Analysis of LMW RNA profiles of Frankia strains by staircase electrophoresis

An optimized technique of polyacrylamide gel electrophoresis, Staircase Ele ctrophoresis (SCE), was applied to determine the stable Low Molecular Weigh t RNA (LMW RNA) profiles of 25 Frankia strains from diverse geographic orig ins and host specificity groups as well as species from other actinomycete genera. Application of the technique permits the rapid identification of Fr ankia strains and their differentiation from other actinomycetes. The isola tes used in this study were grouped in eight clusters, each comprising stra ins with identical LMW RNA profiles. Comparison of these results with other s obtained from DNA sequences or DNA hybridization methods suggest a high d egree of complexity in the genus Frankia. Application of SCE to profile LMW RNA should in the future facilitate biodiversity studies of Frankia and di scrimination of new species.