The Notch-target gene hairy2a impedes the involution of notochordal cells by promoting floor plate fates in Xenopus embryos.
We have previously shown that the early Xenopus organiser contains cells equally potent to give rise to notochord or floor plate, and that Notch signalling triggers a binary decision, favouring the floor plate fate at the expense of the notochord. Now, we present evidence that Delta1 is the ligand that triggers the binary switch, which is executed through the Notch-mediated activation of hairy2a in the surrounding cells within the organiser, impeding their involution through the blastopore and promoting their incorporation into the hairy2a+ notoplate precursors (future floor-plate cells) in the dorsal non-involuting marginal zone.
López
Silvia L
SL
Laboratorio de Embriología Molecular, Instituto de Biología Celular y Neurociencias, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, Argentina.
Rosato-Siri
María V
MV
Franco
Paula G
PG
Paganelli
Alejandra R
AR
Carrasco
Andrés E
AE
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D019070:Cell Lineage; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism*; D008954:Models, Biological; D009672:Notochord / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D051880:Receptors, Notch; D015398:Signal Transduction; D029867:Xenopus Proteins / Q000502:physiology*; D014982:Xenopus laevis
D051792:Basic Helix-Loop-Helix Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D012313:RNA; D051880:Receptors, Notch; D029867:Xenopus Proteins; C439928:HES4 protein, Xenopus; C064045:delta protein