Journal Article
Evolution of the regulation of developmental gene expression in blind Mexican cavefish
Leclercq, J., Torres-Paz, J., Policarpo, M., Agnès, F. and Rétaux, S.
Record Number:
5994
Year:
2022
Journal:
bioRxiv preprint July 14 2022
Pages:
1-29
Notes:
bioRxiv preprint. Tthis version posted July 14, 2022. The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license
Abstract:
Changes in gene expression regulation during development are considered the main drivers of morphological evolution and diversification. Here, we analysed the embryonic transcriptomes of surface-dwelling and blind cave-adapted morphs of the species Astyanax mexicanus and their reciprocal F1 hybrids at tailbud stage. Comparing gene expression in parents and allelic expression ratios in hybrids, we found that ~20% of the transcriptome is differentially expressed and that cis-regulatory changes are the main contributors to variations in early developmental gene expression in the two morphs. We provide a list of 108 cis-regulated genes that could contribute to cavefish developmental evolution, and further explore the regulatory mechanisms controlling the cellular and regional expression of rx3, a “master eye gene”. Using quantitative embryology approaches after fluorescent in situ hybridisation, cell transplantations and interference with signalling pathways, we show that rx3 cellular levels -controlling optic cell fates- are regulated in cis and in a cell-autonomous manner, whereas the size of rx3 domain -controlling eye size- depends on non-autonomous Wnt signalling. Altogether, we reveal how distinct mechanisms and regulatory modules can regulate developmental gene expression and shape developmental evolution, with negligible contribution of coding mutations.
Times Cited:
1
Relevent Species: