Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 14, 2004
Publication Date: N/A
Technical Abstract: Strains available from culture collections are expected to be correctly identified. Frequently, this is not the case because the initial identification was made from phenotype, which often does not fully reflect genotype. Gene sequence comparisons can now be done easily in many laboratories and provide a rapid, accurate means for strain identification. An initial, rapid identification can be made from a single gene sequence. For yeasts, domains D1 and D2 of large subunit (26S) ribosomal DNA (rDNA) are sufficiently substituted to allow identification of individual species or groups of closely related species. Databases of D1/D2 sequences are available for all known yeasts and the sequence of an unknown can be quickly compared in GenBank. Failing a close match with known species, the isolate is probably a new species. Reliance on single gene sequences, however, may result in loss of resolution among closely related species, as has been demonstrated for some species of Saccharomyces and Pichia. Consequently, sequencing additional genes, such as elongation factor-1alpha, actin-1, mitochondrial small subunit rDNA, or cytochrome oxidase II, will provide more precise identification and is likely to detect interspecific hybrids. Additionally, multiple gene sequences are usually required for assignment of species to genera. The effort required for gene sequencing is often less than required for phenotypic characterization and the results are far more definitive, which increases the value of the germplasm to geneticists, biotechnologists and other culture collection customers.