Enrichment and screening of heat-sensitive mutants ofPhysarum polycephalum

Abstract
SUMMARY: A new method for the isolation of temperature-sensitive mutants ofPhysarum polycephalumis described. It involves enrichment and prescreening of mutagenized amoebae followed by screening at both the plasmodial and amoebal stage. A total of 74 temperature-sensitive strains were recovered of which 26 were temperature-sensitive only as plasmodia, 35 only as amoebae and 13 in both stages. After a shift to the nonpermissive temperature, DNA and protein synthesis were followed in temperature-sensitive plasmodia to discover if the lesion affected functions of the nuclear cycle.