Induction, Purification and Determination of Vitellogenin Levels in the European Eel (Anguilla anguilla): Laboratory and Field Studies

• Main Author: Assem, Farida Louise
• Other Authors: Faculty of Science
• Format: Thesis
• Language: English
• Published: 2001
• Subjects: Anguilla anguilla
• Online Access: http://hdl.handle.net/10026.2/1914

In this study high concentrations of VTG were induced in A. anguilla by exposure to estradiol. VTG was then purified from the plasma of E2 treated fish by selective precipitation with MgCl2-EDTA and distilled water, and ion exchange chromatography. VTG of high purity was obtained (assessed by native PAGE and Western blotting), and the protein appeared to exist as a dimer in its native form, with an apparent molecular weight of 550 kDa. The apolipoprotein was assessed by SDS PAGE and Western blotting and had an apparent MW of 235 kDa. A dot blot immuno-assay, using purified VTG as a standard, was used to quantify levels of plasma VTG in feral A. anguilla sampled from the Thames estuary, UK, and the Seine, Bethune and Bresle estuaries in northern France. No significant differences between sites were observed in the Thames estuary, however significantly high concentrations of VTG (53 and 31 ug/ml) were observed in two fish sampled from the Bresle estuary, France in 1998 and 2000. VTG levels of this magnitude have not been previously observed in feral A. anguilla. This field study identifies the possibility that A. anguilla is experiencing endocrine disruption in some estuaries, expressed as elevated plasma VTG levels. Plymouth Marine Laboratory