Investigation of genetic diversity and selection signatures between Sarda and Sardinian Ancestral black, two related sheep breeds with evident morphological differences

Genetic diversity of two closely related sheep breeds, the Sarda and the Sardinian Ancestral Black, was investigated using different statistical approaches. A total of 210 sheep (94 Sarda and 116 Sardinian Ancestral Black) were genotyped using Infinium Ovine SNP50 v1 BeadChip. After filtering, 43,431 markers mapped on the 26 autosomal chromosomes were used in the analysis Basic population statistics (heterozygosity, minor allele frequency), linkage disequilibrium level, indicators of selection sweeps as the Wright fixation index (FST), and of autozygosity (Runs of Homozygosity) were calculated. Sarda breed showed higher linkage disequilibrium levels and a smaller effective population size. The FST and ROH approaches highlighted some regions on chromosomes 7, 10, 14, 19, and 20 that differ between the two breeds. Several known genes involved in morphological traits such as coat color (MC1R, MITF), horned/polled (RXFP2) and body size (NPY, VIP) and new putative ones (MYO5A, INSIG2 and ELOVL1) were detected.