'Telepathic' genes recognize similarities in each other

Genes have the ability to recognise similarities in each other from a distance, without any proteins or other biological molecules aiding the process, according to new research published this week in the Journal of Physical Chemistry B. This discovery could explain how similar genes find each other and group together in order to perform key processes involved in the evolution of species.

This new study shows that genes – which are parts of double-stranded DNA with a double-helix structure containing a pattern of chemical bases - can recognise other genes with a similar pattern of chemical bases.

This ability to seek each other out could be the key to how genes identify one another and align with each other in order to begin the process of ‘homologous recombination’ – whereby two double-helix DNA molecules come together, break open, swap a section of genetic information, and then close themselves up again.

Recombination is an important process which plays a key role in evolution and natural selection, and is also central to the body’s ability to repair damaged DNA. Before now, scientists have not known exactly how suitable pairs of genes find each other in order for this process to begin.

The authors of the new study carried out a series of experiments in order to test the theory, first developed in 2001 by two members of this team, that long pieces of identical double-stranded DNA could identify each other merely as a result of complementary patterns of electrical charges which they both carry. They wanted to verify that this could indeed occur without physical contact between the two molecules, or the facilitating presence of proteins.

Previous studies have suggested that proteins are involved in the recognition process when it occurs between short strands of DNA which only have about 10 pairs of chemical bases. This new research shows that much longer strands of DNA with hundreds of pairs of chemical bases seem able to recognise each other as a whole without protein involvement. According to the theory, this recognition mechanism is stronger the longer the genes are.

The researchers observed the behaviour of fluorescently tagged DNA molecules in a pure solution. They found that DNA molecules with identical patterns of chemical bases were approximately twice as likely to gather together than DNA molecules with different sequences.

Professor Alexei Kornyshev from Imperial College London, one of the study’s authors, explains the significance of the team’s results: “Seeing these identical DNA molecules seeking each other out in a crowd, without any external help, is very exciting indeed. This could provide a driving force for similar genes to begin the complex process of recombination without the help of proteins or other biological factors. Our team’s experimental results seem to support these expectations.”

Understanding the precise mechanism of the primary recognition stage of genetic recombination may shed light on how to avoid or minimise recombination errors in evolution, natural selection and DNA repair. This is important because such errors are believed to cause a number of genetically determined diseases including cancers and some forms of Alzheimer’s, as well as contributing to ageing. Understanding this mechanism is also essential for refining precise artificial recombination techniques for biotechnologies and gene therapies of the future.

The team is now working on a set of further experiments to determine exactly how these interactions work, including the predicted length dependence. In addition, further studies are needed to ascertain whether this interaction, discovered in a test tube, occurs in the highly complex environment of a living cell.

Source: Imperial College London

Related stories:

New technique produces genetically identical stem cells
Adult cells of mice created from genetically reprogrammed cells—so-called induced pluripotent stem (IPS) stem cells—can be triggered via drug to enter an embryonic-stem-cell-like state, without the need for further genetic alteration.
New electrostatic-based DNA microarray technique could revolutionize medical diagnostics
The dream of personalized medicine — in which diagnostics, risk predictions and treatment decisions are based on a patient's genetic profile — may be on the verge of being expanded beyond the wealthiest of nations with state-of-the-art clinics.
Safer, more effective gene therapy
Athens, Ga. – The potential of gene therapy has long been hampered by the risks associated with using viruses as vectors to deliver healthy genes, but a new University of Georgia study helps bring scientists closer to a safe and efficient gene delivery method that doesn't involve viruses.
Team discovers new inhibitors of estrogen-dependent breast cancer cells
Researchers have discovered a new family of agents that inhibit the growth of estrogen-dependent breast cancer cells. The finding, described today at a meeting of the Endocrine Society, has opened an avenue of research into new drugs to combat estrogen-dependent breast cancers.
Researchers create molecule that nudges nerve stem cells to mature
Inspired by a chance discovery during another experiment, researchers at UT Southwestern Medical Center have created a small molecule that stimulates nerve stem cells to begin maturing into nerve cells in culture.
Scientists show why cells starved of iron burn more glucose
Duke University Medical Center scientists have found a mechanism that allows cells starved of iron to shut down energy-making processes that depend on iron and use a less efficient pathway involving glucose. This metabolic reshuffling mechanism, found in yeast cells, helps explain how humans respond to iron deficiency, and may help with diabetes research as well.
Scientists trace causal link between a tumor suppressor gene and liver cancer
Scientists at Cold Spring Harbor Laboratory (CSHL) have taken the search for cancer-causing genes an important step forward. In a newly published paper, they confirm that a gene called DLC1 is a tumor suppressor. They have demonstrated in living mice that its deletion, inactivation or loss precipitates events culminating in an aggressive type of liver cancer closely related to common human epithelial cancers of the liver (also known as hepatocellular carcinoma, or HCC).
The good news in our DNA: Defects you can fix with vitamins and minerals
As the cost of sequencing a single human genome drops rapidly, with one company predicting a price of $100 per person in five years, soon the only reason not to look at your "personal genome" will be fear of what bad news lies in your genes.

News discussion:

General Science news