Long-term corticosterone treatment effects on stress and immune response in cane toads (Rhinella marina)

• Grant number: 17/04802-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): June 10, 2017
• Effective date (End): June 09, 2018
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Fernando Ribeiro Gomes
• Grantee: Vania Regina de Assis
• Supervisor: Mary T. Mendonca
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: Auburn University, United States
• Associated to the scholarship: 15/23801-4 - Immunomodulatory effects of acute stress in toads from Genus Rhinella, BP.PD

Abstract

The introduction of non-native species is a major driver of biodiversity loss. There are hypotheses suggesting that what makes certain species good invaders is that they have different stress and immune response profiles to acute and, especially chronic stressors than native species. The knowledge about physiological reactions to stressors in amphibians and the consequences of elevation of glucocorticoids on their immune response are still poorly understood. In the present proposal, we will investigate changes in stress responsiveness and immunocompetence in invasive cane toads (Rhinella marina) from Florida, during chronic administration of corticosterone (CORT). The toads will receive subcutaneous capsules implants, then faced with an immune challenge (e.g. lipopolysaccharide [LPS], sheep red blood cells [SRBC]), the analyses will be on the genomic, epigenomic, cellular, and physiological levels. We will measure corticosterone biding globulins (CBGs), proinflammatory cytokines, lymphocyte proliferation, phagocytosis, and metabolic rate. We believe that the variation in these parameters, in addition to CORT plasma levels, neutrophil/lymphocyte ratio (N:L) and bacterial killing ability (BKA), might represent a good indicator of stress condition in natural populations. All these analyses together, should give a better perspective of the different components of the immune response in this invasive species and determine energetic tradeoffs among the different arms of the immune response and which response is the most costly. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

GARDNER, STEVEN T.; ASSIS, VANIA R.; SMITH, KYRA M.; APPEL, ARTHUR G.; MENDONCA, MARY T.. Innate immunity of Florida cane toads: how dispersal has affected physiological responses to LPS. JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL, v. 190, n. 3, MAR 2020. (17/04802-5)

ASSIS, VANIA R.; GARDNER, STEVEN T.; SMITH, KYRA M.; GOMES, FERNANDO R.; MENDONCA, MARY T.. Stress and immunity: Field comparisons among populations of invasive cane toads in Florida. JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY, v. 333, n. 10, SI, JUN 2020. (17/04802-5)

GARDNER, STEVEN; ASSIS, VANIA REGINA; ZHA, HONGGANG; GOMES, FERNANDO RIBEIRO; PEATMAN, ERIC; MENDONCA, MARY T.. Differential gene expression to an LPS challenge in relation to exogenous corticosterone in the invasive cane toad (Rhinella marina). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY, v. 88, p. 114-123, NOV 2018. (14/05806-6, 17/04802-5)