Coat Color Roan Shows Association with KIT Variants and No Evidence of Lethality in Icelandic Horses

Abstract

Roan (Rn) horses show a typical seasonal change of color. Their body is covered with colored and white hair. We performed a descriptive statistical analysis of breeding records of Icelandic horses to challenge the hypothesis of roan being lethal in utero under homozygous condition. The roan to non-roan ratio of foals from roan × roan matings revealed homozygous roan Icelandic horses to be viable. Even though roan is known to be inherited in a dominant mode and epistatic to other coat colors, the causative mutation is still unknown. Nevertheless, an association between roan phenotype and the KIT gene was shown for different horse breeds. In the present study, we identified KIT variants by Sanger sequencing, and show that KIT is also associated with roan in the Icelandic horse breed.

Whole Genome Sequencing Provides New Insights Into the Genetic Diversity and Coat Color of Asiatic Wild Ass and Its Hybrids

“…We performed functional enrichment to the 346 genes using KOBAS ( http://kobas.cbi.pku.edu.cn/ ) to find vital KEGG pathways, and there were 11 pathways in the enrichment results ( Supplementary Table S12 ). “Melanogenesis” pathway is essential for color phenotype in animals, and KITLG gene in the pathway has been proved to be associated with the phenotype of horse ( Voß et al, 2020 ), donkey ( Wang et al, 2020 ; Zhou et al, 2020 ), human ( Yang et al, 2018 ) and dog ( Weich et al, 2020 ).…”

“…It was obvious that the Kulan hybrids and other populations had different patterns ( Figure 3C ). The KITLG gene is located on chromosome 2 of donkey, and KITLG have been proven to be involved in the formation of coat color in several species ( Anello et al, 2019 ; Voß et al, 2020 ; Weich et al, 2020 ; Wen et al, 2021 ; Wu et al, 2019 ; Yang et al, 2018 ). Furthermore, there have been some studies on donkey and horse ( Voß et al, 2020 ; Zhou et al, 2020 ).…”

“…The KITLG gene is located on chromosome 2 of donkey, and KITLG have been proven to be involved in the formation of coat color in several species ( Anello et al, 2019 ; Voß et al, 2020 ; Weich et al, 2020 ; Wen et al, 2021 ; Wu et al, 2019 ; Yang et al, 2018 ). Furthermore, there have been some studies on donkey and horse ( Voß et al, 2020 ; Zhou et al, 2020 ). Therefore, our findings may provide new insights into the coat color formation of Asiatic wild ass and its Kulan hybrids.…”

“…The diversiform coat color phenotypes segregating in Duroc hybrid pigs demonstrated that KIT is responsible for the complex variation ( Wu et al, 2019 ). In addition, the coat color phenotypes of several species showed an indispensable association with the KIT gene ( Zhang et al, 2015 ; Anello et al, 2019 ; Voß et al, 2020 ; Wen et al, 2021 ). The KITLG gene encodes the KIT ligand protein, which has a vital function in the pigment formation process ( Yang et al, 2018 ).…”

Vererbung und Charakteristik der Pferdefarben: Weißzeichnungen

“…Zur Identifizierung homozygoter Pferde wurde zunächst ein mit Tobiano assoziierter Marker im equinen c-KIT-Gen herangezogen [7,8]. Als genetische Ursache für Tobiano wurde später die 180°-Drehung eines Stücks im equinen Chromosom 3 (ECA3) in der Nähe des c-KIT-Gens gefunden, die eine Veränderung der regulatorischen Region des c-KIT-Gens bewirkt [9] [12,13]. Es wäre daher durchaus denkbar, dass es mehrere Mutationen gibt, die den Phänotyp Stichel (Roan) in den verschiedenen Rassen hervorrufen, von denen eine oder mehrere letal sind.…”