Submitted to: Yeasts International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2000
Publication Date: N/A
Technical Abstract: Phylogenetic analysis of gene sequences provides a powerful means for identifying yeasts and determining their biodiversity from evolutionary relationships. Yeasts are found among the ascomycetes and the basidiomycetes. Individual species can generally be resolved from divergence in the D1/D2 domain of 26S rDNA or from differences in ITS sequences. Separation of individual strains of a species has been demonstrated from AFLP fingerprinting and from sequence divergence in the IGS region of the rDNA repeat. Resolution of genera is presently a major problem. Species groupings determined from various genes, e.g., 18S, 26S, and ITS of the nuclear rDNA repeat, mitochondrial rDNA, translation elongation factor EF-1alpha, and cytochrome-c oxidase II, are generally congruent for closely related species, but more distant relationships tend to vary and are not statistically well supported. The application of molecular systematics to problems in medicine, agriculture, and biotechnology offers unprecedented opportunities. Rapid, accurate identification of clinical and food safety isolates is now practical with molecular probes and from direct sequencing of species-specific genes. Molecular phylogeny offers a means for predicting the physiological and genetic properties of yeasts useful to agriculture and biotechnology. Additional new species of biotechnological potential can be obtained from nature by selection of colonies on isolation plates with probes specific for the clades of interest.