Page URL:

Reversible gene expression gets the blue light

15 October 2012
Appeared in BioNews 677

Using blue light as the trigger, scientists have developed a laboratory technique to control where and when genes are expressed within cells.

The researchers behind the technology say that controlling gene expression in this way may help scientists to investigate the cause of diseases, to simulate disease states and even one day treat or regenerate damaged tissue.

Laura Polstein, first author on the paper presenting the technique and a graduate student at Duke University in the USA, said: 'We can now, with our method, make gene expression reversible, repeatable, tunable, and specific to different regions of a gene. Current methods of getting genes to express can achieve some of those characteristics, but not all at once'.

To demonstrate the spatial control of the gene expression system, the researchers created patterns - including polka dots and a smiley face - in cell cultures, photographs of which were published in the study.

The technique is called LITEZ, which stands for Light Induced Transcription using Engineered Zinc finger proteins. It uses proteins that allow the plant arabidopsis thaliana to sense the length of a day, in order to target gene expression.

In LITEZ, one light-sensitive protein is attached to an activator of gene expression whilst another is anchored to the gene of interest. When illuminated by blue light the two plant proteins move together, bringing the activator to the gene and triggering targeted gene expression.

Dr Jacqueline Matthews, a molecular biologist and associate professor at the University of Sydney, Australia, who was not involved in the study, told Cosmos magazine that the advantage of LITEZ over other gene expression systems was that 'it's quite reversible, so you can switch on gene expression and then switch it off'.

But Dr Matthews questioned whether LITEZ or similar technology could ever be used clinically: 'You've got to be able to get a light source onto this system and the cells need to have been spiked with LITEZ that targets genes. If you were dealing with cells in a culture it would be easy, but in many cases I don't know how you would get light on the right spots in actual people'.

However Professor Nicholas Dixon at the University of Wollongong, Australia, who was also not involved in the study, told Cosmos: 'In contrast to some other, more conventional methods, it does not require addition of chemical compounds that might have confounding effects - all that is required is to turn the light on and off'.

The study is published in the Journal of the American Chemical Society.

Duke Blue Light Controls Gene Expression
Duke Today (press release) |  1 October 2012
Gene therapy gets the blue light
Cosmos |  5 October 2012
Light-Inducible Spatiotemporal Control of Gene Activation by Customizable Zinc Finger Transcription Factors
Journal of the American Chemical Society |  10 September 2012
6 June 2012 - by Victoria Kay 
Scientists have developed a way of crafting DNA into complex shapes such as letters of the alphabet, symbols and even smiley faces. The nanotechnology may one day be able to create customised DNA structures that can carry therapeutic drugs to specific sites in the human body without triggering an immune response...
28 May 2012 - by Ruth Retassie 
A rewritable memory system using short sections of DNA to hold data in bacterial cells has been developed by synthetic biologists. Dr Drew Endy and his team at Stanford University in California produced the system after three years of work and 750 designs...
23 April 2012 - by Ana Pallesen 
Six new kinds of artificial genetic material have been created by scientists. These XNAs, or xeno-nucleic acids, have similar life-building properties to naturally-occurring DNA...
2 April 2012 - by Dr Louisa Petchey 
Synthetic biology, which uses genetic engineering to build new genomes and organisms, has come under attack in a report published by Friends of the Earth and supported by over 100 other 'public interest' groups...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.