Evolution of sex determination and sexual dimorphism in Squamata: relationships with ecological parameters and embryonic development

• Grant number: 22/07247-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2023
• Status: Discontinued
• Field of knowledge: Biological Sciences - Zoology
• Principal Investigator: Tiana Kohlsdorf
• Grantee: Juliana Luzete Monteiro
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated research grant: 20/14780-1 - Evo-Devo in dynamic environments: implications of climatic changes in the biodiversity, AP.TEM
• Associated scholarship(s): 24/13853-6 - Integrating morphology and transcriptomics to understand the evolution of sexual development in lizards, BE.EP.DR

Abstract

The development integrates genetic and environmental signals to reveal phenotypic variation among different populations. The assessment of developmental responses to environmental conditions, especially temperature, is imperative in the current scenario involving climate change. The sexual development is particularly susceptible to temperature changes in numerous lineages of non-avian reptiles, and environmental perturbations can represent stressful conditions that may severely impact organisms' fitness or bias populations' sex ratios. The evolution of sex determination is a theme that intrigues scientists for decades due to the diversity of existing mechanisms that generate the same phenotype and assumes a great relevance today with the alarming predictions involving global warming. However, most studies concerning the evolution of sex determination systems are dedicated to understanding the evolution of sex chromosomes, such that the current literature lacks works with an integrated perspective connecting ecology, development, and evolution. The present project aims to fill this gap by assessing the evolutionary patterns of sex determination systems in Squamata - an extremely diverse group in this aspect - and test its relationship with the ecological factors on three levels: macroevolutionary, populational, and ontogenetic. Analyzes at the macroevolutionary scale will be implemented using species from different squamate families; on the population and ontogenetic scales, we will use the tropical house gecko Hemidactylus mabouia as the biological system of interest. Preliminary analyzes suggest that H. mabouia potentially exhibits a labile sex-determination system. Considering that H. mabouia is a highly successful invader, this species presents itself as an interesting organism for Eco-Evo-Devo studies with an interface with Conservation.