Tvedte Eric S, Forbes Andrew A, Logsdon John M
Department of Biology, University of Iowa, Iowa City, IA 52242.
J Hered. 2017 Oct 30;108(7):791-806. doi: 10.1093/jhered/esx062.
The cellular mechanisms of meiosis are critical for proper gamete formation in sexual organisms. Functional studies in model organisms have identified genes essential for meiosis, yet the extent to which this core meiotic machinery is conserved across non-model systems is not fully understood. Moreover, it is unclear whether deviation from canonical modes of sexual reproduction is accompanied by modifications in the genetic components involved in meiosis. We used a robust approach to identify and catalogue meiosis genes in Hymenoptera, an insect order typically characterized by haplodiploid reproduction. Using newly available genome data, we searched for 43 genes involved in meiosis in 18 diverse hymenopterans. Seven of eight genes with roles specific to meiosis were found across a majority of surveyed species, suggesting the preservation of core meiotic machinery in haplodiploid hymenopterans. Phylogenomic analyses of the inventory of meiosis genes and the identification of shared gene duplications and losses provided support for the grouping of species within Proctotrupomorpha, Ichneumonomorpha, and Aculeata clades, along with a paraphyletic Symphyta. The conservation of meiosis genes across Hymenoptera provides a framework for studying transitions between reproductive modes in this insect group.
减数分裂的细胞机制对于有性生物中正常配子的形成至关重要。在模式生物中的功能研究已经鉴定出减数分裂所必需的基因，然而，这种核心减数分裂机制在非模式系统中的保守程度尚未完全了解。此外，尚不清楚偏离典型有性生殖模式是否伴随着减数分裂中涉及的遗传成分的改变。我们采用了一种稳健的方法来鉴定膜翅目昆虫中的减数分裂基因并进行分类，膜翅目是一种通常以单倍体二倍体生殖为特征的昆虫目。利用新获得的基因组数据，我们在18种不同的膜翅目昆虫中搜索了43个参与减数分裂的基因。在大多数被调查的物种中发现了八个具有减数分裂特异性作用的基因中的七个，这表明单倍体二倍体膜翅目昆虫中核心减数分裂机制得以保留。对减数分裂基因清单的系统发育基因组分析以及共享基因重复和缺失的鉴定，为原尾目、姬蜂总科和针尾部类群以及并系的叶蜂类群中的物种分组提供了支持。膜翅目昆虫中减数分裂基因的保守性为研究该昆虫类群生殖模式之间的转变提供了一个框架。
