Detection of genetic variation in Ustilago maydis strains by probes derived from telomeric sequences.

Genetic variation using probes derived from telomeric sequences was analysed among several Ustilago maydis strains in an attempt to identify discriminative fingerprint patterns. Three groups of wild isolates from different geographical areas and one group of standard laboratory strains were examined. Analysis of the endmost restriction fragments (EFs) and of the endmost-associated restriction fragments (EAFs) of the chromosomes revealed group differences. Most of the EFs in two groups of strains showed a similar length whereas in the other two groups they were distributed in classes of different lengths. Furthermore, analysis of the EAFs permitted possible fingerprint patterns to be predicted for each group of strains based on the occurrence of amplified bands as well as the presence or absence of distinct bands which were shown to be present in terminal as well as in interstitial sites of the chromosome. The approach evaluated in this work yielded highly polymorphic fingerprint patterns and could be used to distinguish groups of fungal isolates; this approach may also be effective for other fungal systems.