Characterizing Milk Production Related Genes in Holstein Using RNA-seq

Area of Science:

• Animal Genomics
• Molecular Biology
• Biotechnology

Background:

• Bovine milk composition and production are critical for dairy industries.
• Limited research has focused on characterizing milk-synthesizing genes using RNA-sequencing (RNA-seq) data.
• Understanding the genetic basis of milk production is essential for selective breeding and herd improvement.

Purpose of the Study:

• To characterize genes associated with milk production in Holstein cows using RNA-seq data.
• To investigate the relationships between milk traits, parity, and lactation period.
• To identify novel candidate genes and biological pathways involved in milk synthesis.

Main Methods:

• RNA-sequencing data from 21 Holstein samples were analyzed.
• Meta-analysis was employed to identify differentially expressed genes related to milk production.
• Quantitative real-time polymerase chain reaction (qRT-PCR) was used for technical validation.
• DAVID gene-set enrichment analysis was performed to identify enriched biological processes.

Main Results:

• A total of 271 differentially expressed genes related to milk production were identified (false discovery rate [FDR] adjusted p-value < 0.1).
• Milk fat content showed a high correlation with lactation period, influencing gene detection models.
• Eight-three gene ontology (GO) biological processes, including mammary gland development and circulation system processes, were significantly enriched.
• Five candidate genes were validated using qRT-PCR, confirming RNA-seq accuracy.
• Several identified genes have known roles in milk production in other species.

Conclusions:

• The study identified 271 candidate genes significantly associated with milk production in Holstein cows.
• The findings highlight the importance of considering lactation period effects in milk production gene analysis.
• Enriched biological processes suggest key roles for mammary gland function and circulatory system in milk synthesis.
• The identified genes provide valuable targets for future research aimed at enhancing milk production traits in dairy cattle.