(i, j) The cellular levels of Ca2+ ions after ligand (C10ORF99) stimulation of GPR15 in coelacanth, Asian bony tongue, and their mutants. (k, l) The cellular levels of Ca2+ ions after ligand (C10ORF99) stimulating GPR15 in Japanese quail and its mutants. The fold-change in calcium levels was calculated based on the fluorescence intensity (excitation and emission wavelengths: 490 and 520 nm, respectively). 