FIG. 4.

Diagrammatic phylogenetic trees of microbial mat sequences and their cultured and uncultured relatives with associated GenBank accession numbers. Reference sequences of cultured representatives are shown in italics. Wedges represent groups of microbial mat sequences, and single sequences are indicated by their clone names. The length of the top and bottom edges represents the range of sequence divergence. The average depth from which sequences were obtained is indicated next to the wedge, with the total depth range in parentheses. (A) Chloroflexi sequences. Percentages indicate the fraction of Chloroflexi sequences within a given sequence cluster. “Oxic zone” indicates clusters of sequences obtained from surface layers exclusively. (B) Cyanobacterial sequences. Percentages indicate the fraction of cyanobacterial sequences within a given sequence cluster.