Genetics
Genetic Diversity in the Bearded Collie
Dr. Jerry Bell
- Genetic Diversity Analysis – AKC Bearded Collie Stud Book Analysis (2017)
- Genetic Health of the Bearded Collie.
- Video of 2021 BCCA National Specialty Health Seminar
- Pedigrees, gene pool of the breed, and breeding
- Health and genetic testing
- Links to seminar handouts are below the video
- Video of 2021 BCCA National Specialty Health Seminar
Dr. Anita Oberbauer's Lab
Measures of Homozygosity and Relationship to Genetic Diversity in the Bearded Collie Breed. Belanger, J.M. et.al. Genes 2025, 16(4), 378. Lay summary.
In purebred dogs, limited genetic diversity, popular sire effects, and common ancestry can lead to elevated levels of inbreeding and homozygosity. Inbreeding and a high degree of homozygosity are associated with a reduction in health and overall fitness. Historically, breeding goals have focused on maintaining breed-defining characteristics and removing deleterious traits. These goals may increase the level of homozygosity,
thus reducing heterozygosity. To maximize genetic diversity, that is heterozygosity, it has been suggested that breeding decisions should include measures of genetic diversity. In the past, breeders utilized pedigree relatedness to balance mate choice for desirable traits while avoiding excessive inbreeding. Now, commercial companies offer genetic tests for inbreeding based upon single nucleotide polymorphisms (SNPs) in
array analyses. This leads to the question of what are the best measures of genetic diversity?
Measures of genetic diversity rely upon estimates of homozygosity without consideration of whether the homozygosity is desirable or undesirable or if heterozygosity has a functional impact. Pedigree coefficients of inbreeding have been the classical approach yet they are inadequate unless based upon the entire population. Homozygosity measures based upon pedigree analyses (n = 11,898), SNP array data (n = 244), and whole genome sequencing (n = 23) were compared in the Bearded Collie, as well as a comparison of SNP array data to a pedigree cohort (n = 5042) and a mixed-breed cohort (n = 1171).
Conclusions: Using typical DNA-based measures reflect only a single individual and not the population thereby failing to account for regions of homozygosity that reflect ancestral breeding, domestication history, breed-defining regions, or regions positively selected for health traits. Incorporating measures of genetic diversity into dog breeding schemes is meritorious. However, until measures of diversity can distinguish between breed-defining homozygosity and homozygosity associated with positive health alleles, the measures to use as selection tools need refinement before their widespread implementation.
The Applied Genetics of Dog Breeding
A collection of articles from the Australian Shepherd Health and Genetics Institute, Inc. CA Sharp.
Canine Coat Color Genetics of the Bearded Collie with Embark Data on Color Traits
A slide presentation that incorporates color trait data from Embark.
Coat Variation in the Domestic Dog
This research by Cadieu, et. al. (Science, 2009) was about genetic variants influencing coat growth pattern, length, and curl.
Genome wide studies of over 1000 dogs from 80 domestic breeds were studied. The focus was on structured patterns of fur variations to localize the genetic basis of three characteristics of the canine coat. These three mutations in various combinations were found in 95% of dogs sampled; those included 108 of the approximately 160 AKC breeds at the time.
- Presence or absence of “furnishings”, the growth pattern marked by a moustache and eyebrows typically observed in wire-haired dogs
- Hair length
- Presence or absence of curl
Seven phenotypes were identified from various combinations of the three characteristics. The Bearded Collie was in the group having long coat with furnishings with two mutations named FGP5 and RSPO2.