Dcotta Helena_ID
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Helena D’Cotta

Senior researcher
CIRAD

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Work interests

Sex is determined by an extraordinary amount of mechanisms in teleosts, particularly evident in African cichlids. The Nile tilapia cichlid possesses an XX/XY system but sex is also influenced by parental factors and temperature. I work on the co-existence of genetic sex-determination and temperature-influences on sex-differentiation in this species. We are searching for the sex chromosomes, determiners, and LGs carrying temperature-reversal loci in wild African populations. I study how high-temperatures can reverse the sex, leading to male phenotypes that are genetically XX fish. I search for the genes implicated in genetic and temperature-induced differentiation in gonads and brain, finding epigenetic modifications associated with DNA methylation studies coupled to transcriptome analyses. My research has practical implications on Nile tilapia aquaculture, using genetic or temperature to control sex sustainably.
My other activities focus on the genetics and physiological pathways for salinity adaptation (up to 120 ppt) in the black-chinned tilapia in Senegal.

Keywords :

Sex-determination – Sex-differentiation – Tilapia – Temperature – Aquaculture

The Institute of Evolutionary Science of Montpellier (ISEM – University of Montpellier, CNRS, IRD, EPHE, CIRAD, INRAP) has been focusing research on biodiversity origins and dynamics and the associated evolutionary mechanisms.