SPORICHTHYA-POLYMORPHA REPRESENTS A NOVEL LINE OF DESCENT WITHIN THE ORDER ACTINOMYCETALES

The 16S rDNA of Sporichthya polymorpha was PCR amplified from genomic DNA and almost completely sequenced using the dideoxy dye-terminator s equencing approach and automated DNA analysis. The primary structure w as compared to the homologous molecule from 160 representatives of 37 genera of the order Actinomycetales. No higher similarity than 91.7% w as found and the phylogenetic tree shows this morphologically unique o rganism to form an individual line of descent outside the main radiati on of spore- and mycelium-forming organisms.