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Localizing the X-linked orange colour phenotype using feline resource families
R A Grahn1, B M Lemesch, L V Millon
1Department of Population Health and Reproduction, University of California at Davis, Davis, CA 95616, USA.
Animal Genetics
|January 27, 2005
Summary
The orange coat color locus in domestic cats (O) was mapped on the X chromosome. Linkage analysis excluded nine microsatellites, suggesting a location near the centromere (Xcen).
Area of Science:
- Genetics
- Mammalian coat color genetics
- Feline genetics
Background:
- Many mammalian coat color genes are conserved, but the domestic cat's orange locus (O) is unique.
- The orange locus undergoes X-inactivation, leading to tortoiseshell patterns in heterozygous females.
- Orange locus has not been localized on the feline X chromosome.
Purpose of the Study:
- To localize the orange coat color locus on the domestic cat X chromosome.
- To analyze linkage between the orange locus and X-linked microsatellites.
- To establish reference pedigrees for future feline genetic studies.
Main Methods:
- Analysis of 10 feline-derived X-linked microsatellites in two large pedigrees.
- Segregation analysis of the orange phenotype within these pedigrees.
- Linkage and exclusion analyses to determine the locus's chromosomal location.
Main Results:
- Linkage analyses excluded nine informative X-linked microsatellites from close association with the orange locus.
- Exclusion analyses suggested a possible location for the orange locus in a 14 cM region near the X centromere (Xcen).
- Recombination rates in the studied pedigrees were reduced compared to other feline families.
Conclusions:
- The orange locus (O) is localized to the feline X chromosome, likely near Xcen.
- The established pedigrees provide a valuable resource for future domestic cat genetic mapping.
- This study advances understanding of feline coat color genetics and X-linked gene localization.
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