Poster Annual Conference of the Genetics Society of Australasia with the NZ Society for Biochemistry & Molecular Biology

Regulation and Evolution of Complex Developmental Gene Networks (671)

Andrew G Cridge 1 , Elizabeth A Permina 2 , Peter K Dearden 1
  1. University of Otago, Dunedin, New Zealand
  2. Otago Genomics & Bioinformatics Facility, Dunedin, New Zealand

Our aim is to understand how conserved genes change their role in the evolution of the insect segmentation network, how the network buffers change, and how that might constrain, or confer diversity of body plan.

We performed ChIP-seq with antibodies to early segmentation transcription factors caudal, hunchback and orthodenticle on embryonic tissue from Drosophila melanogaster, Apis mellifera and Acyrthosiphon pisum.

The ChIP-seq study identified multiple cis-regulatory motifs (CRMs) and gene targets for the three transcription factors in each of the insect species studied.  Bioinformatic analysis allowed confident prediction of biologically important CRMs, as well as providing information on specific DNA sequences recognized by each of the transcription factors.  In addition, we identified core ancestral genes regulated during embryo development responsible for embryonic patterning.  We also identified genes that are regulated in only one species.  These genes represent evolution of the network through a mechanisms that buffers change but still allow conserved segmentation output.

By continuing to study these genes we will learn how genes become co-opted into developmental networks, how such co-opted genes integrate with the rest of the network, and if these genes act to buffer regulatory changes in the transcription factors themselves.  This also identifies the level of genetic robustness on which embryonic selection can act.  This data has provided us, for the first time, with an understanding of how the targets of key transcription factors change over evolutionary time, effectively a measure of evolutionary change in a complex transcription factor network.