Navigation Links
Biologists map rare case of fitness-reducing interaction in nuclear, mitochondrial DNA
Date:2/5/2013

BLOOMINGTON, Ind. -- 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.

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.


'/>"/>

Contact: Steve Chaplin
stjchap@iu.edu
812-856-1896
Indiana University
Source:Eurekalert  

Related biology news :

1. Campus as laboratory: U-M student biologists use Diag trees to help solve gypsy moth mystery
2. Microbiologists eavesdrop on the hidden lives of microbes
3. Iowa State computer, electrical engineers working to help biologists cope with big data
4. Biologists unlock black box to underground world
5. Integrative and comparative biologists to discuss latest research
6. NYU biologists identify proteins vital to chromosome segregation
7. Biologists engineer algae to make complex anti-cancer designer drug
8. Biologists unlocking the secrets of plant defenses, 1 piece at a time
9. SF State biologists tag zombees to track their flight
10. New book on stereology by Mark West is essential reading for neurobiologists
11. UCLA biologists reveal potential fatal flaw in iconic sexual selection study
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Biologists map rare case of fitness-reducing interaction in nuclear, mitochondrial DNA
(Date:4/18/2017)... , April 18, 2017  Socionext Inc., a global expert in ... media edge server, the M820, which features the company,s hybrid codec ... provided by Tera Probe, Inc., will be showcased during the upcoming ... NAB show at the Las Vegas Convention ... Click ...
(Date:4/11/2017)... BEACH GARDENS, Fla. , April 11, 2017 ... identity management and secure authentication solutions, today announced ... contract by Intelligence Advanced Research Projects Activity (IARPA) ... for IARPA,s Thor program. "Innovation has ... onset and IARPA,s Thor program will allow us ...
(Date:4/6/2017)... -- Forecasts by Product Type (EAC), Biometrics, ... (Transportation & Logistics, Government & Public Sector, Utilities / ... Facility, Nuclear Power), Industrial, Retail, Business Organisation (BFSI), Hospitality ... looking for a definitive report on the $27.9bn Access ... ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... ... May 23, 2017 , ... ... month its 20th anniversary, marking the occasion with a strong presence at Bio-IT ... Welcome Reception and further extends an invitation to all attendees to view ...
(Date:5/23/2017)... ... May 23, 2017 , ... Kathy Goin is joining ... Operations. She brings years of expertise in establishing and leading clinical operations at ... a licensed occupational therapist, through a variety of leadership roles in Clinical Operations, ...
(Date:5/22/2017)... ... May 22, 2017 , ... ... leaders of the Maryland Biohealth community in developing and issuing recommendations to grow ... U.S. BioHealth Innovation Hub by 2023. , The recommendations are ...
(Date:5/19/2017)... ... May 19, 2017 , ... ... Program. Academic researchers with technologies ripe for commercialization, and who are affiliated ... Delaware, are encouraged to submit proposals. QED, now in its tenth round, is ...
Breaking Biology Technology: