Expression of the vitellogenin gene in the liver of juvenile whitefish (Coregonus lavaretus L-s.l.) exposed to effluents from pulp and paper mills

Juvenile whitefish (Coregonus lavaretus L, s.l) were exposed by caging in t he field to diluted effluents from three operating pulp, paper, and paperbo ard mills in Southern Lake Saimaa, Finland, The expression of the vitelloge nin gene, used as a biomarker of estrogenic contamination of effluents, was measured using a Northern blotting method. Increased mRNA levels, the most specific and reliable evidence for estrogen receptor-mediated actions in v ivo, were found in fish caged in the vicinity of one of three mills studied . This mill was found to discharge wood-derived compounds, such as sterols and resin acids, into Lake Saimaa in amounts considerably exceeding those f rom the other two mills. The increased vitellogenin gene expression suggest s that the effluent is a source of estrogenic contaminants. (C) 1999 Academ ic Press.