Mouse genital ridges in organ culture: the effects of temperature on maturation and experimental induction of teratocarcinogenesis.

Testicular teratomas can be induced experimentally by grafting genital ridges from male mouse fetuses to the testes of adults. A high incidence of teratomas occurs in genital ridges grafted to scrotal testes, but not in genital ridges grafted to testes maintained at body temperature. Genital ridges were cultured at 32 degrees C or 37 degrees C prior to grafting to the testes to determine the effect of temperature on the incidence of teratomas. Genital ridges cultured at 32 degrees C for two or three days produced a high incidence of teratomas when grafted to the testes, in contrast to genital ridges cultured at 37 degrees C for two or three days which produced a low incidence. Histologically, genital ridges cultured at 32 degrees C contained disorganized testicular tubules and were retarded in development. Genital ridges continued to develop in vitro at 37 degrees C, but were histologically different from genital ridges maturing in the fetus. Genital ridges cultured at 32 degrees C for 10 to 12 days did not develop teratomas in vitro or after grafting to the testes. Further characterization of temperature effects in vitro may lead to a better understanding of teratocarcinogenesis in vivo.