Loci Associated with Negative Heterosis for Viability and Meat Productivity in Interspecific Sheep Hybrids

Area of Science:

• Animal Genetics
• Genomics
• Livestock Breeding

Background:

• Negative heterosis, or inbreeding depression, impacts economically important traits in livestock.
• The underlying genetic mechanisms of negative heterosis remain largely uncharacterized.
• Interspecific hybridization in sheep (Ovis aries) and argali (Ovis ammon) presents a model for studying heterosis.

Purpose of the Study:

• To identify genetic loci and genes associated with negative heterosis in sheep-argali interspecific hybrids.
• To investigate the inheritance patterns of loci linked to meat productivity.
• To elucidate potential biological mechanisms contributing to negative heterosis.

Main Methods:

• Genome-wide association study (GWAS) to identify significant genetic loci.
• Gene prioritization based on association analysis.
• Analysis of inheritance models for identified loci.

Main Results:

• One locus (rs417431015) associated with viability and two loci (rs413302370, rs402808951) linked to meat productivity were identified.
• The gene ARAP2 was prioritized for viability, while PDE2A, ARAP1, and PCDH15 were prioritized for meat productivity.
• Loci related to meat productivity exhibited an overdominant inheritance pattern.

Conclusions:

• Specific genetic loci and candidate genes are associated with negative heterosis in sheep-argali hybrids.
• The identified loci, particularly those for meat productivity, may play a role in the overdominant inheritance patterns observed in negative heterosis.
• Further research into these genes could reveal mechanisms underlying negative heterosis in livestock.