OMIA:001152-9031 : Feather colour, eumelanin extension in Gallus gallus (chicken)

Categories: Pigmentation phene

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal incomplete dominant

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2021

Species-specific name: Melanotic

Species-specific symbol: Ml

Species-specific description: Li et al. (2021): "Melanotic affects within-feather pigmentation patterns by enhancing the contrast between dark- and light-colored regions in the feather."

Inheritance: Melanotic shows incomplete dominance over wild-type (Carefoot, 1987)

Mapping: Carefoot (1987) mapped this phene to chicken chromosome 1. Li et al. (2021) "linkage mapping using a back-cross between Dark Cornish (Ml/Ml) and Partridge Plymouth Rock (ml+/ml+) chickens assigned Ml to an 820-kb region on chromosome 1. Identity-by-descent mapping, via whole-genome sequencing and diagnostic tests using a diverse set of chickens, refined the localization to the genomic region harboring GJA5 encoding gap-junction protein 5 (alias connexin 40) previously associated with pigmentation patterns in zebrafish."

Molecular basis: Li et al. (2021): "An insertion/deletion [InDel1 = 41-bp deletion and 38-bp insertion] polymorphism located in the vicinity of the GJA5 promoter region was identified as the candidate causal mutation. Four different GJA5 transcripts were found to be expressed in feather follicles and at least two showed differential expression between genotypes. The results showed that Melanotic constitutes a cis-acting regulatory mutation affecting GJA5 expression."

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
GJA5 gap junction protein, alpha 5, 40kDa Gallus gallus 1 NC_052532.1 (92618897..92598058) GJA5 Homologene, Ensembl , NCBI gene


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WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
1362 Feather colour, melanotic GJA5 delins, gross (>20) Naturally occurring variant GRCg6a 1 g.95256761_95256801delinsAAACTACTGCTTATTAAACTACTACTACTATTTAAGAT cis-acting regulatory mutation 2021 34607956

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2021). OMIA:001152-9031: 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.

2021 Li, J., Lee, M.O., Chen, J., Davis, B.W., Dorshorst, B.J., Siegel, P.B., Inaba, M., Jiang, T.X., Chuong, C.M., Andersson, L. :
Cis-acting mutation affecting GJA5 transcription is underlying the melanotic within-feather pigmentation pattern in chickens. Proc Natl Acad Sci U S A 118:e2109363118, 2021. Pubmed reference: 34607956. DOI: 10.1073/pnas.2109363118.
1990 Carefoot, W.C. :
Test for linkage between the eumelanin dilution blue (B1), the extended black (E) allele at the E-locus and the linked pea comb (P) and eumelanin extension (M1) genes in the domestic fowl. British Poultry Science 31:465-472, 1990. Pubmed reference: 2245344. DOI: 10.1080/00071669008417279.
1987 Carefoot, W.C. :
Test for linkage between the eumelanin restrictor (Db) and the eumelanin extension (Ml) genes in the domestic fowl British Poultry Science 28:69-73, 1987. Pubmed reference: 3567691. DOI: 10.1080/00071668708416937.
Carefoot, W.C. :
Relative positions of the loci of the peacomb (P), eumelanin restrictor (Db), eumelanin extension (Ml) and plumage pattern (Pg) genes of the domestic fowl British Poultry Science 28:347-350, 1987. Pubmed reference: 3607559. DOI: 10.1080/00071668708416968.
1971 Moore, J.W., Smyth, J.R. :
Melanotic: key to a phenotypic enigma in the fowl. J Hered 62:215-9, 1971. Pubmed reference: 5137353. DOI: 10.1093/oxfordjournals.jhered.a108153.

Edit History

  • Created by Frank Nicholas on 06 Sep 2005
  • Changed by Imke Tammen2 on 08 Oct 2021