Phylogenetic analysis of human ADAMTS proteins and invertebrate homologs. Unambiguously aligned amino acids were analyzed by distance (Protdist+NJ), maximum parsimony (MP) and maximum likelihood (ML) methods. The trees shown are the ML distance topologies. Numbers at the nodes represent the percent of bootstrap replicates of distance (NJ) and parsimony (MP), and the percent of quartet puzzling steps (QP) in support of each group. (A) Phylogenetic tree of human and distantly related invertebrate ADAMTS homologs inferred from a 359-amino acid alignment, with α = 1.42 and proportion of invariable sites (pI) = 0.09. (B) Phylogeny of human and invertebrate ADAMTS homologs with long branches removed, inferred from 543 aligned amino acids, with α = 1.48 and proportion of invariable sites (pI) = 0.10. For reference, Genbank GI numbers for the sequences are provided [Additional File 2].