Xiang Jie, Reding Katie, Heffer Alison, Pick Leslie
Program in Molecular and Cell Biology, University of Maryland, College Park, MD 20742, USA.
Department of Entomology, University of Maryland, College Park, MD 20742, USA.
Development. 2017 Dec 15;144(24):4625-4636. doi: 10.1242/dev.154039. Epub 2017 Oct 30.
A set of pair-rule (PR) segmentation genes (PRGs) promotes the formation of alternate body segments in Whereas embryos are long-germ, with segments specified more or less simultaneously, most insects add segments sequentially as the germband elongates. The hide beetle represents an intermediate between short- and long-germ development, ideal for comparative study of PRGs. We show that eight of nine PRG orthologs are expressed in stripes in Functional results parse these genes into three groups: -, - and - play roles in both germband elongation and PR patterning; - and - function exclusively as complementary, classic PRGs, supporting functional decoupling of elongation and segment formation; and orthologs of , , and show more variable function in and other species. While extensive cell death generally prefigured PRG RNAi-mediated cuticle defects, an organized region with high mitotic activity near the margin of the segment addition zone is likely to have contributed to truncation of embryos. Our results suggest general conservation of clock-like regulation of PR stripe addition in sequentially segmenting species while highlighting regulatory rewiring involving a subset of PRG orthologs.
一组成对规则（PR）分割基因（PRGs）促进了交替体节的形成。在长胚型胚胎中，体节或多或少同时被指定，而大多数昆虫在胚带伸长时依次添加体节。皮蠹代表了短胚型和长胚型发育之间的一种中间类型，是对PRGs进行比较研究的理想对象。我们发现九个PRG直系同源基因中的八个在[具体物种名称未给出]中以条纹形式表达。功能研究结果将这些基因分为三组：[基因名称1]、[基因名称2]和[基因名称3]在胚带伸长和PR模式形成中都发挥作用；[基因名称4]和[基因名称5]仅作为互补的经典PRGs发挥功能，支持伸长和体节形成的功能解耦；而[基因名称6]、[基因名称7]、[基因名称8]和[基因名称9]的直系同源基因在[具体物种名称未给出]和其他物种中表现出更多可变的功能。虽然广泛的细胞死亡通常预示着PRG RNAi介导的表皮缺陷，但在体节添加区边缘附近有一个具有高有丝分裂活性的有组织区域，可能导致了[具体物种名称未给出]胚胎的截断。我们的结果表明，在依次分割体节的物种中，PR条纹添加的类似时钟的调控具有普遍的保守性，同时突出了涉及一部分PRG直系同源基因的调控重排。
