INRAE M. Dupont-Nivet
Publication GSE H. Lagarde & al.
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Publication GSE H. Lagarde & al.

Genetic selection could help reduce trout farm mortality during heat waves

In a study published in Genetics Selection Evolution, scientists from the UMR de Génétique Animale et Biologie Intégrative - GABI (INRAE/AgroParisTech/UPSaclay, Jouy-en-Josas) have described the genetic architecture of resistance to acute hyperthermia, i.e. the ability of fish to survive high temperatures. They have shown that 29% of performance variation in this trait is genetic in origin in a French commercial population, attesting to significant potential for genetic improvement. Genetic correlations of this trait with the main production traits - growth, % intramuscular fat and carcass yield - are close to zero. Selection for resistance to acute hyperthermia should therefore have no impact on these traits, and vice versa.

QTLs, areas of the genome significantly associated with resistance to acute hyperthermia, were finely identified using a high-density genotyping chip (665K genetic markers) recently developed in the unit. Only 6 QTL were detected, explaining less than 5% of the genetic variance. The genetic determinism of this trait is mainly linked to numerous genes with weak effects. Average performance differences between homozygotes opposite the most significant genetic marker were 69% phenotypic standard deviation. Close to this genetic marker, two convincing candidate genes, dnajc7 and hsp70b, were identified, encoding chaperone proteins already shown to be differentially expressed in response to heat stress in rainbow trout.

This study paves the way for a better understanding of the underlying mechanisms and the use of genetic markers to identify carriers of mutations conducive to resistance to acute hyperthermia.

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See also

Lagarde, H., Lallias, D., Patrice, P. et al. Genetic architecture of acute hyperthermia resistance in juvenile rainbow trout (Oncorhynchus mykiss) and genetic correlations with production traits. Genet Sel Evol 55, 39 (2023). https://doi.org/10.1186/s12711-023-00811-4

Modification date: 02 November 2023 | Publication date: 20 July 2023 | By: Edition P. Huan