Gu Jinni, Bakke Anne Marie, Valen Elin C, Lein Ingrid, Krogdahl Åshild
Department of Basic Sciences and Aquatic Medicine, NMBU School of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway.
Nofima AS, Sunndalsøra, Norway.
PLoS One. 2014 Jun 12;9(6):e99932. doi: 10.1371/journal.pone.0099932. eCollection 2014.
Responses in Atlantic salmon (Salmo salar L.) juveniles (fry) fed diets containing genetically modified maize (Bt-maize, MON810) expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ∼20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize). One pair was fishmeal-based while the other pair included standard (extracted) soybean meal (SBM; 16.7% inclusion level), with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.17±0.01 g; initial mean weight ± SEM) were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine aminopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile salmon, but without affecting overall survival, growth performance, development or health.
在一项为期99天的饲养试验中，研究了大西洋鲑（Salmo salar L.）幼鱼（鱼苗）从初次摄食开始饲喂含有表达Cry1Ab蛋白的转基因玉米（Bt玉米，MON810）的日粮后的反应。制备了四种实验日粮；每种日粮含有约20%的玉米，要么是Bt玉米，要么是其近等基因母本系（非转基因玉米）。一组日粮以鱼粉为基础，而另一组日粮包含标准（提取的）豆粕（SBM；添加水平为16.7%），目的分别是研究健康鱼以及患有SBM诱导的远端肠道炎症的免疫应激鱼对玉米品种的反应。将三重复水箱中的鱼苗（0.17±0.01克；初始平均体重±标准误）饲喂四种日粮中的一种，并在第15、36、48和99天采集样本。评估了存活率、生长性能、全身组成、消化功能、肠道、肝脏和骨骼的形态，以及远端肠道中一些免疫和应激反应参数的mRNA表达。饲喂99天后，存活率提高，两组饲喂SBM的鱼的远端肠道中未出现预期的SBM诱导的炎症反应，这表明幼鲑对SBM具有耐受性。饲喂两种玉米品种的鱼的死亡率、生长性能和身体组成相似。然而，饲喂Bt玉米的鱼在一些采样点显示亮氨酸氨肽酶和麦芽糖酶的消化酶活性轻微但显著降低，同时肠道胆汁盐浓度降低，但淀粉酶活性显著增加。组织形态学、放射学和mRNA表达评估未发现Bt玉米在胃肠道、肝脏或骨骼中有任何生物学相关影响。结果表明，转基因Bt玉米中的Cry1Ab蛋白或其他成分差异可能会导致幼鲑肠道反应出现轻微变化，但不影响总体存活率、生长性能、发育或健康。
