Fargeix N
C R Acad Hebd Seances Acad Sci D. 1976 Jan 19;282(3):305-8.
X rays irradiation of anterior or posterior halves of Duck blastoderms at the non incubated stage is followed by a decrease of the number of germ cells in the germinal crescent at the stage of 10 somites. However, after 6 days of incubation, the genital ridges of such embryos contain the same number of gonocytes as those of normal embryos. A regulation of the number of gonocytes occures at the level of the genital ridges.