Fig. 5.—

The position of amino acid substitutions accumulated in the episodic events. Conserved sequence motifs of teleost V1R proteins are displayed as a sequence logo. The relative frequency of amino acids at given sites is reflected by the height of the single-letter amino acid code. The trans-membrane (TM), extracellular (EC), and intracellular (IC) regions are indicated by bold gray bars. The gray circles above the residues indicate the amino acid sites putatively responsible for ligand binding (not for ligand selectivity) in V1Rs and the other GPCRs, which were predicted in several studies (Katada et al. 2005; Niimura and Nei 2005; Pfister and Rodriguez 2005). The arrowheads and the numbers 1 and 2 indicate that the amino acid replacements accumulated in the given V1R genes.