Genome wide analyses reveal the population distinctiveness of the 'Nera del Mela' sheep

Italy has a long history of sheep breeding and counts several local populations that may represent a unique source of genetic diversity. Among these, Nera del Mela is a sheep genetic resource historically reared in Sicily but not officially recognised as a breed. In this study, we genotyped 36 individuals of Nera del Mela using the OvineSNP50K array, in order to estimate the genetic diversity and evaluate the population structure and relatedness with other Italian sheep breeds. Genetic diversity indices, and inbreeding estimated from runs of homozygosity (F-ROH) revealed a moderate level of variability. Runs of homozygosity islands mapped candidate genes involved in the adaptation to local environment and immune response. Population genetic analyses using different approaches highlighted the hypothesis that this sheep possesses a defined genetic structure, especially if compared with other recognised breeds, despite the influence of other populations such as the Sicilian breeds. Overall, our findings represent a starting point for the possible official acknowledgement of this population, for the creation of a conservation plan, and thus for preserving this genomic heritage.

Automated summary

Italy has a long history of sheep breeding and Nera del Mela, a sheep genetic resource historically reared in Sicily, possesses a defined genetic structure. The genetic diversity and population structure of Nera del Mela were evaluated using the OvineSNP50K array, revealing a moderate level of variability and the influence of other populations. The findings contribute to the possible official acknowledgement, conservation plan, and preservation of this genomic heritage.