Reconstruction of mitogenomes by NGS and phylogenetic implications for leaf beetles

Mitochondrial genome (mitogenome) sequences are frequently used to infer phylogenetic relationships of insects at different taxonomic levels. Next-generation sequencing (NGS) techniques are revolutionizing many fields of biology, and allow for acquisition of insect mitogenomes for large number of species simultaneously. In this study, 20 full or partial mitogenomes were sequenced from pooled genomic DNA samples by NGS for leaf beetles (Chrysomelidae). Combined with published mitogenome sequences, a higher level phylogeny of Chrysomelidae was reconstructed under maximum likelihood and Bayesian inference with different models and various data treatments. The results revealed support for a basal position of Bruchinae within Chrysomelidae. In addition, two major subfamily groupings were recovered: one including seven subfamilies, namely Donaciinae, Criocerinae, Spilopyrinae, Cassidinae, Cryptocephalinae, Chlamisinae and Eumolpinae, another containing a non-monophyletic Chrysomelinae and a monophyletic Galerucinae.

线粒体基因组（mitogenome）序列常被用于推断不同分类层级昆虫的系统发育关系。下一代测序（NGS）技术正革新诸多生物学研究领域，可同时获取大批量物种的昆虫线粒体基因组数据。本研究借助下一代测序技术，从叶甲科（Chrysomelidae）的混合基因组DNA样本中测序获得20条完整或部分的线粒体基因组序列。结合已发表的线粒体基因组序列，本研究采用不同模型与多种数据处理方案，基于最大似然法和贝叶斯推断重建了叶甲科的高级阶元系统发育树。结果支持豆象亚科（Bruchinae）位于叶甲科基部的系统发育位置。此外，本研究还恢复出两个主要的亚科类群：一类包含7个亚科，即距甲亚科（Donaciinae）、茎甲亚科（Criocerinae）、斑叶甲亚科（Spilopyrinae）、龟甲亚科（Cassidinae）、瘤叶甲亚科（Cryptocephalinae）、铁甲亚科（Chlamisinae）和肖叶甲亚科（Eumolpinae）；另一类包含非单系群的叶甲亚科（Chrysomelinae）以及单系群的萤叶甲亚科（Galerucinae）。