Ligand for members of the frizzled family of seven transmembrane receptors (By similarity). Affects male tail development, vulval precursor cell specification and egg laying. Involved in morphogenesis by influencing polarity of asymmetric cell divisions of the B, U, and F cells in the male, and the T cell in males and hermaphrodites. Controls spindle orientation in B-gamma cell division during male copulatory spicule development. Involved in specification of the P7.p lineage during vulval development. Has a role in providing polarity and default lin-17 localization in axon development and positioning of neuromuscular synapses in DA9 regions by negatively regulating synaptogenesis. Plays a role in motorneuron development by promoting the extension of the anterior neurite of ventral D-type GABAergic motorneurons along the anterior-posterior axis of the ventral nerve cord (PubMed:23376536). Expressed in the tail hypodermis. Expressed during embryogenesis and larval development (PubMed:17719547, PubMed:7553861, PubMed:8026318). Mainly expressed in the tail during larval stages (PubMed:20711352). Palmitoleoylation is required for efficient binding to frizzled receptors. Depalmitoleoylation leads to Wnt signaling pathway inhibition. Cell fate decisions disrupted, protein localization altered and neuron translocation disrupted. Defective tail development in males. Defective in egg laying in hermaphrodites. Nuclear localization of wrm-1 and lit-1 appears disrupted. Similar to tau-induced unc phenotype. Deviations in vulval precursor cell fate are observed when knocked down in conjunction with cwn-1 and egl-20. Bivulval phenotype when accompanied by mom-2 and/or cwn-2 knockdowns. Increase in ectopic synaptic vesicle puncta. Belongs to the Wnt family.