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Use of Genetic Markers in Terminal Sire Sheep Sire Reference Schemes. Grant Walling, Geoff Simm, Peter Visscher & Steve Bishop. Aims. Detect genetic markers associated with performance in Suffolk, Texel and Charollais SRSs Detailed investigation of specific genes
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Use of Genetic Markers in Terminal Sire Sheep Sire Reference Schemes Grant Walling, Geoff Simm, Peter Visscher & Steve Bishop
Aims • Detect genetic markers associated with performance in Suffolk, Texel and Charollais SRSs • Detailed investigation of specific genes • Investigate strategies to use genetic markers in sire reference schemes
Data Collection • Blood from commercial SRS farms • Performance data from Signet
Blood Processing • DNA extracted from blood • DNA sent for genotyping on selected chromosomes
Sheep ChromosomesCurrent Knowledge 2 contains a double muscling gene responsible for the extreme muscling in Belgian Blue cattle 4 contains the Leptin gene controlling fat deposition and appetite in the sheep 13 contains a gene controlling scrapie susceptibility 18 contains Callipyge and Carwell genes affecting muscle development 20 contains the MHC region controlling the immune response of the sheep XY determine sex XY=Male XX=Female
Segregation of a major gene affecting body size X AB CC BC AC AC BC Progeny receiving the A allele from their sire are on average larger than those receiving the B allele
Data Analysis • Complex statistics test for evidence of genes • Applied to sires with large numbers of progeny
Texels Chromosome 2 muscle & fat Chromosome 18 muscle Suffolks Chromosome 1 muscle Chromosome 18 growth Results Chromosome 18 results suggest segregation of the Carwell (rib-eye muscling) gene in UK SRS flocks
Future Work • Extend to Charollais Sires • Detailed investigations of current findings • Study the best way of using the findings in SRS
Sponsors & Collaborators Visit: http://www.ri.bbsrc.ac.uk/sheepmap