THE UTILISATION OF THE THREE-SPINED STICKLEBACK {GASTEROSTEUS ACVLEATUS) AS THE EUROPEAN BIOINDICATOR AND TEST SPECIES FOR ENDOCRINE DISRUPTION RESEARCH

This thesis reports the development and validation of an in vivo assay for the detection of environmental anti-androgens. Exposure to exogenous androgens causes female sticklebacks {Gasterosteus aculeatus) to produce the glue protein, spiggin, in their kidneys. This protein can be quantified by an enzyme-linked immunoabsorbent assay (ELISA). The simultaneous exposure female stickleback to a model androgen, 17a-methyltestosterone (at O.5ug/l), and environmental anti-androgens resulted in total inhibition or lower spiggin production, when compared female fish solely exposed to the model androgen. All fish were exposed over a period of 21 days under semi-static conditions. The assay detected the anti-androgenic activity of flutamide, vinclozolin (both at 250ug/l), linuron (at 150ug/l) and fenitrothion (at 15ug/l and 150ug/l). These results provide the first evidence of in vivo anti-androgenic activity of both linuron and fenitrothion in teleosts. In addition, the results suggest the three-spined stickleback is more sensitive than other test species in detecting the antiandrogenic activity of flutamide and vinclozolin. The presence of endogenous levels of androgens in male sticklebacks made their utilisation in the detection of anti-androgens impractical. However, the development of a methodology that standardises the reproductive status of male fish and thus, spiggin production before the commencement of exposure could overcome this problem. The possession of both an androgen and an oestrogen induced protein marker enables the stickleback to detect all classes of reproductive endocrine disrupting chemicals. Furthermore, the species is endemic and ubiquitous in Europe and possesses many ecological traits that make it better suited than other potential species for field research into endocrine disruption. The results obtained from this thesis form the basis of a paper under preparation, to be submitted to The Journal of Environmental Science and Technology. Authors: I. Katsiadaki, C. Squires, S. Morris, M. Hurst, J James and A P. Scott. Title: A sensitive in vivo test for the detection of environmental anti-androgens, based on inhibition of spiggin production in androgen-treated female 3-spined sticklebacks (Gasterosteus aculeatus).Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Weymout