β-Catenin Asymmetries after All Animal/Vegetal- Oriented Cell Divisions in Platynereis dumerilii Embryos Mediate Binary Cell-Fate Specification

By Stephan Q Schneider, B. Bowerman. Developmental Cell, 2007

119 citations recorded by the source corpus.

In response to Wnt signaling during animaldevelopment, b-catenin accumulates in nucleito mediate the transcriptional activation oftarget genes. Here, we show that a highly con-served b-catenin in the annelid Platynereisdumerilii exhibits a reiterative, nearly universalembryonic pattern of nuclear accumulationremarkably similar to that observed in the nem-atode Caenorhabditis elegans. Platynereisexhibits b-catenin sister-cell asymmetries afterall cell divisions that occur along the animal/vegetal axis beginning early in embryogenesis,but not after two transverse divisions thatestablish bilateral symmetry in the trunk. More-over, ectopic activation of nuclear b-cateninaccumulation in Platynereis causes animal-pole sister cells, which normally have lownuclear b-catenin levels, to adopt the fate oftheir vegetal-pole sisters, which normally havehigh nuclear b-catenin levels. The presence ofreiterative and functionally important b-cateninasymmetries in two distantly related animalphyla suggests an ancient metazoan origin ofab-catenin-mediatedbinarycell-fatespecifica-tion module.

Subfields: Cell Biology, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/a6f510fb2897171ba502f3ef9ae92e7b12626ad7