(A) In zebrafish, prior to innervation, Wnt11r interacts with MuSK to activate
Dvl-dependent pathways necessary for forming aneural clusters and guiding motor
growth cones to the middle region of muscle fibers.
(B) In vitro studies suggest that Wnts regulate agrin-induced AChR clustering by
binding to the receptor Frizzled (Fz). They may also act by interacting with
MuSK. Differentiation of motor nerve terminals is regulated by a
β-catenin-dependent pathway. Dashed lines indicate pathways to be
determined.