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(18-31) Patterns in hsp90 / hsp70 and development of oocytes in Gammarus fossarum (Amphipoda) under controlled conditions. Schirling, Martin*,1, Triebskorn, Rita1,2, Köhler, Heinz-R.1, 1 Animal Physiological Ecology, University of Tübingen, Konrad-Adenauerstr. 20, Tübingen, Germany2 Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Kreuzlingerstr. 1, Rottenburg, Germany ABSTRACT- Patterns in hsp90 / hsp70 and development of oocytes in Gammarus fossarum (Amphipoda) under controlled conditions. Schirling M.1, Triebskorn R.1,2, Köhler H.-R.1. 1Animal Pysiological Ecology, University of Tübingen, Konrad-Adenauer-Str. 20, D-72072 Tübingen, Germany; 2Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Kreuzlingerstr. 1, D-72108 Rottenburg, Germany. In view to provide baseline data for the validation of biomarkers as indicators for endocrine disrupting potentials in limnic ecosystems, the present study concentrated on oocyte development, hsp90 expression which is potentially involved in steroid hormone signal transduction, and the universal stress marker hsp70 within the reproductive cycle of Gammarus fossarum. The development of the oocytes was examined using histological techniques and the levels of the heat shock proteins hsp90 and hsp70 were quantified by means of a highly reproducible immunoassay. In the first experiment, animals were kept in the laboratory under constant temperature, photoperiod and with adequate supply of food for three months. Samples for histological and biochemical investigations were collected every 14 days. In the second experiment, gammarids (6 mm, genus not determined) and females of 6 mm in size (collected in the praecopula stage) were sampled at three different sites in the field. One of the sites was at an unpolluted stream, while the other two sites where located along a highly polluted stream. The observations of the female gonads showed various stages of oocytes to occur at different time in the reproductive cycle. At each time, distinct oocyte types were observed to be atretic. The biochemical results showed a fluctating trend corresponding to the egg development. Maximum levels of hsp90 were observed at the praecopula stage, at a time where mature oocytes were found in the gonads. At the same time, the hsp70 level reached its minimum. The results of the field experiment showed a decrease of the hsp70 levels with a concomitant increase of pollution and temperature, which corresponds to earlier investigations in fish. Key words: hsp, endocrine disruption, reproductive cycle, invertebrate |
