Existence Of Ultraviolet-Labile Germ-Cell Determinant In Unfertilized Eggs Of Xenopus-Laevis And Its Sensitivity

Ultraviolet light (uv) irradiation of the vegetal hemisphere of unfertilized eggs was performed in Xenopus laevis. The experiments resulted in the elimination of primoridial germ cells in the tadpoles, demonstrating the existence of uv-labile germ cell determinant in unfertilized eggs. Moreover, through its sensitivity analysis, it was found that the unfertilized eggs were equally as sensitive as (or slightly more sensitive than) the stage of eggs immediately after fertilization. The present experimental results support the idea that the germ cell determinant already exists in unfertilized eggs as “stored information,” which has been postulated by many authors.