Quantitative real-time RT-PCR for determination of vitellogenin mRNA in so-iuy mullet (Mugil soiuy)

A quantitative real-time reverse transcription polymerase chain reaction (Q- RT-PCR) assay was developed for quantification of vitellogenin (Vtg) mRNA normalized to beta-actin in so-iuy mullet. Vtg mRNA in liver samples of so-iuy mullet was induced after a single injection of E2 (0.01, 0.1, 1.0 microg/g body) and a dose-response relationship was obtained. This method was applied to determine Vtg mRNA in so-iuy mullet collected from Liaodong Bay, Bohai Bay, NanDaiHe, and a control site in north China. Compared to the control, a high level of Vtg mRNA expression was detected in so-iuy mullets collected from NanDaiHe, whereas no obvious difference between Vtg mRNA expression from Liaodong Bay and Bohai Bay was found. Thus, this method is expected to be useful for further studying the potential of Vtg mRNA as a biomarker for assessing estrogenic activity in marine environments using the so-iuy mullet as a bioindicator species.