PT07 Chemical and Biological Analysis of Endocrine Disrupting Compounds
Exhibit Hall
8:00 AM - Tuesday
(PT097) evaluation for the effects of ethinylestradiol using GFP-transgenic see-through medaka: Bioimaging analysis of the gonads.
Hano, T1, Oshima, Y1, Kinoshita, M2, Tanaka, M3, Mishima, N4, Wakamatsu, Y4, Ozato, K4, Honjo, T1, 1 Kyushu University, Faculty of Agriculture, Fukoka, Japan2 Kyoto University, Graduate School of Agriculture, Kyoto, Japan3 Hokkaido University, Graduate School of Science, Sapporo, Japan4 Nagoya University, Bioscience and Biotechnology Center, Nagoya, Japan
ABSTRACT- This study was performed to develop an easy and rapid assay system for detecting the effects of endocrine disrupting chemicals (EDCs) without dissection of organisms using olvas-GFP/ST-II YI medaka (Oryzias latipes), which enables us to monitor germ cells in the living specimens by GFP fluorescence. In the first experiment, mature medaka (10 males and 8 females per treatment) were exposed to ethinylestradiol (EE2) for 4 weeks at concentrations of 47.8, 94.8, 216, 522 ng/L. Observation of gonads with GFP fluorescence in the same individuals showed significant reductions of fluorescent area and gonad somatic index in males at >216 ng/L and in females at 522 ng/L. In histological examination, males exposed to EE2 at all treatments exhibited testis-ova and high prevalences of connective tissue at >216 ng/L. In second experiment, mature medaka (6males per treatment) exposed to EE2 for 3 weeks at concentrations of 43.7, 85.8, 215, 473 ng/L were maintained in clean water for 6weeks to investigate any persistent effects of EE2. Continuous observation of gonad showed reduction of GFP fluorescent area initiated at 2week from the beginning of exposure at >85.8 ng/L. However, after the transfer of exposed medaka with atrophied testis to clean water, testis showed gradual recovery of the fluorescent area and normal spermatogenesis was observed in these individuals. These results demonstrate that gonad condition was clearly reflected in the alteration of GFP fluorescent area..
Key words: bioimaging, transgenic , ethinylestradiol, medaka