Meyer Jan M, Markov Gabriel V, Baskaran Praveen, Herrmann Matthias, Sommer Ralf J, Rödelsperger Christian
Department for Evolutionary Biology, Max-Planck-Institute for Developmental Biology, Tübingen, Germany.
Department for Evolutionary Biology, Max-Planck-Institute for Developmental Biology, Tübingen, Germany Present address: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8227 Integrative Biology of Marine Models, Station Biologique de Roscoff, Roscoff Cedex, France.
Genome Biol Evol. 2016 Jul 12;8(7):2093-105. doi: 10.1093/gbe/evw133.
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 Réunion, 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 518 Mb, 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/coleopteran genomics, 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.
甲虫是最大的昆虫目，它们展现出了极端的形态、生态和行为多样性，这使其成为进化研究的理想模型。在此，我们展示了金龟子Oryctes borbonicus的基因组草图，该物种在系统发育位置上比之前测序的两种害虫物种赤拟谷盗（Tribolium castaneum）和西松大小蠹（Dendroctonus ponderosae）更为基础，为序列极化提供了可能。Oryctes borbonicus是留尼汪岛特有的物种，留尼汪岛位于印度洋，它是太平洋小杆线虫（Pristionchus pacificus）的宿主，而太平洋小杆线虫是综合进化生物学中一个成熟的模式生物。Oryctes borbonicus的基因组大小为518 Mb，比赤拟谷盗和西松大小蠹的基因组大得多，编码的基因也更多。我们发现，在九个被研究的昆虫基因组中，Oryctes borbonicus预测基因中只有25%作为单拷贝基因保守存在，这表明昆虫内部存在大量的基因更替。即使在甲虫内部，高达21%的基因仅局限于一个物种，而大多数其他基因经历了谱系特异性的复制和丢失。我们通过对两个基因家族进行详细的系统发育分析来说明谱系特异性复制。这项研究为昆虫/鞘翅目基因组学提供了一个参考点，尽管其最初的动机是寻找Oryctes borbonicus和太平洋小杆线虫之间潜在水平基因转移（HGT）的证据。后者之前已被证明是多个水平转移基因的受体，包括一些来自昆虫供体的基因。然而，我们的研究未能为这两个物种之间的额外水平基因转移提供任何明确的证据。
