FIG. 3.

Parasexual screening. Haploidization of 10 diploid pyrG⁺ niaD⁺ revertants on nonselective (A) and selective (B) media is shown. Random segregation of chromosomes is visualized by the production of differently colored haploid conidia. In the case of plasmid integration in an essential gene, residual growth is observed on selective haploidization medium (arrowheads). For these pyrG⁺ niaD⁺ revertants, haploid spores obtained on nonselective haploidization medium were tested for the absence of the transposable element in order to confirm the essential phenotype.