Genome-wide association studies pathway-based meta-analysis for residual feed intake in beef cattle.

Area of Science:

• Animal Genetics and Genomics
• Quantitative Genetics
• Metabolic Pathways

Background:

• Genome-wide association studies (GWASes) aim to identify genomic regions associated with residual feed intake (RFI) but have yielded inconsistent results.
• Meta-analysis can improve GWAS findings by reducing false-positive rates.
• Pathway analysis complements GWAS by identifying gene sets involved in specific biological pathways relevant to a phenotype.

Purpose of the Study:

• To conduct a pathway-based meta-analysis of existing GWAS results for RFI in beef cattle.
• To identify significant biological pathways underlying the genetic mechanisms of RFI.
• To explore the utility of GWAS pathway-based meta-analysis for uncovering biological insights into complex traits.

Main Methods:

• Utilized multiple GWAS datasets for RFI in beef cattle.
• Employed an efficient permutation hypothesis test accounting for linkage disequilibrium (LD) and gene functional relevance.
• Performed whole-genome pathway analysis to identify significant gene sets.

Main Results:

• Identified one significant pathway associated with RFI: valine, leucine, and isoleucine degradation.
• Three genes within this pathway (MCCC1, AOX1, PCCA) were consistently found across different GWAS studies.
• The identified pathway was also supported by a separate transcriptome analysis in cattle divergently selected for RFI.

Conclusions:

• A GWAS pathway-based meta-analysis is an effective method for uncovering biological insights into complex traits like RFI.
• The valine, leucine, and isoleucine degradation pathway plays a role in the genetic control of feed efficiency in beef cattle.
• Combining information from multiple GWAS studies through pathway analysis enhances the reliability and biological relevance of findings.