Expression of three vitelline envelope protein genes in Arctic char

Several studies have shown effects of estrogenic substances on endocrine an d reproductive systems in wildlife. Measurement of plasma vitellogenin (VTG ) is a commonly used method to determine exposure to estrogenic substances in fish. There is, however, a growing need for additional sensitive and acc urate methods to detect estrogenic substances in vivo. The vitelline envelo pe proteins (VEPs) have been suggested, in other studies, as suitable bioma rkers for estrogenic substances. The present study investigates the inducti on of VEPs in juvenile Arctic char (Salvelinus alpinus). The results demons trate that VEP mRNA exhibits earlier induction than estrogen receptor mRNA or VTG mRNA following injection of juvenile Arctic char with a single dose of 1 7 beta -estradiol (E2; 10 mg/kg bw). These results indicate that the V EPs have a higher sensitivity for E2 than VTG. However, an early and sex-in dependent expression of VEP beta in estrogen-unchallenged juvenile Arctic c har was observed. These findings suggests that the regulatory mechanisms of VEPs might be more complex than previously thought, which in turn may have implications for the usage of VEPs as biomarkers for xenoestrogen exposure . (C) 2001 Academic Press.