ZFIN ID: ZDB-PUB-071227-20
Zebrafish dlx2a contributes to hindbrain neural crest survival, is necessary for differentiation of sensory ganglia and functions with dlx1a in maturation of the arch cartilage elements
Sperber, S.M., Saxena, V., Hatch, G., and Ekker, M.
Date: 2008
Source: Developmental Biology   314(1): 59-70 (Journal)
Registered Authors: Ekker, Marc, Hatch, Gary, Saxena, Vishal, Sperber, Steven
Keywords: Dlx, Pharyngeal arch, Craniofacial, Neural crest, Cartilage, Zebrafish
MeSH Terms:
  • Animals
  • Body Patterning
  • Branchial Region/embryology
  • Branchial Region/physiology*
  • Cartilage/embryology
  • Cartilage/physiology*
  • Cell Survival
  • Ganglia, Sensory/embryology
  • Ganglia, Sensory/physiology*
  • Homeodomain Proteins/physiology*
  • Neural Crest/embryology
  • Neural Crest/physiology*
  • Transcription Factors/physiology*
  • Zebrafish/embryology*
  • Zebrafish/physiology
  • Zebrafish Proteins/physiology*
PubMed: 18158147 Full text @ Dev. Biol.
The Dlx genes are expressed in a coordinate manner, establishing proximal-distal polarity within the pharyngeal arches. In zebrafish, dlx2a is expressed in the migrating cranial neural crest that contributes to the pharyngeal arches. Expression of dlx2a in the arches is subsequently followed by overlapping expression of the physically linked dlx1a gene, and of other paralogues that include dlx5a/dlx6a and dlx3b/dlx4b. To investigate the patterning and establishment of arch proximodistal polarity in zebrafish, we characterized the function of dlx2a and dlx1a, using antisense morpholino oligonucleotides (MOs). We show that embryos injected with dlx1a and dlx2a MOs exhibit reduced and dysmorphic arch cartilage elements. The combined loss of dlx1a and dlx2a causes severe arch cartilage dysmorphology, revealing a role for these genes in maturation and patterning of arch chondrogenesis. Knockdown of dlx2a affects migrating neural crest cells as evidenced by reduced expression of crestin, and sox9a transcripts, in addition to increased levels of apoptosis. During pharyngogenesis, loss of dlx2a results in aberrant barx1 expression and the absence of goosecoid transcripts in the dorsal region of the ceratohyal arch. Defects in the differentiation of ectomesenchymal derivatives, including sensory ganglia and cartilage elements, indicate a role for dlx2a in specification and maintenance of cranial neural crest.