Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

06.02.2013
Incompatible genotype could be better predictor of genetically complex human diseases

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.

The new research, "An Incompatibility Between a Mitochondrial tRNA and Its Nuclear-Encoded tRNA Synthetase Compromises Development and Fitness in Drosophila," was published online Jan. 31 in PLOS Genetics. Additional co-authors with Montooth, Meiklejohn, Siddiq and Rand were Marissa A. Holmbeck and Dawn N. Abt, both of Brown.

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

Steve Chaplin | EurekAlert!
Further information:
http://www.iu.edu

More articles from Life Sciences:

nachricht New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>