Homozygous clones are generated in the germ line of the testis at the same frequency as in wild-type controls, but homozygous germ line stem cells do not establish persistent clones; although clusters of differentiating mutant spermatocytes are seen, no early-stage homozygous germ cells are evident in testes containing clones 7 days after clone induction.
S. Luschnig C. Nusslein-Volhard