Phipps R H, Deaville E R, Maddison B C
Centre for Dairy Research, School of Agriculture, Policy and Development, The University of Reading RG6 6AR, UK.
J Dairy Sci. 2003 Dec;86(12):4070-8. doi: 10.3168/jds.S0022-0302(03)74019-3.
The objective was to determine the presence or absence of transgenic and endogenous plant DNA in ruminal fluid, duodenal digesta, milk, blood, and feces, and if found, to determine fragment size. Six multiparous lactating Holstein cows fitted with ruminal and duodenal cannulas received a total mixed ration. There were two treatments (T). In T1, the concentrate contained genetically modified (GM) soybean meal (cp4epsps gene) and GM corn grain (cry1a[b] gene), whereas T2 contained the near isogenic non-GM counterparts. Polymerase chain reaction analysis was used to determine the presence or absence of DNA sequences. Primers were selected to amplify small fragments from single-copy genes (soy lectin and corn high-mobility protein and cp4epsps and cry1a[b] genes from the GM crops) and multicopy genes (bovine mitochondrial cytochrome b and rubisco). Single-copy genes were only detected in the solid phase of rumen and duodenal digesta. In contrast, fragments of the rubisco gene were detected in the majority of samples analyzed in both the liquid and solid phases of ruminal and duodenal digesta, milk, and feces, but rarely in blood. The size of the rubisco gene fragments detected decreased from 1176 bp in ruminal and duodenal digesta to 351 bp in fecal samples.
目的是确定瘤胃液、十二指肠食糜、牛奶、血液和粪便中是否存在转基因植物DNA和内源植物DNA，若检测到，则确定片段大小。六头装有瘤胃和十二指肠套管的经产泌乳荷斯坦奶牛采食全混合日粮。有两种处理（T）。在T1中，精料含有转基因大豆粕（cp4epsps基因）和转基因玉米籽粒（cry1a[b]基因），而T2含有近等基因的非转基因对应物。采用聚合酶链反应分析来确定DNA序列的存在与否。选择引物以扩增来自单拷贝基因（大豆凝集素、玉米高迁移率蛋白以及转基因作物中的cp4epsps和cry1a[b]基因）和多拷贝基因（牛线粒体细胞色素b和核酮糖-1,5-二磷酸羧化酶）的小片段。仅在瘤胃和十二指肠食糜的固相部分检测到单拷贝基因。相比之下，在瘤胃和十二指肠食糜、牛奶和粪便的液相和固相分析的大多数样品中都检测到了核酮糖-1,5-二磷酸羧化酶基因的片段，但在血液中很少检测到。检测到的核酮糖-1,5-二磷酸羧化酶基因片段大小从瘤胃和十二指肠食糜中的1176 bp降至粪便样品中的351 bp。
