Planar cell polarity (PCP) signaling has been shown to be essential for the polarization of mesenchymal cell behaviors during vertebrate gastrulation. Convergence and extension gastrulation movements narrow the embryonic tissues mediolaterally while extending them in the anteroposterior direction. These movements are driven by polarized directed migration and intercalation of mediolaterally elongated cells. Zebrafish mutants carrying mutations in or overexpressing the core Wnt/PCP proteins present impaired mediolateral cell polarization and movements leading to phenotypically shorter and broader embryos. We have identified the G-protein coupled receptor protein Gpr125/Adgra3 as a novel modulator of the Wnt/PCP pathway. We showed that Gpr125/Adgra3 protein is able to recruit the core Wnt/PCP component Dishevelled (Dvl) to cell membrane subdomains and to promote the localization of Frizzled7 (Fzd7) and Glypican 4 into these subdomains. Molecular analyses demonstrated a direct interaction of Gpr125 intracellular domain with Dvl. Using TALEN technology, we generated gpr125 mutants. Whereas zygotic indel gpr125 mutants do not exhibit any visible gastrulation defects, mutants lacking both maternal and zygotic gpr125/adgra3 function show mild C&E defects and consequently shorter and wider embryonic bodies. gpr125/adgra3 mutants show a strong genetic interaction with the vangl2 and scribble1 mutants. These results indicate an essential role for Gpr125 during early embryogenesis. Gpr125/Adgra3 is a seven pass transmembrane protein with a long N terminal and C-terminal fragment. The specific functional domains of Gpr125/Adgra3 regulating particular morphogenetic behaviors as well as the downstream signaling partners are unknown to date. The results of ongoing analyses of the MZgpr125/adgra3 mutants and the Gpr125/Adgra3 protein’s functional domains will be presented.