Featured Research

from universities, journals, and other organizations

Low-quality genes may cause mutational meltdown: Deficiencies compound over time

Date:
April 16, 2012
Source:
University of Toronto
Summary:
Evolutionary biologists have found that individuals with low-quality genes may produce offspring with even more inferior chromosomes, possibly leading to the extinction of certain species over generations. A study predicts that organisms with such genetic deficiencies could experience an increased number of mutations in their DNA, relative to individuals with high-quality genes.

A genetic study by evolutionary biologists using fruit flies (Drosophila melanogaster) has shown that organisms with low-quality genes may produce offspring with even more inferior chromosomes, possibly leading to the extinction of certain species over generations.
Credit: Nathaniel Sharp

Evolutionary biologists at the University of Toronto have found that individuals with low-quality genes may produce offspring with even more inferior chromosomes, possibly leading to the extinction of certain species over generations.

Their study, published in Proceedings of the National Academy of Sciences, predicts that organisms with such genetic deficiencies could experience an increased number of mutations in their DNA, relative to individuals with high-quality genes. The research was done on fruit flies whose simple system replicates aspects of biology in more complex systems, so the findings could have implications for humans.

"Mutations play a key role in cancer and other health problems affecting humans and other species," said Nathaniel Sharp, PhD candidate in U of T's Department of Ecology & Evolutionary Biology (EEB) and lead author of the study. "Our research suggests that the problem is likely to compound over time, leading to a mutational meltdown that may devastate endangered populations, and increase the risk of health problems in families in poor condition."

Sharp and EEB professor Aneil Agrawal examined the accumulation of mutations in the fruit fly Drosophila melanogaster, the genes of which are arranged on three major chromosomes.

To manipulate genetic quality, they introduced harmful mutations onto the fly's third chromosome. They then observed how the presence of these mutations affected the fitness of the second chromosome over 46 generations.

"Copies of chromosome two maintained in strains with poor-quality copies of chromosome three declined in fitness two to three times faster than those with good copies of chromosome three, suggesting that poor genetic quality elevates the mutation rate," said Sharp.

While the underlying mechanism remains unknown, it could be tied to how an affected individual is less capable of repairing DNA or is more susceptible to DNA damage.

Fruit flies are especially useful for genetic studies such as this for the ability to screen for thousands of genes in thousands of flies much faster than in mammals. Flies are inexpensive to care for and reproduce rapidly, allowing for several generations to be studied in just a few months.

The researchers do, however, offer a more positive possible result of the process. "An elevated mutation rate under conditions of genetic or environmental stress could also accelerate adaptation to new environments," said Sharp.

The findings are reported in the paper Evidence for Elevated Mutation Rates in Low-quality Genotypes. The research is supported by funding from the Natural Sciences and Engineering Research Council of Canada in the form of a Discovery Grant to Agrawal and a Vanier Scholarship to Sharp.


Story Source:

The above story is based on materials provided by University of Toronto. The original article was written by Sean Bettam. Note: Materials may be edited for content and length.


Journal Reference:

  1. N. P. Sharp, A. F. Agrawal. Evidence for elevated mutation rates in low-quality genotypes. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1118918109

Cite This Page:

University of Toronto. "Low-quality genes may cause mutational meltdown: Deficiencies compound over time." ScienceDaily. ScienceDaily, 16 April 2012. <www.sciencedaily.com/releases/2012/04/120416130309.htm>.
University of Toronto. (2012, April 16). Low-quality genes may cause mutational meltdown: Deficiencies compound over time. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2012/04/120416130309.htm
University of Toronto. "Low-quality genes may cause mutational meltdown: Deficiencies compound over time." ScienceDaily. www.sciencedaily.com/releases/2012/04/120416130309.htm (accessed April 20, 2014).

Share This



More Plants & Animals News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins