A SLC45A2 mutation is strongly associated with the cream dilution in Baroque donkeys

Abstract

Objective

Domestic Baroque donkeys are popular animals in many European parks and zoos. Although their cream coat color is very charismatic, the underlying genetics is still undiscovered. Addressing this question, a candidate approach was used to search for the causative mutation.

Material and methods

Considering the knowledge from domestic horses, the Solute Carrier Family 45 Member 2 (SLC45A2) was identified as the most promising candidate. Samples from 77 domesticated donkeys, 11 wild equids, 1 mule and 2 domestic horses were included in comparison. All exons and the flanking intron sequences of the SLC45A2 were sequenced (2774bp).

Results and conclusions

Sequence comparison revealed that a mutation found exclusively in exon 7 transmembrane region 11 (c.1457C>T; p.Ala486Val) is very likely responsible for the charismatic coat color phenotype in Baroque donkeys. Family studies produced evidence for an autosomal recessive mode of inheritance. Since the coat color in Baroque donkeys varies from almost white to gold, the question remains whether the base coloration, which in mammals is regulated by the ASIP and MC1R genes, also have an impact but no remarkable mutations were found in Baroque donkeys.

Zusammenfassung

Gegenstand und Ziel

Barockesel sind den meisten aus Zoos und Tierparks aufgrund ihrer charismatischen Fellfarbe bekannt. Die Genetik der cremefarbenen Aufhellung ist dabei nach wie vor unbekannt. In dieser Studie wurde ein Kandidatengenansatz zur Erforschung der cremefarbenen Aufhellung des Barockesels genutzt.

Material und Methoden

Basierend auf dem Wissen zur Fellfarbgenetik des Pferdes, wurde das Solute Carrier Family 45 Member 2 Gen (SLC45A2) untersucht. Insgesamt 2774 Basenpaare des SLC45A2 von 77 Eseln, 11 Wildequiden, 1 Maultier und 2 Hauspferden wurden sequenziert.

Ergebnisse und Schlussfolgerungen

Ein Aminosäureaustausch im Exon 7 Transmembrane Region 11 (c.1457C>T; p.Ala486Val) konnte als vermutlich ursächliche Mutation für die cremefarbene Aufhellung identifiziert werden. Familienstudien belegten einen autosomalen und rezessiven Erbgang. Zusätzliche Studien an pigmentregulierenden Genen (ASIP und MC1R) brachten keinen zusätzlichen relevanten Mutationen.

Keywords

Coat coloration - domestic animals - Solute Carrier Family 45 Member 2 - MATP - ASIP - MC1R

Schlüsselwörter

Fellfarbe - Haustiere - Solute Carrier Family 45 Member 2 - MATP - ASIP - MC1R

Publikationsverlauf

Eingereicht: 13. August 2025

Angenommen: 08. Oktober 2025

Artikel online veröffentlicht:
28. November 2025

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