Affiliation:
1. Department of Entomology, 4291 Fieldhouse Drive, University of Maryland, College Park, MD 20742, USA
Abstract
The discovery of pair-rule genes (PRGs) in Drosophila revealed the existence of an underlying two-segment-wide prepattern directing embryogenesis. The milkweed bug Oncopeltus, a hemimetabolous insect, is a more representative arthropod: most of its segments form sequentially after gastrulation. Here we report the expression and function of orthologs of the complete set of nine Drosophila PRGs in Oncopeltus. Seven Of-PRG-orthologs are expressed in stripes in the primordia of every segment, rather than every-other segment, Of-runt is PR-like, and several are also expressed in the segment addition zone. RNAi-mediated knockdown of Of-odd-skipped, paired and sloppy-paired impacted all segments, with no indication of PR-like register. We confirm that Of-E75A is expressed in PR-like stripes, although it is not PR in Drosophila, demonstrating the existence of an underlying PR-like prepattern in Oncopeltus. These findings reveal that a switch occurred in regulatory circuits leading to segment formation: while several holometabolous insects are “Drosophila-like,” utilizing PRG-orthologs for PR-patterning, most Of-PRGs are expressed segmentally in Oncopeltus, a more basally-branching insect. Thus, an evolutionarily stable phenotype – segment formation – is directed by alternate regulatory pathways in diverse species.
Funder
National Institutes of Health
Publisher
The Company of Biologists
Subject
Developmental Biology,Molecular Biology
Cited by
19 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献