Conservation of genetic linkage in nonisogenic isolates of Candida albicans

Abstract

A number of laboratories are now engaged in the genetic analysis of Candida albicans. This diploid yeast, the major fungal pathogen of humans, is imperfect. Parasexual techniques have been devised for complementation and recombination analysis in this organism. This paper attempts to address the question of the extent to which nonisogenic strains of C. albicans have conserved a common genetic map. This analysis is a prerequisite for the integration of work done in different laboratories and may also provide useful information on the taxonomy of the genus Candida. The paper also reports the analysis of an interspecific hybrid between C. albicans and Candida stellatoidea. The method employed in these studies was the analysis of the mitotic recombination relationships of a group of linked genes and their centromere. Strains carrying linked auxotrophic mutations were fused with isogenic and nonisogenic complementary strains to form tetraploids. The mitotic recombination analyses of these tetraploids suggest that in the isolates studied the genetic map is conserved. A comparison of tetraploid and diploid mitotic recombination analyses is also presented.