Fig. 3.

Relative abundance distribution of archaeal OTUs among samples. (A) Bootstrapped phylogenetic tree of full-length archaeal 16S rRNA clones showing the relationship of three Lost City clones (in bold) to previously published close relatives. (B) Relative normalized abundance (as percentage of total tag sequences per sample) of each archaeal OTU (clustered at 3% distance threshold) in each of the four chimney samples. The OTUs are labeled according to which of the three groups they belong according to pairwise similarity with the V6 region of the full-length 16S rRNA clones. ANME-1, anaerobic methanotrophic archaea; LCMS, Lost City Methanosarcinales; MGI, Marine Group I Crenarchaeota.