Effects of stress and maternal nutrition on the somatotropic axis development during larval and juvenil stages of zebrafish

• Grant number: 19/26367-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2020
• End date: August 31, 2022
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Inland Water Fishery Resources
• Principal Investigator: Rafael Henrique Nóbrega
• Grantee: Vinícius Prazeres Barbosa Toledo
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Stress is considered as an adaptive response to potentially harmful stimuli in the environment. The main physiological adaptation of this condition is the increased circulating cortisol levels, which in excess, can be transferred and incorporated into the oocytes of maturing females, affecting the embryonic developmental program. Moreover, it is known that availability of maternal energy substrate is also an essential environmental factor that modulates the developmental program. Therefore, the current proposal aims to evaluate the effects of cortisol and maternal nutrition on the development of somatotropic axis in the offspring, using zebrafish as model. For this purpose, maturing females will be divided into 5 groups, according to the diet: cortisol enriched diet (Group 1), commercial diet (Group 2), and diets with increasing levels of proteins of dry matter, 15% (Group 3), 35% (Group 4) and 60% (Group 5). The resulting offspring will be evaluated at 24, 48, 72 hours post-fertilization (hpf) and also during the late larval [14 days post-fertilization (dpf)] and juvenile (30 dpf) periods. Gene expression of the main components of the somatotropic axis, such as GH (growth hormone), Igfs (insulin-like growth factor) and genes related to myogenesis, will be evaluated. Thus, next to basic knowledge, this proposal has an evident importance for aquaculture and animal research sciences regarding how the maternal environment influences the development of the somatotropic axis in the offspring.