Origin of Testicular Teratomas From Primordial Germ Cells in Mice

Summary

Teratomas were experimentally induced in testes of strain 129 mice when 12½-day genital ridges from fetuses were grafted into the testes of adults. Seventy-five percent of 194 testes developing from implanted SI^J/+, SI^d/+, and +/+ genital ridges contained teratomas. These gonads had normal numbers of primordial germ cells. In contrast, only 3% of 75 SI^J/SI^J and SI^d/SI^d testes contained teratomas. These gonads had very few primordial germ cells. This finding supports strongly the hypothesis that testicular teratomas in mice are derived from primordial germ cells.