OMIA:002680-8296 : Skin colour, melanoid in Ambystoma mexicanum (axolotl)

Categories: Pigmentation phene

Mendelian trait/disorder: yes

Considered a defect: no

Key variant known: no

Species-specific description: Kabangu et al. (2023): "The melanoid axolotl is a Mendelian variant characterized by large numbers of melanophores, proportionally fewer xanthophores, and no iridophores."

Mapping: Kabangu et al. (2023) " used bulked segregant RNA-Seq to screen the axolotl genome for melanoid candidate genes and identify the associated locus. Dissimilar frequencies of single-nucleotide polymorphisms were identified between pooled RNA samples of wild-type and melanoid siblings for a region on chromosome 14q. This region contains gephyrin (Gphn), an enzyme that catalyzes the synthesis of the molybdenum cofactor that is required for XDH activity, and leukocyte tyrosine kinase (Ltk), a cell surface signaling receptor that is required for iridophore differentiation in zebrafish. Wild-type Ltk crispants present similar pigment phenotypes to melanoid, strongly implicating Ltk as the melanoid locus."

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2023). OMIA:002680-8296: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2023 Kabangu, M., Cecil, R., Strohl, L., Timoshevskaya, N., Smith, J.J., Voss, S.R. :
Leukocyte tyrosine kinase (Ltk) is the Mendelian determinant of the axolotl melanoid color variant. Genes (Basel) 14:904, 2023. Pubmed reference: 37107662. DOI: 10.3390/genes14040904.
1996 Frost-Mason, S.K., Mason, K.A. :
What insights into vertebrate pigmentation has the axolotl model system provided? Int J Dev Biol 40:685-93, 1996. Pubmed reference: 8877441.
1974 Dalton, H.C., Hoerter, J.D. :
Patterns of purine synthesis related to iridophore development in the wild type, melanoid, and axanthic strains of the Mexican axolotl, Ambystoma mexicanum Shaw. Dev Biol 36:245-51, 1974. Pubmed reference: 4814566. DOI: 10.1016/0012-1606(74)90048-7.
1967 Humphrey, R.R., Bagnara, J.T. :
A color variant in the Mexican axolotl. Journal of Heredity 58:251–256, 1967. DOI:

Edit History

  • Created by Imke Tammen2 on 29 Apr 2023
  • Changed by Imke Tammen2 on 29 Apr 2023