Fig. 5. Wnt-Fz signalling controls anterior-directed projections of
mechanosensory neurons in C. elegans. (A) In the 2-fold
stage C. elegans embryo, egl-20(wnt) is expressed (red
shading) in the tail behind anterior (AVM) and posterior (PVM) ventral
mechanosensory neurons. (B) The position and projections of the
different mechanosensory neurons of the worm (only one of the ALM and PLM
bilateral pairs is shown; PVM and AVM are positioned on opposite hemi-sides of
the embryo). (C) In double Wnt (cwn-1;egl-20)mutants or double
Fz (mig-1; mom-5) mutants, the anterior projection of the AVM and PVM
axons is impaired. Similarly, ALM axons do not branch in the nerve ring.