Integrated effects of xenoestrogens and chytrid infection on the morphological physiology of males and females of the Cururu Toad

• Grant number: 17/18040-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2018
• End date: March 31, 2021
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Luis Felipe de Toledo Ramos Pereira
• Grantee: Raquel Fernanda Salla Jacob
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 16/25358-3 - The chytrid fungus: from its origins to its consequences, AP.TEM
• Associated scholarship(s): 19/04462-5 - Integrated effects of xenoestrogens and chytrid infection on the microbiome of the Brazilian cururu toad (Rhinella icterica), BE.EP.PD

Abstract

Amphibians are frequent targets of several stressors, which have been contributing to the situation of decline and extinction of their populations. Among these factors, xenoestrogens of anthropogenic origin stand out. Once in contact with aquatic populations these compounds act as endocrine disruptors, affecting several physiological functions of amphibians. In Brazil, 17±-ethinylestradiol (EE2) is of one of the xenoestrogens most commonly detected in water bodies. Once exposed to these contaminants, they are also more sensitive to other environmental disturbances and infectious diseases, such as chytridiomycosis. This, in turn, also causes serious declines in amphibian populations, including species from Brazil. In the aquatic environment, all of these factors can occur concomitantly, and an interaction between them can lead to even more severe effects. There are no studies evaluating the synergistic effects of 17±-ethynyloestradiol (EE2) and chytridiomycosis, nor are there comparisons between sexes in this sense. The comparison between the genera is of great relevance considering the potential effects of these factors on reproductive, cardiac and metabolic functions, which can lead to long-term population imbalances as a result of gender changes and important physiological mechanisms. Thus, the aim of this study is to evaluate and compare the effects of an exposure of the EE2 and the chytrid fungus (Batrachochytrium dendrobatidis) on the morphophysiology of male and female Cururu toads (Rhinella icterica). Such targets will be achieved by analyzing biomarkers such as in vivo and in vitro heart function (cardiac contractility), and histology of the skin, liver and gonads (special focus on the Bidder's organ) of both sexes. This study will be a pioneer, not only at the national level but also worldwide, and may reveal a complex web of interactions between pathogens, environmental contaminants and sexual gender in anurans.