Skip to Main content Skip to Navigation
Master thesis

Détection de mutations létales chez les ovins. Mise en évidence de segments chromosomiques homozygotes à partir d’informations moléculaires haute densité (60 000 SNPs)

Abstract : Reproduction and fertility are two main concerns in dairy sheep. Deleterious homozygous recessive mutations may emerge as a result of consanguinity and may have consequences on embryo development or survival of the young animal (so-called lethal mutations). To identify such mutations, a reverse genetic design was conducted to identify homozygous deficit in some chromosome segments. High-density genotyping data from genomic selection were used in two dairy sheep breeds, Lacaune and Manech à Tête Rousse. Eighteen regions with haplotypes covering 0.5 to 3 Mb exhibit deficit in homozygosity (from 81 to 100%). The frequencies of these haplotypes are between 3.9 and 17.4%. Among these regions, four Lacaune haplotypes and three Manech haplotypes show a total deficit of homozygous animals probably associated with lethal mutations. In Lacaune dairy sheep, the screening of whole genome sequence data revealed two highly deleterious variants in the PREB (involved during embryonic development) and CCDC65 genes (establishment of ciliary structures). However, genetic selection can also lead to homozygosity deficits linked to a gene under selection (such as SOCS2 gene associated to resistance to mastitis). If the causality of these variants is confirmed as lethal mutations, their integration in selection schemes could be considered in order to avoid matting between animals carrying the same mutation.
Complete list of metadata

Cited literature [131 references]  Display  Hide  Download

https://hal.inrae.fr/hal-02941680
Contributor : Stéphane Fabre <>
Submitted on : Thursday, September 17, 2020 - 11:20:37 AM
Last modification on : Friday, June 4, 2021 - 2:40:20 PM
Long-term archiving on: : Friday, December 4, 2020 - 6:50:58 PM

File

2019-BENBRAIEK_Maxime-mémoire...
Files produced by the author(s)

Identifiers

  • HAL Id : hal-02941680, version 1

Collections

Citation

Maxime Ben Braiek. Détection de mutations létales chez les ovins. Mise en évidence de segments chromosomiques homozygotes à partir d’informations moléculaires haute densité (60 000 SNPs). Génétique animale. 2019. ⟨hal-02941680⟩

Share