Fig. 1. wnt, frizzled and vps-35 mutants have PLM polarity defects. (A) Wild-type mec-4::gfp, left and right PLM, ventral view. mec-4::gfp is expressed in mechanosensory neurons ALM, PLM, AVM and PVM. (B) lin-17; PLMs with a reversed polarity. The sister of PLM, ALN, can often adopt a PLM-like fate in lin-17 mutants; ALN expresses mec-4::gfp and has an inverted polarity. Asterisks indicate the two PLM and one ALN cell bodies. (C) lin-44; arrows indicate the PLM with a symmetric polarity, the other PLM has a wild-type polarity. (D) lin-44; egl-20; PLMs with a reversed polarity. (E) vps-35; PLMs with a symmetric polarity. (F) ALM and PLM are bilaterally symmetric pairs of neurons located near the midbody and the tail, respectively; only left ALM and PLM are shown. The posterior ALM process is rarely present and is not depicted. Boxed area indicates region shown in fluorescence photomicrographs. Anterior is leftwards and dorsal is towards the top, unless indicated otherwise.