Lay Summary Regions of an animal’s DNA can show signs of having been shaped by natural or human-driven selection. Over generations, sheep breeds living in different environments have adapted to local conditions, and this process has left detectable marks in their DNA. In this study, we compared three groups (plain, hill, and mountain), of Sarda and Valle del Belice sheep to understand how their genomes have changed in response to the environments. Using a more detailed genetic analysis than in our previous work, we confirmed and refined several DNA regions showing signs of adaptation, particularly in mountain sheep. We discovered genetic differences in the mountain groups of both breeds linked to muscle strength and to the regulation of hormonal, neural, cardiovascular, immune, and respiratory functions. These traits likely help mountain sheep remain strong, healthy, and productive in the cold, rugged, and pathogen-rich conditions typical of high-altitude environments. Although the specific genes differ between the two breeds, they influence similar biological functions, suggesting that both Sarda and Valle del Belice evolved similar strategies to thrive at high elevations.
Jemaa et al. (Thu,) studied this question.