The evolution and genomic basis of beetle diversity
The evolution and genomic basis of beetle diversity
复制标题
DOI：
10.1073/pnas.1909655116
复制
发表时间：
2019-12-03
影响因子：
11.1
通讯作者：
Beutel, Rolf G.
中科院分区：
文献类型：
--
作者：
McKenna, Duane D.;Shin, Seunggwan;Beutel, Rolf G.
鞘翅目（甲虫）可以说是物种最丰富的动物类群，但甲虫的进化史，包括植物取食（草食性）对甲虫多样性的影响，仍然知之甚少。我们使用146个物种的4，818个基因推断甲虫的繁殖，使用代表所有主要谱系的521个物种的89个基因估计甲虫多样化的时间和速率，并使用154个基因组或转录组追踪甲虫基因的进化，使木质纤维素的共生体独立消化。这些独特的全面的数据集的系统基因组分析解决了以前有争议的甲虫的关系，追溯到石炭纪的鞘翅目的起源，并支持甲虫和被子植物的共同多样化。此外，植物细胞壁降解酶（PCWDEs）获得的细菌和真菌通过水平基因转移可能是关键的中生代多样化的食草甲虫-值得注意的是，这两个主要的独立起源的专门的食草甲虫与第一次出现的武库的PCWDEs编码在他们的基因组。此外，相应的（侏罗纪）多样化率的增加表明，这些新基因触发了适应性辐射，导致近一半的甲虫物种。我们建议，PCWDEs能够有效地消化植物组织，包括细胞壁中的木质纤维素，促进独特的专门植物饲养习惯的演变，如叶挖掘和茎和木材钻孔。因此，甲虫多样性似乎是由多种因素造成的，包括在漫长的进化历史中的低灭绝率，与被子植物的共同多样化，以及在编码PCWDEs的微生物基因的趋同水平转移后专门食草甲虫的适应性辐射。
The order Coleoptera (beetles) is arguably the most speciose group of animals, but the evolutionary history of beetles, including the impacts of plant feeding (herbivory) on beetle diversification, remain poorly understood. We inferred the phylogeny of beetles using 4,818 genes for 146 species, estimated timing and rates of beetle diversification using 89 genes for 521 species representing all major lineages and traced the evolution of beetle genes enabling symbiont-independent digestion of lignocellulose using 154 genomes or transcriptomes. Phylogenomic analyses of these uniquely comprehensive datasets resolved previously controversial beetle relationships, dated the origin of Coleoptera to the Carboniferous, and supported the codiversification of beetles and angiosperms. Moreover, plant cell wall-degrading enzymes (PCWDEs) obtained from bacteria and fungi via horizontal gene transfers may have been key to the Mesozoic diversification of herbivorous beetles-remarkably, both major independent origins of specialized herbivory in beetles coincide with the first appearances of an arsenal of PCWDEs encoded in their genomes. Furthermore, corresponding (Jurassic) diversification rate increases suggest that these novel genes triggered adaptive radiations that resulted in nearly half of all living beetle species. We propose that PCWDEs enabled efficient digestion of plant tissues, including lignocellulose in cell walls, facilitating the evolution of uniquely specialized plant-feeding habits, such as leaf mining and stem and wood boring. Beetle diversity thus appears to have resulted from multiple factors, including low extinction rates over a long evolutionary history, codiversification with angiosperms, and adaptive radiations of specialized herbivorous beetles following convergent horizontal transfers of microbial genes encoding PCWDEs.