title: Encoding of temporal signals by the TGF-β pathway and implications for embryonic patterning.
abstract: Genetics and biochemistry have defined the components and wiring of the signaling pathways that pattern the embryo. Among them, the transforming growth factor β (TGF-β) pathway has the potential to behave as a morphogen: in vitro experiments established that it can dictate cell fate in a concentration-dependent manner. How morphogens convey positional information in a developing embryo, when signal levels change with time, is less understood. Using integrated microfluidic cell culture and time-lapse microscopy, we demonstrate here that the speed of ligand presentation has a key and previously unexpected influence on TGF-β signaling outcomes. The response to a TGF-β concentration step is transient and adaptive: slowly increasing the ligand concentration diminishes the response, and well-spaced pulses of ligand combine additively, resulting in greater pathway output than with constant stimulation. Our results suggest that in an embryonic context, the speed of change of ligand concentration is an instructive signal for patterning.
authors: Laboratory of Molecular Vertebrate Embryology, The Rockefeller University, New York, NY 10065, USA; Center for Studies in Physics and Biology, The Rockefeller University, New York, NY 10065, USA.
authors: Benoit
authors: B
authors: Sorre
authors: Laboratory of Molecular Vertebrate Embryology, The Rockefeller University, New York, NY 10065, USA; Center for Studies in Physics and Biology, The Rockefeller University, New York, NY 10065, USA.
authors: Aryeh
authors: A
authors: Warmflash
authors: Laboratory of Molecular Vertebrate Embryology, The Rockefeller University, New York, NY 10065, USA. Electronic address: brvnlou@rockefeller.edu.
authors: Ali H
authors: AH
authors: Brivanlou
authors: Center for Studies in Physics and Biology, The Rockefeller University, New York, NY 10065, USA. Electronic address: siggiae@rockefeller.edu.
authors: Eric D
authors: ED
authors: Siggia
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008954:Models, Biological; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta