The genetic consequences of dog breed formation —Accumulation of deleterious genetic variation and fixation of mutations associated with myxomatous mitral valve disease in cavalier King Charles spaniels

by Erik Axelsson, Ingrid Ljungvall, Priyasma Bhoumik, Laura Bas Conn, Eva Muren, Åsa Ohlsson, Lisbeth Høier Olsen, Karolina Engdahl, Ragnvi Hagman, Jeanette Hanson, Dmytro Kryvokhyzha, Mats Pettersson, Olivier Grenet, Jonathan Moggs, Alberto Del Rio-Espinola, Christian Epe, Bruce Taillon, Nilesh Tawari, Shrinivas Mane, Troy Hawkins, Åke Hedhammar, Philippe Gruet, Jens Häggst röm, Kerstin Lindblad-Toh Selective breeding for desirable traits in strictly controlled populations has generated an extraordinary diversity in canine morphology and behaviour, but has also led to loss of genetic variation and random entrapment of disease alleles. As a consequence, specific diseases are now prevalent in c ertain breeds, but whether the recent breeding practice led to an overall increase in genetic load remains unclear. Here we generate whole genome sequencing (WGS) data from 20 dogs per breed from eight breeds and document a ~10% rise in the number of derived alleles per genome at evolutionarily cons erved sites in the heavily bottlenecked cavalier King Charles spaniel breed (cKCs) relative to in most breeds studied here. Our finding represents the first clear indication of a relative increase in levels of deleterious genetic variation in a specific breed, arguing that recent breeding practices probably were associated with an accumulation of genetic load in dogs. We then use the WGS data to identify candidate risk alleles for the most common cause for veterinary care in cKCs–the...
Source: PLoS Genetics - Category: Genetics & Stem Cells Authors: Source Type: research