Xbp1 and Brachyury establish an evolutionarily conserved subcircuit of the notochord gene regulatory network

Yushi Wu, Arun Devotta, Diana S José-Edwards, Jamie E Kugler, Lenny J Negrón-Piñeiro, Karina Braslavskaya, Jermyn Addy, Jean-Pierre Saint-Jeannet, Anna Di Gregorio
2022 eLife  
Gene regulatory networks coordinate the formation of organs and structures that compose the evolving body plans of different organisms. We are using a simple chordate model, the Ciona embryo, to investigate the essential gene regulatory network that orchestrates morphogenesis of the notochord, a structure necessary for the proper development of all chordate embryos. Although numerous transcription factors expressed in the notochord have been identified in different chordates, several of them
more » ... ain to be positioned within a regulatory framework. Here we focus on Xbp1, a transcription factor expressed during notochord formation in Ciona and other chordates. Through the identification of Xbp1-downstream notochord genes in Ciona, we found evidence of the early co-option of genes involved in the unfolded protein response to the notochord developmental program. We report the regulatory interplay between Xbp1 and Brachyury, and by extending these results to Xenopus, we show that Brachyury and Xbp1 form a cross-regulatory subcircuit of the notochord gene regulatory network that has been consolidated during chordate evolution.
doi:10.7554/elife.73992 pmid:35049502 pmcid:PMC8803312 fatcat:lun7t3eqirbb3bfw744qgdz45a