P4041 Pooled whole-genome sequencing reveals molecular signatures of natural adaptive selection in Djallonke sheep of Ghana

Abstract

The Djallonke sheep is of high socioeconomic and cultural importance in at least 14 countries within the sub-Saharan region of Africa, mainly because it is well adapted to the harsh environmental conditions and major livestock disease within this region. The larger-framed Sahelian sheep breed that cohabits large parts of the region is less adapted to all these challenges. The most prominent among these adaptive attributes is resistance to trypanosomiasis and helminthosis, two parasitic diseases, which collectively cost the worldwide animal production industry billions of dollars annually. Here we sequenced and pooled whole genomic DNA from five individuals each of Djallonke and Sahelian sheep breeds sampled from Ghana, at greater than 22-fold average coverage on an ion proton sequencer. A total of approximately 404 million (97%) and 343 million (97%) sequence reads from the Djallonke and Sahelian, respectively, were successfully mapped to the sheep reference genome OviAri3. Preliminary analysis of the sequenced data of Djallonke breed showed several potential selective sweeps, some of which are co-localized within genomic regions known to harbor genes that mediate immune response in sheep. To the best of our knowledge, this is the first-ever whole-genome sequencing of these two sheep breeds. Our ongoing analysis of the sequenced data will provide a valuable resource for elucidating the underlying mutations and mechanisms of the numerous adaptive traits of the Djallonke sheep. This knowledge will not only ensure the sustainable breeding and utilization of the Djallonke sheep but will also have a long-term implication for the food security and poverty alleviation of all the 14 countries in the sub-Saharan African region.