UNIVERSAL ASSAY OF VITELLOGENIN AS A BIOMARKER FOR ENVIRONMENTAL ESTROGENS

Vitellogenin (VTG), the serum phospholipoglycoprotein precursor to egg yolk, is potentially an ideal biomarker for environmental estrogens. This study was undertaken to develop antibodies against conserved regi ons on the VTG molecule that could form the basis for establishing bio assays to detect estrogen exposure in any oviparous vertebrate. We dev eloped monoclonal antibodies (mAbs) generated against purified rainbow trout (Oncorhynchus mykiss) VTG and selected for the property of spec ifically recognizing VTG purified from two phylogenetically distant ve rtebrates, trout and striped bass (Morone saxatilis). Results of enzym e-linked immunosorbent assay and Western blotting indicated that these mAbs specifically recognize purified VTG and VTG or other estrogen-in ducible proteins in plasma or serum from representative species of fou r vertebrate classes (fish, amphibians, reptiles, and birds). Ail of t he mAbs generated were IgM class. A polyclonal antiserum was raised ag ainst a synthetic consensus peptide representing the conserved N-termi nal amino acid sequence of VTG. The results of Western blotting indica te that this antiserum specifically recognizes VTG in plasma or serum from teleost fish of diverse families. it was used to detect VTG in We stern blots of serum from brown bullhead (Ameiurus nebulosus) with can cer (hepatocellular and cholangio-carcinoma) collected from a contamin ated industrial site outside of their normal vitellogenic season. Our results indicate that it is feasible to generate antibodies capable of recognizing VTG without regard to species and that development of a u niversal VTG assay is an achievable goal.