Characterization of Vitellogenin Gene Expression in Round Goby (Neogobius melanostomus) Using a Quantitative Polymerase Chain Reaction Assay

A growing concern over endocrine disruption in aquatic species has prompted the development of molecular assays to monitor environmental impacts. This study describes the development of quantitative polymerase chain reaction (qPCR) assays to characterize the expression of two vitellogenin (Vtg) genes in the invasive round goby (Neogobius melanostomus). Fragments from the 18SrRNA (housekeeping gene) Vtg II and Vtg III genes were cloned and sequenced. The qPCR assays were developed to detect hepatic Vtg expression in goby. The assays detected induction of both Vtg genes in nonreproductive males following a two week laboratory exposure to 1713 estradiol (>= 1 mg/kg i p injection). The assays were applied to goby from Hamilton Harbour Lake Ontario (Canada) including those from sites where feminization and intersex of goby has been documented. Both Vtg genes had significantly higher expression in females compared to males. Male reproductive goby adopt either parental or sneaker tactics Vtg II expression was higher in sneaker than in parental males but parental and nonreproductive males did not differ from each other. The Vtg III expression was significintly higher in sneaker males followed by parental males and nonreproductive males respectively. The Vtg II and III expression in nonreproductive males was elevated in the contaminated site with documented interest. This assay provides an important tool for the use of an invasive species in monitoring endocrine disruption in the Great Lakes region. Environ Toxicol Chem 2010 29 2751 2760 (C) 2010 SETAC