Genetics Response of Small Ruminants to Heat Stress
Joram Mwacharo. (17/1/2018). Genetics Response of Small Ruminants to Heat Stress.
Predictions based on several scenarios suggest more frequent hot and fewer cold temperature extremes, on daily and seasonal timescales, as global mean temperatures rise. This will occasion more frequent droughts and increased water scarcity, which will substantially exacerbate food/feed insecurity and instability. The need for livestock that can support agricultural industries to meet projected increasing demands for animal source foods, and simultaneously cope with stresses arising from increasing global temperatures is thus a priority. Small ruminants (sheep and goats) are particularly important in this regard due to their resilience to adapt to a wide range of climes. Here, through the analysis of SNP genotype data, we present, at the genome-wide level, footprints of adaptation to biotic and abiotic stresses in desert-dwelling/adapted populations of indigenous sheep and goats. Our results suggest that the adaptation mechanisms involve a large network of interacting genes (found across several candidate genomic regions) and biological pathways. In particular, we reveal selection sweeps around candidate regions spanning genes associated with muscle function, energy metabolism, endocrine and nervous system function, thermo-tolerance and autoimmune and inflammatory response. The findings of the study offer a promising step towards mining the genetic potential of adaptable indigenous livestock as the foundation to breed appropriate small ruminants which can provide a viable option to mitigate against food insecurity and instability in increasingly volatile climatic events.