The Rambouillet sheep breed: a unique chance to investigate inbreeding at genome level
| Autor: | Coralie Danchin-Burge, Anna-Charlotte Doublet, Gwendal RESTOUX |
|---|---|
| Přispěvatelé: | Institut de l'élevage (IDELE), Génétique Animale et Biologie Intégrative (GABI), Université Paris-Saclay-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | 68th Annual Meeting of the European Federation of Animal Science 68th Annual Meeting of the European Federation of Animal Science, Nov 2020, Tallin, Estonia HAL |
| Popis: | International audience; The negative effects of inbreeding (higher occurrence of genetic defects, inbreeding depression…) are well knownby breeds’ managers. However we still have a poor insight of how the genome is impacted by inbreeding. Forover a 200 years period, a French sheep breed called the Rambouillet has been kept in a single flock without anyintrogression. Pedigree information was fully recorded since the 1870s. For the last fifty years, minimizing thebreed’s inbreeding level has been the only goal of its management plan. It reached 52% for nowadays animalsaccording to simulation data based on pedigrees. Despite this level, the breed’s weight, prolificacy and fertility havenot changed over the last forty years. Altogether this breed gives a unique opportunity to explore the consequencesof inbreeding at the genome level. To do so, we used a high density chip (600 K SNP) on a panel of 46 individuals.Among these animals, 38 were born between 2006 and 2012, and eight are older males born in the 1980s whosesamples come from the French National Cryobank. First results showed that the genome of the breed was highlystructured with a very low level of diversity. However the genomic inbreeding level based on run of homozygosity(ROH) was about half the estimation based on pedigree information, and a very weak inbreeding depression wasdetected. Therefore, we investigated more precisely at the chromosome level for ‘cold spots’ of diversity basedon ROH. When compared with two related breeds, the Mourerous and the Arles, the Rambouillet showed muchmore ROH segments, but the total length of ROH is actually lower than expected. Linkage disequilibrium (LD)was also calculated at chromosome level and the genome structure appeared to differ between each chromosome.This information suggests a mutational load purge that occurred throughout the years. Ongoing research seems toconfirm this hypothesis since hot spots of diversity are found in regions with genes involved in major developmentpatterns (such as cells division). Finally, the Rambouillet sheep proves to be a valuable source of investigation inthe understanding the genome aspects of inbreeding. |
| Databáze: | OpenAIRE |
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