DIFFERENCES IN THE GENETIC-CONTROL OF THE FORMATION OF INDUCED CHROMOSOMAL-ABERRATIONS AND MITOTIC EXCHANGES

The maternal effect of the mutation mus104(D1) (defect of postreplicat ion repair) on the yield of translocations involving heterochromatin b reaks induced by irradiation of mature spermatozoa has been investigat ed, The mutation has been shown to bring about a threefold increase in the frequency of translocatians. No significant maternal effect of th is mutation an the frequency of mitotic exchanges induced by irradiati on of mature hyperploid spermatozoa has been observed. This is in agre ement with published evidence on properties of the mei41 mutation (all ete mus104(D1)) [2]. However, our results are more accurate as both pr ocesses-formation of translocations and mitotic exchanges-were studied in the same tissue and at the same stage of development.