Vitelline envelope proteins and vitellogenin gene expression in Cichlasoma dimerus (Teleostei, Perciformes) exposed to octylphenol.

GENOVESE, G.; REGUEIRA, M.; LO NOSTRO, F. L.; MAGGESE, M. C.; TOWLE, D. W.

Bulletin of the Mount Desert Island Biological Laboratory

Mount Desert Island Biological Laboratory

Lugar: Salsbury Cove; Año: 2007 vol. 46 p. 161 - 162

0097-0883

Endocrine disrupting chemicals have become ubiquitous in the environment and adversely affect development and physiology by interfering with normal endocrine functions. Octylphenol (OP) is a degradation product of alkylphenol polyethoxylates, a group of non-ionic detergents mainly used in industrial applications, agricultural chemicals, and institutional cleaners3. OP can act as a xenoestrogen and, as a result, cause reproductive impairments. Previous results from our laboratory showed that, in the freshwater teleost Cichlasoma dimerus (as in other fish species1), vitelline envelope proteins (VEP?proteins that form the eggshell) and vitellogenin (VTG?the protein precursor of egg yolk protein) are synthesized by liver of mature females under estrogenic control but are never produced by normal males. It was also demonstrated that exposure of male fish to 150 µg/L OP after 1 day strongly induced the expression of VEP 2. The aim of the present study was to assess the effect of environmentally relevant concentrations of OP on mRNA expression of VTG and VEP and the reversibility of the effect. C. dimerus males were exposed to 150, 15, 1.5, and 0.15 µg/L 4-(tert-octyl)phenol 97% (Aldrich) for 0-28 days. During dissection, livers were preserved in cold RNAlater for RNA extraction. Poly-A mRNA in 2 µg total RNA was reverse transcribed using oligo-dT and SuperScript III reverse transcriptase. Species-specific primers designed to target VEP and VTG were used to quantify mRNA expression by amplifying the respective cDNAs in the presence of SYBR green dye using Brilliant Master Mix (Stratagene) and an MX4000 quantitative PCR system. Liver RNA from estrogenized females was used for the standard curve.