Effects of Lithium on Formation of the Larval Body Pattern of Xenopus Laevis

Authors: Ayper BOĞA, Seçil BİNOKAY, Ayşe KENDİRCİ, Tuncay ÖZGÜNEN

Abstract: Xenopus laevis embryos ranging in development from the 2-to 4-cell stage to the early blastula stage were exposed to Lithium chloride concentrations of from 0.01 M to 0.1 M. (4 hours). Fertilized eggs of Xenopus laevis were obtained by natural mating induced by injecting a male and a female frog with 400 I.U. and 600 I.U. of human chorionic gonadotropin, respectively, and keeping them together overnight in an aquarium at 24 ± 2¼C. Fertilized eggs were selected under dissection microscope. Xenopus embryos failed to neurulate and developed without discernible anteroposterior axis. Treatment with Lithium at progressively later stages reduced developmental defects, and neural differentiation was returned to normal levels. It was observed that from the 2-cell to the early blastula stage, lithium resulted in the reduction of posterior structures (anteriozation).

Keywords: Lithium, Xenopus laevis, neural development, neurulation