<i>Agrobacterium tumefaciens</i>and the Plant: The David and Goliath of Modern Genetics

Valentine, Lisa

doi:10.1104/pp.103.032243

Cited by 44 publications

(19 citation statements)

References 36 publications

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“…Another possibility is that the transgene DNA is directed into the genome through the use of a microhomology search . Such a mechanism has been described in the case of integration of Agrobacterium tumefaciens T-DNA into the host plant genome (Valentine 2003). The use of a RecA mutant that retains its ssDNA-binding properties but is deficient in strand exchange activity (Cazaux et al 1998) may shed light on the role of RecA in the transgenesis process .…”

Section: Recombinase-mediated Pig Transgenesismentioning

confidence: 99%

Production of transgenic piglets using ICSI–sperm-mediated gene transfer in combination with recombinase RecA

García–Vázquez¹,

Ruiz²,

Matás³

et al. 2010

Reproduction

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Sperm-mediated gene transfer (SMGT) is a method for the production of transgenic animals based on the intrinsic ability of sperm cells to bind and internalize exogenous DNA molecules and to transfer them into the oocyte at fertilization. Recombinase-A (RecA) proteincoated exogenous DNA has been used previously in pronuclear injection systems increasing integration into goat and pig genomes. However, there are no data regarding transgene expression after ICSI. Here, we set out to investigate whether the expression of transgenic DNA in porcine embryos is improved by recombinase-mediated DNA transfer and if it is possible to generate transgenic animals using this methodology. Different factors which could affect the performance of this transgenic methodology were analyzed by studying 1) the effect of the presence of exogenous DNA and RecA protein on boar sperm functionality; 2) the effect of recombinase RecA on in vitro enhanced green fluorescent protein (EGFP)-expressing embryos produced by ICSI or IVF; and 3) the efficiency of generation of transgenic piglets by RecA-mediated ICSI. Our results suggested that 1) the presence of exogenous DNA and RecA-DNA complexes at 5 mg/ml did not affect sperm functionality in terms of motility, viability, membrane lipid disorder, or reactive oxygen species generation; 2) EGFP-expressing embryos were obtained with a high efficiency using the SMGT-ICSI technique in combination with recombinase; however, the use of IVF system did not result in any fluorescent embryos; and 3) transgenic piglets were produced by this methodology. To our knowledge, this is the first time that transgenic pigs have been produced by ICSI-SGMT and a recombinase.

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Section: Recombinase-mediated Pig Transgenesismentioning

confidence: 99%

Production of transgenic piglets using ICSI–sperm-mediated gene transfer in combination with recombinase RecA

García–Vázquez¹,

Ruiz²,

Matás³

et al. 2010

Reproduction

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“…Several investigators have recently suggested that particle bombardment will inevitably be supplanted by transformation methods using the soil bacterium Agrobacterium tumefaciens and its relatives, at least for the production of commercial genetically enhanced crops (Gelvin 2003;Tzfira and Citovsky 2003;Valentine 2003). The subject of genetically enhanced crops has ignited an intense, polarized and often hostile debate in many countries, with emotive issues taking the lead over scientific rigor and common sense.…”

Section: Introductionmentioning

confidence: 99%

Particle bombardment and the genetic enhancement of crops: myths and realities

et al. 2005

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DNA transfer by particle bombardment makes use of physical processes to achieve the transformation of crop plants. There is no dependence on bacteria, so the limitations inherent in organisms such as Agrobacterium tumefaciens do not apply. The absence of biological constraints, at least until DNA has entered the plant cell, means that particle bombardment is a versatile and effective transformation method, not limited by cell type, species or genotype. There are no intrinsic vector requirements so transgenes of any size and arrangement can be introduced, and multiple gene cotransformation is straightforward. The perceived disadvantages of particle bombardment compared to Agrobacterium-mediated transformation, i.e. the tendency to generate large transgene arrays containing rearranged and broken transgene copies, are not borne out by the recent detailed structural analysis of transgene loci produced by each of the methods. There is also little evidence for major differences in the levels of transgene instability and silencing when these transformation methods are compared in agriculturally important cereals and legumes, and other non-model systems. Indeed, a major advantage of particle bombardment is that the delivered DNA can be manipulated to influence the quality and structure of the resultant transgene loci. This has been demonstrated in recently reported strategies that favor the recovery of transgenic plants containing intact, singlecopy integration events, and demonstrating high-level transgene expression. At the current time, particle bombardment is the most efficient way to achieve plastid transformation in plants and is the only method so far used to achieve mitochondrial transformation. In this review, we discuss recent data highlighting the positive impact of particle bombardment on the genetic transformation of plants, focusing on the fate of exogenous DNA, its organization and its expression in the plant cell. We also discuss some of the most important applications of this technology including the deployment of transgenic plants under field conditions.

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“…HGT between eukaryotes and other kingdoms is regarded as unusual (Brown 2003). Agrobacterium species, one of the best-characterised examples of HGT, are capable of inserting a defined fragment of its DNA into the genome of dicotyledonous plants (Chilton et al 1977;Schell et al 1979;Gelvin 2003;Valentine 2003). Ngrol genes (NgrolB,NgrolC,NgORF13,and NgORF14), that are similar in sequence to genes in the left transferred DNA (TL-DNA) of Agrobacterium rhizogenes, have been found in the genome of untransformed plants of Nicotiana glauca (Aoki and Syono 1999).…”

Section: Horizontal Gene Transfermentioning

confidence: 99%

“…Since the first reports on transgenic crops in the 1980s (Bevan 1984), the debate surrounding the generation of transgenic plants and the political, ecological and economic ramifications of their development have seldom been far from the public eye (Valentine 2003). GM trees are still very rarely found in nature.…”

Section: Genetically Modified Trees (Gm Trees)mentioning

confidence: 99%

Biosafety in Populus spp. and other forest trees: from non-native species to taxa derived from traditional breeding and genetic engineering

Hoenicka

Fladung

2006

Trees

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Forest trees are fundamental components of our environment, mainly due to their long lifetime and important role in forest ecology. In the past, some non-native tree species and taxa from traditional breeding have induced severe environmental impacts such as biological invasion, changes in the 'gene pool', and spread of diseases in forestry. Genetically modified trees obtained in different research groups worldwide are particularly confronted with increased concerns regarding biosafety issues. In the light of current biosafety research worldwide, various threats facing forests and natural tree populations are evaluated in this review: biological invasions, horizontal gene transfer, vertical gene transfer and effects on other organisms. Results available from groups working in biosafety research and risk avoidance using forest trees, with emphasis on transgenic trees, are reviewed. Independent biosafety research as well as the establishment of biosafety research programs for forest trees financed by national and international authorities is now more important than ever before. Biosafety problems detected in the past clearly show the importance of a prior case-by-case evaluation of non-native species, new taxa and also genetically modified trees according to the precautionary principle before their release to avoid risks to the environment and human health.

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Agrobacterium tumefaciensand the Plant: The David and Goliath of Modern Genetics

Cited by 44 publications

References 36 publications

Production of transgenic piglets using ICSI–sperm-mediated gene transfer in combination with recombinase RecA

Production of transgenic piglets using ICSI–sperm-mediated gene transfer in combination with recombinase RecA

Particle bombardment and the genetic enhancement of crops: myths and realities

Biosafety in Populus spp. and other forest trees: from non-native species to taxa derived from traditional breeding and genetic engineering

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