STEAROYL COENZYME-A DESATURASE ENZYME-ACTIVITY AND MESSENGER-RNA LEVELS ARE NOT DIFFERENT IN SUBCUTANEOUS ADIPOSE-TISSUE FROM ANGUS AND AMERICAN WAGYU STEERS

We proposed that greater stearoyl coenzyme A (CoA) desaturase enzyme a ctivity caused the elevated monounsaturated fatty acids observed in Am erican Wagyu adipose tissue. Stearoyl CoA desaturase mRNA concentratio ns and enzyme activities were measured in subcutaneous adipose samples from Angus (n = 5) and American Wagyu (n = 5), fed to the Japanese ma rket end point. A rat liver stearoyl CoA desaturase cDNA clone was use d to measure the relative amounts of stearoyl CoA desaturase mRNA. Enz yme activities and mRNA concentrations, as measured by laser densitome try of slot-blot autoradiograms, were not significantly different betw een the two breeds at this stage of growth. This investigation has dem onstrated that, at this stage of maturity, differences in fatty acid c omposition between Angus and American Wagyu steers cannot be attribute d to differences in stearoyl CoA desaturase enzyme activity.