Login

Join for Free!
118805 members
table of contents table of contents

Biology Articles » Biochemistry » Nucleic Acid Biochemistry » Unregulated Hazards ‘Naked’ and ‘Free’ Nucleic Acids » Box 4: Reasons to expect that transgenic DNA may be more likely to spread horizontally than non-transgenic DNA

Box 4: Reasons to expect that transgenic DNA may be more likely to spread horizontally than non-transgenic DNA
- Unregulated Hazards ‘Naked’ and ‘Free’ Nucleic Acids

  1. The mechanisms enabling foreign genes to insert into the genome also enable them to jump out again, to re-insert at another site, or to another genome.
  2. The integration sites of most commonly used artificial vectors for transferring genes are ‘recombination hotspots’, prone to break and join up with other DNA, and so have an increased propensity to transfer horizontally.
  3. Viral promoters, such as that from the cauliflower mosaic virus, widely used to boost the expression of transgenes, also contain a recombination hotspots [60], and will therefore further enhance horizontal gene transfer.
  4. The unnatural gene combinations in transgenic DNA tend to be unstable, and hence prone to recombine and transfer horizontally.
  5. The metabolic stress on the host organism due to the continuous over-expression of transgenes may contribute to the instability of the insert, as it is well-known that mobile genetic elements in all genomes are mobilized to jump out of genomes during conditions of stress, to multiply and/or reinsert randomly at other sites resulting in many insertion-mutations. The foreign gene-constructs and the vectors into which they are spliced, are typically mosaics of DNA sequences from numerous species and their genetic parasites; that means they will be more prone to recombine with, and successfully transfer to, the genomes of many species and their genetic parasites [61].

rating: 4.00 from 5 votes | updated on: 25 Sep 2008 | views: 13657 |

Rate article:







excellent!bad…