Adaptmap WG7 & 8 - Global Diversity and Selection Signatures in Goats

The goat ADAPTmap project is an international initiative launched to join and coordinate the genotyping and re-sequencing efforts of the International Goat Genome Consortium (IGGC), the African Goat Improvement Network (AGIN), Feed the Future program of the USAID and NEXTGEN EU project. The study of goat adaptation to different environments is one of the major aims of ADAPTmap project: since goats have a worldwide distribution and thrive across a variety of contrasting habitats, they represent an optimal case study to disentangle the genetics of adaptation. An extensive knowledge of the distribution of diversity is prerequisite to the identification of signatures of selection, thus a first analysis has been undertaken to describe the patterns of molecular variation across Africa, Europe and Western Asia, and a second to identify the signals of adaptation to environmental or human-mediated selective pressures. The analyses have been carried out with a variety of analytical approaches on a set of 144 breeds genotyped with the Illumina GoatSNP50 BeadChip and representing 36 countries from 5 continents. The results obtained so far highlighted the presence of a strong geographical partitioning of diversity among continents and further sub-structuring which mirrors the main post-domestication migration routes. The selection signatures analyses were accomplished by contrasting breed groups according to environments, purposes, and phenotypes, and also by a landscape genomics approach. The first results revealed, as expected, a strong signal on chromosome 6 in the region of the casein genes, while additional signals on other chromosomes are currently under investigation.