Document Type : Research Articles
Authors
1
Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
2
Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
3
Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad
10.22067/jcmr.2026.98868.1137
Abstract
Background: Dairy cattle are economically important livestock due to their role as primary milk producers. Understanding the genetic architecture underlying milk production traits is essential for improving productivity, efficiency, and genetic selection programs in dairy cattle. Methods: In this study, quantitative trait loci (QTLs) associated with milk traits were retrieved from the AnimalQTLdb database, and gene annotations for the cattle reference genome were obtained from the NCBI database. A protein–protein interaction (PPI) network was constructed using the STRING plugin in Cytoscape, and network topology analysis was performed with the NetworkAnalyzer plugin to identify key genes. Cytoscape v3.9.1 was further used to determine significant biological pathways associated with the identified genes. Results: A total of 3034 genes were identified as being associated with 39 milk-related sub-traits. Network analysis revealed several hub genes with the highest degree values, including GAPDH, UBA52, UBC, UBB, POLR2E, HIF1A, POLR2B, H3-4, TLR4, and STAT1. Pathway enrichment analysis indicated that many of these genes are involved in biological processes related to milk production, including regulation of stem cell differentiation, toll-like receptor signaling, ATP metabolic processes, electron transport chain, mitochondrial respiratory chain, NADH dehydrogenase activity, oxidative phosphorylation, pyruvate metabolism, and precursor metabolite and energy generation. Additional pathways included mammary gland development, MAPK activation, chemokine and cytokine production in immune responses, positive regulation of the JAK–STAT signaling cascade, growth factor activity, cellular response to oxygen deprivation, cell cycle arrest, and myoblast differentiation. Conclusion: The identification of central genes and associated biological pathways provides valuable insights into the molecular mechanisms underlying milk production traits in cattle. These findings may contribute to improving genomic selection strategies and enhancing milk productivity in dairy cattle breeding programs.
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