转座因子类。B之间存在高度的同线性保守性。桑和两种鱼。已鉴定基因的保守同线块非常小，然而，在B之间每个块约1.3个基因。mori和两种拟谷盗之间的遗传距离为2.0个基因/块; frugiperda和H. armigera。这对应于每Mb DNA/My大约两个染色体断裂。这是一个更高的进化速度比果蝇属物种，可能与鳞翅目基因组的全着丝粒性质。我们报告了一个大集群的八个成员的氨肽酶N基因家族，我们估计已经存在，因为侏罗纪。与此相反，细胞色素P450基因的几个集群显示多个谱系特异性的重复事件，特别是在鳞翅目CYP 9A亚家族。我们的研究突出了家蚕基因组作为鳞翅目比较基因组学参考的价值。
The recent assembly of the silkworm Bombyx mori genome with 432 Mb on 28 holocentric chromosomes has become a reference in the genomic analysis of the very diverse Order of Lepidoptera. We sequenced BACs from two major pests, the noctuid moths Helicoverpa armigera and Spodoptera frugiperda, corresponding to 15 regions distributed on 11 B. mori chromosomes, each BAC/region being anchored by known orthologous gene(s) to analyze syntenic relationships and genome rearrangements among the three species. Nearly 300 genes and numerous transposable elements were identified, with long interspersed nuclear elements and terminal inverted repeats the most abundant transposable element classes. There was a high degree of synteny conservation between B. mori and the two noctuid species. Conserved syntenic blocks of identified genes were very small, however, approximately 1.3 genes per block between B. mori and the two noctuid species and 2.0 genes per block between S. frugiperda and H. armigera. This corresponds to approximately two chromosome breaks per Mb DNA per My. This is a much higher evolution rate than among species of the Drosophila genus and may be related to the holocentric nature of the lepidopteran genomes. We report a large cluster of eight members of the aminopeptidase N gene family that we estimate to have been present since the Jurassic. In contrast, several clusters of cytochrome P450 genes showed multiple lineage-specific duplication events, in particular in the lepidopteran CYP9A subfamily. Our study highlights the value of the silkworm genome as a reference in lepidopteran comparative genomics.