Whole-body concentrations of cortisol and sex steroids in white sturgeon (Acipenser transmontanus, Richardson 1836) during early development and stress response |
| |
Authors: | Claudia Simontacchi E Negrato M Pazzaglia D Bertotto C Poltronieri G Radaelli |
| |
Institution: | (1) Department of Experimental Veterinary Sciences, University of Padova, Viale dell’Università 16, 35020 Legnaro, PD, Italy;(2) Agroittica Lombarda SpA, Via Kennedy 101, 25012 Viadana di Calvisano, BS, Italy |
| |
Abstract: | In general little is known about hormones and the ontogeny of the stress response in the early developmental stages of chondrostean
fishes and in particular of white sturgeon (Acipenser transmontanus, Richardson 1836). In this study, we measured for the first time cortisol and sex steroids (testosterone and estradiol) in
eggs, larvae, post-larvae, and fry of white sturgeon by radioimmunoassay (RIA), to elucidate some endocrine aspects of its
development. The cortisol, testosterone, and 17β-estradiol of maternal origin found in unfertilized eggs of white sturgeon
probably regulate both growth and development of the embryo. Cortisol decreased after fertilization, whereas testosterone
and 17β-estradiol did not significantly change. During the late stages of embryo development and immediately after hatching,
endogenous production of cortisol and sexual steroids, respectively, occurred. Sex steroids may be physiological inducers
of gonad sex differentiation in sturgeon. All steroids showed an increase 10 days post-hatch (dph), near the transition from
an endogenous to an exogenous energy source. Cortisol maintained the same basal levels even after metamorphosis, whereas testosterone
and 17β-estradiol declined significantly in post-larvae at 35 and 45 days post-hatch. In addition, to evaluate the ontogeny
of a functional hypothalamic-pituitary-interrenal (HPI) axis, larvae and fry were submitted to acute stress. The HPI axis
did not seem to be functional on the first day post-hatch, but became so from the third day post-hatch onward. |
| |
Keywords: | Development Cortisol Eggs Larvae Sexual steroids Stress response White sturgeon |
本文献已被 SpringerLink 等数据库收录! |
|