Various cells including stem cells undergo asymmetric cell divisions to produce daughter cells with distinct cell fates. Most cells in C. elegans have the same anterior-posterior polarity in terms of localizations of Wnt signaling components such as β-catenin, and divide asymmetrically to produce a variety of cell types. Similar asymmetric localization was reported in mouse ES cells. We are studying how each cell knows the correct orientation, how it divides asymmetrically and how the daughter cells acquire specific cell fates.
Asymmetric localization of β-catenin before (A) and at telophase (B) of asymmetric division. Arrowheads indicate cell boundary. (C) Polarity orientation (arrows) of epithelial stem cells (light blue) is redundantly controlled by three Wnt proteins (CWN-1, CWN-2, EGL-20).
Sugioka K, Fielmich LE, Mizumoto K, Bowerman B, van den Heuvel S, Kimura A, Sawa H. Tumor suppressor APC is an attenuator of spindle-pulling forces during C. elegans asymmetric cell division. Proc Natl Acad Sci U S A. 2018 Jan 30;115(5):E954-E963.
Sugioka K, Mizumoto K, Sawa H. Wnt regulates spindle asymmetry to generate asymmetric nuclear β-catenin in C. elegans. Cell. 2011 Sep 16;146(6):942-54.
Yamamoto Y, Takeshita H, Sawa H. Multiple Wnts redundantly control polarity orientation in Caenorhabditis elegans epithelial stem cells. PLoS Genet. 2011 Oct;7(10):e1002308.