Spring and Fall recrudescence in Podarcis siculus ovaries: A role for progesterone

Area of Science:

• Reproductive Biology
• Endocrinology
• Herpetology

Background:

• The lacertid lizard, Podarcis siculus, exhibits a biphasic reproductive cycle with distinct recrudescence phases in Spring and Fall.
• Understanding the hormonal regulation of oogenesis is crucial for comprehending vertebrate reproductive strategies.

Purpose of the Study:

• To investigate the specific roles of progesterone during the Spring and Fall recrudescence periods in Podarcis siculus.
• To determine the effects of exogenous progesterone administration on key reproductive processes, including oogonial proliferation, oocyte recruitment, and follicle cell apoptosis.
• To map the presence and distribution of progesterone receptors within the reproductive tissues.

Main Methods:

• Administration of exogenous progesterone via intraperitoneal injection.
• Assessment of oogonial proliferation and oocyte recruitment.
• Determination of follicle cell apoptosis.
• Immunohistochemistry and Western blotting to detect progesterone receptors.

Main Results:

• Progesterone administration influenced oogonial proliferation, oocyte recruitment, and follicle cell apoptosis differently in the two recrudescence periods.
• Progesterone receptors were detected, with varying distribution patterns observed.
• Evidence suggests distinct mechanisms of action for progesterone during Spring and Fall reproductive phases.

Conclusions:

• Progesterone exhibits differential roles and action pathways during the Spring and Fall recrudescence periods in Podarcis siculus.
• The findings highlight the intricate and complex nature of oogenesis control in this vertebrate species.
• Further research is warranted to fully elucidate the hormonal regulation of reproduction in lizards.