[Runs of Homozygosity Decipher Genetic Diversity in Cattle Breed Dwelling in the Colder Regions of the World].

Background: Our study focuses on Yakutian cattle, a Siberian native breed, examining its inbreeding and diversity through genome-wide analysis of runs of homozygosity (ROHs). Yakutian cattle are adapted to Siberia's harsh sub-arctic conditions, enduring temperatures below -70°C. However, the population genetics studies on this breed are scanty, to document the genetic uniqueness in these cattle.

Results: We analyzed 40 Yakutian cattle with strict quality control for ROH detection yielding 683 homozygous segments, averaging 17 per individual with an average length of 9 Mb. ROH regions were found to be involved in important pathways pertaining to cold adaptation. Autozygosity ranged from 1% to 12% of the genome, with a relatively low average inbreeding coefficient (FROH) of 0.057, as compared to other breeds. Also, the different diversity indicators, namely, principal component analysis, heterozygosity, and effective population size analysis, revealed the prevalence of genetic diversity within the breed.

Conclusion: Our findings on ROH are the first of its kind in Yakutian cattle that support their adaptability to colder environments, as evidenced by low inbreeding and high genetic diversity.