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bioRxiv · 10.1101/200360

Cis-regulatory evolution integrated the Bric-a-brac transcription factors into a novel fruit fly gene regulatory network

Williams, T. M.·Rebeiz, M.·Camino, E. M.·Roeske, M. J.·Grover, S.
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Abstract

Gene expression evolution through gene regulatory network (GRN) changes has gained appreciation as a driver of morphological evolution. However, understanding how GRNs evolve is hampered by finding relevant cis-regulatory element (CRE) mutations, and interpreting the protein-DNA interactions they alter. We investigated evolutionary changes in the duplicated Bric-a-brac (Bab) transcription factors and a key Bab target gene in a GRN underlying the novel dimorphic pigmentation of D. melanogaster and its relatives. It has remained uncertain how Bab was integrated within the pigmentation GRN. Here we show that Bab gained a role in sculpting sex-specific pigmentation through the evolution of binding sites in a CRE of the pigment-promoting yellow gene and without any noteworthy changes to Bab protein coding sequences. This work demonstrates how a new trait can evolve by incorporating existing transcription factors into a GRN through CRE evolution, an evolutionary path likely to predominate newly evolved functions of transcription factors.

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Williams, T. M., Rebeiz, M., Camino, E. M., Roeske, M. J., Grover, S.. 2017-10-09. Cis-regulatory evolution integrated the Bric-a-brac transcription factors into a novel fruit fly gene regulatory network. https://doi.org/10.1101/200360

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