The marker gene issue

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Marker genes – these have usually almost always been antibiotic-resistance genes. They have been the focus of criticism for a long time now. Even though not all scientists agree with the criticism, their use is now restricted as a precaution. In the EU genetically modified plants are no longer authorised if they contain certain antibiotic-resistance genes.

Background

• Antibiotic-resistance genes: once necessary, now undesirable

• New EFSA report: Adverse effects from marker genes "unlikely" (13 June 2009)

Results

• Do bacteria absorb plant genes? Current knowledge
• Horizontal gene transfer: Overview of research projects and results.
• "Selection pressure is critical." Interview with Kornelia Smalla.

 

New marker genes

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Other markers can take on the role of the controversial antibiotic-resistance gene, but it is not easy: Marker genes need to trigger characteristic biochemical reactions that can be detected easily and reliably without affecting the rest of the plant’s metabolism.

A few alternative marker genes fulfil these criteria. A research project has investigated them in greater detail.

Background

• There is another way - alternative markers. Methods and results

 

Negative markers

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Once they have fulfilled their task, marker genes are no longer necessary. It is entirely possible to remove them again after they have been used. An external chemical signal causes plants carrying the marker gene to die.

The concept appears to work in principal. But there is a long way to go before it can be applied in practice.

Background

• Negative marker genes. Information on the method and results