Differentiation of South Italian goat breeds in the focus of biodiversity conservation

Abstract

This study analysed the genetic differentiation of six Italian goat breeds reared in Sicily (Girgentana, Maltese, Rossa Mediterranea, Argentata dell’Etna, Messinese) and Calabria (Capra dell’Aspromonte). The aim was to assess the conservation priorities and to design strategies for a sustainable conservation of these populations. A set of 20 microsatellite markers was used to estimate the main parameters of biodiversity in the Italian breeds and in a sample of Norwegian dairy goat breed which was an out-group for the phylogenetic analysis and for the investigation of the population structure. The conservation priorities were assessed in the six Italian goat breeds, through different scientific approaches. In the whole sample (207 goats), representative of 7 populations, a total of 218 alleles (average 10.9) were found. The gene diversity, in terms of expected heterozygosity (He), had the lowest values in Norwegian (0.614) and Girgentana (0.708), the highest in Argentata dell’Etna (0.753). The overall fixation index (FST) showed a moderate rate of differentiation at population level (5.9%). Norwegian, Girgentana and Maltese reported the highest degree of differentiation in the set. The clustering analysis identified K=5 as the most probable number of ancestral clusters; among the Italian breeds, Girgentana and Maltese revealed a good internal cohesion, whereas Argentata dell’Etna, Messinese, Capra dell’Aspromonte and Rossa Mediterranea showed a rather high rate of admixture. Finally, the methods implemented to assess conservation priorities pointed out Maltese, Girgentana and, at lesser extent, Messinese and Argentata dell’Etna as the breeds of choice in the context of safeguarding programmes.