glp-1 and inductions establishing embryonic axes in C. elegans.
Two successive inductions specify blastomere identities, that is complex cell lineages and not specific tissues, in a major part of the early C. elegans embryo. The first induction acts along the anterior-posterior axis of the embryo and the second along the left-right axis. During the first induction a specific lineage program is induced in the posterior of the two AB blastomeres present in the four cell embryo. During the second induction, almost all of the left-right differences of the embryo are specified by interactions between a single signalling blastomere, MS, and the AB blastomeres that surround it. In both cases the inductions break the equivalence of pairs of blastomeres. The inductions correlate with the cell-cell contacts to the inducing blastomeres. The stereotype cleavage patterns of the early embryo results in invariant cell-cell contacts that guarantee the specificity of the inductions. Both inductions are affected in embryos mutant for glp-1 suggesting that in both cases glp-1 is involved in the reception of the signal.
Hutter
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Max-Planck-Institut für Biochemie, Martinsried, FRG.
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D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins; D002454:Cell Differentiation / Q000502:physiology; D004627:Embryonic Induction / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000502:physiology*; D008846:Micromanipulation; D009024:Morphogenesis / Q000502:physiology; D051880:Receptors, Notch
D029742:Caenorhabditis elegans Proteins; C060620:Glp-1 protein, C elegans; D008562:Membrane Glycoproteins; D051880:Receptors, Notch