Scientists generate the most precise map of genetic recombination ever

July 10, 2008,

Genetic recombination, the process by which sexually reproducing organisms shuffle their genetic material when producing germ cells, leads to offspring with a new genetic make-up and influences the course of evolution.

In the current issue of Nature, researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and the EMBL-European Bioinformatics Institute (EMBL-EBI) in Hinxton, UK, present the most precise map of genetic recombination yet. The study sheds light on fundamental questions about genetic shuffling and has implications for the tracking of disease genes and their inheritance.

In order to generate germ cells, sexually reproducing organisms undergo a complex series of cell divisions (meiosis) that includes the shuffling of genetic material inherited from the two parents. Equivalent chromosomes from mother and father pair up and exchange sections of DNA in a process called crossover.

In a different type of recombination, called non-crossover, a small piece of DNA is copied from one chromosome onto the other without reciprocal exchange leading to gene conversion. Non-crossovers are minute events with a subtler effect than the exchange of larger fragments, but both types of recombination can increase genetic diversity and explain why organisms of the same species differ in many ways. Both types of recombination can also act to separate the transmission of neighbouring genes, which are normally inherited together.

The groups of Lars Steinmetz at EMBL and Wolfgang Huber at EMBL-EBI have produced the most detailed map to date of recombination events in the yeast genome.

"Our map has the highest resolution of recombination events that currently exists for any organism. We can locate crossovers and even hard-to-trace non-crossovers, typically with a precision of about 80 bases. This resolution is 20 times higher than in any existing yeast map and more than 360 times higher than a recent human map," says Steinmetz.

The map revealed many new insights into the organisation of recombination in yeast. On average over 150 recombination events were observed during a typical meiosis. These events did not occur uniformly across the genome. The recombination rate varied according to location, with events concentrated at so-called hotspots, some of which favoured either crossovers or non-crossovers. The researchers also found evidence for interference between crossovers and non-crossovers - a phenomenon previously only known to occur between crossovers - that makes it unlikely for two recombination events to happen in close proximity.

The fundamental principles of recombination are likely to be shared between yeast and humans. "Our map expands our understanding of crossover and provides a wealth of new information about non-crossovers and gene conversion. It will act as a reference for future research into recombination," says Richard Bourgon from Huber's group, who developed the statistical methodology for this new type of data.

The insights gained will not only help tackle questions about the basic mechanisms of recombination; they will also have practical implications for the tracking of disease genes in humans.

Source: European Molecular Biology Laboratory

Explore further: Perovskite solar cells: Perfection not required

Related Stories

Perovskite solar cells: Perfection not required

January 17, 2018

Metal-organic perovskite layers for solar cells are often fabricated using the spin-coating technique on compact substrates. These perovskite layers generally exhibit holes, yet attain astonishingly high levels of efficiency. ...

NASA detects solar flare pulses at Sun and Earth

November 16, 2017

When our Sun erupts with giant explosions—such as bursts of radiation called solar flares—we know they can affect space throughout the solar system as well as near Earth. But monitoring their effects requires having observatories ...

Recommended for you

New fuel cell technology runs on solid carbon

January 22, 2018

Advancements in a fuel cell technology powered by solid carbon could make electricity generation from resources such as coal and biomass cleaner and more efficient, according to a new paper published by Idaho National Laboratory ...

Cells lacking nuclei struggle to move in 3-D environments

January 20, 2018

University of North Carolina Lineberger Comprehensive Cancer Center researchers have revealed new details of how the physical properties of the nucleus influence how cells can move around different environments - such as ...

Information engine operates with nearly perfect efficiency

January 19, 2018

Physicists have experimentally demonstrated an information engine—a device that converts information into work—with an efficiency that exceeds the conventional second law of thermodynamics. Instead, the engine's efficiency ...

Team takes a deep look at memristors

January 19, 2018

In the race to build a computer that mimics the massive computational power of the human brain, researchers are increasingly turning to memristors, which can vary their electrical resistance based on the memory of past activity. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.