RESEARCH ARTICLE Identification of compounds that rescue otic and myelination defects in the zebrafish adgrg6 (gpr126) mutant Elvira Diamantopoulou1†, Sarah Baxendale1†, Antonio de la Vega de Leo´ n2, Anzar Asad1, Celia J Holdsworth1, Leila Abbas1, Valerie J Gillet2, Giselle R Wiggin3, Tanya T Whitfield1* 1Bateson Centre and Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom; 2Information School, University of Sheffield, Sheffield, United Kingdom; 3Sosei Heptares, Cambridge, United Kingdom Abstract Adgrg6 (Gpr126) is an adhesion class G protein-coupled receptor with a conserved role in myelination of the peripheral nervous system. In the zebrafish, mutation of adgrg6 also results in defects in the inner ear: otic tissue fails to down-regulate versican gene expression and morphogenesis is disrupted. We have designed a whole-animal screen that tests for rescue of both up- and down-regulated gene expression in mutant embryos, together with analysis of weak and strong alleles. From a screen of 3120 structurally diverse compounds, we have identified 68 that reduce versican b expression in the adgrg6 mutant ear, 41 of which also restore myelin basic protein gene expression in Schwann cells of mutant embryos. Nineteen compounds unable to rescue a strong adgrg6 allele provide candidates for molecules that may interact directly with the Adgrg6 receptor. Our pipeline provides a powerful approach for identifying compounds that modulate GPCR activity, with potential impact for future drug design. DOI: https://doi.org/10.7554/eLife.44889.001 *For correspondence:
[email protected] †These authors contributed Introduction equally to this work Adgrg6 (Gpr126) is an adhesion (B2) class G protein-coupled receptor (aGPCR) with conserved roles in myelination of the vertebrate peripheral nervous system (PNS) (reviewed in Langenhan et al., Competing interest: See 2016; Patra et al., 2014).