Treatment of pregnant females with corticosterone and the hormone transfer to the yolk of Tropidurus catalanensis eggs.

• Grant number: 23/11308-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2023
• End date: October 31, 2024
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Fernando Ribeiro Gomes
• Grantee: Maria Eduarda Rossa Gandelini
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The hypothalamic-pituitary-adrenal/interrenal (HPA/I) axis secretes glucocorticoids (GC) in a circadian manner, steroid hormones that are essential for signaling the activity period and regulating metabolic, immune, behavioral, and other functions. In many animals, a seasonal elevation of GC during the reproductive season is observed, which appears to be linked to meeting the high costs associated with the development and maintenance of sexual characteristics. Additionally, they function to restore balance in response to environmental stressors. However, it is known that when animals are exposed to elevated GC concentrations for an extended period, leading to chronic exposure, deleterious effects may occur that can be transmitted across generations through alterations in the hormonal environment. This study aims to assess whether plasma concentrations of corticosterone (CORT), the primary GC in reptiles, can be transferred to the yolk of eggs from pregnant females of the species Tropidurus catalanensis. For this purpose, 15 pregnant females will be captured and divided into three groups: 1. Control (no experimental procedures will be performed); 2. Empty Implant (animals will surgically receive na empty silastic implant); and 3. CORT Implant (animals will surgically receive one silastic tube filled with CORT). Blood samples will be collected throughout the experiment to evaluate plasma CORT concentrations. Eggs will be collected to assess CORT concentrations in the yolk. We anticipate that pregnant females in the CORT Implant group will exhibit eggs with higher concentrations of CORT in the yolk compared to eggs from females in the Control and Empty Implant groups.