www.czu.cz ; www.usab-tm.ro ; www.raupp.info

Although gifted with the promise of rendering a plant immune to disease or
insect attack, transgenes can sometimes be unstable and unpredictable. The
sources of such variations include inconsistency in the copy numbers of the
introduced gene or genes; somaclonal variation, or phenotypic differences
amongst the biotech plants created; the site of insertion of the transgene;
and RNA silencing in the host plant. As a result, researchers are spending
more time and money to both achieve stable transgene expression, as well as
to produce biotech crops with the expected level of expression, September
2005.

Katleen M.J. Butaye and colleagues of the Katholieke Universiteit Leuven,
Belgium review these techniques in ?Approaches to minimize variation of
transgene expression in plants.? The article is published in the latest
issue of Molecular Breeding.

The review expounds on such techniques as Cre-Lox co-transformation, where
the introduced gene is flanked by DNA sequences which will allow the gene to
be stably integrated into the host genome. This technique has proven to be
successful in mammalian cells, but is still inefficient for plants.

Other techniques include the use of new gene cassettes, viral suppressor
genes, and, according to the researchers, the ultimate genetic engineering
tool: plant artificial chromosomes.

Read the abstract at [dx.doi.org].
Subscribers to Molecular Breeding can access the full article through the
same page.

[www.isaaa.org]

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