Chromosomal variations in Candida albicans

We report here the separation of chromosomal DNA molecules from the diplokl pathogenic yeast C. albicans by field inversion gel electrophoresls (FIOEK1). Our earlier work on C. albicans ATCC strain 10261 revealed a pulsed field gel electrophoretic pattern of six bands, two of which were possibly doublets (2). In the present study we found that FIGE gave superior resolution with uniform DNA mobility between lanes, and therefore could be used to examine the possibility of electrophoretic karyotype variation in this asexual yeast The extension of our study to other strains of C. albicans showed that local clinical isolates, strain 22114 (from MX).Richardson, Birmingham, England) and our ATCC 10261 reference strain exhibit considerable differences in rheir FIGE banding patterns (Figure). However , certain similarities are apparent, especially in bands 3 and 6. Probing Southern blols with C. albicans DNA probes which complement the HIS3, ADE2 and URA3 genes in S. cerevisiae gave results supporting this conclusion. ri(^» f Tnminntirm nf (h> vpripnt rfimmnntnw, irvjnrllng fmthf-r probing, snggfaited that they may have had common origins, but have undergone rearrangements which involve either one or both bomotogues of a diploid pair. However , we do not believe £hat C. albicans chromosomes are overly unstable, since ATCC 10261 strains freeze-dried in 1960 and 196S gave the same banding pattern as an ATCC 10261 strain in laboratory culture for the last IS years. Thus, FIGE electrophoretic patterns could be a valuable means of characterising and identifying C. albicans strains. The molecular basis of these chromosomal variations and their pbenotypic and medical consequences are of obvious interest Finally, we recommend the use of type strains for the rational genetic analysis of C. albicans. times over the run of forward 10->60i and backward 3->20s. DNA wu prepared and bands are numbered according toRef. 2.