Selection Signatures in Italian Goat Populations Sharing the “facciuto” Phenotype

The presence of light-pigmented facial stripes, parallel on bothsides of the cranial region, is a widespread characteristic in various goat breeds of Europeanorigin and beyond. In Italy, this phenotype is relatively common from the north to the southof the peninsula. The availability of genotypic data at single-nucleotide polymorphism(SNP) loci for breeds and populations characterized by such a pigmentation pattern enabledus to study the genomic regions potentially correlated with this phenotype, for simplicityreferred to as “facciuto”. Methods: We adopted an FST-outlier approach to detect signals ofdifferential selection in 18 pairwise comparisons, each involving 6 genetic goat types withthe “facciuto” phenotype (Facciuta Lucana, Facciuta della Valnerina, Valfortorina, Teramana,Capestrina, and Roccaverano) contrasted with each of 3 “non-facciuto” goat breeds selectedas reference populations (Red Mediterranean, light brown; Saanen, white; Malagueña,mahogany solid). Results: The analysis of the region ±200 kbps upstream and downstreamof the two signifi cant signals on chromosome 13 and 15 allowed us to identify, amongthe annotated genes, ASIP, AHCY, ITCH, DYNLRB1, MAP1LC3A, PIGU, LOC102177263,and DTX4, whose functions could be related to several mechanisms underlying the phe-notype under investigation. Conclusions: This study confi rmed the fundamental role ofASIP in pigmentation, although additional pathways may concurrently contribute to thedeterminism of the considered “facciuto” phenotype in Italian goats.