Figure 1.
Panel A shows the structure of a rat AMPAR with labeled subunits A through D and domains within subunits. Panel B is a phylogenetic tree illustrating the relationships of Bilateria, highlighting three major lineages. Panel C is a detailed branch of the iGluR gene tree focusing on AMPAR, with labels and symbols indicating gene duplications and ancestral genes.
Lineage-specific gene duplications dominate AMPAR evolution. (A) Left, rat AMPAR structure from PDB accession no. 5WEO, and right, cartoon indicating subunits A through D and domains within subunits. (B) Animal tree (branches not to scale) showing relationships of Bilateria. Three major lineages in bold. (C) AMPAR branch from iGluR gene tree (full tree in Fig. S1, branch support values are SH-aLRT and ultrafast bootstrap). Blue labels/arrows: selected putative ancestral genes arising from speciation. Circles, diamonds, squares, and stars: gene duplications discussed in the main text. Bold gene names: studied in subsequent figures.