Communication codes in developmental signaling pathways
A handful of core inter-cellular signaling pathways play pivotal roles in a broad variety of developmental processes.
It has remained puzzling how so few pathways can provide the precision and specificity of cell-cell communication required for multi-cellular development.
Solving this requires us to quantitatively understand how developmentally relevant signaling information is actively sensed, transformed and spatially distributed by signaling pathways.
Recently, single cell analysis and cell-based reconstitution, among other approaches, have begun to reveal the ‘communication codes’ through which information is represented in the identities, concentrations, combinations and dynamics of extracellular ligands.
They have also revealed how signaling pathways decipher these features and control the spatial distribution of signaling in multicellular contexts.
Here, we review recent work reporting the discovery and analysis of communication codes and discuss their implications for diverse developmental processes.
Embryonic development depends on accurate, timely and specific communication between cells. Our understanding of cell-cell communication has evolved over many decades.
developmental signaling systems are not passive transmitters of information from an extracellular ligand to an intracellular effector. The information they sense is represented in diverse ways, many of which could not be inferred from knowledge of molecular interactions alone.
Currently, we represent pathways predominantly in molecular terms. But a complementary understanding will come from the ability to represent them as programs that address messages to specific cell types, control the ‘content’ (target program) of a message, and specify the precise spatial distribution of intercellular messages
Common Design 