Fig. 2.

Dose–response curves of adrenergic G-protein-coupled receptors from Platynereis dumerilii, Priapulus caudatus, and Saccoglossus kowalevskii treated with varying concentrations of ligand. Data, representing luminescence units relative to the maximum of the fitted dose–response curves, are shown as mean ± standard error of the mean (n = 3). Half maximal effective concentration (EC₅₀) values and significance values are listed in Table 1