(A-C, G-J) Whole-mount in situ hybridization for mbp in PLLn of gpr126st63 (A-C) or gpr126stl215 (G-J) with control, apomorphine, or forskolin (FSK) treatment at 5 dpf. Black arrows indicate PLLn. (D, K) Quantification expressed as a percentage of larvae with each mbp PLLn phenotype at 5 dpf. * p<0.05, *** p<0.001, Fisher’s Exact Test, “wild-type” vs. “mutant” (gpr126st63 or gpr126stl215) categories for treated vs. control. (E-F) Survival curve following 24-hour treatment with indicated concentrations of apomorphine. Dots indicate mean ± SD % alive across technical replicates. *** p<0.001, 0 vs.100 μM apomorphine. Sample numbers in Detailed Methods.