Effects of the estrogen mimic genistein as a dietary component on sex differentiation and ethoxyresorufin-O-deethylase (EROD) activity in channel catfish (<Emphasis Type="Italic">Ictalurus punctatus</Emphasis>) |
| |
Authors: | C C Green A M Kelly |
| |
Institution: | (1) Department of Zoology, Fisheries and Illinois Aquaculture Center, Southern Illinois University, 1125 Lincoln Drive, Mailcode 6511, Carbondale, IL 62901, USA;(2) Aquaculture Research Station, Louisiana State University Agricultural Center, 2410 Ben Hur Rd., Baton Rouge, LA 70820, USA;(3) Present address: Cooperative Extension Program, Aquaculture and Fisheries Center, University of Arkansas at Pine Bluff, P.O. Box 357, Lonoke, AR 72086, USA |
| |
Abstract: | A number of aquaculture species, including channel catfish Ictalurus punctatus, are fed high proportions of soybean meal in their diet. We have investigated the potential for the most common phytoestrogen
in soybean meal to alter phenotypic sex during sexual differentiation in channel catfish. Channel catfish were fed four dietary
concentrations of the phytoestrogen genistein (0, 2, 4, and 8 mg g−1) to determine its effect on gonadal sex differentiation. The four treatment diets were fed to sexually undifferentiated channel
catfish between 5 and 140 days post hatch (dph) and between 60 and 150 dph. Phenotypic sex was determined by histological
examination of the gonads. Ethoxyresorufin-O-deethylase activity was not significantly different among the treatment and control
groups. Phenotypic sex was significantly dependant on dietary phytoestrogen concentration (P = 0.01). Additionally, logistic regression showed a significant relation between genistein concentration in the diet and
gonadal sex (P = 0.02). Intersex individuals were present at all treatment concentrations, with increasing proportions of intersex fish
as the genistein concentration increased for individuals fed treated diets between 5 and 140 dph. Increased proportions of
phenotypically male individuals resulted from chronic dietary exposure to the estrogen mimic genistein. There were no significant
differences in the proportions of males and females between feed treatment durations. These findings establish that dietary
concentrations of genistein can alter sex ratios in cultured channel catfish populations and demonstrates the need to further
understand the actions of this and other prominent phytoestrogens in aquaculture species. |
| |
Keywords: | Aromatase Endocrine disruption Intersex Phytoestrogens Soybean meal |
本文献已被 PubMed SpringerLink 等数据库收录! |
|