Application of genomic data to assist a community-based breeding program: A preliminary study of coat color genetics in Morada Nova sheep

Abstract

The Brazilian Sheep Breeders' Association recognizes two varieties of the Morada Nova hair breed, white and red. However, the black variety and/or animals with a pigmented nose has frequently been disqualified from genealogical records. Previous studies suggest that this genetic group might be similar to the red variety. Thus, the aim of this study was to conduct a Genome-wide association study (GWAS) to identify genomic regions related to hair color and confirm the position of black relative to other Morada Nova varieties. After quality controls, 48 animals were genotyped for 45.982 SNPs using the OvineSNP50k BeadChip. Estimated Fst values between white and red animals, white and black, and red and black were 10.78% (p<0.00001), 9.23% (p<0.00001), and 2.93% (p<0.00001), respectively. The comparison between white and red (n=30) versus black (n=18) animals revealed 10 highly significant SNPs, most located in a 6.8Mb window in Oar14 which contains the MC1R gene. Differences between black and red coats are the result of the expression of different alleles of the same gene without directly affecting productive/reproductive characteristics. These two varieties showed low genetic variation, insufficient to define them as different groups, and to increase the breeding herd, the animals with black hair and/or pigmentation of the nose should be used breeding purposes. The results of this study contribute to the discussion of the importance in reconciling conservation, traditional breed standards and breeding of farm animals.