Draft Genome of the Scarab Beetle Oryctes borbonicus on La Reunion Island
Draft Genome of the Scarab Beetle Oryctes borbonicus on La Reunion Island
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DOI：
10.1093/gbe/evw133
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发表时间：
2016-07-01
影响因子：
3.3
通讯作者：
Roedelsperger, Christian
中科院分区：
文献类型：
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作者：
Meyer, Jan M.;Markov, Gabriel V.;Roedelsperger, Christian
甲虫是最大的昆虫目，在形态、生态和行为方面表现出极大的多样性，这使它们成为进化研究的理想模型。在这里，我们提出了圣甲虫Oryctes borbonicus的基因组草图，它比之前测序的两个害虫物种Tribolium castaneum和Dendroctonus ponderosae具有更基础的系统发育位置，为序列极化提供了可能。Oryctes borbonicus是印度洋留尼旺岛的特有物种，它是太平洋Pristionchus的宿主，而太平洋Pristionchus是一种公认的综合进化生物学模式生物。在518Mb的基因组中，O. borbonicus比T. castaneum和D. ponderosae大得多，编码的基因也更多。我们发现，在9种昆虫基因组中，只有25%的预测基因被保守为单拷贝基因，这表明昆虫内部存在大量的基因周转。即使在甲虫体内，高达21%的基因也只局限于一个物种，而大多数其他基因都经历了特定谱系的复制和丢失。我们使用两个基因家族的详细系统发育分析来说明谱系特异性重复。本研究为昆虫/鞘翼基因基因组学提供了一个参考点，尽管其最初的动机是寻找波氏倭蛾和太平洋倭蛾之间潜在的水平基因转移（HGT）的证据。后者先前被证明是多个水平转移基因的接受者，包括来自昆虫供体的一些基因。然而，我们的研究未能提供任何明确的证据表明两个物种之间存在额外的hgt。
Beetles represent the largest insect order and they display extreme morphological, ecological and behavioral diversity, which makes them ideal models for evolutionary studies. Here, we present the draft genome of the scarab beetle Oryctes borbonicus, which has a more basal phylogenetic position than the two previously sequenced pest species Tribolium castaneum and Dendroctonus ponderosae providing the potential for sequence polarization. Oryctes borbonicus is endemic to La Reunion, an island located in the Indian Ocean, and is the host of the nematode Pristionchus pacificus, a well-established model organism for integrative evolutionary biology. At 518Mb, the O. borbonicus genome is substantially larger and encodes more genes than T. castaneum and D. ponderosae. We found that only 25% of the predicted genes of O. borbonicus are conserved as single copy genes across the nine investigated insect genomes, suggesting substantial gene turnover within insects. Even within beetles, up to 21% of genes are restricted to only one species, whereas most other genes have undergone lineage-specific duplications and losses. We illustrate lineage-specific duplications using detailed phylogenetic analysis of two gene families. This study serves as a reference point for insect/coleopterangenomics, although its original motivation was to find evidence for potential horizontal gene transfer (HGT) between O. borbonicus and P. pacificus. The latter was previously shown to be the recipient of multiple horizontally transferred genes including some genes from insect donors. However, our study failed to provide any clear evidence for additional HGTs between the two species.