Fig. 4

Protein family evolution in four vestimentiferan tubeworms. A Venn diagram of shared and unique gene families in four vestimentiferan tubeworm species. Lineage-specific gene families of R. piscesae and R. pachyptila are much less than those of L. luymesi and P. echinospica. B Gene family expansion/contraction analysis of 4 vestimentiferan tubeworms and 8 other lophotrochozoans. The numbers of protein families that were significantly expanded (red) and contracted (green) (P < 0.05) in each species are denoted beside the species names