A family of conserved repetitive DNA elements from the fungal plant pathogenGlomerella cingulata (Colletotrichum lindemuthianum)

Glomerella cingulata (Colletotrichum lindemuthianum) was transformed with the hygromycin B phosphotransferase gene and the DNA flanking the site of integration in one transformant was isolated for analysis. This flanking DNA was found to contain a nucleotide sequence which was repeated many times and dispersed in the fungal genome. Genomic locations of the repeats were conserved among different isolates of the fungus. The repetitive element did not hybridize to mitochondrial or ribosomal DNA and therefore appears to be nuclear. The nucleotide sequence of the repeated element consists of tandemly arranged CAX triplets, in which X is most commonly G or A. Nucleotide sequences of three independently isolated copies of the repeated element indicated that it represents a family of repeats, each varying in length, genomic location, and the nucleotide representing X in the CAX triplet. A probe representing this family of repeats was found to hybridize in distinct patterns with genomic DNAs of several different fungal genera and that of a higher plant. A DNA minipreparation procedure which is rapid and economical, allowing for 90 samples to be processed in an 8-h period is described. This procedure typically yielded between 200 and 500 μg DNA from a 100-ml fungal culture and the DNA could be digested with a variety of restriction enzymes.