There are provided compositionsand methods for modulating stem cell divisiondecisions, in particular, division symmetry.It has been demonstrated that wnt7a actsthrough frizzled-7 receptor expressed on thesurface of adult stem cells, e.g. satellite stemcells, to activate the planar cell polarity (PCP)pathway, thereby promoting symmetrical expansionof stem cells. The compositions andmethods of the invention are useful, for example,in modulating stem cell division symmetryin vitro and in vivo, in replenishing and expandingthe stem cell pool, and in promotingthe formation, maintenance, repair and regenerationof tissue.
