From U.N. Observer & International Report :
2008-03-17 New evidence may pull the plug on GMOs. Dr. Mae-Wan Ho
Transgenes unstable in more ways than one
Transgene instability has been known at least since 1994 [1] (reviewed in Genetic Engineering Dream or Nightmare, p.140), though it is seldom, if ever, reported in the popular media. Transgenes (the synthetic foreign genes transferred into the genetically modified organism (GMO)) can become silent or inactive during growth and development of the GMO, or in its progeny. This has been attributed to defence mechanisms that silence genome invaders such as viruses. But transgenes can also stop working on account of structural factors intrinsic to the transgenic DNA inserted into the genome of the GMO [2] (reviewed in Living with the Fluid Genome, pp. 128-135). Transgenic DNA has been artificially constructed by stitching together synthetic copies of DNA from different sources, and often contain additional weak points that tend to break and rejoin (recombination hotspots). The most widely used cauliflower mosaic virus (CaMV) 35S promoter is associated with such a recombination hotspot [3], as we have warned [4-6]. Transgenic constructs are also designed with ends that can break into genomes such as the repeated sequences of viral vectors, and the left and right borders of the T-DNA of Agrobacterium, widely used as a vector. These ends too, are recombination sequences, and facilitate movement of the transgenic DNA within as well as between genomes. For more details see [7] (Horizontal Gene Transfer from GMOs Does Happen, SiS 38)
Transgene instability makes transgenic varieties illegal and ineligible for patent protection
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http://www.i-sis.org.uk/transgenicLinesUnstable2.php
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