Histological Characterization and Genomic Localization of the Lykoi Breed Hair Variant

Naturally occurring hair type variants are often used to establish new feline breeds. Often a novel mutation associated with a hair texture variant can be fixed within several generations in a line used to create a new variety of cats. A new breed of cats called Lykoi characterized by a roaning coat type, was developed in United States from a domestic shorthair cat. The phenotype resembles a werewolf, due to the even mixture of black and white hair in their coat. Breeding experiments confirmed that the novel hair type variant has an autosomal recessive mode of inheritance. Histological examination of Lykoi and Domestic shorthair control skin biopsies showed a significant difference in follicles per hair follicle unit as well as the number of hairs per follicle. The Lykoi showed a significantly lower number in both measurements. A genome-wide association study was conducted by genotyping on the 63K Feline Illumina Infinium array, 20 cases and 12 controls sampled from the Lykoi breed. After SNPs frequency and genotyping pruning, over 40,000 SNPs were available for the analyses. A significant association was detected on cat chromosome B1, localizing the phenotypic locus within a haplotype block conserved across all cases spanning over 1 Mb in length. MDS and genomic inflation showed that the association is significant without biases by population stratification. To unravel the variant associated with the aesthetic trait, genes within the haplotype block will be sequenced and variants typed in several feline populations to confirm the association with the hair coat phenotype.