Investigating gene expression patterns in aquatic mammal lineage cells under hypoxia and oxidative stress induced by reoxygenation

• Grant number: 23/09947-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: January 15, 2024
• End date: January 14, 2025
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Mariana Freitas Nery
• Grantee: Giovanna Selleghin Veiga
• Supervisor: José Pablo Vázquez-Medina
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of California, Berkeley (UC Berkeley), United States
• Associated to the scholarship: 22/01183-0 - Molecular evolution and gene expression pattern of antioxidant enzymes of hypoxia-tolerant aquatic mammals, BP.DD

Abstract

Cetaceans and pinnipeds are two lineages of mammals that evolved to the aquatic environment, facing many selective pressures compared to their terrestrial close relatives. One of the challenges of a breathing-air animal living in water is the limitation of oxygen available during the dive periods, restricted to the amount of oxygen dissolved in blood the animal can carry. One adaptation to deal with this is the elevated control of tissue vasoconstriction, allowing the irrigation of oxygen-dependent tissues and leading to ischemia in peripheral ones. Ischemic tissues that go through blood reperfusion, increasing the concentration of oxygen available, activate metabolic pathways that produce toxic molecules called reactive oxygen species (ROS), such as O2- and H2O2. However, there is a system composed of enzymes and other antioxidant molecules that, in response to Nrf2 transcription factor during the state of oxidative stress induced by reperfusion, are activated and help eliminate ROS. Previous studies measured the enzyme activity of these proteins and observed an increased response in pinnipeds and cetaceans species, preventing tissue damage in response to elevated ROS. Still, little is known about the cellular response in gene expression levels during each stage of diving (normoxia, hypoxia, and reoxygenation). In this context, our aim is to generate a transcriptome of culture cells of aquatic mammals stressed in different levels of oxygen availability. (AU)