Vitellogenin detection in surface mucus of a cichlid fish: a useful biomarker for estrogenic substances.

N. MONCAUT, F. LO NOSTRO, F. MEIJIDE AND C. MAGGESE

Buenos Aires, Argentina

Congreso; 4ta Reunión Anual de SETAC Latinoamérica. Society of Environmental Toxicology and Chemistry; 2001

SETAC Latinoamérica. Society of Environmental Toxicology and Chemistry.

During the last decade, there has been a significant effort to determine the effects of endocrine disrupting chemicals on reproduction, growth and development in wildlife species. Special attention has been addressed on the consequences of exposure to environmental estrogens on fish reproduction. For this reason, characterization of  biomarkers of such exposures could result in useful tools for these studies. The detection of vitellogenin (Vtg), a precursor of yolk proteins, is being intensely studied since its synthesis in the liver is regulated by the 17b-estradiol and influenced by other estrogenic compounds. The aim of this work was to detect Vtg in the surface mucus of males of Cichlasoma dimerus (Heckel, 1840) (Teleostei, Perciformes), a typical South American freshwater cichlid fish, after hormonal induction with 17b-estradiol. Plasma analysis by Western blot revealed that heterologous antisera against Vtg bound to putative plasma protein from females and treated males, whereas no reaction was found with plasma of untreated males. The same profile was observed in mucus samples using Dot blot, a very easy and direct technique. As a correlation of these results, testis and liver structures were assessed by histological techniques. Marked alterations in their morphology and cytology were observed, indicating an important impairment in the general physiology of this wildlife species. The possibility of detecting Vtg in the surface mucus of fishes treated with an estrogenic compound would be a very useful and extremely easy tool to monitor the presence of endocrine disrupting chemicals in the environment.