Tetraspanin Cd9b and Cxcl12a/Cxcr4b have a synergistic effect on the control of collective cell migration

PLoS One. 2021 Nov 30;16(11):e0260372. doi: 10.1371/journal.pone.0260372. eCollection 2021.


Collective cell migration is essential for embryonic development and homeostatic processes. During zebrafish development, the posterior lateral line primordium (pLLP) navigates along the embryo flank by collective cell migration. The chemokine receptors, Cxcr4b and Cxcr7b, as well as their cognate ligand, Cxcl12a, are essential for this process. We corroborate that knockdown of the zebrafish cd9 tetraspanin orthologue, cd9b, results in mild pLL abnormalities. Through generation of CRISPR and TALEN mutants, we show that cd9a and cd9b function partially redundantly in pLLP migration, which is delayed in the cd9b single and cd9a; cd9b double mutants. This delay led to a transient reduction in neuromast numbers. Loss of both Cd9a and Cd9b sensitized embryos to reduced Cxcr4b and Cxcl12a levels. Together these results provide evidence that Cd9 modulates collective cell migration of the pLLP during zebrafish development. One interpretation of these observations is that Cd9 contributes to more effective chemokine signalling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified / embryology
  • Animals, Genetically Modified / genetics
  • Cell Movement*
  • Chemokine CXCL12 / genetics
  • Chemokine CXCL12 / metabolism*
  • Gene Knockdown Techniques
  • Receptors, CXCR4 / genetics
  • Receptors, CXCR4 / metabolism*
  • Signal Transduction*
  • Tetraspanin 29 / genetics
  • Tetraspanin 29 / metabolism*
  • Zebrafish / embryology*
  • Zebrafish / genetics
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*


  • CXCR4b protein, zebrafish
  • Chemokine CXCL12
  • Receptors, CXCR4
  • Tetraspanin 29
  • Zebrafish Proteins
  • cxcl12a protein, zebrafish