Reclassification of current Dictyostelium mucoroides strain Dm7 based on rRNA sequences and morphological features

Recent classification and phylogenetic analyses of dictyostelids are based on molecular sequences, but not all strains have been examined using this approach. Since the original identification in 1869, several strains called Dictyostelium mucoroides have been isolated; however, molecular taxonomic analyses of these strains remain insufficient. We therefore attempted to verify classification of one of these strains (Dm7) using rRNA sequences. As a result, strain Dm7 was found to be phylogenetically closer to D. clavatum and D. longosporum than to D. mucoroides. Comparisons of the morphological features of these strains further supported the classification based on sequence data, suggesting that Dm7 should be classified as a strain of D. clavatum.