A Comparative Analysis of the Gene Expression Profiles in the Mammary Glands of Lactating and Nonlactating Mares at the Second Month of Gestation.
Authors: Ulaangerel Tseweendolmaa, Wang Min, Zhao Bilig, Yi Minna, Shen Yingchao, Mengkh Yibeeltu, Wen Xin, Dugarjav Manglai, Bou Gerelchimeg
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers compared gene expression patterns in mammary tissue from pregnant Mongolian mares at two months gestation, contrasting those actively lactating with non-lactating animals to understand the molecular mechanisms governing concurrent lactation and pregnancy in equines. Using transcriptomic analysis, they identified 4,197 differentially expressed genes between the two groups, with 1,974 genes showing substantially elevated expression in lactating mares—notably including milk protein genes such as αs1-casein, κ-casein, lactalbumin, and lactoferrin. Beyond these structural proteins, the differentially expressed genes clustered into several functional pathways relevant to milk synthesis and secretion, including endoplasmic reticulum protein processing, Toll-like receptor signalling, steroid biosynthesis, and amino acid and nucleotide metabolism. For equine professionals managing pregnant and lactating mares—particularly in breeding operations—these molecular signatures offer insight into the physiological demands of maintaining lactation during gestation, potentially informing nutritional and management strategies to support the substantial metabolic load placed on concurrently pregnant and nursing animals. This foundational work opens avenues for targeted investigation into optimising maternal health outcomes and milk quality during this metabolically demanding period.
Read the full abstract on PubMed
Practical Takeaways
- •Understanding gene expression differences in lactating versus non-lactating pregnant mares may inform management strategies for pregnant mares that continue lactation
- •Identification of milk protein genes and associated metabolic pathways provides molecular basis for nutritional and immunological support during concurrent pregnancy and lactation
- •This foundational transcriptomic data could guide future studies on optimizing mare and foal health outcomes when lactation occurs during pregnancy
Key Findings
- •4,197 differentially expressed genes were identified between lactating and non-lactating pregnant mares at second month of gestation
- •Milk protein-related genes (CSN1S1, CSN3, LALBA, LTF) were highly expressed in lactating mares
- •Differentially expressed genes were primarily associated with endoplasmic reticulum protein processing, Toll-like receptor signaling, steroid biosynthesis, and cytokine-cytokine receptor interactions