Thesis
Evolution of the eye in Astyanax mexicanus : contribution of maternal and early developmental regulations
Leclercq, J.
Record Number:
6022
Year:
2022
University:
Université Paris-Saclay
Notes:
The full text of this thesis will be freely accessible from 26-09-2024
Abstract:
We are interested in understanding the developmental variations at the origin of morphological evolution and adaptation of species to their environment. For this, we use as a model the fish Astyanax mexicanus, which has the advantage of having two interfertile morphotypes living in very different environments: surface fish that live in the rivers of Central America, and cavefish, blind and depigmented, living in the dark caves in northern Mexico. This thesis aims to study the early developmental variations that cause the defective eye development in cavefish.First, we analyzed the transcriptome of surface, cave and reciprocal hybrids embryos at the end of gastrulation, to study the evolution gene expression regulation at this stage. Our results allowed us to identify 108 genes with expression changes due to modification in cis-regulatory sequences. Among these genes, we studied the regulation of rx3 expression, a transcription factor responsible for eye formation.In another study, we analyzed by in situ hybridization the differences during gastrulation between cave and surface embryos. We highlighted a change in the migration rate of axial mesoderm cells between the two morphotypes. Analysis of reciprocal hybrids revealed maternal control of this phenotype. Next, RNA-seq analysis of the maternal transcriptome revealed many differences in gene expression between the two morphotypes. The current work aims to develop a technique for the degradation of RNAs by CRISPR-cas13d to functionally study the role of identified maternal and zygotic candidate genes in the development of the eye.
Times Cited:
1
Relevent Species: