Evaluation of a reproductive toxicity assay using Xenopus laevis: Boric acid, cadmium and ethylene glycol monomethyl ether

Cadmium (Cd), boric acid (BA) and ethylene glycol monomethyl ether (EGME) w ere evaluated for reproductive and developmental toxicity in Xenopus laevis . Eight reproductively mature adult male and eight superovulated female Xen opus laevis were exposed to at least five separate sublethal concentrations of each material via the culture water for a period of 30 days. Four respe ctive pairs were mated and the offspring evaluated for developmental effect s; an evaluation of reproductive status was performed on the remaining four specimens. Ovary pathology, oocyte count, oocyte maturity and maturation c apacity (germinal vesicle breakdown, GVBD) and necrosis were evaluated in t he female, whereas testis pathology, sperm count, dysmorphology and motilit y were studied in the male. Based on this assessment, each test material ex erted reproductive toxicity in Xenopus laevis, but with varying potencies. Adult female exposure to Cd and EGME particularly, and to a lesser extent t o BA, resulted in transgenerational toxicity to the developing progeny. Fur ther, this model appears to be a useful tool in the initial assessment and prioritization of potential reproductive toxicants for further testing. Cop yright (C) 2001 John Wiley & Sons, Ltd.