Mitotic recombination in Candida albicans: Recessive lethal alleles linked to a gene required for methionine biosynthesis

Abstract

Genetic analysis by ultraviolet-induced mitotic segregation indicated that Candida albicans wild-type strain Ca526 was heterozygous at a gene (MET) required for biosynthesis of methionine. The MET gene was shown to be linked to two other genes (LET1, LET2) whose recessive alleles (let1, let2) each determined lethality when homozygous. The phenotype determined by let1 was temperaturesensitive. The inferred genotype of strain Ca526 was: $$\frac{{MET let1 LET2 \bullet }}{{met LET1 let2 \bullet }}$$ Mitotic recombination was directly demonstrated in the intergenic intervals MET-LET1, Let1-LET2, MET-LET2. The frequency of ultraviolet-induced mitotic segregation generated a linkage map which displayed excellent additivity in the MET-LET2 interval and approximate additivity in the MET-centromere interval.