Featured Research

from universities, journals, and other organizations

Biologists map rare case of fitness-reducing interaction in nuclear, mitochondrial DNA

Date:
February 5, 2013
Source:
Indiana University
Summary:
Biologists believe they have discovered the mechanism by which interacting mutations in mitochondrial and nuclear DNA produce an incompatible genotype that reduces reproductive fitness and delays development in fruit flies.

A team of biologists from Indiana University and Brown University believes it has discovered the mechanism by which interacting mutations in mitochondrial and nuclear DNA produce an incompatible genotype that reduces reproductive fitness and delays development in fruit flies.

Related Articles


The new research, led by IU biologists Kristi Montooth and Colin Meiklejohn and including former IU undergraduate researcher Mo Siddiq, describes the cause and consequences of an interaction between the two genomes that co-exist within eukaryotic cells. Animal mitochondrial DNA, or mtDNA, is a small but important genome that encodes a handful of proteins that are essential to oxidative phosphorylation, the pathway that produces the adenosine triphosphate molecule that fuels cellular metabolism.

With this new characterization of a disruptive interaction between mtDNA and nuclear DNA mutations, the scientists provide one of the few mapped cases of a fitness-reducing mitochondrial-nuclear incompatibility.

The genetic interaction that IU biologists mapped, in collaboration with Brown University biologist David Rand, is between mutations that are present in natural populations, rather than being induced in the lab. This has important consequences for understanding genetically complex human diseases.

Many human diseases, such as neuromuscular and neurodegenerative disorders, are associated with mutations in mitochondrial transfer RNAs, or tRNAs, but a single mutation can be highly variable in the degree to which it leads to disease. Montooth and her colleagues' findings suggest that the combined mitochondrial-nuclear genotype for tRNAs and their tRNA synthetases may, in fact, be a better predictor of disease.

"Interactions between mitochondrial and nuclear DNA for fitness have been documented in many organisms, but rarely has the genetic or mechanistic basis of these interactions been elucidated," said Montooth, an assistant professor in the IU College of Arts and Sciences' Department of Biology. "This has limited our understanding of which genes harbor variants causing mitochondrial-nuclear disruption and the processes that are impacted by the co-evolution of these genomes."

Using genetic techniques and many resources available from IU's own Bloomington Drosophila Stock Center, the scientists mapped an interaction between a single mutation in a mitochondrial tRNA gene, mt-tRNA-Tyr, and an amino acid change in its nuclear-encoded charging enzyme, the mitochondrially targeted amino acyl tRNA synthetase, mt-TyrRS -- the enzyme that places the proper amino acid on the tRNA to allow for mitochondrial protein synthesis.

"As a result, the incompatibility decreases the activity of the oxidative phosphorylation pathway," Montooth said, "demonstrating that decreased mitochondrial protein synthesis compromises the energetic function required for proper development of adult structures, such as the ovary and sensory bristles."

These types of fitness-reducing genetic incompatibilities are one hypothesized mechanism that can maintain the formation of new species.

This research was funded by the National Institutes of Health, the National Science Foundation, IU and the IU Hutton Honors College.


Story Source:

The above story is based on materials provided by Indiana University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Colin D. Meiklejohn, Marissa A. Holmbeck, Mohammad A. Siddiq, Dawn N. Abt, David M. Rand, Kristi L. Montooth. An Incompatibility between a Mitochondrial tRNA and Its Nuclear-Encoded tRNA Synthetase Compromises Development and Fitness in Drosophila. PLoS Genetics, 2013; 9 (1): e1003238 DOI: 10.1371/journal.pgen.1003238

Cite This Page:

Indiana University. "Biologists map rare case of fitness-reducing interaction in nuclear, mitochondrial DNA." ScienceDaily. ScienceDaily, 5 February 2013. <www.sciencedaily.com/releases/2013/02/130205123015.htm>.
Indiana University. (2013, February 5). Biologists map rare case of fitness-reducing interaction in nuclear, mitochondrial DNA. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2013/02/130205123015.htm
Indiana University. "Biologists map rare case of fitness-reducing interaction in nuclear, mitochondrial DNA." ScienceDaily. www.sciencedaily.com/releases/2013/02/130205123015.htm (accessed October 31, 2014).

Share This



More Health & Medicine News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

U.S. Ebola Response Measures Demonstrated

U.S. Ebola Response Measures Demonstrated

AP (Oct. 31, 2014) Officials in the Washington area showed off Ebola response measures being taken at Dulles International Airport and the National Institutes of Health. (Oct. 31) Video provided by AP
Powered by NewsLook.com
Fauci Says Ebola Risk in US "essentially Zero"

Fauci Says Ebola Risk in US "essentially Zero"

AP (Oct. 30, 2014) NIAID Director Anthony Fauci said the risk of Ebola becoming an epidemic in the U.S. is essentially zero Thursday at the Washington Ideas Forum. He also said an Ebola vaccine will be tested in West Africa in the next few months. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Nurse Defies Ebola Quarantine With Bike Ride

Nurse Defies Ebola Quarantine With Bike Ride

AP (Oct. 30, 2014) A nurse who vowed to defy Maine's voluntary quarantine for health care workers who treated Ebola patients followed through on her promise Thursday, leaving her home for an hour-long bike ride. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Pot-Infused Edibles Raise Concerns in Colorado

Pot-Infused Edibles Raise Concerns in Colorado

AFP (Oct. 30, 2014) Colorado may have legalized marijuana for recreational use, but the debate around the decision still continues, with a recent - failed - attempt to ban cannabis-infused edibles. Duration: 01:53 Video provided by AFP
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:

More Coverage


Mitochondrial Mutations: When the Cell's Two Genomes Collide

Feb. 5, 2013 Plant and animal cells contain two genomes: One in the nucleus and one in the mitochondria. When mutations occur in each, they can become incompatible, leading to disease. To increase understanding ... read more

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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