转Cry1Ab-ma基因玉米的蛋白质功效比

Protein efficiency ratio of genetically modified corn with Cry1Ab-ma gene

目的评价转Cry1Ab-ma基因玉米和亲本玉米的蛋白质功效比。方法 60只SD大鼠,按体重随机分为酪蛋白对照组、亲本玉米组和转基因玉米组,每组20只,雌雄各半。酪蛋白对照组酪蛋白添加量占饲料的10%,亲本玉米组和转基因玉米组饲料按照玉米最大掺入的原则掺入后蛋白质含量仍不够10%时,以酪蛋白补充。大鼠自由饮食饮水,喂养28天。每周记录各组摄食量及体重,试验末期采血测定血常规和血生化指标,主要脏器称重计算脏器体重比,并计算蛋白质功效比及校正蛋白质功效比。结果各组动物的体重均呈增长趋势,体重增长正常,末期的血液学和血生化指标中个别指标差异虽有统计学意义,但并无生物学意义。各主要脏器系数也均未发现有生物学意义的改变。转基因玉米、亲本玉米和酪蛋白的蛋白质功效比分别为2.01±0.22、1.77±0.30和3.64±0.48。转基因玉米和亲本玉米的校正蛋白质功效比分别为1.38和1.22。结论该批次转Cry1Ab-ma基因玉米的蛋白质功效比优于亲本玉米,劣于酪蛋白。

OBJECTIVE To evaluate the protein efficiency ratio(PER) of genetically modified corn with Cry1Ab-Ma gene and parental corn. METHODS Sixty SD rats(60-80 g) were randomly divided into genetically modified corn group, parental corn group and casein control group, with 20 rats in each group and half male and half female. Casein was added to 10% of the diet in casein control group. When the protein content of the diets in the genetically modified corn group and parental corn group was still less than 10% according to the principle of maximum incorporation, the defective part was supplemented with casein. Rats were free to drink and eat for 28 days. Food intake and body weight of each group were recorded every week. Blood was collected at the end of the experiment to determine hematology and blood biochemical indexes. The main organs were weighed and organ/body weigh indexes were calculated. PER and corrected PER were calculated. RESULTS The body weight of all the animals in each group showed an increasing trend, and the weight growth was normal. Although there were statistical differences in the individual indexes of end-stage hematology and blood biochemical indexes, there was no biological significance. There were no significant change in the organ/body weigh indexes. PER of genetically modified corn, parental corn and casein were 2.01±0.22, 1.77±0.30 and 3.64±0.48, respectively. The corrected PER of genetically modified corn and parent corn were 1.38 and 1.22, respectively. CONCLUSION The PER of this batch of genetically modified corn with Cry1Ab-ma gene was better than that of parental corn, but worse than that of casein.