ZFIN ID: ZDB-PUB-101201-11
Collagen XIXa1 is crucial for motor axon navigation at intermediate targets
Hilario, J.D., Wang, C., and Beattie, C.E.
Date: 2010
Source: Development (Cambridge, England)   137(24): 4261-4269 (Journal)
Registered Authors: Beattie, Christine, Hilario, Jona, Wang, Chunping
Keywords: Zebrafish, Motor axons, Axon guidance, Collagen, Intermediate targets
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Axons/metabolism*
  • Collagen/genetics
  • Collagen/metabolism*
  • Gene Expression Regulation, Developmental/genetics
  • Gene Expression Regulation, Developmental/physiology
  • In Situ Hybridization
  • Mice
  • Motor Neurons/cytology
  • Motor Neurons/metabolism*
  • Mutation
  • Reverse Transcriptase Polymerase Chain Reaction
  • Spinal Cord/cytology
  • Zebrafish/embryology*
PubMed: 21098567 Full text @ Development
During development, motor axons navigate from the spinal cord to their muscle targets in the periphery using stereotyped pathways. These pathways are broken down into shorter segments by intermediate targets where axon growth cones are believed to coordinate guidance cues. In zebrafish stumpy mutants, embryonic development proceeds normally; however, as trunk motor axons stall at their intermediate targets, suggesting that Stumpy is needed specifically for motor axon growth cones to proceed past intermediate targets. Fine mapping and positional cloning revealed that stumpy was the zebrafish homolog of the atypical FACIT collagen collagenXIXa1 (colXIX). colXIX expression was observed in a temporal and spatial pattern, consistent with a role in motor axon guidance at intermediate targets. Knocking down zebrafish ColXIX phenocopied the stumpy phenotype and this morpholino phenotype could be rescued by adding back either mouse or zebrafish colXIX RNA. The stumpy phenotype was also partially rescued in mutants by first knocking down zebrafish ColXIX and adding back colXIX RNA, suggesting that the mutation is acting as a dominant negative. Together, these results demonstrate a novel function for a FACIT collagen in guiding vertebrate motor axons through intermediate targets.