THE FREQUENCY OF INTEGRATIVE TRANSFORMATION AT PHASE SPECIFIC GENES OF CANDIDA-ALBICANS CORRELATES WITH THEIR TRANSCRIPTIONAL STATE

The phase transition between the white and opaque phenotypes in the switching system of Candida albicans strain WO-1 is accompanied by the differential expression of the white-specific gene WH11 and the opaque-specific gene PEP1. The frequency of integrative transformation at the white-specific gene locus WH11 is between 4.5 and 7.0 times more frequent in white than in opaque spheroplasts, and the frequency of disruptive transformation at the opaque-specific gene locus PEP1 is 30.5 times more frequent in opaque spheroplasts than in white spheroplasts. In contrast, the frequencies of integrative transformation at the constitutively expressed loci ADE2 and EF1 alpha 2 are similar in the white and opaque phases. Therefore, the frequency of integration of linear plasmid DNA containing sequences of phase-specific genes correlates with the transcriptional state of the targeted locus.