Science：干细胞如何指导分裂

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A Localized Wnt Signal Orients Asymmetric Stem Cell Division in Vitro
4 v% S, \4 D7 [$ D5 m1 NShukry J. Habib1,2,*, Bi-Chang Chen2, Feng-Chiao Tsai3, Konstantinos Anastassiadis4, Tobias Meyer3, Eric Betzig2, Roel Nusse1,*, A. a/ {$ w. @2 N( B! V* f  @
+ Author Affiliations
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1Department of Developmental Biology, Howard Hughes Medical Institute, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, 265 Campus Drive, Stanford, CA 94305, USA. 7 u4 L* S) s6 I, e# I3 J
2Janelia Farm Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA. : V' _2 N4 D/ y; D- p" D( W
3Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA.
. O; ]* J+ S* T7 ~+ M4BIOTEC, Technische Universität Dresden Tatzberg 47-51, 01307 Dresden, Germany. 9 y, P) j# }8 T3 z
↵*Corresponding author. E-mail: rnusse@stanford.edu (R.N.); shabib@stanford.edu (S.J.H.) ! u& Q. X6 `+ F% D
AbstractEditor's SummaryDevelopmental signals such as Wnts are often presented to cells in an oriented manner. To examine the consequences of local Wnt signaling, we immobilized Wnt proteins on beads and introduced them to embryonic stem cells in culture. At the single-cell level, the Wnt-bead induced asymmetric distribution of Wnt–β-catenin signaling components, oriented the plane of mitotic division, and directed asymmetric inheritance of centrosomes. Before cytokinesis was completed, the Wnt-proximal daughter cell expressed high levels of nuclear β-catenin and pluripotency genes, whereas the distal daughter cell acquired hallmarks of differentiation. We suggest that a spatially restricted Wnt signal induces an oriented cell division that generates distinct cell fates at predictable positions relative to the Wnt source. $ L" @2 _0 c7 K6 S) D8 _