ZFIN ID: ZDB-PUB-070806-13
Zebrafish Hoxb1a regulates multiple downstream genes including prickle1b
Rohrschneider, M.R., Elsen, G.E., and Prince, V.E.
Date: 2007
Source: Developmental Biology   309(2): 358-372 (Journal)
Registered Authors: Elsen, Gina, Prince, Victoria E., Rohrschneider, Monica
Keywords: Zebrafish, Hox, Hindbrain, Rhombomere 4, Branchiomotor neurons, Facial neurons, Neuronal migration, Prickle
Microarrays: GEO:GSE5199
MeSH Terms:
  • Adaptor Proteins, Signal Transducing
  • Animals
  • Carrier Proteins/biosynthesis*
  • Cell Movement
  • Expressed Sequence Tags
  • Face/innervation
  • Gene Expression Regulation
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism*
  • LIM Domain Proteins
  • Motor Neurons/physiology
  • Oligonucleotide Array Sequence Analysis
  • Signal Transduction
  • Zebrafish/embryology
  • Zebrafish/metabolism*
  • Zebrafish Proteins/biosynthesis*
PubMed: 17651720 Full text @ Dev. Biol.
Despite 30 years of Hox gene study, we have a remarkably limited knowledge of the downstream target genes that Hox transcription factors regulate to confer regional identity. Here, we have used a microarray approach to identify genes that function downstream of a single vertebrate Hox gene, zebrafish hoxb1a. This gene plays a critical and conserved role in vertebrate hindbrain development, conferring identity to hindbrain rhombomere (r) 4. For example, zebrafish Hoxb1a, similar to mouse Hoxb1, is required for the migration of r4-derived facial branchiomotor neurons into the posterior hindbrain. We have screened microarrays carrying more than 16,000 expressed sequence tags (ESTs) for genes that are differentially regulated in normal versus Hoxb1a-deficient r4 tissue. Using this approach, we have identified both positively and negatively regulated candidate Hoxb1a target genes. We have used in situ hybridization to validate twelve positively regulated Hoxb1a targets. These downstream targets are expressed in a variety of subdomains within r4, with one gene, a novel prickle homolog (pk1b), expressed specifically within the facial branchiomotor neurons. Using morpholino knock-down and cell transplantation, we demonstrate that the Hoxb1a target Prickle1b functions cell-autonomously to control facial neuron migration, a single aspect of r4 identity.