Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Sirai Ramirez - William Paterson University
Co-Author(s): Jaishri Menon, William Paterson University, Wayne, NJ
Amphibian skin is a multifunctional organ acting in defense, respiration and water regulation. Amphibians being the first group of organisms to invade land from an aquatic life, they have adopted to survive in various conditions laden with pathogens and predators. The larval skin is made up of a two layered epidermis with three types of cells including apical, skin and basal cells, without any glandular cells present. Basal cells of the larval skin, survive during metamorphosis and differentiate into adult basal cells, whereas the other two types undergo apoptosis during climax. We hypothesize that a) as an organ directly exposed to reactive oxygen species (ROS) from the environment as well as endogenous sources, it is bound to be equipped with antioxidant defense and b) oxidative stress might act as a signal for structural and functional changes in the body skin during metamorphic process. In this study, we carried out western blot analysis as well as immunohistochemistry for superoxide dismutase (SOD) and catalase (which removes superoxide and hydrogen peroxide) and in situ staining for ROS, during different stages of metamorphosis. Results of western blots for skin showed stronger bands for SOD and catalase as metamorphosis progresses. Histologically, a two layered epidermis is visible during earlier stages, showing mostly presence of catalase in epidermal cells and some SOD along the periphery of the epidermis. At stage 60, two types of glands – mucosal and granular glands begin to develop but secretion does not show presence of either enzymes. At the climax of metamorphosis, the epidermis is multilayered and the mucosal glands are more SOD positive whereas granular glands are more catalase positive. We conclude that because the amphibian skin is exposed to a variety of physiological and chemical factors which can result in oxidative stress, the skin is armed with antioxidant defenses including glandular secretions. In future studies we would like to explore the role of morphological structures called tubercles and to also differentiate those cells during metamorphosis that are undergoing apoptosis or autophagy (a physiological process that maintains the turnover of the destroyed cell organelles for new cell formation.
Funder Acknowledgement(s): The funder of this summer research project is the GS-LSAMP organization which is run by Dr. Danielle Desroches of the Biology department.
Faculty Advisor: Jaishri Menon, email@example.com
Role: I completed the entire project on my own this summer. I carried out the western blots for SOD and catalase, the immmunohistochemistry as well as the