FIG. 1.

Phylogenetic relationships among OCS and OM plastid rDNA clones and plastid SSU rRNA gene sequences from cultured organisms. This phylogenetic tree was constructed by the neighbor-joining method with a LogDet matrix as the input (36). A conserved mask of 987 nucleotides, spanning the entire length of the plastid SSU rRNA gene, was included. Bootstrap values (100 replications) generated by the neighbor-joining method and the Kimura 2-parameter model for nucleotide change are shown above relevant nodes, and bootstrap values generated by maximum-parsimony analysis are shown below relevant nodes. All the sequences used, except for those of Corethron criophilum (38), Cyanidium caldarium (17), Closterium ehrenbergii, Chlamydomonas parkeae, Yamagishiella unicocca, and P. parkeae (30), are available from the GenBank or RDP database. str., strain.