Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, Storrs, CT 06269, USA.
Dev Genes Evol. 2010 Jun;220(1-2):11-24. doi: 10.1007/s00427-010-0324-6. Epub 2010 Apr 29.
The expression of the segment polarity genes wingless (wg) and engrailed (en) is highly conserved across arthropods, and these genes play a crucial role in patterning of the segmental body plan. Investigations of the expression and function of wg and en have focused primarily upon holometabolous insects, with the notable exception of recent detailed work in Oncopeltus (Hemiptera), Schistocerca, and Gryllus (Orthoptera). An increase in the phylogenetic breadth of our understanding of molecular patterning is crucial to ascertain the extent of conservation and divergence in molecular patterning mechanisms during insect embryogenesis. We examined the expression of wg mRNA transcripts and localization of En protein during embryogenesis in the mayfly Ephoron leukon (Ephemeroptera: Polymitarcyidae). These data represent one of the first embryonic gene expression pattern data for a mayfly, a lineage that may be the sister group to all other winged insects. Many aspects of wg and En expression are highly conserved, notably their expression in juxtaposed stripes in each parasegment, as well as expression domains in the procephalon, mouthparts, thoracic limbs, and nervous system. Future work in mayflies can be used to determine if conservation extends to other components of the segmentation hierarchy.
节段极性基因 wingless（wg）和 engrailed（en）的表达在节肢动物中高度保守，这些基因在节段体模式的形成中起着关键作用。对 wg 和 en 的表达和功能的研究主要集中在完全变态昆虫上，最近在 Oncopeltus（半翅目）、Schistocerca 和 Gryllus（直翅目）的详细研究是一个显著的例外。增加我们对分子模式形成的理解的系统发育广度对于确定昆虫胚胎发生过程中分子模式形成机制的保守性和分歧程度至关重要。我们检查了 Ephemeroptera：Polymitarcyidae 中的 Ephoron leukon（蜉蝣目）胚胎发生过程中 wg mRNA 转录本的表达和 En 蛋白的定位。这些数据代表了蜉蝣的第一个胚胎基因表达模式数据之一，蜉蝣可能是所有有翅昆虫的姊妹群。wg 和 En 表达的许多方面高度保守，特别是它们在每个节段中的相邻条纹中的表达，以及在前脑、口器、胸肢和神经系统中的表达域。在蜉蝣中的未来工作可以用来确定保守性是否扩展到节段层次结构的其他组成部分。
