Genetic diversity and variability in Alpine sheep breeds.

The aim of this study was to analyze, through the use of microsatellite molecular markers, the genetic diversity and variability of nine Alpine sheep breeds reared in Italy (Bergamasca, Biellese, Schwarzbraunes Bergschaf, Tiroler Bergschaf, and Schnalserschaf), Germany (Brillenschaf and Weisses Bergschaf) and Slovenia (Bov\u2c7ska and Jezerzk\u2c7o Sol\u2c7cavska), and one Italian crossbreed population. Allelic richness was rather high in each breed highlight- ing a considerable genetic diversity. However, the study evidenced a signi\ufb01cant departure from Hardy\u2013Weinberg equilibrium in all analyzed breeds caused by a heterozygote de\ufb01ciency. Such lack seems to be caused both to the presence of population substructure within breed and to a rather high level of inbreeding. The genetic differentiation among breed was rather low (F ST = 0.057) but signi\ufb01cant. The clustering analysis performed with STRUCTURE detected the presence of eight clusters; Schwarzbraunes Bergschaf and Tiroler Bergschaf were grouped together and Biellese and Bergamasca as well, evidencing a high similarity of their genetic make up. Reynolds\u2019 genetic distance estimates con\ufb01rmed the close relationship between these pairs of breeds. Moreover, Bov\u2c7ska, Jezerzk\u2c7o-Sol\u2c7cavska and Brillenschaf resulted rather similar as expected according to their region of origin and to their com- mon ancestors. Molecular coancestry con\ufb01rmed as well such \ufb01ndings, suggesting that the studied breeds had origin from different ancestral populations. Concluding, microsatellite resulted a useful tool to investigate breed variability and to characterize Alpine sheep breeds. Obtained \ufb01ndings suggest the need to set up a conservation plan aiming to safeguard and increase the genetic variability of the studied breeds compromised by the high level of inbreeding. Microsatellites genotyping could help to monitor breed variability and to organize matings