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Updated: Jun 25, 2026
13:42
Clinical Examination Protocol to Detect Atypical and Classical Scrapie in Sheep
Published on: January 19, 2014
Scrapie-resistant sheep show certain coat colour characteristics
R M Sawalha1, L Bell, S Brotherstone
1Scottish Agricultural College, Sustainable Livestock Systems, West Mains Road, Edinburgh EH93JG, UK. rami.sawalha@sac.ac.uk
Genetics Research
|February 18, 2009
Summary
Prion protein (PrP) genotype influences sheep coat color, not just scrapie resistance. Selection for disease resistance may alter sheep
Area of Science:
- Animal Genetics
- Sheep Breeding
- Coat Color Genetics
Background:
- Scrapie susceptibility is linked to prion protein (PrP) gene polymorphisms, forming the basis of control programs.
- Selective breeding for scrapie resistance may unintentionally impact other traits associated with PrP genotype.
- UK native sheep breeds possess distinctive coat color patterns valuable for study.
Purpose of the Study:
- To investigate the relationship between PrP genotype and coat color characteristics in Badgerfaced Welsh Mountain and Shetland sheep.
- To determine if selection for scrapie resistance affects coat color patterns and associated traits.
Main Methods:
- Analysis of coat color pattern, darkness, spotting, and PrP genotype data from 11,674 Badgerfaced Welsh Mountain and 2338 Shetland sheep.
- Utilized a log-linear model with maximum likelihood for data analysis.
Main Results:
- A strong, significant association was found between PrP genotype and coat color pattern in both breeds.
- PrP genotype was also significantly associated with white spotting in Shetland sheep.
- Sheep with the ARR/ARR genotype (highly scrapie resistant) showed a higher likelihood of a light dorsum/dark abdomen pattern.
Conclusions:
- PrP genotype significantly influences coat color patterns in specific sheep breeds.
- Selection for scrapie resistance based solely on PrP genotype could lead to reduced morphological diversity.
- Potential unintended consequences for fitness and other associated traits warrant consideration in breeding programs.
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