FIG. 3.

Phylogenetic analysis of archaeal SSU rRNA gene clones from sample AT425. This unrooted phylogenetic tree was obtained by methods described in the legend to Fig. 2. A mask of 695 nucleotides, including all nonambiguously aligned positions, spanning approximately 900 nucleotides of the 5′ end of the SSU rRNA gene, was included in the analysis. Sequences from isolates are in italics, sequences from environmental gene clones are in plain text, and sequences from the AT425 sample are in boldface. Sequences labeled “Eel” are from a study of the Eel River area off the coast of northern California (15), and sequences labeled “2C” or “2M” are from a study of a coastal salt marsh (31). GenBank accession numbers of the sequences from other studies are included.