|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online 13 June 2007
doi: 10.1242/dev.008268
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390, USA.
* Author for correspondence (e-mail: rueyling.lin{at}utsouthwestern.edu)
Accepted 15 May 2007
C. elegans embryos exhibit an invariant lineage comprised primarily of a stepwise binary diversification of anterior-posterior (A-P) blastomere identities. This binary cell fate specification requires input from both the Wnt and MAP kinase signaling pathways. The nuclear level of the TCF protein POP-1 is lowered in all posterior cells. We show here that the ß-catenin SYS-1 also exhibits reiterated asymmetry throughout multiple A-P divisions and that this asymmetry is reciprocal to that of POP-1. Furthermore, we show that SYS-1 functions as a coactivator for POP-1, and that the SYS-1-to-POP-1 ratio appears critical for both the anterior and posterior cell fates. A high ratio drives posterior cell fates, whereas a low ratio drives anterior cell fates. We show that the SYS-1 and POP-1 asymmetries are regulated independently, each by a subset of genes in the Wnt/MAP kinase pathways. We propose that two genetic pathways, one increasing SYS-1 and the other decreasing POP-1 levels, robustly elevate the SYS-1-to-POP-1 ratio in the posterior cell, thereby driving A-P differential cell fates.
Key words: C. elegans, TCF/POP-1, ß-catenin/SYS-1, Cell fate specification
This article has been cited by other articles:
![]() |
M. Hebeisen and R. Roy CDC-25.1 stability is regulated by distinct domains to restrict cell division during embryogenesis in C. elegans Development, April 1, 2008; 135(7): 1259 - 1269. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Iglesias, J. L. Gomez-Skarmeta, E. Salo, and T. Adell Silencing of Smed-{beta}catenin1 generates radial-like hypercephalized planarians Development, April 1, 2008; 135(7): 1215 - 1221. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Y. Sokol and K. A. Wharton Jr WNTers in La Jolla Development, October 1, 2007; 134(19): 3393 - 3399. [Abstract] [Full Text] [PDF] |
||||