Satety Assessment Of Rice Genetically Modified With Cry1Ac And Sck By Feeding Studies On Carp (Cyprinus Carpio)

A 56 days feeding study was used to evaluate whether a carp diet prepared with brown rice derived from transgenic rice modified with Cry1Ac gene and sck gene had any unanticipated adverse effects on carp (Cyprinus carpio) as compared with diet prepared with brown rice derived from non-transgenic control rice. 240 healthy carps were divided into two treatment groups randomly, and each group was divided into four replicates, furthermore every replicate fed with 30 fish. The control group (86) fed with ordinary 86 brown rice diet, the test group (FM86) was fed transgenic brown rice diet. Effects of transgenic brown rice on nutritional safety, immunotoxicological safety, intestinal microflora were studie and Cry1Ac gene protein was detected in foregut, midgut and hindgut of carp.The test results were as follows:Experiment 1: The nutrient composition of the brown riceThe content of Moisture, Crude protein, Crude fat, Ash, Crude fiber, Nitrogen-free-extract, Amino acid, Calcium and Phosphorus between non-transgenic control rice and transgenic rice had no statistic difference.Experiment 2: Nutritional safety assessment of rice genetically modified with Cry1Ac and sck by feeding studies on carpDuring the period of 0 to 28d, the period of 29 to 56d and the whole 0 to 56d period, no significant statistically differences in the growth performance and Muscle content were observed between carps reared on the diets prepared with transgenic brown rice or control rice.With 0.4% Cr2O3 as the exogenous indicator, the apparent digestibility of total energy, dry material, crude protein, crude fat, crude ash, amino acid, Calcium and Phosphorus between non-transgenic control rice and transgenic rice had no statistic difference. The feeding value of transgenic rice and parental rice were similar in this study, and no unexpected effects were observed in rice genetically modified with Cry1Ac gene and sck gene.During the period of 0 to 28 d, the period of 29 to 56d and the whole 0 to 56d period, the carp in both groups grew well without marked differences in food intake and body weight. the organ index of liver pancreas, spleen, kidney, foregut, midgut and hindgut between non-transgenic control rice and transgenic rice had no statistic difference. Necropsy indicated neither pathological symptoms nor histopathological abnormalities in the liver, spleen, kidney, foregut, midgut and hindgut. Length of intestine villus and crypt depth of intestinalsegment were observed no significantly different. Judging from these results: no detrimental unexpected effects were observed in rice genetically modified with Cry1Ac gene and sck gene.Experiment 3: Immunotoxicological safety assessment of rice genetically modified with Cry1Ac and sck by feeding studies on carpDuring the period of 0 to 28d, the period of 29 to 56d and the whole 0 to 56d period, the carp in both groups grew well without marked differences in food intake, body weight and the growth of immune organs. There were also no significant differences in the physiological indexes of whole blood, serum regular parameters, serum lysozyme activity, serum hormone and antioxidant capacity indexs and immune factors in serum (TNFα, IL-1β, IFNγ, iNOS2a, IL-10 and TLR5) of carp. Necropsy at the end of the experiment indicated neither pathological symptoms nor histopathological abnormalities in the liver, spleen, foregut, midgut and hindgut. Judging from these results, the rice genetically modified with Cry1Ac and sck is considered to have been essentially the same in nutritional and Immunotoxicological characteristics as the control rice.Experiment 4: Intestinal microflora safety assessment of rice genetically modified with Cry1Ac and sck by feeding studies on carpDuring the period of 0 to 28d, the period of 29 to 56d and the whole 0 to 56d period, no significant differences were observed between carps reared on the diets prepared with transgenic brown rice or control rice.The Number of colonies for E. coli, Lactobacillus and Bifidobacterium which were residing in foregut, midgut and hindgut had no significant differences. The carps were not observed statistically significant difference in the impact of Intestinal microbial flora of carp. Experiment 5: Cry1Ac gene protein was detected in foregut, midgut and hindgut of carpExogenous Cry1Ac protein was not detected in foregut, midgut and hindgut. The transgenic protein will not spread to nature by way of excreta.To sum up, transgenic brown rice has substantial equivalence as compared with ordinary brown rice, and has no negative effects to carp.