Safety assessment of transgenic potatoes with soybean glycinin by feeding studies in rats

Feeding studies of transgenic potatoes with native and designed soybean gly cinins in rats were done for four seeks. The designed glycinin has four add itional methioninyl residues in the middle of the glycinin molecule. Rats s ere divided into Pour groups fed (I) only a commercial diet, (II) the diet plus non-transgenic potatoes, (III) the diet plus transgenic potatoes with native glycinin, and (IV) the diet plus transgenic potatoes with designed g lycinin. Rats were fed 2,000 mg/ kg-weight potatoes every day by oral admin istration. During the period tested, rats in each group (groups II, III, an d IV) grew well without marked differences in appearance, food intake, body weight, or in cumulative body weight gain. No significant differences sere also found in blood count, blood composition, and in internal organ weight s among the rats after feeding potatoes (groups II, III, and IV) for four w eeks. Necropsy at the end of experiment indicated neither pathologic sympto ms in all rats tested nor histopathological abnormalities in liver and kidn ey. Judging from these results, the transgenic potatoes with glycinins are confirmed to have nearly the same nutritional and biochemical characteristi cs as non-transgenic one.