Apolipoprotein E polymorphism and plasma lipid levels in Native Mongolian sheep

Apolipoprotein E (apoE) phenotypes were determined in 199 unrelated native sheep (Khalkhas line) of Central Mongolia, using a polyacrylamide gel isoelectric focusing-immunoblotting technique, and the plasma lipid levels in different phenotypes were assayed enzymatically. Twenty-eight phenotypes were identified in this sheep. In addition to all the previously detected seven apoE variants composing the phenotypes, four new variants were discovered, which were called E8, E9, E10, and E11. From the population data, these were found to be genetically controlled by four codominant alleles, designated APOE8, APOE9, APOE10, and APOE11, based on the same mode of inheritance as in the seven variants. These alleles were detected at a low frequency, in the range of 0.005 to 0.0126. The Khalkhas sheep differed most significantly from the Baruwal and Lampuchhre sheep of Nepal and the Vietnamese sheep with respect to the allele frequencies found in some Asian local sheep previously examined. Type 1/1 and/or 2/7 sheep had significantly higher plasma levels of total cholesterol and low-density lipoprotein cholesterol than type 7/7 sheep (P < 0.05 and/or P < 0.02).