GEPHE SUMMARY Print
Entry Status
Published
GepheID
GP00001461
Main curator
Prigent
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Dun horse characterized by diluted pigment with dark primitive markings - radially asymmetric deposition of pigment in hair
Trait State in Taxon B
Non-dun horse intensely pigmented associated with markings - circumferential distribution of melanocytes and pigment granules in hair
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Latin Name
Common Name
horse
Synonyms
Equus przewalskii f. caballus; Equus przewalskii forma caballus; horse; domestic horse; equine; Equus caballus Linnaeus, 1758
Rank
species
Lineage
Show more ... rata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Perissodactyla; Equidae; Equus; Equus
NCBI Taxonomy ID
is Taxon A an Infraspecies?
Yes
Taxon A Description
-
Taxon B
Latin Name
Common Name
horse
Synonyms
Equus przewalskii f. caballus; Equus przewalskii forma caballus; horse; domestic horse; equine; Equus caballus Linnaeus, 1758
Rank
species
Lineage
Show more ... rata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Perissodactyla; Equidae; Equus; Equus
NCBI Taxonomy ID
is Taxon B an Infraspecies?
Yes
Taxon B Description
-
GENOTYPIC CHANGE
Generic Gene Name
TBX3
Synonyms
UMS; XHL; TBX3-ISO
Sequence Similarities
-
GO - Biological Process
GO:0043066 : negative regulation of apoptotic process ... show more
GO - Cellular Component
UniProtKB
Homo sapiens
GenebankID or UniProtKB
Presumptive Null
No
Molecular Type
Aberration Type
SNP
Molecular Details of the Mutation
G>T predicted to affect binding of the CCAT box-binding transcription factors NF-Y and NF-I ; Differs from the wild-type allele by a SNP downstream of the wild-type TBX3 sequence (located 1067bp downstream of the start of the larger nd2 deletion described in the nd2 entry) with allele nd1 = T compared with the wild-type D allele = G); an ancient variant
Experimental Evidence
Authors
Imsland F; McGowan K; Rubin CJ; Henegar C; Sundström E; Berglund J; Schwochow D; Gustafson U; et al. ... show more
Abstract
Dun is a wild-type coat color in horses characterized by pigment dilution with a striking pattern of dark areas termed primitive markings. Here we show that pigment dilution in Dun horses is due to radially asymmetric deposition of pigment in the growing hair caused by localized expression of the T-box 3 (TBX3) transcription factor in hair follicles, which in turn determines the distribution of hair follicle melanocytes. Most domestic horses are non-dun, a more intensely pigmented phenotype caused by regulatory mutations impairing TBX3 expression in the hair follicle, resulting in a more circumferential distribution of melanocytes and pigment granules in individual hairs. We identified two different alleles (non-dun1 and non-dun2) causing non-dun color. non-dun2 is a recently derived allele, whereas the Dun and non-dun1 alleles are found in ancient horse DNA, demonstrating that this polymorphism predates horse domestication. These findings uncover a new developmental role for T-box genes and new aspects of hair follicle biology and pigmentation.
Additional References
EXTERNAL LINKS
COMMENTS
@AllelicSeries ; Dun is dominant over non-dun. This allele was already present in horse before domestication ; https://omia.org/OMIA001972/9796/
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