[Action of DDT on colonization of the chick embryonic genital ridges, by primordial germ cells (author's transl)].

Colonization of the genital ridges by primordial germ cells was quantitatively studied, at stages 18-24, in Chick embryos issued from eggs treated with commercial DDT before incubation. The pesticide provokes, dating from the 4th day of development (stage 24), a significant reduction in the gonadal germ population. This deficit may be due to 3 different actions of DDT on the primordial gonocytes: an inhibition of their gonadic colonizing capacity, a failure of proliferation and, at last, an excessive rate of cell death. However, the DDT modifies neither the initial number of blastodermal germ cells nor their migratory capacity toward the gonadal region.