Fig. 4.

Evolution of RIM superfamily proteins across phylogenetic groups and domain structure of Aplysia unc13 proteins. Dendrogram for RIM, Piccolo, Bassoon, Fife, and Chalumeau family members from a RAxML analysis (with alignment trimmed with TrimAI; Methods and SI Appendix, Table S2). Bootstrap values ≥50% shown. Additional arthropods and echinoderms were added in this analysis to clarify the representation of Fifes, Piccolos, and Chalumeaus. Species abbreviations for species not defined in previous figure legends: Ami, Acropora millepora; Hv, Hydra vulgaris; Nv, Nematostella vectensis (cnidarians); Cse, Cryptotermes secundus; Haz, Hyalella azteca; Fo, Frankliniella occidentalis; Pt, Parasteatoda tepidariorum (arthropods); Aj, Anneissia japonica; Ar, Asterias rubens; Ap, Acanthaster planci; Lv, Lytechinus variegatus; Pv, Patiria miniata (echinoderms), Bf, Branchiostoma floridae (cephalochordate). For two genes characterized in C. elegans, we use the original gene names, clairnet, Clar, for a Piccolo family member, and Unc10 for RIM in this nematode. The outgroup was Aplysia rabphilin (not shown). Several unanticipated family members are indicated with specific names: ArPicc, arthropod Piccolo; SpFife, spiralian Fife; DeFife, deuterostome Fife. Note: Limulus has three Fife genes, and Bassoon is recently derived from Piccolo in vertebrates.