Neurospora prototroph selection system for studying aneuploid production.

Various environmental agents have been tested for their ability to produce aneuploid products of meiosis in a Neurospora cross. The cross was between two multiply marked strains designed specifically for this purpose. These parental strains were heterozygous for four auxotrophic mutations on chromosome 1. Prototrophic disomics could be selected by plating ascospores on minimal medium. Out of 48 agents tested, at least 10 increased the aneuploid frequency significantly above control levels. Some of these positive-testing agents have also been found active in other aneuploid detection systems. It is suggested that if it should become necessary to perform widespread testing of agents in the human environment for their ability to generate aneuploids at meiosis, the Neurospora system could be successfully applied for this purpose.