The use of<i>p</i>-fluorophenylalanine with ‘master strains’ of<i>Aspergillus nidulans</i>for assigning genes to linkage groups

Abstract

Four ‘master’ strains of Aspergillus nidulans , three of which are marked on each of the eight chromosomes, are used for assigning genes of unknown location to linkage groups. In this technique a heterozygous diploid is synthesized between one ‘master’ strain and a strain carrying an unlocated marker. This diploid is haploidized by growth on p -fluorophenylalanine, and the haploids thus obtained are classified for recombination between the unlocated marker and each of the markers of the ‘master’ strains. The marker or markers of the ‘master’ strain which show no recombination with the unlocated marker identify the chromosome pair on which the latter is located. One example is presented for each of the four ‘master’ strains.