Wnts play a central role in the development of many cells and tissue types in all species studied to date. Like many other extracellular signaling pathways, secreted Wnt proteins are involved in many different processes; inC. elegansthese include: cell proliferation, differentiation, cell migration, control of cell polarity, axon outgrowth and control of the stem cell niche. Perturbations in Wnt signaling are also key factors in cancer formation, and therefore of interest to oncobiologists. Wnts are secreted glycoproteins, which bind to Frizzled transmembrane receptors and signal either through, or independently of β -catenin. Both β -catenin-dependant (Wnt/ β -catenin) and -independent pathways function during postembryonic development inC. elegansand allow Wnt researchers to explore aspects of Wnt signaling both in common with other organisms and unique to the nematode.Chapter 9inVolume 2discusses various processes controlled by Wnt signaling duringC. elegansembryonic development; this chapter discusses Wnt controlled processes that occur during postembryonic development, including an overview of methods used to observe their function.
