Genomic Footprints of Natural Selection for Ecological Adaptation in Ethiopian Cattle Populations

Natural selection has shaped the genetic diversity of African indigenous cattle genetic resources to adapt to their local environments and to changing environmental conditions. This diversity is detectable in the form of diseases resistance and tolerance to climatic conditions, but has not yet been well understood at the molecular level. Genomic scans for ecological adaptation between breeds adapted to specific ecological conditions could help to elucidate the genomic basis of local adaptation and to understand the genomic changes associated with the responses of organisms to their a biotic  environments. We have sampled indigenous Ethiopian cattle populations from arid/semi-arid and highland agro-ecologies and identified highly differentiated loci using Bovine SNP 80 K chip derived from the indicine breeds. Some of the highly differentiated loci were positioned within biologically important genes for skin pigmentation, hypoxia, feeding behavior, heat stress responses, immunity, body weight and meat quality. The follow-up study will include Ethiopian indigenous sheep populations collected in the same ecological zones/geographical regions. Positive selection of animals under similar local conditions might have accumulated key genomic components overlapping between species.