| MON810's unexpected genetic characteristics (7/3/2008) | |
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1.GM Bt corn MON 810 has unexpected genetic characteristics EXTRACT: the insertion of the GM Bt genetic construct into this gene of the plant could enable the formation of new 'hybrid' insecticidal toxins. The consequences for biosecurity are not known. (item 1) --- 1.GM Bt corn MON 810 has unexpected genetic characteristics Prof Buiatti Marcello and his team from the University of Florence, Italy, just published in a prestigious international journal (Rosati et al. Plant. Mol. Biol. 2008) surprising results that call into question the genetic characterisation of GM Bt corn MON 810. Prof Buiatti is a member of the scientific council CRIIGEN and also presented his findings at a meeting of the Society of Biology in Paris recently, where other scientific studies from CRIIGEN were revealed. The article is entitled 'CHARACTERISATION OF THE 3' INTEGRATION SITE IN MON810 YIELDGARD® MAIZE COMMERCIAL LINES' by Alessio Rosati, Patrizia Bogani, Alisa Santarlasci, and Marcello Buiatti. Plant Mol. Biol. (2008) DOI 10.1007/s11103-008-9315-7. [see below for Abstract] This article reveals that the added gene characteristic of the GMO, and coding for the insecticide Bt toxin MON 810, inserted itself into another maize gene which 80% resembles a ubiquitin ligase [a protein]. The ubiquitin ligases are enzymes that are particularly important for the regulation of several cellular functions. In addition, the insertion of the GM Bt genetic construct into this gene of the plant could enable the formation of new 'hybrid' insecticidal toxins. The consequences for biosecurity are not known. In any case, these results are proof of the need to renew the techniques used in molecular and biochemical description of GMOs that are now obsolete. CRIIGEN emphasizes that the regulation of GMOs should move towards an obligation to obtain the sequence of artificial genes after their integration into living organisms, along with that of the surrounding genes, and that the toxicity of new Bt insecticides should be better and longer studied. The insecticidal Bt corn MON 810 is the only true GMO commercially cultivated in Europe today, growing on at least 1% of farmland. Its re-evaluation is scheduled for 2008. France has recently pleaded for a moratorium on the cultivation of GMOs due to the many questions of the Committee [prefiguration??] of the supreme authority on GMOs which had not taken into account these recent results. The moratorium on the consumption and import of animal feed could be considered. --- Abstract The construct inserted in YieldGard MON810 maize, produced by Monsanto, contains the CaMV 35S promoter, the hsp70 intron of maize, the cryI(A)b gene for resistance to lepidopterans and the NOS terminator. In a previous work a truncation event at the 30 end of the cryI(A)b gene leading to the complete loss of the NOS terminator was demonstrated. The 30 maize genome junction region was isolated in the same experiment not showing any homology with known sequences. The aim of the experiments here reported was therefore to isolate and characterize a larger portion of the 30 integration junction from genomic DNA of two commercial MON810 maize lines. Specific primers were designed on the 30 integration junction sequence for the amplification of a 476 bp fragment downstream of the sequence previously detected. In silico analysis identified the whole isolated 30 genomic region as a gene putatively coding for the HECT E3 ubiquitin ligase. RT-PCR performed in this region produced cDNA variants of different length. In silico translation of these transcripts identified 2 and 18 putative additional aminoacids in different variants, all derived from the adjacent host genomic sequences, added to the truncated CRY1A protein. These putative recombinant proteins did not show homology with any known protein domains. Our data gave new insights on the genomic organization of MON810 in the YieldGard maize and confirmed the previous suggestion that the integration in the genome of maize caused a complex recombination event without, apparently, interfering with the activity of the partial CRY1A endotoxin and both the vigor and yield of the YieldGard maize. Acknowledgments We thank Dr. G. Monastra for providing seeds of MON810 and isogenic control maize. This work was supported by a grant from MIPAF (Ministero delle Politiche Agricole, Alimentari e Forestali), Project: ''OGM in Agricoltura''. [NOTE: See also Proceedings of the 51st Italian Society of Agricultural Genetics Annual Congress Riva del Garda, Italy – 23/26 September, 2007 ISBN 978-88-900622-7-8 Poster Abstract – E.01 CHARACTERISATION OF THE 3' INTEGRATION SITE IN MON810 YIELDGARD® MAIZE COMMERCIAL LINES ROSATI A., BOGANI P., BUIATTI M. Dipartimento di Biologia animale e Genetica 'Leo Pardi', Università degli Studi di Firenze, Italy http://www.siga.unina.it/SIGA2007/SIGA_2007/Session_E.pdf ] --- 3.Le maïs OGM Bt MON 810 a des caractéristiques génétiques inattendues Le Pr. Marcello Buiatti et son équipe de l’Université de Florence, en Italie, viennent de publier dans une revue internationale de haut niveau (Rosati et al., Plant. Mol. Biol., 2008) des résultats étonnants qui remettent en cause la caractérisation génétique du maïs OGM Bt MON 810. Le Pr. Buiatti est membre du conseil scientifique du CRIIGEN et a également présenté ses résultats lors d’une séance de la Société de Biologie à Paris récemment, où d’autres études de scientifiques du CRIIGEN ont été exposées. L’article est intitulé « Characterisation of 3’ transgene insertion site and derived mRNAs in MON810 YieldGard® maize » par Alessio Rosati, Patrizia Bogani, Alisa Santarlasci, et Marcello Buiatti. Plant Mol. Biol. (2008) DOI 10.1007/s11103-008-9315-7. Cet article révèle que le gène ajouté, caractéristique de l’OGM, et codant pour la toxine insecticide Bt MON 810 s’est inséré dans un autre gène du maïs qui ressemble à 80% à une ubiquitine-ligase. Les ubiquitine-ligases sont des enzymes importantes notamment pour la régulation de plusieurs fonctions cellulaires. De plus, l’insertion de la construction génétique de l’OGM Bt dans ce gène de la plante pourrait permettre la formation de nouvelles toxines insecticides « hybrides ». Les conséquences sur la biosécurité de ces faits ne sont pas connues. En tout cas, ces résultats sont la preuve de la nécessité de renouveler les techniques utilisées dans la description moléculaire et biochimique des OGM désormais obsolètes. Le CRIIGEN souligne combien la réglementation des OGM devrait évoluer vers une obligation d’obtenir la séquence des gènes artificiels après leur intégration dans des organismes vivants, avec celle des gènes les entourant, et combien la toxicité des nouveaux insecticides Bt devrait être mieux et plus longtemps étudiée. Le maïs-insecticide Bt MON 810 est le seul OGM vraiment cultivé commercialement en Europe aujourd’hui, sur moins de 1% des surfaces agricoles. Sa réévaluation est prévue en 2008. La France a plaidé récemment pour un moratoire sur ses cultures, suite à de nombreuses interrogations du Comité de préfiguration de la haute autorité sur les OGM, qui n’avait pas pris en compte ces récents résultats. Le moratoire à la consommation et à l’importation de la nourriture animale pourrait être étudié. |
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