Phylogenetic analysis of Glutamate GPCRs. Maximum parsimony tree of Glutamate family GPCRs. TM domains I-VII were used for phylogenetic analysis with the alignment bootstrapped 1000 times (bootstrap support values are provided). Schistosoma sequences are shown in green and Schmidtea sequences are shown in blue. GSMD007320 and GSMD015264 were excluded as they remain incomplete over the sequence range used. GABA
receptors are highlighted, along with the primary vertebrate mGluR groupings and the more recently discovered insect Group X receptors. A human Calcium-sensing receptor (AAA86503.1) was used as an outgroup. Putative flatworm GPCRs that are diverged from both the GABA
and glutamate-responsive receptors are outlined in red. The ligand-binding domains of these receptors are further analyzed in Figure 9.