Figure 8

Predicted events in the evolution of perforin: A. Locus, transcript and protein domain architectures of: i. the gene cluster of MPEG1 and a hypothetical perforin/C6 common ancestor (P/C6); ii. the MPEG1, perforin gene cluster and a C6-like gene from early chordates. Domains are abbreviated as follows: secretion signal peptide, SP; membrane attack complex/perforin, MACPF; transmembrane anchor, TM; epidermal growth factor-like, EGF; C2 domain, C2; thrombospondin, TSP; low-density lipoprotein-receptor class A, LR; unknown region, ?. B. Phylogenetic tree showing the relationship of species from major branches of Metazoa. The loci for MPEG1, perforin and C6 are shown and loci not found in some genomes are crossed out. Genus/species abbreviations are: Amphimedon queenslandica, A. queenslandica; Crassostrea gigas, C. gigas; Patiria miniata, P. miniata; Strongylocentrotus purpuratus, S. purpuratus; Branchiostoma floridae, B. floridae; Ciona intestinalis, C. intestinalis.