OBJECTIVE To investigate the develop mental toxicity of muscone to embryos. METHODS With zebrafish embryos as a model,The 3 h post fertilization (hpf)embryos were exposed to muscone at 5,10,20,40,80 and 160 μmol·L -1 culture solutions for 96 h and inspected daily with mi-croscopy for larval morphology.The drug solution was replaced every 24 h.Spontaneous move ments were checked at 24 hpf.Heart rate at 48 hpf,hatching rate,e mbryo deformity rate and mortality rate were evaluated.The expression of sepn1 was determined with real-ti me quantitative PCR technique at 96 hpf.RESULTS The 24 hpf spontaneous move ments showed no significant difference.At 48 hpf, spine curvature,pericardial ede ma,yolk sac ede ma,and abnormal swi mming were observed.In addition, the 48 hpf heart beats(10 s)was decreased fro m 26.5 ±1 .0 to 18.0 ±1 .9(P <0.01 ).At 48 hpf , hatching rate of 5 ~40 μmol·L -1 decreased(P <0.05),while of 160 μmol·L -1 increased (P <0.05) co mpared with muscone 0 μmol·L -1 .Muscone had little effect on hatching rate at other ti me points;Mal-formation rate and mortality rate at higher concentrations were up to 100%.The sepn1 gene expression at 96 hpf in the exposure groups decreased co mpared with that of control group(P <0.01 ).CONCLU-SION Muscone had toxic effects on the develop ment of zebrafish embryos,including spine curvature, abnormal swi mming,and pericardial ede ma.These effects may be related to the inhibition of sepn1 gene expression by muscone.

OBJECTlVE To establish Tg(-6.3CYP3A65∶EGFP) transgenic zebrafish for quick, intuitive detection of heavy metals ( copper, cadmium and zinc) , dioxin-like PCBs ( PCB126) and other environmental pollutants. METHODS Tol2 transposon system was used to generate transgenic zebrafish lines Tg(-6.3CYP3A65∶EGFP) in which CYP3A65 promoter regualated labeled fluorescence. The effect of heavy mentals ( copper, cadmium and zinc ) and PCB126 on the relative amounts of CYP3A65 gene expression was determined by observing the change in fluorescence intensity. RESULTS The relative gene expression of CYP3A65 was significantly increased after 96 h exposure to copper 0.1 and 0.2μmol·L-1 , cadmium 0.35 and 0.7μmol·L-1 , zinc 1.5 and 3μmol·L-1 , and PCB126 2-32μmol·L-1 , respectively ( P<0.01) , but decreased after 96 h exposure to copper 0. 9 μmol·L-1 , cadmium 2. 7 and 5.4 μmol·L-1 , and zinc 24μmol·L-1 , respectively( P<0.01) . CYP3A65 gene expression was significantly increased after 168 h exposure to copper 0.1 and 0.2 μmol·L-1 , cadmium 0.35 and 0.7 μmol·L-1 , zinc 1.5 and 3 μmol·L-1, and PCB126 2-32 μmol·L-1, respectively(P<0.01), but decreased after 168 h exposure to copper 0.9 μmol·L-1, cadmium 2.7 and 5.4 μmol·L-1, and zinc 12 and 24 μmol·L-1( P<0.05) , in a concentration-dependent manner. CONCLUSlON The results suggest that zebrafish CYP3A65 gene expression and the CYP3A65 labeled fluorescence lines can be another candidate biomarker for detecting environmental pollutants.