Sex differences in anoxia resistance in Trachemys scripta

• Grant number: 21/11359-6
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2022
• End date: July 31, 2024
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Luciane Helena Gargaglioni Batalhão
• Grantee: Luciane Helena Gargaglioni Batalhão
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated researchers: Raphael Escorsim Szawka

Abstract

To maintain and modulate the homeostasis and vital functions, vertebrates depend on oxygen. Despite that, freshwater turtles are able to tolerate oxygen depletion conditions, anoxia, by lowering their metabolic rate drastically. In the environment, these anoxic periods, that are dependent on temperature, can endure up to forty days. The cellular metabolism of turtles changes from an aerobic oxidative phosphorylation to anaerobic glycolysis, a process which rise significantly the lactate concentration. During the depletion of oxygen in water, plasma pH decrease, rising the monoamine concentration (especially noradrenaline) and resulting in the elevation of muscular glycogenolysis and blood hyperglycemia. Despite the number of studies regarding the genetic, metabolic, physiological, evolutionary and behaviour adaptations in fresh water turtles in anoxia, nothing has been explored in the sexual differences of these adaptations. This project aims to evaluate differences linked to sexual hormones in the anoxia resistance in male and female adults of Trachemys scripta. That will be addressed by analysing lactate and glycogen metabolism in the plasma, arterial pH, temperature, HIF-1 expression and the amount of catecholamines in the brain of male and female after 12 hours of normoxia, hypoxia and anoxia exposure, comparing to the different phases of the reproductive cycle in these animals. (AU)