Scientists identify DNA ‘hotspots' that tell zebrafish to change sex in warmer waters
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Loading... - Wariba Nkoa
- 05 Oct 2022
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Scientists identify 54 ‘hotspots’ in the genome for cross-talk between the environment, in particular water temperature, and genes predisposing zebrafish to develop into either sex. There, DNA methylation prompts genetic pathways to change, allowing the influence of temperature to ‘overrule’ the sex-determining genes. As a result, certain born females develop into males.
Higher water temperatures induce specific chemical tags at targeted locations on the DNA of embryonic zebrafish. These ‘epigenetic’ changes can then reroute genetic pathways, so that the embryos change sex. This finding, in Frontiers in Cell and Developmental Biology, is not just of fundamental scientific interest. It’s also relevant for conservation, since an influence of temperature on sex determination could be recipe for disaster for species living through rapid climatic change.
The study’s first author, Dr Shahrbanou Hosseini, a postdoctoral researcher at the Molecular Livestock Science and Diagnostics Group of the Department of Animal Sciences at Göttingen University, said: “Here we show that epigenetic modifications influence the variation in sex ratio between zebrafish families. This implies that the interaction between genotype and environment in determining sex is mediated by epigenetics.”
Genes interact with environment to determine sex
From high school biology, most of us are familiar with chromosomal sex determination, for example the XX/XY system of mammals. But in many species, sex is partly or completely determined by the environment. There, genes can predispose to a particular sex, but may be ‘overruled’ by the influence of the environment, for example temperature or population density. But through which mechanisms might the environment make its mark on the genome in such species? Read More...
