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A huge variety of naked/free nucleic acids are being produced in …
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
- 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.
- 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.
- Viral promoters, such as
that from the cauliflower mosaic virus, widely used to boost the
expression of transgenes, also contain a recombination hotspots ,
and will therefore further enhance horizontal gene transfer.
- The unnatural gene
combinations in transgenic DNA tend to be unstable, and hence prone
to recombine and transfer horizontally.
- 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 .
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