FIG. 1.

Phylogenetic tree of the γ-Proteobacteria clones and isolates from Horseshoe Bend. Sequence names are coded. For the clones, the names are in boldface where the letter C or S before the number indicates cast or soil, respectively, e.g., C102. For the isolates from 1996 and 1997, the names include the letter C, S, or B, followed by a unique number; the letter M or D; and the number 1 or 2. The first letter indicates the habitat: cast, soil, or burrow, respectively. The first number is the sample number. The second letter indicates the isolation medium: MMSA or DNB, respectively. The last number indicates whether the isolate was the first or second isolate from the particular sample, e.g., S84D1. For the isolates from 1999, the names include the letters NC or NS for cast or soil isolates, respectively, and a unique number, e.g., NC8. Brackets after sequence names denote the total number of sequences in the OTU when that number was greater than 1. Accession numbers appear in parentheses for all reference sequences. Open circles (○) denote bootstrap support of ≥95%, and closed circles (•) denote bootstrap support of ≥50%. The scale bar represents the Jukes-Cantor evolutionary distance.