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Genetic diversity and selection signatures in sheep breeds
Julia Lisboa Rodrigues1, Larissa Graciano Braga1, Rafael Nakamura Watanabe1
1Departamento de Ciências Exatas, Universidade Estadual Paulista (UNESP), Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal, Brazil.
Journal of Applied Genetics
|January 30, 2025
Summary
This study identified selection signatures in Irish sheep breeds, revealing genes linked to reproduction, milk, meat, and parasite resistance. Moderate genetic diversity was observed across breeds.
Area of Science:
- Animal Genetics
- Genomics
- Evolutionary Biology
Background:
- Domestication involves natural and artificial selection, creating distinct genomic regions called selection signatures.
- Understanding these signatures in livestock like sheep is crucial for breeding and conservation.
Purpose of the Study:
- To identify and characterize selection signatures in five Irish sheep breeds.
- To investigate genetic diversity and linkage disequilibrium patterns.
- To pinpoint genes associated with economically important traits.
Main Methods:
- Employed integrated haplotype score (iHS) and Tajima's D tests on 9498 sheep across five breeds.
- Analyzed non-overlapping 100 kb windows to detect selection signatures.
- Estimated genetic diversity and linkage disequilibrium.
Main Results:
- All breeds exhibited selection signatures, with some overlapping regions indicating longer segments under selection.
- Suffolk and Texel breeds showed the least genetic variation and slower linkage disequilibrium decay.
- Identified genes within selection signatures related to immunity (e.g., ITGA4, TLR3), reproduction (e.g., DLG1, ROBO2), milk (WDR70), meat (SCHM1), and adaptive traits (TAS2R family).
Conclusions:
- The studied sheep breeds possess moderate genetic diversity.
- Selection signatures were successfully detected and characterized, highlighting genes crucial for various production and adaptive traits.
- Findings provide valuable insights for sheep breeding programs and genetic resource management.
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