History, insights, and future perspectives on studies into luteal function in cattle

Area of Science:

• Reproductive biology
• Endocrinology
• Veterinary science

Background:

• The corpus luteum (CL) is a vital endocrine tissue formed after ovulation, producing progesterone essential for pregnancy maintenance in ruminants.
• Subfertility in cattle leads to significant economic losses and impacts global protein production.
• Maternal recognition of pregnancy involves complex ovarian and uterine interactions regulated by the embryo.

Purpose of the Study:

• To review seminal research on the regulation of the ruminant corpus luteum (CL).
• To identify mechanisms of CL formation, function, and luteolysis requiring further validation in cattle.
• To discuss the roles of prostaglandins, immune cells, and steroidogenesis in the CL.

Main Methods:

• Review of existing literature on bovine and ruminant corpus luteum function.
• Discussion of established and novel hypotheses regarding luteolysis.
• Analysis of the interplay between immune, endothelial, and luteal cells.

Main Results:

• The CL's lifespan is regulated by embryonic signals, determining either its prolongation for pregnancy or destruction via luteolysis.
• Prostaglandins, immune cells, and steroidogenesis are key factors in CL regulation.
• A triadic model of luteolysis highlights the interaction between immune, endothelial, and luteal cells.

Conclusions:

• Further research is needed to fully validate mechanisms regulating the bovine CL.
• Understanding luteolysis is critical for improving cattle fertility and reproductive efficiency.
• Novel hypotheses regarding CL function and luteolysis offer avenues for future investigation.