The experimental induction of gynogenesis in the mouse. III. Treatment of sperm with trypaflavine, toluidine blue, or nitrogen mustard.

Mouse spermatozoa were treated with trypaflavine, toluidine blue or nitrogen mustard before fertilization in attempts to destroy the sperm chromosomes and so induce haploid gynogenetic development of the egg. High concentrations of either chemical decreased the activity of spermatozoa. Trypaflavine and toluidine blue had a photodynamic action on spermatozoa and lowered the fertilization rate; neither was proved effective in inducing gyno­ genesis, though a class of highly retarded embryos might have been gynogenetic or parthenogenetic in origin. Combination of trypaflavine treatment with ultra-violet irradiation of spermatozoa gave no haploid embryos. After treating spermatozoa with nitrogen mustard three haploids or near-haploids were found at days gestation, though these embryos were not certainly gynogenetic. Nitrogen mustard induced changes in eggs at fertilization and caused extreme damage to the chromosomes of many embryos. The three chemicals did not appear to be as effective as ultraviolet or X-irradiation of spermatozoa for inducing gynogenesis in the mouse. These results contrast with those pre­ viously obtained for amphibia.