Genome-wide association studies and candidate genes networks affecting reproductive traits using Iranian Holstein...

Area of Science:

• Animal Genetics
• Reproductive Biology
• Dairy Science

Background:

• Reproductive efficiency is crucial for dairy herd profitability.
• Genomic information offers potential for improving fertility traits.
• Genome-Wide Association Studies (GWAS) are key for linking genetic variations to performance.

Purpose of the Study:

• To identify genomic regions associated with key reproductive traits in Iranian Holstein cows.
• To pinpoint specific single nucleotide polymorphisms (SNPs) influencing traits like days open and age at first calving.
• To discover candidate genes related to reproductive performance.

Main Methods:

• Utilized SNP chip data for genome-wide association studies (GWAS).
• Analyzed reproductive traits including interval between first and last insemination (IFL), days open (DO), days from calving to first service (DFS), number of services per conception (NSPC), age at first calving (AFC), and age at first insemination (AFI).
• Performed gene ontology analysis to identify candidate genes near significant SNPs.

Main Results:

• Identified 55 significant single nucleotide polymorphisms (SNPs) across IFL, DO, NSPC, AFI, and AFC traits.
• Discovered 54 candidate genes associated with reproductive traits.
• Highlighted key genes such as ATG7, PTPN5, LPL, and SERP2 with potential roles in heifer and cow reproduction.

Conclusions:

• The study successfully identified 55 marker-trait associations (MTAs) and 54 candidate genes linked to reproductive traits.
• These identified SNPs and genes provide valuable genomic resources for enhancing reproductive performance in Iranian Holstein dairy cows.
• The findings contribute to a deeper understanding of the genetic architecture underlying bovine reproductive traits.