Generating Cellular Diversity and Spatial Form: Wnt Signaling and the Evolution of Multicellular Animals

Publication date: 26 September 2016
Source:Developmental Cell, Volume 38, Issue 6
Author(s): Kyle M. Loh, Renée van Amerongen, Roel Nusse
There were multiple prerequisites to the evolution of multicellular animal life, including the generation of multiple cell fates ("cellular diversity") and their patterned spatial arrangement ("spatial form"). Wnt proteins operate as primordial symmetry-breaking signals. By virtue of their short-range nature and their capacity to activate both lineage-specifying and cell-polarizing intracellular signaling cascades, Wnts can polarize cells at their site of contact, orienting the axis of cell division while simultaneously programming daughter cells to adopt diverging fates in a spatially stereotyped way. By coupling cell fate to position, symmetry-breaking Wnt signals were pivotal in constructing the metazoan body by generating cellular diversity and spatial form.

Teaser

Loh, van Amerongen, and Nusse propose how Wnt proteins might have driven symmetry breaking during evolution, culminating in speciation of patterned animals from simple multicellular aggregates. By simultaneously activating lineage-specifying and cell-polarizing signaling cascades, short-range Wnt signals directly couple cell fate and position—an evolutionary prerequisite for the emergence of animals.


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