MUTAGENESIS WITH METHYL METHANESULFONATE IN MOUSE

The toxicity of methyl methanesulfonate was tested in several mouse strains as a preliminary to the design of further experiments on mutagenesis. Doses of 30 and 60 mg/kg were selected for further investigations. By direct cytological observations, it was found that the end of pachytene shows a special sensitivity. The doses induced dominant lethal mutations. Treatment of post-meiotic stages resulted in a considerable amount of deciduomata. In contrast the proportion of deciduomata arising from meiotic or pre-meiotic stages was low. Experiments involving the sex-linked marker Tabby and XO females were designed to test chromosome non-disjunction. The frequency of non-disjunctions induced in our strain is discussed. From these experiments it appears that methyl methanesulfonate is efficient for inducing structural changes in chromosomes of the mouse. This confirms several reports in the literature. © 1969.