Molecular evolution of genes related to cetaceans' brain development and the possible relation to their social complexity.

• Grant number: 23/03740-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2023
• End date: September 02, 2025
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Vera Nisaka Solferini
• Grantee: Mariana Santos Melo
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 23/16141-4 - Using ecological and transcriptomic data to investigate brain evolution and cognition: an experimental study using eurasian magpies, BE.EP.MS

Abstract

The brain, an organ of the central nervous system, can process, store, and learn from the information. Comprising glial cells and neurons, it is metabolically expensive and holds significant adaptive value. Understanding the environmental pressures that have shaped complex brains is a long-standing question in biology. Advances in molecular biology and genetics can help reveal genes associated with brain development and infer selective pressure models, as well as the evolutionary landscape of this organ. Cetaceans are aquatic mammals with intricate behaviors, displaying variations in brain size and social expressions, making them ideal subjects for comparative studies on the evolution of these traits. In this context, the project aims to investigate genes related to cetaceans' brain development and test the applicability of the social brain hypothesis, which links social complexity to brain evolution. To achieve this, we will employ selective pressure models on chosen genes, genotype-phenotype mapping, and phylogenetic generalized least squares regressions. The proposed genes are associated with neuronal density, brain size, and development and are candidates for positive selection in highly encephalized lineages. This analysis will correlate these aspects with cetaceans' sociability using social structure data. The results will contribute to the understanding of the genetic basis of mammalian brain development, elucidating the evolutionary mechanisms of cerebral complexity and advancing phylogenetic approaches in ethological research. Additionally, the generated data can be applied to ethical debates concerning the treatment of captive mammals.