Fig. 2.

Molecular phylogeny of Brachyury family members. The tree was estimated based on a DNA dataset comprising 872 unambiguously aligned sites (excluding 3rd codon positions) of the sequences selected from the estimated gene tree of T-box family members (Additional file 2). Numbers at nodes are bootstrap probabilities obtained for 100 replicates. Because base-pair change is apparently faster in urochordates than in other deuterostomes, urochordate Brachyury forms a clade with that of other deuterostomes. It should be noted that the two species of cephalochordate each have two copies of Brachyury