Genetic diversity of Cornigliese sheep breed using STR markers

tTo preserve sheep biodiversity is an important issue as the most productive breeds arebecoming dependent on intensive management and breeders are abandoning the tradi-tional breeds. The Cornigliese sheep is a local breed from Parma Apennine. In the lastcenturies it was crossed with Merino and Bergamasca breeds. The aim of this work is toinvestigate the genetic variability in the Cornigliese breed using 27 microsatellite markers.A total of 144 individual blood samples were randomly collected from the following breeds:Cornigliese, Bergamasca, Appenninica and Spanish Merino. The Palmera breed was used asout-group. A total of 344 alleles were detected. The average expected heterozygosity rangedfrom a maximum of 0.77 in Appenninica to a minimum of 0.68 in Bergamasca. In general,Cornigliese showed heterozygosity estimates less than expected. The Reynolds weightedgenetic distance among the breeds highlighted a clear cluster, including Cornigliese andBergamasca. As expected, they appeared in close neighbourhood in the tree because of thehistoric crossbreeding practices between these two breeds. Results of STRUCTURE analy-ses show that the four studied breeds were discriminated into separate clusters, even ifCornigliese has some individual related to Bergamasca and Spanish Merino. This work con-firmed the historical information about the origin of Cornigliese breed which reports geneflow among these breeds. The genetic parameters show a moderate value of inbreeding inCornigliese and therefore this breed should be monitored due the low number of individualsthat compose it.