意大利转基因大豆有害论文涉嫌造假遭撤稿
描述喂食转基因作物对动物造成有害影响的论文,正因受控存在数据操纵行为而接受审查。从一项正由意大利那不勒斯大学进行的调查泄露出来的结果显示,论文中的图片可能被故意改动过。开展此项研究的实验室负责人则表示,这些指控没有任何意义。
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全球食品和药物机构进行的无数安全测试显示,和食用转基因食品相关的危险并不存在,但上述论文结果却背道而驰。此项研究被反对转基因的网站广泛引用,而论文描述的实验结果也在去年7月举行的意大利参议院听证会上被援引。听证会就该国是否应允许种植获得安全验证的转基因作物进行了讨论。
“这起事件非常重要还因为这些论文被用于关于转基因作物的政治争论中。”意大利参议员、米兰大学神经学家Elena Cattaneo表示。她对于该项研究的担忧触发了此次调查。
意大利参议员、神经学家艾琳娜·卡塔内奥(Elena Cattaneo)展开了对这些论文的分析
在去年参议院的听证会后,Cattaneo更加仔细地研究了这3篇论文。它们均出自那不勒斯大学一个由兽医学家Federico
Infascelli领导的实验室。论文描述了在被喂食转基因大豆的“母亲”产下的山羊羔身上开展的试验,并且提出,大豆中外来基因的碎片能通过肠道传输并隐藏在奶中,从而影响所养育“孩子”的生物学特征。
附录:果壳网关于该意大利论文造假相关证据的摘录
例1:消失的阴性对照结果
在因法塞利2010年10月发表在《动物》(Animal)杂志上的论文[1]中,论文图1的凝胶电泳结果疑似遭到篡改。下图右一泳道(-)呈现的是阴性对照结果,对论文原图进行调整后发现该泳道的结果疑似被人为清除。DNA胶中阴性对照的作用在于确保受检测的DNA并非污染产物。对阴性对照泳道的结果进行修改可能是试图掩盖污染。(文图来源与果壳,后同)
2010年论文[1]中的DNA电泳图片。经过处理后发现,关键的阴性对照泳道明显经过人为篡改。
例2:老图新用,变更描述
值得注意的是,上面这张很可能经过篡改的图片还可能出现在了两篇不同的论文里——在因法塞利2015年发表于《小型反刍动物研究》(Small Ruminant Research)的论文中,极度相似的电泳图片(连左一Marker栏的背景噪音特征都完全一致)再次出现,而这一次,论文描述的DNA样本来源却与2010年论文对应图片下的描述不一致。
疑似重复使用的论文图片。2010年的论文[1]称泳道1、2和泳道3、4的DNA分别来源于乳汁和血液样本,而在2015年的论文[3]中,疑似相同的电泳图再次出现,论文却称四条泳道的DNA都来自初乳样本。
2010年论文[1]中的另一张图片,也被发现疑似与2013年因法塞利发表在《食品与营养科学》(Food and Nutrition Sciences)上的论文[2]图片重复,并且同样有样本表述前后不一的现象。
值得注意的是,2010年论文小图d(左下)的6号泳道,在2013年论文中的描述变成了阴性对照泳道。
例3:图片拼接
布奇的分析结果还提示,2010年的论文[1]中一张电泳图中五条泳道的结果被摘取出来,拼接到了2015年论文[3]的一张电泳图中。
时隔5年的两篇论文图片出现部分雷同。
Cattaneo提出了3篇论文中看上去存在问题的地方:电泳凝胶的部分图片似乎被涂抹过,而且一些出现在不同论文中的图片看上去相同,但说明文字描述的是不同试验。
随后,她委托该国生物医学服务和信息咨询公司BioDigitalValley,对所有3篇文章进行取证分析。结果显示,论文的确含有经过处理和重复使用的图片。去年9月,Cattaneo联系了相关期刊,并在11月将分析结果转发给那不勒斯大学。该校校长Gaetano
Manfredi立即启动了校内调查。他表示,该校可能会在2月底宣布对此采取的举措。
《自然》杂志称,2006年到2015年间,意大利那不勒斯大学的费德里科·因法塞利(Federico
Infascelli)的动物营养研究团队因涉嫌篡改图片和/或捏造关键数据而遭受攻击。其中发表于《食品与营养科学》杂志的一篇论文已经被撤稿,有报道说其他三篇文章也在接受重新评议。
因法塞利所发表的这些研究大都是在反对转基因的组织资助下进行的。以下仅举几例:
1)新研究表明:转基因大豆造成山羊后代体重下降,《转基因观察》,2015年3月2日
2)研究人员发现:转基因大豆改变了羊奶成分,并使后代发育迟缓,《独立科学新闻》,2015年10月26日
3)研究发现:以转基因大豆为食的母羊产下的幼崽遭受发育迟缓和营养不良困扰,《转基因新闻》,2015年10月29日
作为一名科学家,真正令人不敢相信是的面对那些涉嫌人为篡改图片的幻灯片。这些幻灯片显示了图像的篡改过程,以及或许是怕麻烦而在时隔多年的不同文章中引用同一张图片,却配以不同的图释来描述不同的试验。
进行过凝胶电泳实验的人都知道对于每次电泳都会有一个类似于特征指纹的特殊不规则形状存在。对于那些认为可以随意重复使用电泳图像而不会被发现的人来说,这无疑是一记响亮的耳光,尤其是考虑到转基因相关研究本身就是具有争议性的课题,人们更不会轻易放过每一个实验细节。同时,这也不禁让人对该研究小组的一系列文章中其他数据的真实性表示怀疑。
对于许多科学文献中类似的动物饲喂实验,该研究小组这些文章的结论毫无意义。已有许多研究都仔细审查过那些食用转基因饲料动物的表现以及那些食用转基因饲料动物所产生的乳、肉和蛋中重组DNA以及蛋白质的情况。事实上,由动物科学学会联盟(the
Federation of Animal Science
Societies,FASS)保存着相关研究的记录可供查询。农业科学与技术委员会(The Council for Agricultural
Science and Technology ,CAST)和欧洲食品安全局(European Food Safety Authority
,EFSA)对此均有过报告。在这一次又一次的研究中,研究人员均未能从来自于饲喂动物中检测到任何来源于植物的基因的片段(单拷贝的植物内源性片段)。
这些结论在2013年格哈德·弗莱彻斯基(Gerhard Flachowsky)编写《转基因植物喂养动物的营养学(Animal nutrition
with transgenic plants)》一书中由德国研究学者拉尔夫·爱因斯班尼尔(Ralf
Einspanier)总结在了一个表格里,这一章节名为《转基因DNA和新表达蛋白的去向(The fate of transgenic DNA
& newly expressed proteins)》。
上述表格展示了《自然》杂志中所讨论的拉菲乐·图第斯科(Raffaella Tudisco)教授的两篇论文为什么相比于其他研究来说显得与众不同。在另一项研究中,作者夏尔玛(Sharma)在猪的肌肉中发现了重组DNA的研究中,并总结道:
本研究证实,饲料摄入的DNA片段(内源性和转基因),确实会在消化道终端存在,并被肠上皮组织吸收。猪体内确实会发生非常低频率的(基因片段)在内脏组织中的转移,但羊体内未发现该现象。众所周知,在动物组织中检测转基因饲料来源的低拷贝转基因片段的是一项技术挑战,但是,没有任何证据表明,重组DNA在肠道内与常规饲料摄入的内源性遗传物质的代谢去向有何不同。
不同寻常的是,该研究在那些食用了转基因饲料的动物的新鲜乳汁中发现了重组DNA(rDNA)序列。世界范围内的许多研究都对此进行了大量的实验,除了这一研究小组之外仅有另一项研究中检测到了rDNA。在这个研究中,研究者从食用了转基因饲料的对照组和实验组动物的乳汁中都发现了rDNA,因此作者下结论说:认为乳汁中检测到转基因DNA可能来自于排泄物或者空气污染,而不是动物所食用的转基因饲料。然而,更多的实验并未检测到rDNA。总之,许多大量的数据表明并不存在饲料中DNA或蛋白质转移到乳汁中的现象。考虑到这一点,意大利小组的研究结果是极其异常的。
为什么强调这一点如此重要呢?其实它并不涉及公众健康的安全性问题,而是如爱因斯班尼尔在那一章节中所总结的那样:
1)饲料中的DNA和蛋白质片段会在肠道中出现。并且饲料中的DNA片段可能会经过一种自然过程而转移到动物组织中。
2)现有证据表明,动物组织中存在饲料来源的DNA片段并不意味着对动物或消费者可能具有安全风险。
3)当食物来源的DNA中基因片段出现在器官中时,这些外源DNA片段并不具有生物学功能,因此并不会对动物产生显著的影响,也没有发现这些DNA片段会整合到动物基因组中。
审议所有现有数据之后,并未发现有任何证据表明,对于消费者来说那些食用商业化转基因饲料的动物的乳汁、肉和蛋相比于那些食用传统饲料而言更加不安全。
然而,从标识的角度来说,这是个非常重要的问题。那些来源于食用了转基因饲料的牲畜的乳汁、肉类和蛋类目前并不属于欧盟标识法规的管辖范围。如果在动物的乳汁、肉类和蛋类中检测到了重组DNA,那么就很有可能引发对这类动物产品的强制性标识,同时,考虑到欧盟动物饲料的很大比例都是进口的转基因饲料,那些执着反对将转基因技术用于农业生产系统的人肯定不会忽视这些重大影响。
原文作者:Alison Van Eenennaam 博士,加州大学戴维斯分校动物科学系的动物遗传学家。
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Alison Van Eenennaam:
Why botched Italian GMO soy study never made science sense
A series of journal articles published between 2006 and 2015 by an Italian research team led Federico Infascelli, an animal nutrition researcher at the University of Naples, are under fire for allegedly manipulating images and/or fabricating key data, according to Nature magazine. One of the papers published in Food and Nutrition Science, has already been retracted. News reports suggest that three other papers are under review.
The Infrascelli et al. articles have been widely and aggressively promoted by anti-GMO groups. Here are three examples:
1)GM soybeans reduce weight of goats’ offspring – new study, GMWatch, March 2, 2015
2)GE Soybeans Give Altered Milk and Stunted Offspring, Researchers Find, Independent Science News, October 26, 2015
3)Baby goats born to mothers fed GMO soy suffer stunted growth and nutrition deficiencies, study finds, GMO.News, October 29, 2015
What is really mind-boggling to me as a scientist is looking at the slideshow
of allegedly manipulated images. They appear to show doctoring of
images and, perhaps as troubling, the use of the same image in papers
that were published years apart but with captions describing different
experiments. I will leave formal judgement on the doctoring of images to
the University of Naples, but remain incredulous at the apparent reuse
of the same gel in multiple papers.
Anyone that has ever run an agarose gel knows they have unique
irregularities that are akin to a fingerprint. Below is a copy of
perhaps my favorite irregularity that unintentionally appeared
on a Southern Blot transfer that was run by students at the University
of California, Davis. It just defies reason that anyone would think such
image duplication would go unnoticed, especially given the
controversial nature of GMO research. And this really brings into
question the veracity of the other data presented in these papers.
Image Courtesy J. D. Murray, UC Davis
The results of these papers never quite made sense when considered in
the context of the many other animal feeding studies in the scientific
literature. There have been many studies
looking at the performance of animals consuming GM feed and the fate of
recombinant DNA and protein in the milk, meat and eggs derived from
animals that have consumed GM feed. In fact, a list of such studies is maintained by the Federation of Animal Science Societies (FASS). The Council for Agricultural Science and Technology (CAST) has a report on it, as does the European Food Safety Authority (EFSA).
Time and time again the findings were that researchers have been unable
to detect fragments from naturally occurring plant-based (single-copy,
endogenous) genes in food samples from farm animals.
This was summarized in a table in a chapter by independent German researcher Ralf Einspanier “The fate of transgenic DNA & newly expressed proteins” from a 2013 book by Gerhard Flachowsky entitled “Animal nutrition with transgenic plants.”
It shows how two of the papers authored by Professor Raffaella Tudisco discussed in the Nature article are outliers relative to many other studies. The authors of the other study that found rDNA in pig muscle (Sharma et al. 2006) concluded:
This study confirms that feed-ingested DNA fragments (endogenous and
transgenic) do survive to the terminal GI tract and that uptake into gut
epithelial tissues does occur. A very low frequency of transmittance to
visceral tissue was confirmed in pigs, but not in sheep. It is
recognized that the low copy number of transgenes in GM feeds is a
challenge to their detection in tissues, but there was no evidence to
suggest that recombinant DNA would be processed in the gut in any manner
different from endogenous feed-ingested genetic material.
What is particularly unusual is the finding of recombinant DNA (rDNA)
sequences in fresh milk from animals that have consumed GM feed.
Multiple studies from around the world have tested extensively for this,
and aside from this group only one other study has detected rDNA. In
that case it was found in milk from both the control and group receiving GM feed leading the authors to conclude that “the detection of GM DNA in milk can be interpreted as an indicator of fecal or airborne contamination”,
rather than from being from the feed consumed by the animal. There are
however many, many studies that document no such finding. Bottom line is
that there is a lot of data showing no transfer of feed DNA and
proteins, whether endogenous or GM, into milk. In this regard, the
studies from the Italian group are real outliers.
Why is this important? It is not from a public health standpoint. As the Einspanier (2013) chapter summarized:
1)Fragmented feed DNA and proteins are present in the intestinal tract.
Feed DNA fragments may be transferred into the tissues of animals as a
natural process.
2)Evidence indicates that the presence of feed DNA fragments in animal
tissues does not represent a safety risk to the animal or the consumer.
3)When gene fragments from ingested DNA are found in organs, these foreign
DNA fragments do not possess biological function and will not account
for apparent effects in the animal, nor have they been found to be
integrated in the animal genome
4)When finally reviewing all available data, there is no scientific
evidence that milk, meat or eggs derived from animals fed recently
commercialized GM forage are less safe for the consumer than those
produced with conventional feed.
However, from a labeling standpoint this is an important issue. Products
such as milk, meat, and eggs that are derived from livestock fed
transgenic feeds are currently exempt from EU-labeling laws. If rDNA can
be detected in the milk, meat, and/or eggs of animal products then this
could trigger mandatory labeling of animal products and a sizable
proportion of imported EU animal feed is from GM varieties, two points
not lost on those opposed to the use of GM in agricultural production
systems.
Alison Van Eenennaam, Ph.D. is an animal geneticist and
Cooperative Extension specialist in the Department of Animal Science at
the University of California, Davis. My Twitter handle: @BioBeef