Fyn/Yes and non-canonical Wnt signalling converge on RhoA in vertebrate gastrulation cell movements

Convergent extension (CE) cell movements during gastrulation mediate extension of the anterior - posterior body axis of vertebrate embryos. Non-canonical Wnt5 and Wnt11 signalling is essential for normal CE movements in vertebrate gastrulation. Here, we show that morpholino ( MO)- mediated double knockdown of the Fyn and Yes tyrosine kinases in zebrafish embryos impaired normal CE cell movements, resembling the silberblick and pipetail mutants, caused by mutations in wnt11 and wnt5, respectively. Co-injection of Fyn/ Yes- and Wnt11- or Wnt5-MO was synergistic, but wnt11 or wnt5 RNA did not rescue the Fyn/ Yes knockdown or vice versa. Remarkably, active RhoA rescued the Fyn/ Yes knockdown as well as the Wnt11 knockdown, indicating that Fyn/ Yes and Wnt11 signalling converged on RhoA. Our results show that Fyn and Yes act together with noncanonical Wnt signalling via RhoA in CE cell movements during gastrulation.