FIG. 2.

Phylogenetic trees illustrating the target groups of the new probes and related species. (A) Tree showing the relationship among the major genera, groups, and organisms known be present in the human gut. The heights of the boxes reflect the numbers of sequences used in the tree construction, and the horizontal lengths reflect the phylogenetic depths of the corresponding groups. Boxes and group names in boldface type indicate the groups that are represented in more detail in succeeding panels (B to F). The trees in panels B to F show the target organisms in bold italic typeface and related but nontarget organisms in normal typeface. (B) The complete genera Streptococcus and Lactococcus, all species of which are targets for the Strc493 probe. (C) The genus Bacteroides and related genera, with the target organisms for the Bfra602 and Bdis656 probes indicated. (D) Clostridium lituseburense group as a part of Clostridium cluster XI (classification according to reference 5), with the target organisms for the Clit135 probe indicated. (E) Clostridium histolyticum group (Clostridium clusters I and II), with the targets of the Chis150 probe indicated. (F) Clostridium coccoides-Eubacterium rectale group (Clostridium cluster CIV), with the targets for the Erec482 probe indicated. All bars represent 10% sequence divergence.