Orchestrating ontogenesis: variations on a theme by sonic hedgehog.
Embryonic development is an emergent process in which increasing complexity is generated by sequential cellular interactions. Recently, it has become clear that such interactions are mediated by just a few families of signalling molecules; but how does this limited repertoire elicit the diversity of form that is characteristic of multicellular organisms? Here we review the various ways in which a member of one such family, the sonic hedgehog (SHH) protein, is deployed during embryonic development. These examples of SHH function provide paradigms for inductive interactions that should help to inform attempts to recapitulate cellular programming and organogenesis in vitro.
Ingham
Philip W
PW
Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, 138673, Singapore. pingham@imcb.a-star.edu.sg
Placzek
Marysia
M
D000818:Animals; D002465:Cell Movement; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology; D004331:Drosophila melanogaster; D047108:Embryonic Development; D005246:Feedback; D053823:Hedgehog Proteins / Q000235:genetics* / Q000502:physiology*; D008954:Models, Biological; D009420:Nervous System / Q000196:embryology; D015398:Signal Transduction; D014714:Vertebrates
D029721:Drosophila Proteins; D053823:Hedgehog Proteins; C077245:hh protein, Drosophila