tRNA genes are generally found clustered, head-to-tail in eubacterial, mitochondrial and chloroplast genomes, and in assorted orientations in the nuclear genomes of species in other kingdons. Unlike the tRNA genes, the spacer regions between genes evolve rapidly and vary in length between related species. PCR primers that are derived from tRNA gene consensus sequences can be developed from each major group of pathogenic fungi. When these primers are used for low stringency PCR, a species-specific fingerprint is generated that detects gene rearrangements and length polymorphisms in the spacers. In this six month feasibility project, the investigators will demonstrate that a set of tRNA gene consensus primers can be developed for major groups of fungal pathogens of humans. In later studies, intergenic spacers showing length polymorphisms among related species or sub-species can be cloned and sequenced. Then a single pair of primers can be designed to detect the spacer length polymorphisms, a feature that makes these PCR products diffeent from most conventional PCR. Such primer will find many uses in diagnosis.
