Use of polymorphic short and clustered coding-region microsatellites to distinguish strains ofCandida albicans

Abstract

We describe the identification of polymorphic microsatellite loci in the pathogenic yeast, Candida albicans. A search for all coding-region microsatellites with more than four repeats that can be found in Candida sequences in GenBank was conducted. Nine such microsatellite sequences consisting of trinucleotide motifs were found. Three of these were perfect microsatellites while the remaining six sequences were found in one imperfect microsatellite and two compound microsatellites. Because of the close proximity of some of these repeats, all could be assayed with six PCR primer pairs. All of these microsatellite sequences were found in five nuclear genes, ZNF1, CCN1, CPH1, EFG1, and MNT2. Except for a single (CTT)5 serine tract, all coded for polyglutamine tracts. Another locus with seven alleles, a region of the ERK1 protein kinase gene, was also examined, and may be a representative of a new class of highly polymorphic "clustered' microsatellites. Such loci, in which several non-contiguous but closely linked microsatellites are clustered together, may be a useful source of DNA polymorphisms in microorganisms in which long microsatellite sequences are unavailable. All seven regions amplified were polymorphic, having between two and seven variable length alleles in the 11 strains of Candida albicans examined. The results of this and similar searches will facilitate epidemiological and evolutionary studies of Candida and other microorganisms.

Isolation, Identification and Characterization of Yeasts from Fermented Goat Milk of the Yaghnob Valley in Tajikistan

“…Microsatellites are tandem repetitive DNA sequences of up to 10 nucleotides, which are spread throughout the genome and are inherited in a codominant matter (Pérez et al, 2001). Yeast microsatellite loci are reported to have a high degree of variability (Field et al, 1996). Previous articles described a set of microsatellite loci as successful in the discrimination between different S. cerevisiae strains (Field and Wills, 1998; Gallego et al, 1998; Pérez et al, 2001) enabling to discriminate beer, wine and bread strains from strains from other sources (Legras et al, 2005).…”

A database of microsatellite genotypes for Saccharomyces cerevisiae

“…Primer sequences and concentrations used in the multiplex are given on our website (http://www.sbs.auckland.ac.nz/uoa/science/about/ departments/sbs/research/wine-science/wine-science_ home.cfm). To perform the PCR, DNA was prepared from colonies or liquid cultures by Chelex extraction (Field et al 1996) and amplified using the Qiagen multiplex PCR kit (#206143) with standard reaction conditions (54°C annealing). The band sizes listed were obtained using an ABI 3730 with a DS30 matrix.…”