RUNS OF HOMOZYGOSITY, RECESSIVE DISEASE GENOTYPES, AND INBREEDING DEPRESSION IN DOMESTIC DOGS
SENIOR SCIENTIST, EMBARK VETERINARY INC.
Inbreeding leaves distinct genomic traces, most notably long genomic tracts that are identical by descent and completely homozygous. These runs of homozygosity (ROH) can contribute to inbreeding depression if they contain deleterious variants that are fully or partially recessive. The aim of this study was to examine the relationship between inbreeding measured from ROH the severity of inbreeding depression in several breeds for which phenotype data was available.
We examined genome-wide data from over 200,000 markers, which we used to build high-resolution ROH density maps for over 3,000 dogs, recording ROH down to 500 kilobases. Additionally, we utilized reproductive fitness-related phenotype data from the Morris Animal Foundation’s Golden
Retriever Lifetime Study, Doberman Pinscher longevity data from the Doberman Diversity Project, and other phenotype data collected from Embark Veterinary customers. We find that over the range of coefficient of inbreeding (COI) levels observed within several dog breeds, inbreeding depression is clearly evident using various types of phenotypic measures.
In most breeds, genetic testing to reduce the incidence of high COI litters will have a greater impact on animal welfare and population health than the current testing of known Mendelian disorders recommended by breed clubs.
Aaron Sams received his Master of Science in Biological Anthropology in 2010, as well as his Doctorate in Philosphy in 2012, both from the University of Wisconsin-Madison.
After spending almost four years post- graduation in Madison, Aaron went on to be a postdoctoral researcher at Cornell University before settling in at Embark, where he has been for almost four years.
He is an experienced interdisciplinary scientist with a background in biological anthropology, genomics, and computational biology. Aaron has a demonstrated history of working in the veterinary industry and uses computational methods to understand problem sin human evolutionary genomics. He is now applying those skills to canine genomics to help improve the lives of dogs.