PUBLICATION

Rhombomere boundaries are Wnt signaling centers that regulate metameric patterning in the zebrafish hindbrain

Authors

Riley, B.B., Chiang, M.Y., Storch, E.M., Heck, R., Buckles, G.R., and Lekven, A.C.

ID

ZDB-PUB-040916-2

Date

2004

Source

Developmental Dynamics : an official publication of the American Association of Anatomists 231(2): 278-291 (Journal)

Registered Authors

Heck, Rebecca, Lekven, Arne, Riley, Bruce

Keywords

boundary-formation, Wnt, tcf/lef, Delta-Notch, erm, ephA4, pou2, radial glia, reticulospinal, commissural neuron

MeSH Terms

Rhombencephalon/anatomy & histology
Rhombencephalon/embryology*
Rhombencephalon/physiology
DNA-Binding Proteins/genetics
DNA-Binding Proteins/metabolism
Zebrafish
Animals
Intracellular Signaling Peptides and Proteins
Wnt Proteins
Intercellular Signaling Peptides and Proteins/genetics
Intercellular Signaling Peptides and Proteins/metabolism*
Signal Transduction/physiology*
In Situ Hybridization
Transcription Factors/genetics
Transcription Factors/metabolism
Membrane Proteins/genetics
Membrane Proteins/metabolism
Mutation
Hepatocyte Nuclear Factor 3-beta
Body Patterning*
Wnt1 Protein
Nuclear Proteins/genetics
Nuclear Proteins/metabolism
Zebrafish Proteins/genetics
Zebrafish Proteins/metabolism
Morphogenesis*
Receptors, Notch
Embryonic Structures/anatomy & histology
Embryonic Structures/physiology*

(all 29)

PubMed

15366005 Full text @ Dev. Dyn.

Abstract

The vertebrate hindbrain develops from a series of segments (rhombomeres) distributed along the anteroposterior axis. We are studying the roles of Wnt and Delta-Notch signaling in maintaining rhombomere boundaries as organizing centers in the zebrafish hindbrain. Several wnt genes (wnt1, wnt3a, wnt8b, and wnt10b) show elevated expression at rhombomere boundaries, whereas several delta genes (dlA, dlB, and dlD) are expressed in transverse stripes flanking rhombomere boundaries. Partial disruption of Wnt signaling by knockdown of multiple wnt genes, or the Wnt mediator tcf3b, ablates boundaries and associated cell types. Expression of dlA is chaotic, and cell types associated with rhombomere centers are disorganized. Similar patterning defects are observed in segmentation mutants spiel-ohne-grenzen (spg) and valentino (val), which fail to form rhombomere boundaries due to faulty interactions between adjacent rhombomeres. Stripes of wnt expression are variably disrupted, with corresponding disturbances in metameric patterning. Mutations in dlA or mind bomb (mib) disrupt Delta-Notch signaling and cause a wide range of patterning defects in the hindbrain. Stripes of wnt1 are initially normal but subsequently dissipate, and metameric patterning becomes increasingly disorganized. Driving wnt1 expression using a heat-shock construct partially rescues metameric patterning in mib mutants. Thus, rhombomere boundaries act as Wnt signaling centers required for precise metameric patterning, and Delta signals from flanking cells provide feedback to maintain wnt expression at boundaries. Similar feedback mechanisms operate in the Drosophila wing disc and vertebrate limb bud, suggesting coaptation of a conserved signaling module that spatially organizes cells in complex organ systems. Developmental Dynamics 231:278-291, 2004. Copyright 2004 Wiley-Liss, Inc.

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