Genome-Wide Association Studies of Growth Trait Heterosis in Crossbred Meat Rabbits

Area of Science:

• Animal Genetics
• Genomics
• Livestock Breeding

Background:

• Heterosis enhances livestock disease resistance, meat quality, reproduction, and growth.
• Genome-wide association studies (GWAS) are crucial for identifying genes influencing economic traits in meat rabbits.

Purpose of the Study:

• To screen candidate genes with dominant effects on economic traits in meat rabbits.
• To analyze runs of homozygosity (ROH) for population homozygosity and identify high-frequency ROH regions.
• To discover molecular markers for assisted selection in meat rabbit breeding.

Main Methods:

• Genome-wide association studies (GWAS) on F2 crossbred meat rabbits.
• High-throughput sequencing to obtain single nucleotide polymorphisms (SNPs).
• Runs of homozygosity (ROH) analysis to assess population inbreeding.
• Logistic growth curve modeling to identify growth inflection points.

Main Results:

• Identified 10 SNP loci and seven candidate genes significantly related to 84-day body weight in meat rabbits.
• Revealed functional roles of 20 candidate genes within high-frequency ROH regions associated with economic traits.
• Found a growth inflection point at 49 days of age using logistic growth curve modeling.
• Evaluated homozygosity using 78,579 SNPs and 42,018 ROHs in 380 F2 rabbits.

Conclusions:

• Identified potential genes associated with growth and development in high-frequency ROH regions of meat rabbits.
• Candidate genes can serve as molecular markers for assisted selection in meat rabbit breeding.
• ROH-based inbreeding assessment provides valuable reference for meat rabbit breeding and preservation programs.