Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study backs theory that accumulating mutations of ’quiet’ genes foster aging

15.10.2002


A theory that suggests the aging process might be safely slowed by targeting genes that are quiet early but threaten damage later in life has gotten a boost from new findings from the University of Illinois at Urbana-Champaign.



The researchers don’t promote such tinkering in their paper, which appears online this week in advance of publication by the Proceedings of the National Academy of Sciences. Rather they detail their tests, based on models of mathematical prediction, of the two leading evolutionary theories of aging on the reproductive success of 100 different genotypes of fruit flies (Drosophila melanogaster) across various age groups.

The results suggest that more needs to be learned about which genes do what and when in the aging process so that artificial manipulation does not cause evolutionary damage in future generations, said Kimberly A. Hughes, an animal biologist in the Program in Ecology and Evolutionary Biology at Illinois.


The study provides the strongest support yet for the theory of mutation accumulation (MA), Hughes said. The theory, which has been difficult for scientists to test, proposes that aging is the result of an accumulation of mutations of genes that are kept in check by reproductive-oriented selection processes early in life and only are active later on.

Examples are genes associated with Huntington’s disease and forms of cancer that strike late in life. Such mutations exist in prime reproductive years but only have noticeable effects late in life. In old age, when reproduction is not an organism’s primary function, accumulating mutations are no longer checked by selection, increasing the risk of disease.

The other, more widely accepted theory of antagonistic pleiotrophy (AP) says that aging occurs when genes that offer help during the reproductive years -- those that produce estrogen, for example -- take on harmful roles later in life. Selection under AP theory favors the early life effects because these lead to the production of offspring but does not oppose the deleterious effects in late life, Hughes said.

Building on her theoretical study of age-related inbreeding depression and genetic variability (PNAS, June 1996) while a doctoral student at the University of Chicago, Hughes and colleagues raised fruit flies to test the effect of delayed mutations.

The new study found that the deleterious effects of mutations on reproduction rose dramatically with age during the reproductive years in both genotypes -- homozygous (those with many identical genes, or inbreeding) and heterozygous (those having a variety of genes present). Reproductive success declined more rapidly, however, in the homozygous lines, as predicted by the MA theory.

"This study allowed us to detect certain kinds of genetic effects called dominance variance that are predicted to increase with age only under the MA theory," Hughes said. "The power to detect these effects is critical to tests of evolutionary aging theories, because an age-related increase appears to be a unique prediction of the MA theory, while other kinds of genetic effects can increase under either model."

While the study shows support for the MA theory, the scenario under the antagonistic pleiotrophy theory is not discounted. "They are not mutually exclusive,Ó Hughes said. "They can both be happening. Both kinds of genes can be accumulating.Ó

If geneticists try to remove bad late-in-life effects of a gene that has a positive role early in life, then its overall function could be negatively altered in future generations, Hughes said. Manipulating genes with no early life benefits to negate their deleterious late life effects, she said, might not cause negative evolutionary changes in the future.


The authors of the paper are Hughes, postdoctoral researcher Jenny M. Drnevich and doctoral student Rose M. Reynolds, all of Illinois, and former postdoctoral associate Julie A. Alipaz, who now is at Harvard University.

The National Science Foundation, National Institutes of Health and the School of Integrative Biology at Illinois funded the research.

Jim Barlow | EurekAlert!

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>