Extended Data Figure 6. G protein-coupled receptors.

GPCRs, also known as 7-transmembrane (7TM) or serpentine receptors, form a large superfamily that activates intracellular second messenger systems upon ligand binding. This figure considers a subset of the 329 GPCRs we identified in O. bimaculoides. The full complement of GPCRs is presented in Supplementary Note 8.5. a and b, As reported for other lophotrochozoan genomes, the octopus genome contains chemosensory-like GPCRs: 74 GPCRs are similar to the Aplysia chemosensory GPCRs⁵⁷ and 11 GPCRs are similar to vertebrate olfactory receptors. c, We identified 4 opsins in the octopus genome (from top to bottom): rhodopsin, rhabdomeric opsin, peropsin, and retinochrome. d, The octopus Class F GPCRs comprises 6 genes: 5 Frizzled genes and 1 Smoothened gene (*). e, Thirty octopus genes show similarity to vertebrate adhesion GPCRs.