全球視角:轉(zhuǎn)基因作物與生物多樣性
Peter H. Raven
(美國(guó)密蘇里植物園)
雙價(jià)抗蟲轉(zhuǎn)基因棉花研究
郭三堆,崔洪志,夏蘭芹,等
熱點(diǎn)追蹤
轉(zhuǎn)基因
·編者按·
二十世紀(jì)七十年代以來(lái),隨著分子生物學(xué)和轉(zhuǎn)基因技術(shù)的出現(xiàn),人類獲得了打破物種間固有屏障并根據(jù)意愿重塑生物的能力.轉(zhuǎn)基因技術(shù)就是將某些生物的優(yōu)良基因轉(zhuǎn)移到目標(biāo)生物物種中,從而實(shí)現(xiàn)改造其遺傳物質(zhì)的目的,使其具備或產(chǎn)生原有物種不具有的性狀或產(chǎn)物.轉(zhuǎn)基因生物(遺傳改良生物,genetically modified organism,GMO)是指利用基因工程技術(shù)在基因水平上對(duì)生物的某些性狀進(jìn)行修飾和改良,用于農(nóng)業(yè)生產(chǎn)或農(nóng)產(chǎn)品加工的植物、動(dòng)物、微生物及其產(chǎn)品.
目前,轉(zhuǎn)基因技術(shù)在農(nóng)業(yè)、工業(yè)、醫(yī)療、環(huán)保領(lǐng)域都有著廣泛的應(yīng)用.農(nóng)業(yè)方面的應(yīng)用集中于新型優(yōu)良植物品種的培育,例如抗蟲、抗除草劑的轉(zhuǎn)基因大豆、玉米、水稻等.在工業(yè)方面,主要用來(lái)生產(chǎn)各種酶制劑、食品添加劑、培養(yǎng)各類益生菌等,以提高其性能和利用價(jià)值.在醫(yī)療方面,則利用此技術(shù)生產(chǎn)各種基因工程藥物、疫苗和抗體,或進(jìn)行基因治療.在保護(hù)環(huán)境方面,轉(zhuǎn)基因技術(shù)已成為環(huán)境修復(fù)治理的新途徑,如利用轉(zhuǎn)基因微生物來(lái)降解塑料、用轉(zhuǎn)基因植物富集土壤中的重金屬、降解有機(jī)磷農(nóng)藥等等.其中,轉(zhuǎn)基因作物技術(shù)是當(dāng)今最具活力、效益最大的高技術(shù),已成為近代農(nóng)業(yè)史上發(fā)展最快的技術(shù),產(chǎn)生了巨大的經(jīng)濟(jì)、社會(huì)和環(huán)境效益.自1996年轉(zhuǎn)基因作物產(chǎn)業(yè)化以來(lái),已累計(jì)推廣15億公頃,2014年全球種植面積達(dá)到1.815億公頃,是1996年的100多倍.目前,全世界有28個(gè)國(guó)家種植轉(zhuǎn)基因作物,美國(guó)是最大的轉(zhuǎn)基因作物種植國(guó)(7010萬(wàn)公頃),約90%的玉米、大豆、棉花為轉(zhuǎn)基因品種.據(jù)統(tǒng)計(jì),全球轉(zhuǎn)基因植物研究涉及至少35科200多個(gè)種,有近50個(gè)國(guó)家對(duì)60余種轉(zhuǎn)基因植物進(jìn)行了田間試驗(yàn).同時(shí),美國(guó)、俄羅斯、中國(guó)等20多個(gè)國(guó)家正在開展豬、牛、羊、雞、魚、兔等轉(zhuǎn)基因動(dòng)物的研發(fā).
環(huán)顧全球,基因組學(xué)、蛋白組學(xué)、代謝組學(xué)、系統(tǒng)生物學(xué)等新興基礎(chǔ)科學(xué)的飛速進(jìn)步不斷向生物技術(shù)領(lǐng)域注入新的活力.轉(zhuǎn)基因技術(shù)作為一種定向改良作物性狀的手段,本質(zhì)上與常規(guī)育種一樣,都是為人類和社會(huì)造福的.然而,轉(zhuǎn)基因作物技術(shù)的發(fā)展依然在一些國(guó)家受到各種阻力的影響,相關(guān)法律制度不完善、科學(xué)認(rèn)知不足、科普教育不到位等也是重要的影響因素,在一定程度上限制和阻礙了該技術(shù)的產(chǎn)業(yè)化進(jìn)程.為解決此類現(xiàn)狀,應(yīng)從國(guó)家和社會(huì)層面制定積極的政策導(dǎo)向,確定重點(diǎn)項(xiàng)目,加大科研投入、健全法律制度,加強(qiáng)監(jiān)管和科普宣傳,引導(dǎo)公眾參與,從而使轉(zhuǎn)基因技術(shù)更好地造福人類.
·熱點(diǎn)數(shù)據(jù)排行·
截至2015年3月10日,中國(guó)知網(wǎng)(CNKI)和Web of Science(WOS)的數(shù)據(jù)報(bào)告顯示,以轉(zhuǎn)基因(Genetically modified)為詞條可以檢索到的期刊文獻(xiàn)分別為5143與4271條,本專題將相關(guān)數(shù)據(jù)按照:研究機(jī)構(gòu)發(fā)文數(shù)、作者發(fā)文數(shù)、期刊發(fā)文數(shù)、被引用頻次進(jìn)行排行,結(jié)果如下.
研究機(jī)構(gòu)發(fā)文數(shù)量排名(C NKI)機(jī)構(gòu)名稱 發(fā)文數(shù)量(篇)中國(guó)農(nóng)業(yè)大學(xué) 185中國(guó)科學(xué)院遺傳遺傳與發(fā)育生物學(xué)研究所134揚(yáng)州大學(xué) 120浙江大學(xué)122
(數(shù)據(jù)來(lái)源:中國(guó)知網(wǎng)、Web of Science,檢索時(shí)間:2015-3-10)
作者發(fā)文數(shù)量排名(CNKI)
作者發(fā)文數(shù)量排名(WOS)
期刊發(fā)文數(shù)量排名(CNKI)
期刊發(fā)文數(shù)量排名(WOS)
根據(jù)中國(guó)知網(wǎng)(CNKI)數(shù)據(jù)報(bào)告,以轉(zhuǎn)基因(Genetically modified)為詞條可以檢索到的高被引論文排行結(jié)果如下.
國(guó)內(nèi)數(shù)據(jù)庫(kù)高被引論文排行
根據(jù)Web of Science統(tǒng)計(jì)數(shù)據(jù),以轉(zhuǎn)基因(Genetically modified)為詞條可以檢索到的高被引論文排行結(jié)果如下.
國(guó)外數(shù)據(jù)庫(kù)高被引論文排行
·推薦綜述·
全球視角:轉(zhuǎn)基因作物與生物多樣性*
Peter H. Raven
(美國(guó)密蘇里植物園)
能參與到討論轉(zhuǎn)基因植物在農(nóng)業(yè)中的作用是一件很榮幸的事情.全球農(nóng)業(yè)中轉(zhuǎn)基因作物的比重日益增多,但是這一特殊形式的植物育種為這個(gè)高速發(fā)展而又饑餓的世界在農(nóng)作物增產(chǎn)方面所帶來(lái)的期望遠(yuǎn)遠(yuǎn)超過(guò)我們目前的認(rèn)知.在這里,我們將討論目前已取得的成果、可能存在的問(wèn)題以及未來(lái)的前景.
作為背景知識(shí),我們必須認(rèn)識(shí)到以下幾點(diǎn):基因的橫向轉(zhuǎn)移在自然界是普遍存在的;在對(duì)生物體成功進(jìn)行轉(zhuǎn)基因操作1年后,也就是30年前,各種深思熟慮的討論均表明這種生物體的安全性沒(méi)有一般性的問(wèn)題;數(shù)以億計(jì)的人和數(shù)十億計(jì)的家畜食用來(lái)源于轉(zhuǎn)基因生物體的食物將近20年,但是卻沒(méi)有一個(gè)疾病、異?;蛘咂渌麊?wèn)題的案例與轉(zhuǎn)基因制品的食用有關(guān).此外,幾乎全世界生產(chǎn)的所有啤酒和奶酪以及我們使用的很大比例的藥物均有利用轉(zhuǎn)基因生物體合成的產(chǎn)物,但是卻沒(méi)有登記在冊(cè)的反對(duì)聲.治療埃博拉病毒用的試驗(yàn)藥物以及唯一可將全球柑橘產(chǎn)業(yè)從黃龍病中挽救回來(lái)的策略都涉及到轉(zhuǎn)基因生物體的應(yīng)用.世界上每個(gè)國(guó)家科學(xué)院在對(duì)同行評(píng)審的證據(jù)和大量科學(xué)文獻(xiàn)全面研究后均已推斷這些方法是不存在內(nèi)在問(wèn)題的.基于這些事實(shí),我認(rèn)為那些仍然堅(jiān)持認(rèn)為轉(zhuǎn)基因存在一些潛在問(wèn)題的人要么缺乏對(duì)科學(xué)的基本理解,要么是因?yàn)槟承┰蚨耆幌肴ソ邮芸茖W(xué)的發(fā)現(xiàn)和結(jié)論.
根據(jù)國(guó)際農(nóng)業(yè)生物技術(shù)應(yīng)用服務(wù)組織[3]的數(shù)據(jù),2013年有27個(gè)國(guó)家的1800萬(wàn)農(nóng)民種植轉(zhuǎn)基因作物,種植面積達(dá)到1.75億hm2.盡管這些轉(zhuǎn)基因作物得以快速應(yīng)用,一些人仍堅(jiān)持?jǐn)嘌运鼈冇幸恍┪粗?、潛在的危險(xiǎn),企圖阻礙轉(zhuǎn)基因作物的應(yīng)用.事實(shí)上,也沒(méi)有任何客觀原因使得中國(guó)或者其他國(guó)家在轉(zhuǎn)基因技術(shù)上的開發(fā)和使用上選擇落后,與此同時(shí),其競(jìng)爭(zhēng)對(duì)手在這一領(lǐng)域快速穩(wěn)步前進(jìn).如果違反科學(xué)結(jié)論和無(wú)視過(guò)去20年的實(shí)踐經(jīng)驗(yàn),除了造成嚴(yán)重的經(jīng)濟(jì)損失并同時(shí)增加緩解營(yíng)養(yǎng)不良及解決饑餓問(wèn)題的難度之外,不會(huì)有任何益處.舉例來(lái)說(shuō),中國(guó)的環(huán)境問(wèn)題廣泛存在[4],任何延緩采用現(xiàn)代科學(xué)項(xiàng)目的舉措都將使這個(gè)國(guó)家的環(huán)境更加脆弱,同時(shí)增加更多的問(wèn)題,并且令局部地區(qū)的貧困問(wèn)題更加難以解決.
在我們對(duì)于世界糧食形勢(shì)的綜述中,Perry Gustafson、Norman borlaug 和我[5]列出了7種常規(guī)改良作物遺傳特性的方法,這7種方法分別是:組織培養(yǎng)、花藥培養(yǎng)、誘變劑技術(shù)、分子標(biāo)記輔助選擇的利用、基因組選擇的應(yīng)用、全基因組測(cè)序以及可繞過(guò)有性生殖過(guò)程的植物轉(zhuǎn)化技術(shù).這7種最新的方法均可以產(chǎn)生高產(chǎn)作物.令人匪夷所思的是,一些人堅(jiān)持認(rèn)為其中某一種方法產(chǎn)生的作物是很危險(xiǎn)并且應(yīng)該避免,但是對(duì)同一情景下的其他幾種方法卻絕口不提!
1作物的馴化
1.2萬(wàn)年前,耕作農(nóng)業(yè)由我們的祖先發(fā)展起來(lái),往此前溯200萬(wàn)年,整個(gè)世界人口才僅僅100萬(wàn).農(nóng)業(yè)出現(xiàn)之前,人們通常是20至40人一起群居生活,他們都是采獵者,必須通過(guò)不停地搜尋食物并且立即吃掉來(lái)維持生命.早期農(nóng)民不斷地選擇和播種繁殖能力強(qiáng)或者高大強(qiáng)壯的植株種子來(lái)改良這些植物的特性,用來(lái)獲得容易收獲的植株和在他們生活的地方長(zhǎng)勢(shì)良好的植株.當(dāng)農(nóng)民從這些作物中獲得大部分食物之后,他們將盈余的食物儲(chǔ)存起來(lái)以度過(guò)艱難的時(shí)節(jié).因此,人們可以更大規(guī)模地聚集在村莊、小鎮(zhèn)或者城市生活.個(gè)人可以選擇在人口密集的中心地區(qū)從事更加專業(yè)化的工作,這種分工發(fā)展出了許多特色文明.5000多年前,書寫讓人類發(fā)展的進(jìn)程更加快速,書寫可以保證事件和發(fā)現(xiàn)被準(zhǔn)確地記錄下來(lái),這樣人們就可以不斷傳閱、討論并用于將來(lái)的實(shí)踐.
農(nóng)業(yè)耕地在地球上不斷擴(kuò)張,使得人口數(shù)目已增長(zhǎng)到了72億,但是全球每天仍以25萬(wàn)人的速度不斷增長(zhǎng),不幸的是,目前仍沒(méi)有確鑿的證據(jù)表明在下個(gè)世紀(jì)人口的增長(zhǎng)速度會(huì)有所減緩.目前有將近10億人口處于營(yíng)養(yǎng)失衡狀態(tài),這一龐大比例顯然會(huì)給我們帶來(lái)許多難題.由營(yíng)養(yǎng)失衡導(dǎo)致的身心發(fā)育不正常,使得這些人難以成為可以正常生活的人.同時(shí)又有將近1億人飽受饑餓致死的困擾.考慮到我們目前已經(jīng)使用全球可承受的生產(chǎn)能力估計(jì)值的156%,該比例還在增長(zhǎng),而我們的人口和消費(fèi)需求均在不斷地膨脹,因此想要顯著地改善這一狀況將是非常困難的.
2轉(zhuǎn)基因作物會(huì)導(dǎo)致生態(tài)破壞嗎?
轉(zhuǎn)基因作物的耕種有多大可能性會(huì)導(dǎo)致生態(tài)破壞,這種破壞的本質(zhì)又是什么呢?這些問(wèn)題是我們必須弄清楚的.為了弄清楚這些關(guān)系,我們首先應(yīng)該明白,農(nóng)業(yè)本身可能是過(guò)去一直存在并延續(xù)至今的對(duì)生物多樣性最具破壞性的人類活動(dòng).人類用來(lái)生產(chǎn)糧食的面積在過(guò)去1.2萬(wàn)年內(nèi)從0到如今覆蓋全球約1/3的陸地面積.很顯然,伴隨著草地、森林以及其他自然植被在如此短的時(shí)間內(nèi)轉(zhuǎn)變成耕地,必然導(dǎo)致成千上萬(wàn)的不同物種滅絕殆盡,其中大多數(shù)物種甚至還不為人知就已滅絕.在現(xiàn)代農(nóng)業(yè)中,我們通過(guò)限制雜草和蟲害以保持土壤肥力來(lái)達(dá)到最大的產(chǎn)量.當(dāng)然,我們需要盡可能有效、高產(chǎn)地使用我們的耕地,這樣我們就不會(huì)試圖擴(kuò)張到周圍那些低產(chǎn)的土地.這樣做也必然導(dǎo)致這些區(qū)域生物多樣性遭到更為嚴(yán)重的破壞,而且地球上適宜耕種或放牧的土地大都已經(jīng)被人類所利用.由于這些因素的限制,以及人口數(shù)目增長(zhǎng)過(guò)快,人類對(duì)糧食的需求不斷增加,更多富裕國(guó)家的出現(xiàn)需要更多的肉類和魚類,糧食產(chǎn)量的增長(zhǎng)明顯趕不上人口數(shù)目的增加.據(jù)估計(jì),到21世紀(jì)中葉,必須增加目前糧食產(chǎn)量的50%才能養(yǎng)活這個(gè)世界不斷增長(zhǎng)的人口,要實(shí)現(xiàn)這一目標(biāo)我們必須提高現(xiàn)有耕地的生產(chǎn)力.
關(guān)于作物的馴化,我們必須強(qiáng)調(diào)以下幾點(diǎn).當(dāng)野生植物被人類栽培種植,這些植物的遺傳多樣性就開始減少.隨著2個(gè)世紀(jì)以前科學(xué)耕作和遺傳性狀的精確測(cè)量的出現(xiàn),作物遺傳同質(zhì)性加強(qiáng),改良的步伐大大加快.在此基礎(chǔ)上,隨著20世紀(jì)30年代雜交玉米的開發(fā),耕種面積隨之大增.在此背景下,農(nóng)民會(huì)自然而然地選擇種植已被證明比他們之前種植的品種更高產(chǎn)的轉(zhuǎn)基因作物或者通過(guò)其他手段改良的作物.斷言轉(zhuǎn)基因品種的種植會(huì)導(dǎo)致土地更加遺傳同質(zhì)化明顯是毫無(wú)根據(jù)的:自從第1個(gè)轉(zhuǎn)基因作物得以培育種植以來(lái)這一過(guò)程就一直在進(jìn)行中,不同之處在于我們現(xiàn)在可以更好地、更有效地控制這一過(guò)程.事實(shí)上,轉(zhuǎn)基因方法的應(yīng)用有時(shí)會(huì)直接保護(hù)作物遺傳多樣性.當(dāng)我們種植數(shù)百種遺傳背景不同的作物,例如種植美國(guó)大豆,都可以獲得每個(gè)品種轉(zhuǎn)基因作物的遺傳多樣性,因此,轉(zhuǎn)基因方法應(yīng)用于作物改良對(duì)于作物的遺傳多樣性是沒(méi)有影響的.
3兩類生物多樣性:農(nóng)業(yè)生物多樣性(農(nóng)作物多樣性)
討論種植轉(zhuǎn)基因作物對(duì)生物多樣性的影響通常使人混淆特定作物和他們的近緣種的遺傳多樣性和生物多樣性殘存的關(guān)系.前面我已經(jīng)指出,自栽培伊始,作物的遺傳多樣性一直在減少.同時(shí),農(nóng)民也在努力地、有意識(shí)地選育一致的、高產(chǎn)的作物,這一選育過(guò)程通過(guò)選擇特定性狀來(lái)實(shí)現(xiàn),如抗旱、抗蟲或抗?。痪哂休^大和較多的種子、果實(shí)、葉片或者其他被人類收獲后可利用的部位.這些對(duì)于作物遺傳多樣性保留所進(jìn)行的努力也具有重大意義.尤其是在20世紀(jì)20年代至30年代俄國(guó)科學(xué)家N.I.Vavilov做出重要的基礎(chǔ)性研究之后,人們同時(shí)將注意力轉(zhuǎn)向了野生親緣種,以保持遺傳多樣性.作物起源的中心地帶保留著栽培作物與它的近緣種種間變異.這些中心地帶有玉米起源的墨西哥南部、誕生向日葵的美國(guó)西部平原、產(chǎn)生大豆的熱帶到亞熱帶的東亞.水稻的野生近緣種僅局部存在于印度到中國(guó)的部分地區(qū).
改良的作物品種均是在最初產(chǎn)生此作物品種的地區(qū)培育種植的.自從人們開始栽培植物,基因流回野生或者似草的近緣種中已成為農(nóng)業(yè)的不變特征.以Edgar Anderson為開端,許多學(xué)者揭示了不同屬和種之間的雜交在許多植物的進(jìn)化中一直扮演重要角色.從植物進(jìn)化的這一特征來(lái)看,作物與其野生或者似雜草的近緣物種之間的雜交是不足為奇的,這提高了這些作物的遺傳變異性并有助于一系列目標(biāo)性狀的選擇.比如六倍體(2n=42)面包小麥(Triticum aestivum)的起源,雜交后有一個(gè)多倍體化過(guò)程,這樣就可以保證雜交種及其性狀的穩(wěn)定性,并作為后續(xù)混合種植的選擇目標(biāo).在另一個(gè)例子中,玉米起源于大約8000年前的野生雜草——大芻草,是對(duì)其部分農(nóng)藝性狀進(jìn)行選擇改良的過(guò)程.目前沒(méi)有自然存在的植物與面包小麥或者玉米類似,當(dāng)然面包小麥僅可以與其他六倍體面包小麥雜交形成可育雜交種.相反,玉米可以與具有相同染色體數(shù)目(2n=20)的大芻草雜交,野生的和培育出的植物各自具有的性狀均可以在作物和他們的野生親緣種中以不同的方式進(jìn)行重組.墨西哥及其他地方玉米的當(dāng)?shù)仄贩N、農(nóng)家種的多樣性與前述伴隨著雜交所得到的重組性狀有很大關(guān)系.在一個(gè)多世紀(jì)以前,當(dāng)雜種玉米和其他改良品種被引入墨西哥之后,這些新品種的遺傳性狀與當(dāng)?shù)匾汛嬖诘摹稗r(nóng)家種”進(jìn)行組合.即便在這些品種引入之前,這些農(nóng)家種也由于農(nóng)民不斷選擇栽培它們和其他地方的玉米新品種的引入而不斷改變.將農(nóng)家種認(rèn)為是一個(gè)很多年都固定不變的品種是不合理的,而應(yīng)該更準(zhǔn)確地將它們看作是類似于萬(wàn)花筒中不斷變化的顏色,是人們會(huì)根據(jù)自己的偏好與所得資源進(jìn)行品種改良的結(jié)果.
以上2個(gè)例子幾乎與其他所有栽培作物在起源及隨后的改良過(guò)程中均有類似之處.因此,轉(zhuǎn)基因作物與其他作物進(jìn)化過(guò)程中發(fā)生的雜交具有相同的方式、相同程度[6-7],這一點(diǎn)是絲毫不足為奇的.但是,需要強(qiáng)調(diào)的是,從基因在同一物種的栽培種和野生種之間的擴(kuò)散或可能對(duì)他們的棲息地產(chǎn)生的影響上來(lái)看,轉(zhuǎn)基因是否發(fā)生,對(duì)這些多樣性并沒(méi)有影響,可能會(huì)有影響的是,雜交可能導(dǎo)致某些特定的基因會(huì)發(fā)生作用并且一些新基因在新的環(huán)境中出現(xiàn)適應(yīng)性問(wèn)題.
4基因轉(zhuǎn)移在作物和自然界中如何進(jìn)行?
由于這兩者已經(jīng)廣泛討論,現(xiàn)在我們將注意力轉(zhuǎn)向基因轉(zhuǎn)移,來(lái)看看在栽培種和它們的野生及似草的近緣種群體中有哪些特殊表現(xiàn).目前廣泛使用的轉(zhuǎn)基因產(chǎn)品主要是抗蟲的Bt轉(zhuǎn)基因作物、抗草甘膦除草劑的作物以及抗病毒作物.盡管這些基因在本質(zhì)上是不同的,但是我們可以從這幾個(gè)例子來(lái)窺視整體情況.我們首先會(huì)問(wèn),如果這些基因存在于野生種或似草的近緣種中會(huì)產(chǎn)生什么樣的結(jié)果.如果似草或者野生植物從害蟲中獲得了Bt抗蟲特性并且這些害蟲在這一特定環(huán)境中產(chǎn)生了明顯的選擇壓力,那么這些基因可能會(huì)存留在似草的物種或似草的群體中.如果它們真被保留了下來(lái),那么植物將會(huì)得到更好的保護(hù)不被害蟲侵食.Snow等[8]和Poppy和Wilkison[9]已經(jīng)分析Bt基因從向日葵栽培種轉(zhuǎn)移到野生種的具體實(shí)例了.他們發(fā)現(xiàn)含有Bt基因的野生植株比不含Bt基因的同種野生植株更不易被蟲食且具有更強(qiáng)的繁殖力.這一基因轉(zhuǎn)移過(guò)程使得栽培種的田塊有更多的野生雜草,但是其他農(nóng)藝操作可以除去這些轉(zhuǎn)基因雜草.
除草劑耐受的問(wèn)題就更復(fù)雜.不論何時(shí)使用除草劑,目標(biāo)物種或其他物種由于經(jīng)常暴露于除草劑之下,最終總會(huì)產(chǎn)生抗性品種.例如,廣泛使用的草甘膦除草劑就導(dǎo)致了不同地區(qū)尤其是美國(guó),一些抗性雜草品種的出現(xiàn).這是使用除草劑(或者農(nóng)藥)必然會(huì)出現(xiàn)的問(wèn)題,原則上是與轉(zhuǎn)基因作物沒(méi)有任何關(guān)系的,只與除草劑如何使用有關(guān).與人類或其他動(dòng)物解決抗生素抗性一樣,已有多種策略被用于處理對(duì)除草劑有抗性的雜草;不論是否涉及轉(zhuǎn)基因植物,這些策略將會(huì)一直在農(nóng)業(yè)生產(chǎn)中發(fā)揮作用.在常綠草的例子中,盡管大多數(shù)基因擴(kuò)散僅限2 km的范圍,但是草甘膦抗性品種在距離轉(zhuǎn)基因植株種植地21 km的地方出現(xiàn)了[10].由于草甘膦是控制某種草皮中雜草生長(zhǎng)的主要方式(該種草皮引自歐洲,并在在森林和公園的空地中廣泛種植),這就成了一個(gè)不得不考慮的問(wèn)題.這一例子也證明了花粉散播的方式對(duì)轉(zhuǎn)基因作物或其他栽培作物與他們的野生近緣種分隔種植具有很大的影響.雖然換一種除草劑可以對(duì)付這類侵襲,但是種植抗草甘膦除草劑草皮的優(yōu)勢(shì)和劣勢(shì)需要考慮整體環(huán)境中它們本身的優(yōu)點(diǎn).
以上實(shí)例說(shuō)明了伴隨目前廣泛使用的基因轉(zhuǎn)移而產(chǎn)生的各種情況以及特定基因轉(zhuǎn)移到作物中與他們?cè)谧匀恢刑囟ㄇ闆r下的適應(yīng)性并沒(méi)有任何關(guān)系.由于額外的基因被引入各種作物中,如果這些基因被轉(zhuǎn)移到野生近緣物種中,那么不管這些基因是以何種方式轉(zhuǎn)移到基因組中的,都必須評(píng)估這些基因可能的效應(yīng).除草劑抗性可以直接從一種作物擴(kuò)散到與之種在一起的雜草中是毋庸置疑的,但是除草劑的濫用會(huì)更直接地導(dǎo)致同樣的結(jié)果.顯然,即便轉(zhuǎn)基因性狀不參與其中,每一種情形都必須用正確的農(nóng)藝實(shí)踐來(lái)解決.
5作物遺傳多樣性的保護(hù)
為了保護(hù)現(xiàn)存于作物以及栽培植物和它們野生近緣種中的基因,我們應(yīng)該做些什么呢?目前已了解到這些基因可能在未來(lái)急劇變化的世界對(duì)作物性狀的改良具有重要意義.對(duì)于農(nóng)家種以及更古老的栽培品種,期望農(nóng)民來(lái)栽培古老品種是不大可能的,因?yàn)檫@些古老品種產(chǎn)量低,而且與新品種或他們?cè)诠爬掀贩N與附近引入的品種進(jìn)行雜交后代中選育出的品種相比,古老品種均不是理想選擇.理論上,我們可以資助農(nóng)民來(lái)保持這些傳統(tǒng)品種的種植,但是實(shí)際上卻并沒(méi)有任何此類實(shí)際行動(dòng).最有效的保護(hù)遺傳多樣性的方法可能是保留代表遺傳多樣性的、某一給定物種的所有栽培種、雜草和野生植物的種子.位于墨西哥中部的非常重要的農(nóng)業(yè)組織——國(guó)際玉米與小麥改良中心已經(jīng)對(duì)玉米的種質(zhì)資源進(jìn)行了搜集.此外,我們可以嘗試在他們自然生長(zhǎng)的地方保護(hù)野生種和這一作物的相關(guān)物種.總之,那些被轉(zhuǎn)入用來(lái)改良作物特性基因的轉(zhuǎn)基因作物在作物和他們的野生近緣種中的轉(zhuǎn)移對(duì)這種作物和他們的近緣種生物多樣性的幸存并不構(gòu)成挑戰(zhàn),并且實(shí)際上還有可能促進(jìn)了遺傳多樣性的保留.
6生物多樣性總體概括
第二種具有討論和分析價(jià)值的生物多樣性類型則是總體上的生物多樣性了.據(jù)估計(jì),地球上目前有1200萬(wàn)種原核生物和數(shù)百萬(wàn)種細(xì)菌和古細(xì)菌,這些生物體是地球上生命的基礎(chǔ).這些生物體數(shù)十億年的生命活動(dòng)不僅改變了土地、水和大氣的特性,還使得他們生存了下來(lái)并支撐起我們的生命.植物則直接或間接地為我們提供糧食以及大部分的醫(yī)藥;作為一個(gè)整體的生態(tài)系統(tǒng)維持了我們賴以生存的土地和水;那些美麗、多樣的生物體則極大地豐富了我們的精神世界.人類未來(lái)的發(fā)展很大一部分需要依賴于我們維持生物多樣性以及可持續(xù)地利用生物體特性的能力.由于這些原因,轉(zhuǎn)基因作物的栽種是否會(huì)威脅到生物整體多樣性是至關(guān)重要的.我們知道物種會(huì)很快滅絕的許多原因.其中一個(gè)就是由于農(nóng)業(yè)、城市擴(kuò)張、林業(yè)或者其他原因所導(dǎo)致的自然棲息地的嚴(yán)重破壞;還有就是物種入侵以及全球氣候變化等原因.全球氣候變化正日趨加快,據(jù)政府間氣候變化委員會(huì)(IPCC)最近發(fā)布的報(bào)告估計(jì),截至本世紀(jì)末,氣候變化將導(dǎo)致約1/5或更多物種的滅絕.這些因素共同作用的結(jié)果就是,地球上超過(guò)一半的物種將在本世紀(jì)末到來(lái)前滅絕,其中絕大多數(shù)物種在滅絕前我們都未能有所了解.現(xiàn)有生物體如此大比例的滅絕將導(dǎo)致我們重建全球可持續(xù)發(fā)展的能力面臨重大損失;顯然,在減緩目前和將來(lái)的共同利益損失方面我們有一致的訴求.
轉(zhuǎn)基因作物的種植和生物體的滅絕之間會(huì)有什么關(guān)系呢?我們已注意到,農(nóng)業(yè)本身就會(huì)導(dǎo)致嚴(yán)重的生物滅絕,低層次農(nóng)業(yè)相比于密集的、高產(chǎn)的農(nóng)業(yè)對(duì)生物滅絕的危害更大,因?yàn)樗采w的面積更大、影響的物種更多.傳統(tǒng)農(nóng)業(yè)的重點(diǎn)是排除那些在富饒的土地上生存的動(dòng)植物,選擇優(yōu)良品種保持下來(lái),它的成功往往是以在多大程度上成功排除一些動(dòng)植物來(lái)衡量的.將傳粉昆蟲或其他有益生物體生存的棲息地保留下來(lái)對(duì)人類來(lái)說(shuō)顯然是有益的,但是土地本身則大體上應(yīng)盡可能地?cái)[脫生物多樣性.在轉(zhuǎn)基因作物的例子中,降低或消除對(duì)農(nóng)藥應(yīng)用的需求,附近的生物群體由于不會(huì)受到化學(xué)藥品的傷害,也將獲益良多.我之前已經(jīng)提及,更高產(chǎn)的、密集的農(nóng)業(yè)更有可能保護(hù)生物多樣性.一般來(lái)說(shuō),栽種轉(zhuǎn)基因作物和生物多樣性的幸存是正相關(guān)的關(guān)系,為什么《生物多樣性公約》在轉(zhuǎn)基因作物種植以及在不同國(guó)家之間運(yùn)移如此畏首畏尾,這對(duì)我來(lái)說(shuō)仍然是一個(gè)謎.
7轉(zhuǎn)基因作物對(duì)非目標(biāo)物種的影響
僅根據(jù)轉(zhuǎn)基因作物種植田塊之外物種受到影響的幾個(gè)特例,就聲稱Bt毒蛋白轉(zhuǎn)基因作物可能對(duì)其他并非目標(biāo)生物產(chǎn)生影響是不對(duì)的.同樣的情況也發(fā)生在除草劑農(nóng)達(dá)(Roundup)的抗性上,這種情況下,可以利用對(duì)特定除草劑有抗性的轉(zhuǎn)基因作物來(lái)除掉耕地上的雜草.如果除草劑從田間擴(kuò)散出去,對(duì)生態(tài)系統(tǒng)的真正破壞將不可避免;但是如果它們真能提高產(chǎn)量,那么這將對(duì)其周邊地區(qū)生物多樣性的幸存是有利的.如果除草劑或者農(nóng)藥隨意在農(nóng)田之外或其他地方濫用,那么必然會(huì)引起問(wèn)題.另一方面,如果能夠像歐洲那樣有效地控制農(nóng)藥的使用,那么對(duì)生物多樣性和人類健康的主要負(fù)面影響就可以避免.
8基因從轉(zhuǎn)基因作物轉(zhuǎn)移到同一物種的非轉(zhuǎn)基因作物中
這個(gè)問(wèn)題本質(zhì)上是我們?nèi)祟愖约阂鸬?它在很大程度上是由于美國(guó)農(nóng)業(yè)部不合理地將轉(zhuǎn)基因作物歸為“非有機(jī)”導(dǎo)致的,這反過(guò)來(lái)又催生了對(duì)其是否“純凈”的擔(dān)憂,這一概念對(duì)植物如何演化以及作物遺傳特性如何通過(guò)多種方式進(jìn)行改變給出了非常奇怪的見(jiàn)解.這一理念或者見(jiàn)解絲毫沒(méi)有一點(diǎn)理性的基礎(chǔ),反而會(huì)在可持續(xù)農(nóng)業(yè)的發(fā)展道路上增加額外的障礙;我尤其認(rèn)可M. S. Swaminathan 所給出的建議,他認(rèn)為這2種方法可以攜手促進(jìn)作物優(yōu)良性狀的改良.就像我之前強(qiáng)調(diào)的那樣,農(nóng)業(yè)本身就不是自然狀態(tài);所有的栽培作物和馴化的動(dòng)物都是經(jīng)過(guò)多年遺傳操作改良之后產(chǎn)生的.在全球急需增加糧食產(chǎn)量的大背景下,如果僅僅以它們具有潛在威脅為理由,在這種意識(shí)形態(tài)下排斥特定的作物育種的方法是極其不明智的.不論某一作物的花粉是否如胡桃、白楊、松樹或草一樣通過(guò)風(fēng)來(lái)傳播,花粉都有可能傳播很遠(yuǎn)的距離,導(dǎo)致某些性狀在離它原來(lái)位置很遠(yuǎn)的地方表現(xiàn)出來(lái).對(duì)于許多其他作物,比如蘋果、馬鈴薯、油菜、南瓜、苜蓿、萵苣、向日葵、果樹和漿果作物,他們的花粉是由昆蟲傳播的,這些作物花粉傳播的距離則取決于那些傳粉昆蟲的習(xí)性、數(shù)量和習(xí)慣以及他們所接觸的花的特性了.一些作物,比如水稻、小麥、大麥和大豆,則是自花授粉,他們的花粉只有極少的一部分可以通過(guò)風(fēng)擴(kuò)散出去.這些基因是否會(huì)像通常一樣在新環(huán)境下存留下來(lái)往往取決于那些接受這些外來(lái)花粉的植株所在環(huán)境的選擇壓力.通常,如果不考慮特殊情況下發(fā)生的基因轉(zhuǎn)移的話,沒(méi)有任何理由擔(dān)心這些花粉擴(kuò)散可能引起一些問(wèn)題.
9新品種雜草產(chǎn)生的可能性
目前共有2萬(wàn)多種植物被認(rèn)為是雜草,平均每20個(gè)物種中就有1個(gè)是雜草.這些雜草廣泛分布在世界各地的自然或人工環(huán)境中.有些甚至生長(zhǎng)在作物之間,這種類型的雜草往往對(duì)作物產(chǎn)量有負(fù)面影響.大多數(shù)雜草是伴隨著農(nóng)業(yè)或園藝被人類從一個(gè)地方引入另一個(gè)地方的.有些雜草則是由于偶然地污染或粘附在一些產(chǎn)品或物品上被運(yùn)輸?shù)狡渌胤饺サ?抵制轉(zhuǎn)基因作物的觀點(diǎn)之一即是使用轉(zhuǎn)基因會(huì)導(dǎo)致新的、極具侵略性的雜草的產(chǎn)生.事實(shí)上,有些非常重要的雜草,如約翰遜草和紅色雜草稻(栽培水稻和野生水稻雜交產(chǎn)生),就與農(nóng)作物有關(guān).這些雜草往往為農(nóng)業(yè)生產(chǎn)帶來(lái)麻煩,因?yàn)樗麄兌加幸恍┡c起源作物類似的特性,因此很難得到控制.然而,這些例子都與轉(zhuǎn)基因技術(shù)無(wú)關(guān);并且沒(méi)有例子表明:相比其他雜草,我們應(yīng)該對(duì)這些假定的雜草更加畏懼.
不可否認(rèn)的是,對(duì)害蟲及除草劑有抗性的基因從作物轉(zhuǎn)移到特定雜草確實(shí)會(huì)增加在農(nóng)田中控制這些雜草的難度.因此,對(duì)食用甜菜而言,獲得除草劑抗性的野生甜菜就是一個(gè)大麻煩.目前人們已知道若干此類的例子了,前文討論提到的向日葵就是一個(gè).但是,我們應(yīng)該在數(shù)千個(gè)已知的極具侵略性的雜草的大背景下考慮這個(gè)問(wèn)題并且應(yīng)該秉承具體問(wèn)題具體分析的態(tài)度.有些人認(rèn)為,雜草的特性與大多數(shù)栽培植物是截然不同的,許多作物在自然界中不能自己繁殖——玉米和大豆就是最好的明證,因此認(rèn)為它們促進(jìn)新種雜草的形成是不太可能的.
10法律
20世紀(jì)80年代,我參與了《生物多樣性公約》的制定,對(duì)當(dāng)前斤斤計(jì)較轉(zhuǎn)基因作物這一事實(shí)我感到非常難過(guò).其所謂的生物安全準(zhǔn)則并不是基于任何有根據(jù)的科學(xué)原理,是以《卡塔赫納生物安全議定書》或其他形式向某些人授權(quán),而這些人出于個(gè)人原因——可能是政治性的原因——希望減緩我們用來(lái)生產(chǎn)這個(gè)世界急需糧食的工具的付諸使用.伴隨監(jiān)管轉(zhuǎn)基因作物而來(lái)的是不明智、無(wú)意義的爭(zhēng)論,這已經(jīng)消耗了數(shù)百位外交官和理想主義者的精力,但對(duì)保護(hù)世界生物多樣性沒(méi)有產(chǎn)生絲毫作用,而保護(hù)世界生物多樣性正是我們希望在生物多樣性公約下能得到的結(jié)果.就像我在這些評(píng)論中解釋的那樣,目前沒(méi)有明確的科學(xué)基礎(chǔ)來(lái)假定與轉(zhuǎn)基因生物相關(guān)的生物安全原則會(huì)對(duì)全球范圍內(nèi)飽受威脅的生物多樣性幸存起到任何作用.從這一角度來(lái)說(shuō),《生物安全議定書》明顯正在向其設(shè)定初衷靠攏——即保護(hù)生物多樣性,這對(duì)我來(lái)說(shuō)是一件值得高興的事,因?yàn)楸Wo(hù)生物多樣性也是我為之奉獻(xiàn)一生的事業(yè).
11結(jié)論
1.2萬(wàn)年前農(nóng)業(yè)的出現(xiàn)就一直是生物多樣性的主要敵人.在人口數(shù)目由100萬(wàn)增加到現(xiàn)在的70多億的過(guò)程中,盡管我們已經(jīng)在大量土地上密集地種植了許多作物,但是仍有約10億人處于營(yíng)養(yǎng)不良的狀態(tài).目前,人口數(shù)目已經(jīng)超過(guò)了這個(gè)星球承載能力的50 %,我們還在以不斷增長(zhǎng)的速度消耗著這個(gè)星球的資源.而一些組織和個(gè)人置這些重要的事實(shí)于不顧,用毫無(wú)科學(xué)支持的觀點(diǎn),去抵制可以對(duì)作物進(jìn)行改良進(jìn)而提高產(chǎn)量并使得人類能夠持續(xù)發(fā)展的方法.對(duì)任何國(guó)家而言,基于政治原因?qū)@一技術(shù)不聞不問(wèn)都是一個(gè)可恥的錯(cuò)誤.
在任何情況下,自然系統(tǒng)中廣泛分布的進(jìn)行必要耕作的低等級(jí)農(nóng)業(yè)生產(chǎn),對(duì)生物多樣性的破壞遠(yuǎn)超過(guò)在特定區(qū)域集中的、大規(guī)模的農(nóng)業(yè)生產(chǎn).與之相反的是,一些無(wú)轉(zhuǎn)基因作物的耕作系統(tǒng)——尤其是大量使用化學(xué)藥品的歐洲,對(duì)環(huán)境的破壞更為巨大.我認(rèn)為,由于非科學(xué)的原因而拒絕接受轉(zhuǎn)基因作物,并使數(shù)十億人承受多種傷害,這是非常不道德的.
·高被引論文摘要·
被引頻次:454
雙價(jià)抗蟲轉(zhuǎn)基因棉花研究
郭三堆,崔洪志,夏蘭芹,等
構(gòu)建了攜帶人工合成的GFM Cry IA殺蟲基因和經(jīng)過(guò)修飾的Cp TI基因的高效雙價(jià)殺蟲基因植物表達(dá)載體pGBI121S4ABC.采用花粉管通道法,將pGBI121S4ABC轉(zhuǎn)入到石遠(yuǎn)321、中棉所19號(hào)、3517和541中國(guó)棉花生產(chǎn)品種中,首次獲得了雙價(jià)轉(zhuǎn)基因抗蟲棉株系.葉片室內(nèi)抗蟲生物學(xué)鑒定表明,抗性好的株系棉鈴蟲幼蟲校正死亡率大于96%;經(jīng)分子檢測(cè),證實(shí)了雙價(jià)殺蟲基因在棉花基因組中的整合與表達(dá).
雙價(jià);Cp TI;Bt殺蟲基因;植物轉(zhuǎn)化;棉花
來(lái)源出版物:中國(guó)農(nóng)業(yè)科學(xué), 1999, 32(3):1-7
被引頻次:351
用花粉管途徑獲得小麥轉(zhuǎn)基因植株
曾君祉,王東江,吳有強(qiáng),等
摘要:本文將帶GUS標(biāo)記基因的質(zhì)粒pBI121用花粉管途徑轉(zhuǎn)化普通小麥(T.aestivum L)品種小山3號(hào)的小花.從結(jié)實(shí)的106粒種子中,經(jīng)點(diǎn)雜交初步篩選,再經(jīng)Southern分子雜交鑒定,選出5株轉(zhuǎn)基因小麥,轉(zhuǎn)化率為4.7%.同時(shí)用熒光法和X-Gluc染色法測(cè)試,檢測(cè)到這些植株中有GUS基因的表達(dá)產(chǎn)物β-葡糖苷酸酶(GUS)存在,證明GUS基因已整合到小麥植株中,并能在植物體中表達(dá).
關(guān)鍵詞:小麥;GUS基因;花粉管途徑;轉(zhuǎn)基因小麥植株
來(lái)源出版物:中國(guó)科學(xué)(B輯), 1993, 23(3):256-262
被引頻次:295
轉(zhuǎn)基因植物食品中標(biāo)記基因的安全性評(píng)價(jià)
賈士榮
摘要:標(biāo)記基因是篩選轉(zhuǎn)基因植物的有效方法.目前轉(zhuǎn)基因植物已廣泛進(jìn)行了田間試驗(yàn),有些已被批準(zhǔn)商業(yè)化應(yīng)用.鑒于幾乎所有轉(zhuǎn)基因植物中都含有標(biāo)記基因,且同一標(biāo)記基因已轉(zhuǎn)入不同的作物中,因此今后人們消費(fèi)的食品中標(biāo)記基因及其產(chǎn)物的含量將增大,其安全性引起了普遍關(guān)注.國(guó)際機(jī)構(gòu)如FAO、WHO、OECD以及美國(guó)的FDA、北歐部長(zhǎng)委員會(huì)等都在研究和制訂條例,我國(guó)尚未將遺傳工程體(GMO)食品安全性的評(píng)價(jià)提到議事日程上.有鑒于此,本文試圖重點(diǎn)以北歐部長(zhǎng)委員會(huì)的出版物(1996)為蘭本,結(jié)合國(guó)際機(jī)構(gòu)的咨詢研討結(jié)論,就植物食品中標(biāo)記基因的安全性評(píng)價(jià)作一綜述,以供讀者參考.
關(guān)鍵詞:轉(zhuǎn)基因植物;標(biāo)記基因;食品;安全性
來(lái)源出版物:中國(guó)農(nóng)業(yè)科學(xué), 1997, 30(2):1-15
被引頻次:247
表達(dá)β-1,3-葡聚糖酶及幾丁質(zhì)酶基因的轉(zhuǎn)基因煙草及其抗真菌病的研究
藍(lán)海燕,麗華,王蘭嵐,等
摘要:利用煙草堿性β-1,3-葡聚糖酶及菜豆堿性幾丁質(zhì)酶基因構(gòu)建了組成型表達(dá)的雙價(jià)植物表達(dá)載體PBLGC,利用農(nóng)桿菌介導(dǎo)法轉(zhuǎn)化了煙草,并得到了轉(zhuǎn)基因植株.對(duì)其進(jìn)行分子生物學(xué)分析的結(jié)果表明,部分轉(zhuǎn)基因植株在所有檢測(cè)中都顯示較強(qiáng)的陽(yáng)性反應(yīng),這說(shuō)明外源基因已整合到煙草基因組中并得到正確表達(dá).活體接菌實(shí)驗(yàn)初步表明,轉(zhuǎn)基因植株與對(duì)照相比,對(duì)赤星病的侵染具有較強(qiáng)的抵抗能力.
關(guān)鍵詞:β-1, 3-葡聚糖酶基因;幾丁質(zhì)酶基因;轉(zhuǎn)基因煙草;抗真菌病
來(lái)源出版物:遺傳學(xué)報(bào), 2000, 27(1):70-77
被引頻次:243
用基因槍將Bt毒蛋白基因轉(zhuǎn)入玉米及轉(zhuǎn)基因植株再生
王國(guó)英,杜天兵,張宏,等
摘要:用玉米懸浮細(xì)胞、愈傷組織和幼胚作受體,通過(guò)基因槍轟擊法成功地將Bt毒蛋白基因轉(zhuǎn)入玉米細(xì)胞,并再生了大量轉(zhuǎn)基因植株,部分植株得到種子.雖然基因槍轟擊愈傷組織和耒成熟幼胚比轟擊懸浮細(xì)胞所得到的轉(zhuǎn)化體少,但由于它們易于培養(yǎng)和再生植株,故適合于大部分玉米品種的遺傳轉(zhuǎn)化研究.部分轉(zhuǎn)基因植株的室內(nèi)玉米螟飼喂試驗(yàn)表明,這些植株的抗蟲性差異很大,有少量植株表現(xiàn)高度抗性,個(gè)別植株幾乎沒(méi)有抗蟲性.
關(guān)鍵詞:玉米轉(zhuǎn)化;基因槍;Bt毒蛋白基因;抗蟲性
來(lái)源出版物:中國(guó)科學(xué)(B輯), 1995, 25(1):71-76
被引頻次:235
根癌農(nóng)桿菌對(duì)甘藍(lán)型油菜的轉(zhuǎn)化及轉(zhuǎn)基因植株的再生
程振東,衛(wèi)志明,許智宏
摘要:用根癌農(nóng)桿菌(Agrobacterium tume faciens)共培養(yǎng)法把外源基因?qū)敫仕{(lán)型油菜(Brassica napus L)主要栽培品種“云北2號(hào)”,獲得轉(zhuǎn)基因植株.所用外植體為帶有1-2 mm子葉柄的完整子葉,根癌農(nóng)桿菌為A208SE(pTiT37-SE, pROA93).Ti質(zhì)粒pROA93帶有NPTⅡ及GUS嵌合基因.共培養(yǎng)2天后轉(zhuǎn)到附加25 mg/L卡那霉素的分化培養(yǎng)基(MS+4.5 mg/LBAP)上.AgNO3和羧芐青霉素促進(jìn)芽的分化,頭孢霉素則有抑制作用.最高轉(zhuǎn)化頻率為27%.把分化出的莖芽切下,插入含有25 mg/L卡那霉素的生根培養(yǎng)基中.羧芐青霉素不利于根的形成.把完整抗性植株移入盛土壤的盆中,生長(zhǎng)狀況良好.測(cè)定β-葡糖苷酸酶活性,84%明顯高于對(duì)照.以NPTⅡ基因作探針進(jìn)行Southern blot分析,證實(shí)外源基因已插入到植物細(xì)胞基因組中.
關(guān)鍵詞:甘藍(lán)型油菜;根癌農(nóng)桿菌;轉(zhuǎn)基因植株
來(lái)源出版物:植物學(xué)報(bào), 1994, 36(9):657-663
被引頻次:218
轉(zhuǎn)基因抗蟲棉的培育
倪萬(wàn)潮,張震林,郭三堆
摘要:采用花粉管通道途徑,將合成的Bt殺蟲蛋白基因?qū)朊藁▋?yōu)良品種泗棉3號(hào)和中棉所12,獲得了轉(zhuǎn)基因植株.組織化學(xué)分析表明,GUS標(biāo)記基因已在R1代植株中表達(dá).根據(jù)對(duì)GUS陽(yáng)性轉(zhuǎn)基因植株的PCR分析,證明Bt殺蟲蛋白基因出現(xiàn)在R1代植株中,并通過(guò)自交傳遞至R2代.經(jīng)抗蟲性鑒定,獲得了5株對(duì)棉鈴蟲有高度毒殺作用的R1代轉(zhuǎn)基因抗蟲植株S545、S591、S636、S1001(泗棉3號(hào)+Bt/GUS)和 Zh1109(中棉所12+Bt/GUS),對(duì)棉鈴蟲幼蟲的致死率分別達(dá)到91.6%、93.8%、92.3%、85.7%和75.0%.通過(guò)自交和選育,獲得了R5代轉(zhuǎn)基因抗蟲棉,并進(jìn)行了抗蟲性和轉(zhuǎn)基因的跟蹤鑒定,表明通過(guò)基因工程方法獲得了抗棉鈴蟲的棉花新種質(zhì).
關(guān)鍵詞:Bt基因;轉(zhuǎn)基因抗蟲棉;棉鈴蟲;抗蟲性鑒定
來(lái)源出版物:中國(guó)農(nóng)業(yè)科學(xué), 1998, 31(2):8-13
被引頻次:216
干旱誘導(dǎo)性啟動(dòng)子驅(qū)動(dòng)的海藻糖-6-磷酸合酶基因載體的構(gòu)建及轉(zhuǎn)基因煙草的耐旱性
趙恢武,陳楊堅(jiān),胡鳶雷
摘要:通過(guò) PCR程序克隆擬南芥(Arabidopsisthaliana(L)Heynh)的干旱誘導(dǎo)性啟動(dòng)子 Prd29A及來(lái)自釀酒酵母(Saccharomy cescerevisiae Hansen)的海藻糖-6-磷酸合酶基因(TPS),并將它們組成可在植物中表達(dá)的載體RT.通過(guò)根癌土壤桿菌(Agrobacterium tumefaciens(SmithetTownsend)Conn)LBA4404介導(dǎo),獲得轉(zhuǎn)基因煙草(Nicotianat abacumL.).Southern分析表明TPS基因已經(jīng)整合到煙草基因組中.Northern分析表明TPS基因的表達(dá)受干旱脅迫的誘導(dǎo).轉(zhuǎn)基因煙草的形態(tài)發(fā)生多種改變,包括變矮,莖變細(xì),葉子呈柳葉狀,腋芽明顯,同時(shí)耐旱性得到增強(qiáng).
關(guān)鍵詞:干旱誘導(dǎo)性啟動(dòng)子;海藻糖-6-磷酸合酶基因;煙草;耐旱性
來(lái)源出版物:植物學(xué)報(bào), 2000, 42(6):616-619
被引頻次:209
利用基因槍法獲得可遺傳的抗除草劑轉(zhuǎn)基因水稻植株
朱冰,黃大年,楊煒,等
摘要:利用基因槍轉(zhuǎn)化系統(tǒng),將含有由CaMV 35S啟動(dòng)子啟動(dòng)的bar基因的轉(zhuǎn)化質(zhì)粒pCB1導(dǎo)入水稻幼胚,經(jīng)篩選、再生得到3株抗除草劑Basta的轉(zhuǎn)基因植株.經(jīng)PCR及Southern分析,在轉(zhuǎn)基因植株基因組中均檢測(cè)到了bar基因的整合;經(jīng)RNA點(diǎn)雜交分析,檢測(cè)到了bar基因在轉(zhuǎn)基因植株中RNA水平的表達(dá).在轉(zhuǎn)基因植株JY119-2的總計(jì)321株T1代自交后代中,有274株表現(xiàn)出除草劑抗性,47株敏感.從該274株抗性植株中隨機(jī)選取8株進(jìn)行Southern分析,結(jié)果均檢測(cè)到了bar基因的整合,表明bar基因已遺傳到了T1代植株中.
關(guān)鍵詞:水稻;抗除草劑;基因槍;轉(zhuǎn)基因植株
來(lái)源出版物:中國(guó)農(nóng)業(yè)科學(xué), 1996, 29(6):15-20
被引頻次:186
抗蟲轉(zhuǎn)基因歐洲黑楊的培育
田穎川,李太元,莽克強(qiáng)
摘要:用帶有35S-?-Bt-NOS嵌合基因的雙元載體的農(nóng)桿菌LBA 4404轉(zhuǎn)化歐洲黑楊的葉片外植體,共獲得54株轉(zhuǎn)化再生植株.用這些再生植株對(duì)楊尺蠖(Apochimia cinerarius)進(jìn)行毒力測(cè)定,昆蟲校正死亡率在80~96%的再生植株占總測(cè)定植株的15%.部分再生植株對(duì)舞毒娥進(jìn)行測(cè)定,表明在5~9天內(nèi)校正死亡率高達(dá)100%,存活昆蟲的生長(zhǎng)和發(fā)育也明顯地受到抑制.根據(jù)苗木在苗圃中高生長(zhǎng)和昆蟲校正死亡率采用重心聚類法進(jìn)行分析,初步選出高生長(zhǎng)良好和殺蟲率居中的3株再生值株.以選出的植株為主進(jìn)行了PCR及PCR產(chǎn)物的Southern blot和再生植株DNA Southern blot測(cè)定,結(jié)果證明Bt基因已插入到這些植株的DNA上,并表達(dá)出蘇云金桿菌殺蟲蛋白的殺蟲活性.
關(guān)鍵詞:楊樹;Bt基因;抗蟲
來(lái)源出版物:生物工程學(xué)報(bào), 1993, 9(4):291-297
被引頻次:973
來(lái)源出版物:Cancer Research, 1993, 53(21):5274-5283
被引頻次:553
An adenovirus vector with genetically modified fibers demonstrates expanded tropism via utilization of a coxsackievirus and adenovirus receptor-independent cell entry mechanism
Dmitriev, I; Krasnykh, V; Miller, CR; et al.
Abstract:Recombinant adenoviruses(Ad) have become the vector system of choice for a variety of gene therapy applications. However,the utility of Ad vectors is limited due to the low efficiency of Ad-mediated gene transfer to cells expressing marginal levels of the coxsackievirus and adenovirus receptor(CAR). In order to achieve CAR-independent gene transfer by Ad vectors in clinically important contexts, we proposed modification of viral tropism via genetic alterations to the viral fiber protein. We have shown that incorporation of an Arg-Gly-Asp(RGD)-containing peptide in the HI loop of the fiber knob domain results in the ability of the virus to utilize an alternative receptor during the cell entry process. We have also demonstrated that due to its expanded tissue tropism, this novel vector is capable of efficient transduction of primary tumor cells. An increase in gene transfer to ovarian cancer cells of 2 to 3 orders of magnitude was demonstrated by the vector, suggesting that recombinant Ad containing fibers with an incorporated RGD peptide may be of great utility for treatment of neoplasms characterized by deficiency of the primary Ad type 5 receptor.
Keywords:extraovarian cancer-patients; previously treated ovarian; phage display library; amino-acid-sequence; alpha-v integrins;recombinant adenovirus; vitronectin receptor; crystal-structure; binding domain; virus type-1
來(lái)源出版物:Journal of Virology, 1998, 72(12):9706-9713
被引頻次:528
Metabolic profiling allows comprehensive phenotyping of genetically or environmentally modified plant systems
Roessner, U; Luedemann, A; Brust, D; et al.
Abstract:Metabolic profiling using gas chromatography-mass spectrometry technologies is a technique whose potential in the field of functional genomics is largely untapped, To demonstrate the general usefulness of this technique, we applied to diverse plant genotypes a recently developed profiling protocol that allows detection of a wide range of hydrophilic metabolites within a single chromatographic run. For this purpose, we chose four independent potato genotypes characterized by modifications in sucrose metabolism. Using data-mining tools, including hierarchical cluster analysis and principle component analysis, we were able to assign clusters to the individual plant systems and to determine relative distances between these clusters. Extraction analysis allowed identification of the most important components of these clusters. Furthermore, correlation analysis revealed close linkages between a broad spectrum of metabolites. In a second, complementary approach, we subjected wild-type potato tissue to environmental manipulations, The metabolic profiles from these experiments were compared with the data sets obtained for the transgenic systems, thus illustrating the potential of metabolic profiling in assessing how a genetic modification can be phenocopied by environmental conditions. In summary, these data demonstrate the use of metabolic profiling in conjunction with data-mining tools as a technique for the comprehensive characterization of a plant genotype.
Keywords:solanum-tuberosum l; potato-tubers; mass-spectrometry; leuconostoc-mesenteroides; sucrose phosphorylase; gaschromatography; threonine synthase; dna microarrays; organic-acids; expression
來(lái)源出版物:Plant Cell, 2001, 13(1):11-29
被引頻次:418
Genetically Modified skin fibroblasts persist long after transplantation but gradually inactivate introduced genes
Palmer, TD; Rosman, GJ; Osborne, WRA; et al.
Abstract:Genetically engineered fibroblasts have been successfully used to produce therapeutic proteins in animals, but sustained production of the proteins has not been achieved. This limits the potential of fibroblast-mediated gene therapy in humans. We have studied the phenomenon of decreased production in rats by using retroviral vectors carrying genes encoding human adenosine deaminase and neomycin phosphotransferase. While transplanted skin fibroblasts containing vector sequences persisted at constant levels for at least 8.5 mo, vector expression decreased by >1500-fold after 1 mo. Cellular or antibody-mediated immune responses were not detected in transplanted animals, and expression could not be restored in fibroblasts recultivated from the grafts. This phenomenon is reminiscent of sequence-specific gene inactivation observed in other cell types. Because genetic manipulation and expression of foreign proteins did not affect survival of the transplanted cells, effective long-term therapy may be possible with the use of alternative gene regulatory elements.
Keywords:gene therapy; retroviral vectors; adenosine deaminase; neomycin phosphotransferase; severe combined immunodeficiency
來(lái)源出版物:Proceedings of the National Academy of Sciences of the United States of America, 1991, 88(4):1330-1334
被引頻次:344
Transplants of fibroblasts genetically modified to express BDNF promote regeneration of adult rat rubrospinal axons and recovery of forelimb function
Liu, Y; Kim, DH; Himes, BT; et al.
Abstract:Adult mammalian CNS neurons do not normally regenerate their severed axons. This failure has been attributed to scar tissue and inhibitory molecules at the injury site that block the regenerating axons, a lack of trophic support for the axotomized neurons, and intrinsic neuronal changes that follow axotomy, including cell atrophy and death. We studied whether transplants of fibroblasts genetically engineered to produce brain-derived neurotrophic factor(BDNF) would promote rubrospinal tract(RST) regeneration in adult rats. Primary fibroblasts were modified by retroviral-mediated transfer of a DNA construct encoding the human BDNF gene, an internal ribosomal entry site,and a fusion gene of lacZ and neomycin resistance genes. The modified fibroblasts produce biologically active BDNF in vitro. These cells were grafted into a partial cervical hemisection cavity that completely interrupted one RST One and two months after lesion and transplantation, RST regeneration was demonstrated with retrograde and anterograde tracing techniques. Retrograde tracing with fluorogold showed that similar to 7% of RST neurons regenerated axons at least three to four segments caudal to the transplants. Anterograde tracing with biotinylated dextran amine revealed that the RST axons regenerated through and around the transplants, grew for long distances within white matter caudal to the transplant, and terminated in spinal cord gray matter regions that are the normal targets of RST axons. Transplants of unmodified primary fibroblasts or Gelfoam alone did not elicit regeneration. Behavioral tests demonstrated that recipients of BDNF-producing fibroblasts showed significant recovery of forelimb usage, which was abolished by a second lesion that transected the regenerated axons.
Keywords:spinal cord injury; cell transplantation; retrovirus; axon regeneration; anterograde tracing; retrograde tracing; neurotrophin;recovery of function
來(lái)源出版物:Journal of Neuroscience, 1999, 19(11):4370-4387
被引頻次:341
Targeting exogenous genes to tumor angiogenesis by transplantation of genetically modified hematopoietic stem cells
De Palma, M; Venneri, MA; Roca, C; et al.
Abstract:Angiogenic tumor vessels are promising targets for the activity and the selective delivery of cancer therapeutics(1, 2). The bone marrow contributes different cell types to the tumor stroma, including hematopoietic cells(3,4) and, as recently suggested, vascular endothelial cells(ECs)(5). Thus, transplantation of genetically modified bone marrow progenitors may represent a vehicle for the transport of gene therapy to tumors. We transduced bone marrow progenitors with lentiviral vectors expressing genes from transcription-regulatory elements of Tie2/Tek gene(6). When tumors were grown in the transplanted mice, the new vector marked a distinct hematopoietic population that 'homed' to the tumor and closely interacted with vascular ECs at the tumor periphery. These Tie2-expressing mononuclear(TEM) cells had a distinguishable phenotype and were present selectively at angiogenic sites. Unexpectedly, we did not find bone marrow-derived ECs in tumor vessels when we transplanted bone marrow progenitors constitutively expressing a marker gene from the Tie2 or ubiquitously active promoters. By delivering a 'suicide' gene, we selectively eliminated the TEM cells and achieved substantial inhibition of angiogenesis and slower tumor growth without systemic toxicity. Thus, TEM cells may account for the proangiogenic activity of bone marrow-derived cells in tumors, may represent a new target for drug development and may provide the means for selective gene delivery and targeted inhibition of tumor angiogenesis.
Keywords:bone-marrow; lentiviral vectors; expression; growth; cancer; mice; macrophages; receptor; origin; marker
來(lái)源出版物:Nature Medicine, 2003, 9(6):789-795
被引頻次:331
Dendritic cells genetically modified with an adenovirus vector encoding the cDNA for a model antigen induce protective and therapeutic antitumor immunity
Song, W; Kong, HL; Carpenter, H; et al.
Abstract:Dendritic cells(DCs) are potent antigen-presenting cells that play a critical role in the initiation of antitumor immune responses. In this study, we show that genetic modifications of a murine epidermis-derived DC line and primary bone marrow-derived DCs to express a model antigen beta-galactosidase(beta gal) can be achieved through the use of a replication-deficient, recombinant adenovirus vector, and that the modified DCs are capable of eliciting antigen-specific, MHC-restricted CTL responses. Importantly, using a murine metastatic lung tumor model with syngeneic colon carcinoma cells expressing beta gal, we show that immunization of mice with the genetically modified DC line or bone marrow DCs confers potent protection against a lethal tumor challenge, as well as suppression of preestablished tumors, resulting in a significant survival advantage. We conclude that genetic modification of DCs to express antigens that are also expressed in tumors can lead to antigen-specific, antitumor killer cells, with a concomitant resistance to tumor challenge and a decrease in the size of existing tumors.
Keywords:tumor-associated antigen; cytotoxic t-lymphocytes; bone-marrow; in-vivo; cystic-fibrosis; murine tumors; gene; cancer;
immunotherapy; immunization
來(lái)源出版物:Journal of Experimental Medicine, 1997, 186(8):1247-1256
被引頻次:318
Intrathecal delivery of CNTF using encapsulated genetically modified xenogeneic cells in amyotrophic lateral sclerosis patients
Aebischer, P; Schluep, M; Deglon, N;et al.
Abstract:Neuronal growth factors hold promise for providing therapeutic benefits in various neurological disorders. As a means of ensuring adequate central nervous system delivery of growth factors and minimizing significant adverse side effects associated with systemic delivery methods, we have developed an ex vivo gene therapy approach for protein delivery using encapsulated genetically modified xenogeneic cells. Ciliary neurotrophic factor(CNTF) has been shown in various rodent models to reduce the motor neuron cell death similar to that seen in amyotrophic lateral sclerosis(ALS)(1-3). The initial trials focusing on the systemic administration of CNTF for ALS have been discontinued as a result of major side effects, thus preventing determination of the potential efficacy of the molecule(4,5). In order to deliver CNTF directly to the nervous system, we conducted a phase I study in which six ALS patients were implanted with polymer capsules containing genetically engineered baby hamster kidney cells releasing approximately 0.5 mug of human CNTF per day in vitro. The CNTF-releasing implants were surgically placed within the lumbar intrathecal space. Nanogram levels of CNTF were measured within the patients' cerebrospinal fluid(CSF) for at least 17 weeks post-transplantation, whereas it was undetectable before implantation. Intrathecal delivery of CNTF was not associated with the limiting side effects observed with systemic delivery. These results demonstratethat neurotrophic factors can be continuously delivered within the CSF of humans by an ex vivo gene therapy approach, opening new avenues for the treatment of neurological diseases.
Keywords:neurotrophic factor prevents; motor-neurons; motoneurons
來(lái)源出版物:Nature Medicine, 1996, 2(6):696-699
被引頻次:268
Assessment of the food safety issues related to genetically modified foods
Kuiper, HA; Kleter, GA; Noteborn, HPJM; et al.
Abstract:International consensus has been reached on the principles regarding evaluation of the food safety of genetically modified plants. The concept of substantial equivalence has been developed as part of a safety evaluation framework, based on the idea that existing foods can serve as a basis for comparing the properties of genetically modified foods with the appropriate counterpart. Application of the concept is not a safety assessment per se, but helps to identify similarities and differences between the existing food and the new product, which are then subject to further toxicological investigation. Substantial equivalence is a starting point in the safety evaluation, rather than an endpoint of the assessment. Consensus on practical application of the principle should be further elaborated. Experiences with the safety testing of newly inserted proteins and of whole genetically modified foods are reviewed, and limitations of current test methodologies are discussed. The development and validation of new profiling methods such as DNA microarray technology, proteomics, and metabolomics for the identification and characterization of unintended effects, which may occur as a result of the genetic modification, is recommended. The assessment of the allergenicity of newly inserted proteins and of marker genes is discussed. An issue that will gain importance in the near future is that of postmarketing surveillance of the foods derived from genetically modified crops. It is concluded, among others that, that application of the principle of substantial equivalence has proven adequate, and that no alternative adequate safety assessment strategies are available.
Keywords:biotechnology; genetic modification; genetic engineering; food crops; food safety; toxicology; substantial equivalence;
legislation; risk assessment; profiling techniques; post market surveillance
來(lái)源出版物:Plant Journal, 2001, 27(6):503-528
被引頻次:268
Systemic delivery of recombinant proteins by genetically modified myoblasts
Barr, E; Leiden, JM
Abstract:The ability to stably deliver recombinant proteins to the systemic circulation would facilitate the treatment of a variety of acquired and inherited diseases. To explore the feasibility of the use of genetically engineered myoblasts as a recombinant protein delivery system, stable transfectants of the murine C2C12 myoblast cell line were produced that synthesize and secrete high levels of human growth hormone(hGH) in vitro. Mice injected with hGH-transfected myoblasts had significant levels of hGH in both muscle and serum that were stable for at least 3 weeks after injection. Histological examination of muscles injected with beta-galactosidase-expressing C2C12 myoblasts demonstrated that many of the injected cells had fused to form multinucleated myotubes. Thus, genetically engineered myoblasts can bc used for the stable delivery of recombinant proteins into the circulation.
Keywords:mediated gene-transfer; human adenosine-deaminase; troponin-c gene; human factor-ix; hemophilia-b; bone-marrow; stem-cells;expression; muscle; transplantation
來(lái)源出版物:Science, 1991, 254(5037):1507-1509
被引頻次:259
Genetically modified Plasmodium parasites as a protective experimental malaria vaccine
Mueller, AK; Labaied, M; Kappe, SHI; et al.
Abstract:Malaria is a mosquito-borne disease that is transmitted by inoculation of the Plasmodium parasite sporozoite stage. Sporozoites invade hepatocytes(1), transform into liver stages, and subsequent liver-stage development ultimately results in release of pathogenic merozoites(2). Liver stages of the parasite are a prime target for malaria vaccines because they can be completely eliminated by sterilizing immune responses, thereby preventing malarial infection(3). Using expression profiling, we previously identified genes that are only expressed in the pre-erythrocytic stages of the parasite(4,5). Here, we show by reverse genetics that one identified gene, UIS3(upregulated in infective sporozoites gene 3), is essential for early liver-stage development. uis3-deficient sporozoites infect hepatocytes but are unable to establish blood-stage infections in vivo, and thus do not lead to disease. Immunization with uis3-deficient sporozoites confers complete protection against infectious sporozoite challenge in a rodent malaria model. This protection is sustained and stage specific. Our findings demonstrate that a safe and effective, genetically attenuated whole-organism malaria vaccine is possible.
Keywords:sporozoite stage; genome sequence; berghei; falciparum; liver
來(lái)源出版物:Nature, 2005, 433(7022):164-167
·推薦論文摘要·
轉(zhuǎn)基因水稻基因飄流研究十年回顧
賈士榮,袁潛華,王豐,等
摘要:中國(guó)是世界最大的水稻生產(chǎn)國(guó)和亞洲栽培稻的起源中心之一.隨著中國(guó)轉(zhuǎn)基因水稻研發(fā)的快速發(fā)展,需要研究水稻轉(zhuǎn)基因飄流可能對(duì)環(huán)境和食品安全帶來(lái)的潛在風(fēng)險(xiǎn).基因飄流及其數(shù)據(jù)是對(duì)轉(zhuǎn)基因水稻進(jìn)行科學(xué)評(píng)估和監(jiān)管的重要參數(shù).為此,從2002年開始組建了研究團(tuán)隊(duì),對(duì)轉(zhuǎn)基因水稻的基因飄流進(jìn)行了為期10 年的系統(tǒng)研究.取得的結(jié)果主要包括:(1)闡明了水稻基因飄流的基本規(guī)律,揭示了影響水稻基因飄流的生物學(xué)和氣象學(xué)主控因子.沿水稻開花期的主流風(fēng)向,采用長(zhǎng)方形田間試驗(yàn)設(shè)計(jì),分別在三亞、廣州和杭州3個(gè)點(diǎn)2-3個(gè)生長(zhǎng)季,研究了純合轉(zhuǎn)bar 基因花粉供體L201或B2(姐妹系,抗除草劑Basta)向19個(gè)非轉(zhuǎn)基因受體(包括不育系、常規(guī)稻品種、雜交稻F1 和普通野生稻)在不同距離上的基因飄流率,明確了轉(zhuǎn)基因向不育系的飄流率最高,向普通栽培稻品種的基因飄流率最低(相鄰種植時(shí)小于1%或0.1%),向普通野生稻的基因飄流率介于不育系和常規(guī)稻之間,向不育系的最大基因飄流率比向普通野生稻和栽培稻要大1-3個(gè)數(shù)量級(jí);基因飄流率隨距離增加呈負(fù)指數(shù)曲線衰減,且存在急劇降低的“拐點(diǎn)”,“拐點(diǎn)”的距離與試驗(yàn)點(diǎn)水稻開花期的風(fēng)速密切相關(guān),廣州和杭州為1-2 m,三亞約為5 m;采用圓形、以花粉供體為中心的田間試驗(yàn)設(shè)計(jì),以異交結(jié)實(shí)率很高的不育系博A作受體,清晰地解析了風(fēng)向與基因飄流率的數(shù)值關(guān)系,主流和次主流風(fēng)向下游4個(gè)扇區(qū)的基因飄流事件累計(jì)達(dá)90%-96%,而逆風(fēng)向和側(cè)逆風(fēng)向4 個(gè)扇區(qū)僅為4%-10%.綜上所述,水稻轉(zhuǎn)基因飄流率與常規(guī)育成品種間的異交率(一般在1%以下)基本相同,在數(shù)量級(jí)上轉(zhuǎn)基因并未增加新的風(fēng)險(xiǎn).(2)建立了以氣象資料為參數(shù)的水稻花粉擴(kuò)散和基因飄流普適模型,計(jì)算和預(yù)測(cè)了中國(guó)南方稻區(qū)17省、市的最大基因飄流閾值距離(maximum threshold distances, MTDs).受東南季風(fēng)和地形地貌的影響,中國(guó)南方稻區(qū)MTDs的空間分布特征為:東西之間有自東向西逐漸減小的趨勢(shì),南北之間首先在南方丘陵地區(qū)逐漸減小、越過(guò)南嶺后再向東南沿海地區(qū)逐漸增大.(3)利用人工構(gòu)建的普通野生稻與基因(Bt或bar)飄流后代栽/野F1雜種混栽群體,經(jīng)多年多代跟蹤觀察,分析了轉(zhuǎn)基因飄流至普通野生稻后的命運(yùn),發(fā)現(xiàn)栽/野F1雜種在3-5年后完全消失,混栽群體中檢測(cè)不到外源的Bt和bar,有理由推測(cè)普通野生稻具有自我保護(hù)的機(jī)制.(4)研究了小規(guī)模田間試驗(yàn)中采用花期隔離和布帳隔離措施降低水稻基因飄流率的效果;調(diào)查了海南、廣東、廣西普通野生稻原生境居群與相鄰種植的栽培稻花期相遇情況,建立了相應(yīng)的數(shù)據(jù)庫(kù);研究了基因拆分技術(shù)作為生物學(xué)限控措施從根本上限控基因飄流的效果;以本研究的結(jié)果及對(duì)國(guó)際上主要農(nóng)作物基因飄流的調(diào)研數(shù)據(jù)為基礎(chǔ),提出了在水稻基因飄流風(fēng)險(xiǎn)評(píng)估和監(jiān)管中采用分類管理和閾值管理的原則.在10年回顧和科學(xué)分析的基礎(chǔ)上,對(duì)未來(lái)研究的重點(diǎn)也進(jìn)行了展望.
關(guān)鍵詞:水稻;普通野生稻;轉(zhuǎn)基因;花粉擴(kuò)散;基因飄流;風(fēng)險(xiǎn)評(píng)估;風(fēng)險(xiǎn)管理
來(lái)源出版物:中國(guó)農(nóng)業(yè)科學(xué),2014, 47(1):1-10聯(lián)系郵箱:賈士榮,srjia@126.com
轉(zhuǎn)基因抗蟲玉米研究及應(yīng)用
呂霞,王慧,曾興,等
摘要:Bt是轉(zhuǎn)基因抗蟲玉米育種應(yīng)用的主要外源基因,包含編碼殺蟲晶體蛋白(ICPs)的Cry類和Cyt類基因,以及編碼營(yíng)養(yǎng)期殺蟲蛋白(Vip)的vip類基因.迄今已有40余種轉(zhuǎn)Bt基因玉米事件被26個(gè)國(guó)家批準(zhǔn)進(jìn)入商業(yè)化種植或飼料食品加工.目前,Bt基因研發(fā)仍在進(jìn)行,并逐步向分離克隆和改造新基因以及構(gòu)建高效表達(dá)載體方向發(fā)展.轉(zhuǎn)Bt基因育種工程逐漸擴(kuò)大靶標(biāo)昆蟲抗性范圍,并向復(fù)合性狀抗蟲玉米發(fā)展.轉(zhuǎn)化技術(shù)亦向高效化和安全化發(fā)展.綜述了Bt基因作用機(jī)理、轉(zhuǎn)Bt基因玉米研發(fā)及應(yīng)用,擬為我國(guó)轉(zhuǎn)Bt基因抗蟲玉米研發(fā)提供參考.
關(guān)鍵詞:玉米;Bt基因;玉米螟;轉(zhuǎn)化體;商業(yè)化應(yīng)用
來(lái)源出版物:作物雜志,2013,(2):7-12
轉(zhuǎn)基因食品安全評(píng)價(jià)研究進(jìn)展
祁瀟哲,黃昆侖
摘要:自1996年轉(zhuǎn)基因作物大規(guī)模商業(yè)化生產(chǎn)以來(lái),以年均10%左右的速度快速增長(zhǎng),2012年種植面積達(dá)1.7億 hm2.其在解決全球饑餓問(wèn)題、保護(hù)環(huán)境、提高糧食營(yíng)養(yǎng)品質(zhì)以及方便的獲取藥物方面具有巨大的應(yīng)用前景.但是轉(zhuǎn)基因技術(shù)具有一定的風(fēng)險(xiǎn)性,加強(qiáng)轉(zhuǎn)基因作物的安全評(píng)價(jià)是保障轉(zhuǎn)基因食品安全性的有效手段.在轉(zhuǎn)基因食品進(jìn)入市場(chǎng)前,要經(jīng)過(guò)嚴(yán)格的食用安全性評(píng)價(jià),包括營(yíng)養(yǎng)學(xué)、毒理學(xué)、過(guò)敏性等方面,另外有非期望效應(yīng)和腸道健康評(píng)價(jià)作為補(bǔ)充,為轉(zhuǎn)基因食品的風(fēng)險(xiǎn)規(guī)避及大力發(fā)展提供了有效的保障手段.凡是經(jīng)過(guò)了安全性評(píng)價(jià),獲得了安全證書的轉(zhuǎn)基因食品都有安全保障,消費(fèi)者可以放心食用.
關(guān)鍵詞:轉(zhuǎn)基因作物;益處;食品安全評(píng)價(jià)
來(lái)源出版物:中國(guó)農(nóng)業(yè)科技導(dǎo)報(bào),2013, 15(4):14-19聯(lián)系郵箱:黃昆侖,hkl009@163.com
轉(zhuǎn)基因生物產(chǎn)業(yè)化情況
盛耀,許文濤,羅云波
摘要:轉(zhuǎn)基因生物的產(chǎn)業(yè)化自上世紀(jì)80年代以來(lái)發(fā)展非常迅速,經(jīng)過(guò)30多年的歷程,轉(zhuǎn)基因技術(shù)已經(jīng)被應(yīng)用到農(nóng)業(yè)、醫(yī)藥、化工、食品、環(huán)境保護(hù)、能源等領(lǐng)域.目前,轉(zhuǎn)基因生物的產(chǎn)業(yè)化規(guī)模呈逐年遞增趨勢(shì),到2012年轉(zhuǎn)基因作物種植面積達(dá)到1.703億hm2,比1996年增長(zhǎng)了100倍.與此同時(shí),轉(zhuǎn)基因生物上市品種不斷豐富,其產(chǎn)業(yè)化帶來(lái)的經(jīng)濟(jì)效益和環(huán)境效益也得到充分顯現(xiàn).此外,轉(zhuǎn)基因生物安全評(píng)價(jià)體系的不斷完善進(jìn)一步保障了產(chǎn)業(yè)化的轉(zhuǎn)基因品種食用和環(huán)境安全性.轉(zhuǎn)基因生物產(chǎn)業(yè)未來(lái)的發(fā)展重點(diǎn)主要包括復(fù)合性狀轉(zhuǎn)基因作物、藥用工業(yè)用轉(zhuǎn)基因植物、品種改良轉(zhuǎn)基因作物以及轉(zhuǎn)基因動(dòng)物的產(chǎn)業(yè)化,而現(xiàn)在已經(jīng)比較成熟的轉(zhuǎn)基因微生物產(chǎn)業(yè)也將有更加廣泛的應(yīng)用.但不可否認(rèn)的是,轉(zhuǎn)基因產(chǎn)業(yè)化的發(fā)展仍面臨著來(lái)自安全、產(chǎn)權(quán)、科技、科普等各方面爭(zhēng)議和挑戰(zhàn).在我國(guó),轉(zhuǎn)基因產(chǎn)品的自主研發(fā)能力亟需提高,產(chǎn)業(yè)標(biāo)準(zhǔn)化體系和風(fēng)險(xiǎn)交流制度也需要逐步建立和完善.為此,我國(guó)政府應(yīng)加大科研和科普力度,適時(shí)適度推動(dòng)轉(zhuǎn)基因生物產(chǎn)業(yè)化進(jìn)程.
關(guān)鍵詞:轉(zhuǎn)基因生物;轉(zhuǎn)基因技術(shù);產(chǎn)業(yè)化
來(lái)源出版物:農(nóng)業(yè)生物技術(shù)學(xué)報(bào),2013, 21(12):1479-1487聯(lián)系郵箱:羅云波,lyb@cau.edu.cn
營(yíng)養(yǎng)改良型轉(zhuǎn)基因植物研究進(jìn)展
劉升,羅云波,黃昆侖
摘要:研究證實(shí)營(yíng)養(yǎng)素在疾病預(yù)防中發(fā)揮著重要作用,攝入不足將影響人體健康,所以營(yíng)養(yǎng)素的補(bǔ)充強(qiáng)化已成為各領(lǐng)域的研究熱點(diǎn).隨著轉(zhuǎn)基因技術(shù)的日益成熟,營(yíng)養(yǎng)改良型轉(zhuǎn)基因植物的研究也逐漸增多.本文圍繞轉(zhuǎn)基因技術(shù)在植物營(yíng)養(yǎng)改良方面的應(yīng)用,綜述了轉(zhuǎn)基因技術(shù)在提高植物中維生素含量、必需氨基酸含量、礦質(zhì)元素含量和降低植物中有害因子、改善脂肪酸組成等方面最新研究成果,對(duì)其未來(lái)的發(fā)展方向及應(yīng)用前景進(jìn)行了展望,同時(shí)對(duì)轉(zhuǎn)基因食品的安全性評(píng)價(jià)及商業(yè)化進(jìn)程提出了建議.以期使讀者能全面正確地認(rèn)識(shí)和了解轉(zhuǎn)基因技術(shù)在改良植物營(yíng)養(yǎng)價(jià)值方面的研究進(jìn)展和未來(lái)發(fā)展方向.
關(guān)鍵詞:轉(zhuǎn)基因植物;營(yíng)養(yǎng)改良;營(yíng)養(yǎng)成分;有害因子
來(lái)源出版物:核農(nóng)學(xué)報(bào),2015,29(2):337-343聯(lián)系郵箱:黃昆侖,hkl009@163.com
Simultaneous editing of three homoeoalleles in hexaploid bread wheat confers heritable resistance to powdery mildew
Wang, Yanpeng; Cheng, Xi; Shan, Qiwei; et al.
Abstract:Sequence-specific nucleases have been applied to engineer targeted modifications in polyploid genomes(1), but simultaneous modification of multiple homoeoalleles has not been reported. Here we use transcription activator like effector nuclease(TALEN)(2,3) and clustered, regularly interspaced, short palindromic repeats(CRISPR)-Cas9(refs. 4,5) technologies in hexaploid bread wheat to introduce targeted mutations in the three homoeoalleles that encode MILDEW-RESISTANCE LOCUS(MLO) proteins(6). Genetic redundancy has prevented evaluation of whether mutation of all three MLO alleles in bread wheat might confer resistance to powdery mildew, a trait not found in natural populations(7). We show that TALEN-induced mutation of all three TaMLO homoeologs in the same plant confers heritable broad-spectrum resistance to powdery mildew. We further use CRISPR-Cas9 technology to generate transgenic wheat plants that carry mutations in the TaMLO-A1 allele. We also demonstrate the feasibility of engineering targeted DNA insertion in bread wheat through nonhomologous end joining of the double-strand breaks caused by TALENs. Our findings provide a methodological framework to improve polyploid crops.
Keywords:zinc-finger nucleases; targeted mutagenesis; plants; gene; arabidopsis; system; specificity; effectors; talen; rice
來(lái)源出版物:Nature Biotechnology, 2014, 32(9):947-951聯(lián)系郵箱:Gao, Caixia; cxgao@genetics.ac.cn
Genome editing in rice and wheat using the CRISPR/Cas system.
Shan, Qiwei; Wang, Yanpeng; Li, Jun; Gao, Caixia
Abstract:Targeted genome editing nucleases, such as zinc-finger nucleases(ZFNs) and transcription activator-like effector nucleases(TALENs), are powerful tools for understanding gene function and for developing valuable new traits in plants. The clustered regularly interspersed short palindromic repeats(CRISPR)/Cas system has recently emerged as an alternative nuclease-based method for efficient and versatile genome engineering. In this system, only the 20-nt targeting sequence within the single-guide RNA(sgRNA) needs to be changed to target different genes. The simplicity of the cloning strategy and the few limitations on potential target sites make the CRISPR/Cas system very appealing. Here we describe a stepwise protocol for the selection of target sites, as well as the design,construction, verification and use of sgRNAs for sequence-specific CRISPR/Cas-mediated mutagenesis and gene targeting in rice andwheat. The CRISPR/Cas system provides a straightforward method for rapid gene targeting within 1-2 weeks in protoplasts, and mutated rice plants can be generated within 13-17 weeks.
Keywords:ZINC-finger nucleases; adaptive immune-systems; RNA-guided endonuclease; targeted mutagenesis; cas system; crispr-Cas9 system; DNA cleavage; human-cells; plants; arabidopsis
來(lái)源出版物:Nature Protocols, 2014, 9(10):2395-2410聯(lián)系郵箱:Gao, Caixia; cxgao@genetics.ac.cn
Genome editing in crops:from bench to field
GAO Cai-xia
Abstract:Conventional plant breeding can accelerate crop improvement by crossing superior plants with other compatible plants, or randomlyinduced variants generated by chemical- or radiation-induced mutagenesis. However, its contribution to crop improvement may be limited by a declining genetic base that depends on existing natural allelic variations. Moreover, conventional mutation is time consuming and requires expensive screening of large populations. During the past 20 years, transgenesis has been used for crop improvement. For example, inthe USA, more than 90% of cultivated soybeans and corn containtransgenes that confer traits such as resistance to insects or herbicides. Unlike conventional breeding, the production of transgenic plants can overcome natural barriers to breeding, and thereby increase the available genetic variation. Transgenesis, however, has its limitations. Transgenic crops generally carry foreign genes inserted randomly in the genome, and their commercialization is frequently prevented by public concern over health and environmental safety issues. Hence, the needs of an ever-increasing human population call for new and publically acceptable breeding techniques that can rapidly, efficiently, and accurately produceinnovative varieties.
來(lái)源出版物:National Science Review, 2015, 2(1):13-15聯(lián)系郵箱:Gao, Caixia; cxgao@genetics.ac.cn
Unintended Compositional Changes in Genetically Modified(GM) Crops:20 Years of Research
Herman, Rod A
Abstract:The compositional equivalency between genetically modified(GM) crops and nontransgenic comparators has been a fundamental component of human health safety assessment for 20 years. During this time, a large amount of information has been amassed on thecompositional changes that accompany both the transgenesis process and traditional breeding methods; additionally, the genetic mechanisms behind these changes have been elucidated. After two decades, scientists are encouraged to objectively assess this body of literature and determine if sufficient scientific uncertainty still exists to continue the general requirement for these studies to support the safety assessment of transgenic crops. It is concluded that suspect unintended compositional effects that could be caused by genetic modification have not materialized on the basis of this substantial literature. Hence, compositional equivalence studies uniquely required for GM crops may no longer be justified on the basis of scientific uncertainty.
Keywords:transgenic; GM; composition; equivalence; unintended
來(lái)源出版物:Journal of Agricultural and Food Chemistry, 2013, 61(48):11695-11701聯(lián)系郵箱:Herman, RA; raherman@dow.com
Development and Validation of Duplex, Triplex, and Pentaplex Real-Time PCR Screening Assays for the Detection of Genetically Modified Organisms in Food and Feed
Huber, Ingrid; Block, Annette; Sebah, Daniela; et al.
Abstract:Worldwide, qualitative methods based on PCR are most commonly used as screening tools for genetically modified material in food and feed. However, the increasing number and diversity of genetically modified organisms(GMO) require effective methods for simultaneously detecting several genetic elements marking the presence of transgenic events. Herein we describe the development and validation of a pentaplex, as well as complementary triplex and duplex real-time PCR assays, for the detection of the most common screening elements found in commercialized GMOs:P-35S, T-nos, ctp2-cp4-epsps, bar, and pat. The use of these screening assays allows the coverage of many GMO events globally approved for commercialization. Each multiplex real-time PCR assay shows high specificity and sensitivity with an absolute limit of detection below 20 copies for the targeted sequences. We demonstrate by intra- and interlaboratory tests that the assays are robust as well as cost- and time-effective for GMO screening if applied in routine GMO analysis.
Keywords:real-time PCR; multiplex; GMO; screening; validation; LOD
來(lái)源出版物:Journal of Agricultural and Food Chemistry, 2013, 61(43):10293-10301聯(lián)系郵箱:Huber, I; ingrid.huber@lgl.bayern.de
Genetically modified whole-cell bioreporters for environmental assessment
Xu, Tingting; Close, Dan M; Sayler, Gary S; et al
Abstract:Living whole-cell bioreporters serve as environmental biosentinels that survey their ecosystems for harmful pollutants and chemical toxicants, and in the process act as human and other higher animal proxies to pre-alert for unfavorable, damaging, or toxic conditions. Endowed with bioluminescent, fluorescent, or colorimetric signaling elements, bioreporters can provide a fast, easily measuredlink to chemical contaminant presence, bioavailability, and toxicity relative to a living system. Though well tested in the confines of the laboratory, real-world applications of bioreporters are limited. In this review, we will consider bioreporter technologies that have evolved from the laboratory towards true environmental applications, and discuss their merits as well as crucial advancements that still require adoption for more widespread utilization. Although the vast majority of environmental monitoring strategies rely upon bioreporters constructed from bacteria, we will also examine environmental biosensing through the use of less conventional eukaryotic-based bioreporters, whose chemical signaling capacity facilitates a more human-relevant link to toxicity and health-related consequences.
Keywords:Bioluminescence; Bioremediation; Bioreporter; Ecotoxicology; Fluorescence
來(lái)源出版物:Ecological Indicators, 2013,28(S1):125-141聯(lián)系郵箱:Ripp, S; saripp@utk.edu
Genetically modified crops:Detection strategies and biosafety issues
Kamle, Suchitra; Ali, Sher
Abstract:Genetically modified(GM) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. The introduction of Bacillus thuringiensis(Bt) genes into the plants has raised issues related to its risk assessment and biosafety. The International Regulations and the Codex guidelines regulate the biosafety requirements of the GM crops. In addition, these bodies synergize and harmonize the ethical issues related to the release and use of GM products. The labeling of GM crops and their products are mandatory if the genetically modified organism(GMO) content exceeds the levels of a recommended threshold. The new and upcoming GM crops carrying multiple stacked traits likely to be commercialized soon warrant sensitive detection methods both at the DNA and protein levels. Therefore, traceability of the transgene and its protein expression in GM crops is an important issue that needs to be addressed on a priority basis. The advancement in the area of molecular biology has made available several bioanalytical options for the detection of GM crops based on DNA and protein markers. Since the insertion of a gene into the host genome may even cause copy number variation, this may be uncovered using real time PCR. Besides, assessing the exact number of mRNA transcripts of a gene, correlation between the template activity and expressed protein may be established. Here, we present an overview on the production of GM crops, their acceptabilities,detection strategies, biosafety issues and potential impact on society. Further, overall future prospects are also highlighted.
Keywords:International regulation; Labeling; Gene expression; mRNA transcription; Copy number variation
來(lái)源出版物:Gene, 2013, 522(2):123-132聯(lián)系郵箱:Ali, S; alisher@nii.ac.in
Practical Experiences with an Extended Screening Strategy for Genetically Modified Organisms(GMOs) in Real-Life Samples
Scholtens, Ingrid; Laurensse, Emile; Molenaar, Bonnie; et al
Abstract:Nowadays most animal feed products imported into Europe have a GMO(genetically modified organism) label. This means that they contain European Union(EU)-authorized GMOs. For enforcement of these labeling requirements, it is necessary, with the rising number of EU-authorized GMOs, to perform an increasing number of analyses. In addition to this, it is necessary to test products for the potential presence of EU-unauthorized GMOs. Analysis for EU-authorized and -unauthorized GMOs in animal feed has thus become laborious and expensive. Initial screening steps may reduce the number of GMO identification methods that need to be applied, but with the increasing diversity also screening with GMO elements has become more complex. For the present study, the application of an informative detailed 24-element screening and subsequent identification strategy was applied in 50 animal feed samples. Almost all feed samples were labeled as containing GMO-derived materials. The main goal of the study was therefore to investigate if a detailed screening strategy would reduce the number of subsequent identification analyses. An additional goal was to test the samples in this way for the potential presence of EU-unauthorized GMOs. Finally, to test the robustness of the approach, eight of the samples were tested in a concise interlaboratory study. No significant differences were found between the results of the two laboratories.
Keywords:GMO element; screening plate; multidetection; unauthorized GMO; TaqMan; PCR; Cry3Bb1; Cty1F
來(lái)源出版物:Journal of Agricultural and Food Chemistry, 2013, 61(38):9097-9109
聯(lián)系郵箱:Scholtens, I; ingrid.scholtens@wur.nl
Genetically Modified Crops and Food Security
Qaim, Matin; Kouser, Shahzad
Abstract:The role of genetically modified(GM) crops for food security is the subject of public controversy. GM crops could contribute to food production increases and higher food availability. There may also be impacts on food quality and nutrient composition. Finally,growing GM crops may influence farmers' income and thus their economic access to food. Smallholder farmers make up a large proportion of the undernourished people worldwide. Our study focuses on this latter aspect and provides the first ex post analysis of food security impacts of GM crops at the micro level. We use comprehensive panel data collected over several years from farm households in India,where insect-resistant GM cotton has been widely adopted. Controlling for other factors, the adoption of GM cotton has significantly improved calorie consumption and dietary quality, resulting from increased family incomes. This technology has reduced food insecurity by15-20% among cotton-producing households. GM crops alone will not solve the hunger problem, but they can be an important component in a broader food security strategy.
Keywords:BT cotton; golden-rice; impact; india; world; poor; agriculture; adoption; poverty; china
來(lái)源出版物:PLOS ONE, 2013, 8(6) 文獻(xiàn)號(hào):e64879聯(lián)系郵箱:Qaim, M; mqaim@uni-goettingen.de
Biosafety management and commercial use of genetically modified crops in China
Li, Yunhe; Peng, Yufa; Hallerman, Eric M; et al
Abstract:As a developing country with relatively limited arable land, China is making great efforts for development and use of genetically modified(GM) crops to boost agricultural productivity. Many GM crop varieties have been developed in China in recent years; in particular,China is playing a leading role in development of insect-resistant GM rice lines. To ensure the safe use of GM crops, biosafety risk assessments are required as an important part of the regulatory oversight of such products. With over 20 years of nationwide promotion of agricultural biotechnology, a relatively well-developed regulatory system for risk assessment and management of GM plants has been developed that establishes a firm basis for safe use of GM crops. So far, a total of seven GM crops involving ten events have been approved for commercial planting, and 5 GM crops with a total of 37 events have been approved for import as processing material in China. However, currently only insect-resistant Bt cotton and disease-resistant papaya have been commercially planted on a large scale. The planting of Bt cotton and disease-resistant papaya have provided efficient protection against cotton bollworms and Papaya ringspot virus(PRSV), respectively. As a consequence, chemical application to these crops has been significantly reduced, enhancing farm income while reducing human and non-target organism exposure to toxic chemicals. This article provides useful information for the colleagues, in particular for them whose mother tongue is not Chinese, to clearly understand the biosafety regulation and commercial use of genetically modified crops in China.
Keywords:Genetically modified crop; Biosafety regulation; Environmental risk assessment; Ecological impact; Bt cotton
來(lái)源出版物:Plant Cell Reports, 2014, 33(4):565-573聯(lián)系郵箱:Wu, KM; kmwu@ippcaas.cn
GMO matrix:A cost-effective approach for screening unauthorized genetically modified events in India
Randhawa, Gurinder Jit; Morisset, Dany; Singh, Monika; et al
Abstract:Use of a pragmatic, affordable and reliable approach for screening and detection of a large number of genetically modified(GM)crops/events is the need of hour. A cost-effective matrix approach to check the GM status of food/feed products and for screening the presence of authorized and unauthorized GM events in India is being reported in the present study. A genetically modified organism(GMO)screening matrix, with the information on 106 genetic element targets for detection of 141 GM events of 21 crops, is being presented. These include commercially cultivated Bt cotton events and other GM events, under field trials during the past six years(2006—2012) in the country. The information on GM events, which were either indigenously developed or imported for research purposes, is also presented in brief. Ten most frequently present targets, viz., [P-35S[ [T-nos[ [Os-Msca1[ [cu1Ab[ [cu1Ac[ [cry1C[ [cry2Ab[ [GA20 oxidase1[ [nptII[[bar[, were identified to screen these events using a GMOseek algorithm. This user-friendly screening tool is flexible for further updates with the new GM events and targets/elements. The data reported here related to the Gm crops/events in India and the related GMO matrix are valuable tools to assist in the detection of accidental presence of unauthorized GM events in the food and supply chain globally, as well as in the context of the new labelling requirements for food commodities, as per the amendment to enforce GM food labelling from January 2013 in India. The reported GMO matrix' approach would facilitate efficient, rapid and cost-effective preliminary screening by eliminating the need for development of specific testing methodologies for each GM event.
Keywords:GMO matrix; GM crops; Real-time PCR; Screening table; Unauthorized events
來(lái)源出版物:Food Control, 2014, 38:124-129聯(lián)系郵箱:Randhawa, GJ; gjr@nbpgr.ernet.in
DNA degradation in genetically modified rice with Cry1Ab by food processing methods:Implications for the quantification of genetically modified organisms
Xing, Fuguo; Zhang, Wei; Selvaraj, Jonathan Nimal; et al.
Abstract:Food processing methods contribute to DNA degradation, thereby affecting genetically modified organism detection and quantification. This study evaluated the effect of food processing methods on the relative transgenic content of genetically modified rice with Cry1Ab. In steamed rice and rice noodles, the levels of Cry1Ab were >=100% and <83%, respectively. Frying and baking in rice crackers contributed to a reduction in Pubi and Cry1Ab, while microwaving caused a decrease in Pubi and an increase in Cry1Ab. The processing methods of sweet rice wine had the most severe degradation effects on Pubi and Cry1Ab. In steamed rice and rice noodles,Cry1Ab was the most stable, followed by SPS and Pubi. However, in rice crackers and sweet rice wine, SPS was the most stable, followed by Cry1Ab and Pubi. Therefore, Cry1Ab is a better representative of transgenic components than is Pubi because the levels of Cry1Ab were less affected compared to Pubi.
Keywords:Genetically modified rice; Cry1Ab gene; Pubi gene; DNA degradation; Food processing; GMO detection; Real-time PCR
來(lái)源出版物:Food Chemistry, 2015, 174:132-138聯(lián)系郵箱:Liu, Y; liuyang01@caas.cn
Genetically Modified Feeds in Poultry Diet:Safety, Performance, and Product Quality
Tufarelli, V; Selvaggi, M; Dario, C; et al.
Abstract:Concerns have been expressed regarding the safety of using biotechnology derived feeds in diets of livestock animals and in regard to human consumption of products from species fed transgenic crops. As a consequence, a large number of poultry nutrition studies have been conducted to evaluate the wholesomeness of transgenic crops by examining performances of animals during growth or egg laying. Studies also evaluated whether foreign DNA and proteins could be detected in meat, egg, and tissue samples from broiler chickens and laying hens fed diets containing transgenic feeds. In all studies, the conclusions were in agreement that the transgenic crops provided comparable performance, carcass and egg yields, and meat and egg composition, when compared with conventional grains. Moreover, it was demonstrated that transgenic proteins and DNA present in livestock feeds are not detectable in food products derived from these animals,using the most sensitive detection methods available, confirming that they are rapidly degraded by normal digestive processes. The lack of significant differences were a result of the similarity in nutrient composition of the genetically modified feeds and lack of differences in intake and digestibility, while there were no evidences that the differences reported for performance response variables and carcass measurements between treatment groups were attributable to the presence of the transgenic gene and protein in the biotechnology derived plants. Results demonstrated that genetically modified feeds are substantially equivalent and they result as safe as existing conventional feeds.
Keywords:performance; safety; poultry; Genetically modified feeds
來(lái)源出版物:Critical Reviews in Food Science and Nutrition, 2015, 55(4):562-569
聯(lián)系郵箱:Tufarelli, V; vincenzo.tufarelli@uniba.it
Biocontainment of genetically modified organisms by synthetic protein design
Mandell, Daniel J; Lajoie, Marc J; Mee, Michael T; et al.
Abstract:Genetically modified organisms(GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code(Escherichia coli strain C321.Delta A) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.
Keywords:escherichia-coli k-12; biological containment; system; recombination; algorithms; bacteria; acid
來(lái)源出版物:Nature, 2015, 518(7537):55-60聯(lián)系郵箱:Church, GM; gchurch@genetics.med.harvard.edu
A novel trait-specific real-time PCR method enables quantification of genetically modified(GM) maize content in ground grain samples containing stacked GM maize
Noguchi, Akio; Akiyama, Hiroshi; Nakamura, Kosuke; et al.
Abstract:Stacked genetically modified(GM) maize is increasingly produced; thereby, current event-specific quantitative real-time polymerase chain reaction(qPCR) methods have led to the overestimation of GM organism(GMO) content compared with the actual weight/weight percentage of GM organism in maize samples. We developed a feasible qPCR method in which the GMO content is calculated based on the quantification of two herbicide-tolerant trait genes, 5-enolpyruvylshikimate-3-phosphate synthase from Agrobacterium sp. strain CP4(cp4epsps) and phosphinothricin N-acetyl-transferase from Streptomyces viridochromogenes(pat) to quantify the GMO content in ground grain samples containing stacked GM maize. The GMO contents of two genes were quantified using a plasmid calibrant and summed for quantification of total GMO content. The trait-specific method revealed lower biases for examination of test samples containing stacked GM maize compared with the event-specific method. Our results clearly show that the trait-specific method is not only simple and cost-effective, but also useful in quantifying the GMO content in ground grain samples containing stacked GM maize, which are expected to be major events in the near future. The developed method would be the only feasible way to conduct the quantification of GMO content in the ground maize samples containing stacked GM maize for the verification of the labeling regulation.
Keywords:Genetically modified maize; qPCR; Trait-specific method; Stacked GM maize
來(lái)源出版物:European Food Research and Technology, 2015, 240(2):413-422
聯(lián)系郵箱:Kondo, K; kondo@nihs.go.jp
(責(zé)任編輯衛(wèi)夏雯,王帥帥)
The Bystander Effect-Tumor-Regression When a Fraction of The Tumor mass is Genetically-Modified
Freeman, SM; Abboud, CN; Whartenby, KA; et al.
Tumor cells expressing the herpes simplex virus thymidine kinase(HSV-TK) gene are sensitive to the drug ganciclovir(GCV). We demonstrate here that HSV-TK-positive cells exposed to GCV were lethal to HSV-TK-negative cells as a result of a “bystander effect”HSV-TK-negative cells were killed in vitro when the population of cultured cells contained only 10% HSV-TK-positive cells. The mechanism of this “bystander effect” on HSV-TK-negative cells appeared to be related to the process of apoptotic cell death when HSV-TK-positive cells were exposed to GCV. Flow cytometric and electron microscopic analyses suggested that apoptotic vesicles generated from the dying gene-modified cells were phagocytized by nearby, unmodified tumor cells. Prevention of apoptotic vesicle transfer prevented the bystander effect. The toxic effect of HSV-TK-positive cells on HSV-TK-negative cells was reproduced in an in vivo model. A mixed population of tumor cells consisting of HSV-TK-positive and HSV-TK-negative cells was inoculated s.c. into mice. Regression of the tumor mass occurred when the inoculum consisted of as few as 10% HSV-TK-expressing tumor cells. The bystander effect was also demonstrated in i.p. tumor studies. Initial experiments demonstrated that prolonged survival(>70 days) occurred when a mixture containing 50% HSV-TK-positive and 50% HSV-TK-negative cells was injected i.p. followed by GCV treatment. Further, survival was prolonged for mice with a preexisting HSV-TK-negative i.p. tumor burden by injecting HSV-TK-positive cells and GCV. These results suggest that genetic modification of tumor cells may be useful for developing cancer therapies.
thymidine kinase genes; retroviral vectors; brain-tumors; renal-cancer; cells; in vivo; apoptosis; interleukin-4; lymphocytes;expression
*摘編自《華中農(nóng)業(yè)大學(xué)學(xué)報(bào)》2014年33卷6期24~30頁(yè)