Adverse developmental and reproductive effects of copper deficiency in Xenopus laevis

The effect of copper (Cu) deficiency on the reproduction and development in Xenopus laevis was evaluated, culminating in the development of a defined concentration-response relationship. Separate groups of four adult frog pai rs were fed one of three diets for 28 d: (1) low-copper (-Cu); (2) copper s upplemented (+Cu); and (3) ASTM standard beef Liver and lung (BLL). Embryos collected from frogs administered the -Cu diet had markedly decreased egg masses and viability rates and an increased rate of necrosis when compared to the other dietary treatments. Malformations in -Cu larvae included malde velopment of the heart, eye, craniofacial region, brain, and notochord. Lar vae from adults administered the -Cu diet showed delayed abnormal hindlimb development, characterized as selective reductive deficiencies distal to th e femur, with poor cartilaginous development. A U-shaped dose-response curv e characteristic of nutritional essentiality was developed for Cu. Overall, these studies indicated that embryos produced from frogs administered a -C u diet are substantially less viable than embryos from frogs administered a +Cu or copper-adequate (BLL) diet.