Genome footprints of selection to environmental stresses and reproductive fitness in Crossbreed taurine x Zebu cattle populations

Abstract

The immediate challenge of the livestock agricultural sector is to improve its productivity in a sustainable way. The most promising and shorter-term solution is crossbreeding, which is commonly practiced in the tropics and allows for improvement of productivity at first generation. However, the random processes of chromosomes segregation and recombination lead to a loss of productivity, adaptation to the local production systems and fitness in subsequent generations. Principal Investigators Olivier Hanotte (OH - UoN) and José Fernando Garcia (JFG - UNESP) propose to work together to understand how different cattie breeds/individuals could cope with environmental stress during its recent evolution and adaptation to tropical environments. The novelty of our approach relies on the study and comparison of a unique set of ancient and recent crossbreed taurine x zebu cattle on two continents (Africa and South America) and on the power of the latest genomic technologies (next generation sequencing and full genome genotyping by sequencing). It will allow us to go through genome wide surveys of fine mapped chromosomal regions of relevance to survival and productivity improvement, while identifying key mechanisms underlying the fitness of hybrid cattle' in tropical environments. We will aim to identify signatures of selection for adaptive traits in East African and Brazilian crossbreed cattle breeds and to identify genes and gene networks underlying these adaptations. (AU)