Sheep lymphocyte antigens and scrapie

The frequencies of 15 lymphocyte antigens were determined in 2 experimental flocks of Herdwick sheep derived from the same foundation stock. The Blue flock had been bred for resistance, and the Red flock for susceptibility, to a standard dose of the SSBP/1 source of scrapie injected subcutaneously. Although there were marked frequency differences between the 158 Red flock and 51 Blue flock sheep tested these differences could be attributed to genetic drift. Within the Red flock no significant frequency differences were observed between 16 sheep which developed natural scrapie and their healthy flockmates. All Red flock lambs born in 1980 were injected subcutaneously with SSBP/1 scrapie; there was no difference in antigen frequency between the group which subsequently developed experimental scrapie (30) and the group which did not (21). The segregation of antigen haplotypes in the Red flock pedigrees showed no evidence of MHC linkage with either natural or experimental scrapie.