Canonical and non-canonical Wnt signaling in the patterning of multipotent stem cells during feather development

Restricted until 29 July 2010.The formation of complex ectodermal organs begins with multipotent stem cells that undergo many basic cellular events. During the formation of a complex organ, there are many factors that need to be considered such as patterning, size, and shape in order to maintain proper organ function. Feather development is a good model. The feather field must be patterned to establish how many feathers, the size must be determined, and the shape of the feather must be appropriate for its function. Canonical and non-canonical Wnt signaling has been implicated in many crucial steps in feather bud development.; Canonical Wnt signaling involves the stabilization and accumulation of beta-catenin, which is subsequently translocated to the nucleus. There, beta-catenin interacts with various coactivators including CREB-binding protein (CBP) and p300, which results in the expression of different genes downstream of beta-catenin/TCF that may direct cells towards a path of pluripotency or differentiation. One of the genes downstream of beta-catenin/p300 interaction is Myc. Myc activation has been shown to deplete epidermal stem cells and has been found to be important in the regulation of cell growth and cell size. The last consideration of shape can be addressed by non-canonical Wnt signaling. Planar cell polarity (PCP) genes have been identified in Drosophila to be important for establishing polarity in various processes, including hair follicle orientation.; Through perturbation of normal embryonic chicken dorsal skin explant, it has been found that beta-catenin interaction with p300 is indispensable for proper development of feather buds, Myc activation results in enlargement of forming feather buds, and PCP genes have great potential for involvement in polarity