Linked markers exclude KIT as the gene responsible for appaloosa coat colour spotting patterns in horses.

The research article presents the investigation on whether the KIT gene was responsible for the Appaloosa coat color pattern in horses. However, with the study results, it was concluded that this gene was not linked to this particular coat color pattern.

Objective of the Study

• The objective of the research was to investigate whether the KIT gene, which has been linked to certain color patterns in mice, is responsible for the Appaloosa coat color pattern in horses.

About the KIT Gene

• KIT is a gene that plays a critical role in haematopoiesis, gametogenesis, and melanogenesis in living organisms.
• The KIT gene encodes a transmembrane tyrosine kinase receptor that belongs to the PDGF/CSF-1/c-KIT receptor subfamily.

The Study Methodology

• A number of genes located close to KIT on horse chromosome 3 were also investigated. These genes included albumin (ALB), serum carboxylesterase (ES), vitamin D-binding protein (GC), and some microsatellite markers.
• Family studies were conducted with eight half-sib families of Appaloosa stallions and solid-coloured mares.
• The researchers then used a computer program called GENEHUNTER to conduct a multipoint linkage analysis to investigate possible links of the Lp gene responsible for the Appaloosa coat to these other markers.

Results and Conclusion

• LOD scores representing the evidence for linkage between these markers and the Lp gene ranged from -4.28 to -12.48.
• A score of -12.48 was obtained at the location for ASB23, a marker gene.
• These results led to the conclusion that the Lp gene, which is considered responsible for the Appaloosa coat colour pattern, is not linked to any of the tested markers on ECA3 chromosome, indicating that the KIT gene is not the gene responsible for the Appaloosa colour.