Investigating Energy Metabolism in Aquatic Mammals: Molecular Evolution and Gene Expression Patterns

• Grant number: 24/04938-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2025
• End date: March 31, 2028
• Field of knowledge: Biological Sciences - Genetics
• Principal Investigator: Mariana Freitas Nery
• Grantee: Beatriz Helena Macari Daros
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Aquatic mammals exhibit metabolic adaptations to manage energy demand and resource scarcity. Carnivorous species such as odontocetes and pinnipeds have adapted to low-carbohydrate diets, developing insulin resistance to maintain glycemic homeostasis. Moreover, various aquatic mammal species experience prolonged fasting periods for migratory and reproductive purposes. Extreme diets and fasting are factors that induce energetic stress, requiring efficient management of energy reserves and an optimized metabolic response. Enzymatic activity modulation and hormonal regulation are crucial for maintaining energy homeostasis. Thus, this project aims to investigate the molecular adaptations in the energy metabolism of these mammals, exploring how genes associated with lipolysis, proteolysis, gluconeogenesis, and glyceroneogenesis have evolved to meet energy demands under conditions of carbohydrate scarcity and fasting. Through an integrative approach combining systematic review, molecular evolution analyses, and ex vivo experiments, this study intends to characterize the evolutionary patterns and gene expression underpinning energy management in these animals. Specifically, we will analyze signs of selection in genes encoding enzymes critical to the aforementioned pathways and conduct experiments mimicking fasting states in key energy-supplying tissues, such as adipose and muscle tissue. The results are expected to deepen the understanding of metabolic strategies enabling aquatic mammals to survive under extreme conditions, such as prolonged fasting.