Genetic analysis of steel and the PG-M/versican-encoding gene AxPG as candidates for the white (d) pigmentation mutant in the salamander Ambystoma mexicanum

David M. Parichy, Michael Stigson, S. Randal Voss

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Vertebrate non-retinal pigment cells are derived from neural crest (NC) cells, and several mutations have been identified in the Mexican axolotl Ambystoma mexicanum (Ambystomatidae) that affect the development of these cell lineages. In 'white' (d) mutant axolotls, premigratory NC cells differentiate as pigment cells, yet fail to disperse, survive, or both, and this leads to a nearly complete absence of pigment cells in the skin. Previous studies revealed that d affects pigment cell development non-autonomously, and have reported differences between white and wild-type axolotls in the structure and composition of the extracellular matrix through which NC and pigment cells migrate. Here we test the correspondence of d and two candidate genes: steel and AxPG. In amniotes, Steel encodes the cytokine Steel factor (mast cell growth factor; stem cell factor; kit ligand), which is expressed along the migratory pathways of melanocyte precursors and is required by these cells for their migration and survival; mammalian Steel mutants resemble white mutant axolotls in having a deficit or complete absence of pigment cells. In contrast, AxPG encodes a PG-M/versican-like proteoglycan that may promote the migration of A. mexicanum pigment cells, and AxPG expression is reduced in white mutant axolotls. We cloned a salamander orthologue of steel and used a partial genetic linkage map of Ambystoma to determine the genomic locations of steel, AxPG, and d. We show that the three genes map to different linkage groups, excluding steel and AxPG as candidates for d.

Original languageEnglish
Pages (from-to)349-356
Number of pages8
JournalDevelopment Genes and Evolution
Issue number6
StatePublished - 1999

Bibliographical note

Funding Information:
Acknowledgements This research was supported by NSF IBN-9423116 and NSF-Sloan DBI-9750006 to D.M.P. and NSF BSR-9101128 and NSF IBN-9509802 to S.R.V. D.M.P. thanks C.A. Er-ickson (University of California at Davis) for support (NIH GM53258), M.S. thanks P. Hakanssons Stiftelse for a Druvan postdoctoral scholarship, and S.R.V. thanks D. Heckel (Clemson University) and H.B. Shaffer (University of California at Davis) for advice and support. The Indiana University Axolotl Colony (Bloomington, Ind.) supplied A. mexicanum embryos, and J. Löfberg kindly provided the photographs in Fig. 1.


  • Extracellular matrix
  • Growth factor
  • Neural crest
  • Pigment cell
  • Proteoglycan

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology


Dive into the research topics of 'Genetic analysis of steel and the PG-M/versican-encoding gene AxPG as candidates for the white (d) pigmentation mutant in the salamander Ambystoma mexicanum'. Together they form a unique fingerprint.

Cite this