Zebrafish Leucocyte tyrosine kinase controls iridophore establishment, proliferation and survival

Pigment Cell Melanoma Res. 2016 May;29(3):284-96. doi: 10.1111/pcmr.12454.


The zebrafish striped pattern results from the interplay among three pigment cell types; black melanophores, yellow xanthophores and silvery iridophores, making it a valuable model to study pattern formation in vivo. It has been suggested that iridophore proliferation, dispersal and cell shape transitions play an important role during stripe formation; however, the underlying molecular mechanisms remain poorly understood. Using gain- and loss-of-function alleles of leucocyte tyrosine kinase (ltk) and a pharmacological inhibitor approach, we show that Ltk specifically regulates iridophore establishment, proliferation and survival. Mutants in shady/ltk lack iridophores and display an abnormal body stripe pattern. Moonstone mutants, ltk(mne) , display ectopic iridophores, suggesting hyperactivity of the mutant Ltk. The dominant ltk(mne) allele carries a missense mutation in a conserved position of the kinase domain that highly correlates with neuroblastomas in mammals. Chimeric analysis suggests a novel physiological role of Ltk in the regulation of iridophore proliferation by homotypic competition.

Keywords: homotypic competition; iridophores; leucocyte tyrosine kinase; pigment cells; tumorigenesis; zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Behavior, Animal
  • Body Patterning
  • Cell Communication
  • Cell Proliferation
  • Cell Survival
  • Chromatophores / cytology*
  • Chromatophores / enzymology*
  • Melanophores / cytology
  • Melanophores / metabolism
  • Mutation / genetics
  • Phenotype
  • Protein-Tyrosine Kinases / chemistry
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Zebrafish / metabolism*
  • Zebrafish Proteins / chemistry
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*


  • Zebrafish Proteins
  • Ltk protein, zebrafish
  • Protein-Tyrosine Kinases