The study led by the Roslin Institute and Centre for Tropical Livestock Genetics and Health (CTLGH), analysed the DNA of indigenous sheep living in different parts of Ethiopia
Rainfall may have a significant influence on the evolution of sheep in Ethiopia, researchers have found. Genetic variations in sheep DNA are more linked to precipitation levels than to temperature or altitude, analysis of their genetic make-up and climatic data suggests.
A better understanding of environmental adaptation in native livestock breeds may help inform breeding and management strategies in tropical countries such as Ethiopia, where one-third of smallholders own sheep.
The Roslin Institute’s group sought to investigate if the environment had influenced changes in the sheep’s DNA to help them to thrive in different climates.
In one of the largest studies based on a single region, the researchers analysed the genomes of 94 sheep from 12 different areas of Ethiopia and examined them alongside detailed climatic information for each of the geographic regions.
Researchers compared the genomes of the sheep and found more than three million small differences in specific segments of their DNA. They then looked at the altitude, temperature and rainfall in each of the 12 geographical regions in the study and measured how many times these genetic variations occurred in sheep living under each of the environmental conditions.
There was a stronger association between the frequency of these genetic variations and precipitation levels compared with temperature or altitude, suggesting that rainfall is a more important environmental driver for genetic adaptation in Ethiopian sheep.