초록
Effect of cadmium on the early amphibian development was analyzed through FETAX (Frog Embryo Teratogenesis Assay: Xenopus). Embryos manifested concentration-dependent mortality and realformations; shortage of anterior-posterior axis gut realformation, ocular anomalies, bent notochord, misshapen dorsal fin, and derreal blisters. The treatment with 1.5ppm cadmium solution caused 100% mortality and concentration of lppm did not kill the embryos that caused 100% anomaly. The teratogenic index (TI = LC50 /EC50) was 2.8 indicating that $CdCl_2$ is teratogenic for Xenopus laevis. Embryos that were pulsetreated with at early to late blastula stage (St. 3-9) and mid to late blastula stage (St. 6-10) showed relatively strong resistance to cadmium, but the embryos treated at gastrula stage (St. 10-13) showed high mortality. And the embryos treated at tailbud stage (after St. 25) showed highest mortality of any other early stages. Effects of temperature were studied through pulse- treatment during gastrula stage at $20^{\circ}C$ and $30^{\circ}C$. The embryos treated with 7.5ppm at $30^{\circ}C$ and 15ppm at $20^{\circ}C$ caused 100% mortality respectively, indicating that higher temperature had more severe toxic effect. One of the most peculiar effect of cadmium at gastrulation was distortion of the tail. The probable cause of toxic effect of Cd was discussed.