Nasoniasegmentation is regulated by an ancestral insect segmentation regulatory network also present in flies

Abstract

AbstractInsect segmentation is a well-studied and tractable system with which to investigate the genetic regulation of development. Though insects segment their germband using a variety of methods, modelling work implies that a single gene regulatory network can underpin the two main types of insect segmentation. This means limited genetic changes are required to explain significant differences in segmentation mode between different insects. Evidence for this idea is limited toDrosophila melanogaster, Tribolium castaneum, and the spiderParasteatoda tepidariorum, and the nature of the gene regulatory network (GRN) underlying this model has not been tested. Some insects, for exampleNasonia vitripennisandApis melliferasegment progressively, a pattern not examined in studies of this segmentation model, producing stripes at different times throughout the embryo, but not from a segment addition zone.Here we aim to understand the GRNs patterningNasoniausing a simulation-based approach. We found that an existing model ofDrosophilasegmentation (Clark, 2017) can be used to recapitulateNasonia’s progressive segmentation, if provided with altered inputs in the form of expression of the timer genesNν-caudalandNν-odd paired. We also predict limited topological changes to the pair rule network. Together this implies that very limited changes to theDrosophilanetwork are required to simulateNasoniasegmentation, despite the differences in segmentation modes, implying thatNasoniause a very similar version of an ancestral GRN also used byDrosophila.