Dominant lethality in Xenopus laevis induced with triethylenemelamine (TEM).

Adult male South African clawed toads, Xenopus laevis, were injected intraperitoneally with triethylenemelamine (TEM) dissolved in water over a dose range of 13-1,300 micrograms/kg or with water (controls). Mating of the treated males with untreated females was induced seven days later by injection of human chorionic gonadotropic hormone (HCG). Accumulated lethality one week after fertilization among progeny was dose related. Morphological abnormalities among embryos that survived to hatching were similarly dose related. Because anatomically anomalous embryos may have impaired behavior, swimming capacity was tested, and anomalies in swimming behavior were also found to be dose related. Finally, short-term cell cultures were made on minced embryos to obtain chromosome spreads. Structural aberrations, rings, dicentrics, etc of somatic chromosomes were also dose related.