PUBLICATION

Pbx proteins cooperate with Engrailed to pattern the midbrain-hindbrain and diencephalic-mesencephalic boundaries

Authors
Erickson, T., Scholpp, S., Brand, M., Moens, C.B., and Waskiewicz, A. Jan
ID
ZDB-PUB-060911-6
Date
2007
Source
Developmental Biology   301(2): 504-517 (Journal)
Registered Authors
Brand, Michael, Moens, Cecilia, Scholpp, Steffen, Waskiewicz, Andrew
Keywords
Zebrafish, Engrailed, Pbx, Midbrain, Midbrain–hindbrain boundary, Diencephalic-mesencephalic boundary, Hexapeptide, Lineage restriction, Neural patterning
MeSH Terms
  • Animals
  • Animals, Genetically Modified
  • Body Patterning
  • Gene Deletion
  • Gene Expression Regulation, Developmental
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism*
  • Mesencephalon/embryology*
  • Mesencephalon/metabolism*
  • Mutation/genetics
  • Nerve Tissue Proteins/genetics
  • Nerve Tissue Proteins/metabolism
  • Rhombencephalon/embryology*
  • Rhombencephalon/metabolism
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish/metabolism*
PubMed
16959235 Full text @ Dev. Biol.
Abstract
Pbx proteins are a family of TALE-class transcription factors that are well characterized as Hox co-factors acting to impart segmental identity to the hindbrain rhombomeres. However, no role for Pbx in establishing more anterior neural compartments has been demonstrated. Studies done in Drosophila show that Engrailed requires Exd (Pbx orthologue) for its biological activity. Here, we present evidence that zebrafish Pbx proteins cooperate with Engrailed to compartmentalize the midbrain by regulating the maintenance of the midbrain-hindbrain boundary (MHB) and the diencephalic-mesencephalic boundary (DMB). Embryos lacking Pbx function correctly initiate midbrain patterning, but fail to maintain eng2a, pax2a, fgf8, gbx2, and wnt1 expression at the MHB. Formation of the DMB is also defective as shown by a caudal expansion of diencephalic epha4a and pax6a expression into midbrain territory. These phenotypes are similar to the phenotype of an Engrailed loss-of-function embryo, supporting the hypothesis that Pbx and Engrailed act together on a common genetic pathway. Consistent with this model, we demonstrate that zebrafish Engrailed and Pbx interact in vitro and that this interaction is required for both the eng2a overexpression phenotype and Engrailed's role in patterning the MHB. Our data support a novel model of midbrain development in which Pbx and Engrailed proteins cooperatively pattern the mesencephalic region of the neural tube.
Genes / Markers
Figures
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Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes