Genome-Wide Association Study Reveals Additive and Non-Additive Effects on Growth Traits in Duroc Pigs.

Area of Science:

• Animal Genetics
• Quantitative Trait Genetics
• Molecular Breeding

Background:

• Growth rate is crucial for the swine industry, influenced by complex genetic factors.
• Identifying causative mutations and genes is key to improving economically important traits in pigs.

Purpose of the Study:

• To identify causative mutations and candidate genes for pig growth traits using a large Duroc population.
• To analyze additive, dominance, and epistatic genetic effects on growth performance indicators.

Main Methods:

• Genomic analysis of 2360 Duroc pigs to detect significant single nucleotide polymorphisms (SNPs).
• Association analysis for traits including age at specified weight (AGE), average daily gain (ADG), backfat thickness (BF), and loin muscle depth (LMD).
• Construction of gene networks based on significant epistatic effects.

Main Results:

• 32 significant SNPs associated with additive or dominance effects were identified for AGE, ADG, BF, and LMD.
• Significant SNPs explained varying percentages of trait variance, with dominance SNPs showing notable effects on backfat thickness.
• 805 significant epistatic SNPs were linked to ADG, AGE, and LMD, leading to the construction of 11 sub-networks.
• 46 candidate genes, including CD55, NRIP1, TRIP11, MIS2, VRTN, and ZEB2, were implicated in muscle development, fat deposition, and cell growth regulation.

Conclusions:

• Both new and previously reported genetic variants and candidate genes for Duroc pig growth traits were identified.
• The identified genetic factors provide valuable targets for future molecular breeding strategies.
• This research contributes to enhancing pig growth performance through informed breeding programs.