Genetic Structure and Selective Signature Analysis of Xinjiang Local Sheep Populations.

Area of Science:

• Genomics
• Animal Genetics
• Evolutionary Biology

Background:

• Xinjiang's diverse environments harbor unique sheep genetic resources.
• Understanding population structure and adaptive mechanisms is crucial for conservation and breeding.

Purpose of the Study:

• To investigate the population genetic structure of seven indigenous Xinjiang sheep breeds.
• To identify genes and pathways underlying adaptation to extreme environments (high-altitude, heat stress).
• To uncover the genetic basis of economically important traits like body size.

Main Methods:

• Whole-genome resequencing of 140 sheep individuals.
• Identification of over 18.7 million high-quality single nucleotide polymorphisms (SNPs).
• Application of population genetics analyses and selection signature detection methods (F_ST, π ratio, XP-CLR).

Main Results:

• All populations showed comparable genetic diversity, with variations across breeds.
• Geographic isolation primarily drives genetic differentiation, with Kirgiz sheep most distinct.
• Identified genes under selection related to high-altitude adaptation (Kirgiz) and heat stress tolerance (Turpan Black).
• Discovered candidate genes (e.g., CUX1, KIT) influencing body size through regulatory networks.

Conclusions:

• Provides a comprehensive genomic framework for Xinjiang sheep breeds.
• Elucidates genetic adaptations to extreme environments and the basis of economic traits.
• Offers valuable genetic targets for future sheep breeding programs and functional studies.