Mating, ovulation and corpus luteum function in the vole, Microtus agrestis

Area of Science:

• Reproductive biology
• Mammalian reproduction
• Endocrinology

Background:

• The vole is an induced ovulator, meaning ovulation is triggered by external stimuli.
• Corpus luteum (CL) function is crucial for maintaining pregnancy in mammals.
• Understanding factors affecting CL maintenance is important for reproductive success.

Purpose of the Study:

• To investigate the relationship between mating behavior and ovulation/CL function in voles.
• To determine the stimuli required for ovulation and CL maintenance.
• To compare vole reproductive mechanisms with spontaneous ovulators.

Main Methods:

• Observing vole mating behavior and its effect on ovulation.
• Administering luteinizing hormone-releasing factor (LH-RF) to induce ovulation.
• Applying mechanical genital stimulation at various time points post-ovulatory stimulus.
• Assessing CL formation and degeneration.

Main Results:

• A single intromission or LH-RF injection induces ovulation but leads to rapid CL degeneration.
• Prolonged mating or post-ovulatory mechanical genital stimulation maintains CL function.
• Mechanical stimulation up to 48 hours after LH-RF injection effectively maintains the CL.

Conclusions:

• Vole mating behavior, specifically prolonged copulation or genital stimulation, is critical for CL maintenance.
• The vole's reproductive system exhibits similarities to spontaneous ovulators like rats, mice, and hamsters regarding CL maintenance mechanisms.