STUDIES OF GENETIC MECHANISM OF RADIATION-INDUCED MITOTIC SEGREGATION IN YEAST

Sectoring was induced with x-rays or ultraviolet in a diploid yeast strain heterozygous for seven genes located on one chromosome arm. The frequencies of sectoring of different genes were approximately linearly related to their distance from the centromere. If two or more adjacent genes sectored, the event could be explained by mitotic crossing over. Sectoring of single genes, however, was mostly nonreciprocal and resembled a conversion-type event. Approximately 80% of the sectored colonies could be explained single mitotic crossovers in one of the intergenic regions. © 1969 Springer-Verlag.