Most cells in your body come with two genetic libraries; one in the nucleus, and the other inside structures called mitochondria - also known as the 'powerhouses of the cell'.
Until now, we've only had a way to make changes to one.
A combined effort by several research teams in the US has led to a process that could one day allow us to modify the instructions making up the cell's 'other' genome, and potentially treat a range of conditions that affect how we power our bodies.
The molecular foundation of this revolutionary gene editing tool is a toxin called DddA, secreted by the bacterium Burkholderia cenocepacia to sabotage other microbes when competition over resources turns serious.
Researchers from the University of Washington have had an interest in the toxin's talents for a while, finding it converts a nucleic acid base called cytosine into a different one commonly found in RNA, called uracil.
It's far from the first time researchers have looked to bacterial weapons for clues on how to tweak DNA in this way. In fact, a whole family of so-called deaminase enzymes had already been put to use in genetic engineering.
Unfortunately deaminase enzymes tend to only perform their code-swapping trick on single strands of DNA.
To get around this, another research team from the Broad Institute of MIT and Harvard combined their code-swapping deaminase with CRISPR technology, which entails using an RNA template to identify the sequence and then using enzymes to unzip the strands and make changes.
That isn't too much of a problem when you want to make edits to double strands of DNA inside something as welcoming as a cell's nucleus. But smuggling the RNA templates through the more selective membrane of a mitochondrion isn't quite so simple.
That's becausemore than a billion years ago, mitochondria were organisms in their own right, and over time they evolved to share responsibilities with the cells they now occupy, being delegated the business of breaking down glucose for power.
While many mitochondrial genes have long since been filed away in the host's nucleus, these tiny power units have held onto a few important sequences, which are tightly locked away behind a veil of membranes that don't take kindly to stray bits of RNA wafting through.
Fortunately, DddA had a unique talent for making changes to both DNA strands, opening the way to ditching CRISPR and its bulky RNA template in favour of alternative methods for targeting the sequence you want to change.
That third piece of the puzzle came in the form of an old school genetic engineering tool called a transcription activator-like effector, or TALE.
This class of enzyme can be tailored to find specific nucleic acid codes and break them apart. Just the thing for guiding a cytosine-swapping toxin into place.
Teamed up with DddA, a specially crafted TALE enzyme can find a target sequence inside mitochondria and turn any cytosine it finds into a uracil, which will later transform into a similar DNA-specific base called thymine.
In testing, this change occurred roughly half of the time.
A fifty-fifty change might not seem like a big win, but given there were no signs of potentially disastrous changes outside of target sequences, it makes for a promising precision engineering tool.
What's more, given there's no other contenders for editing mitochondrial genes, it's a landmark achievement with even this success rate.
Just as mutations in nuclear DNA can give rise to a wide variety of health conditions, mutations in the mitochondria's genes can also be problematic, affecting anything from brain development to muscle growth, energy levels, metabolism, and immunity.
Usually (though not always) passed through the eggs down from mothers, mitochondria and any damaging mutations can be inherited through the generations. Right now the best we might be able to do is combine cells from two different mothers to remove affected mitochondria.
But with this new DddA technology, we might finally be able to create animal models that mimic a range of debilitating mitochondrial conditions in humans. And, maybe one day, even fix them inside our own bodies.
This research was published in Nature.
Read the original post:
For The First Time, Scientists Find a Way to Make Targeted Edits to Mitochondrial DNA - ScienceAlert
- Who are We? - November 7th, 2009 [November 7th, 2009]
- Vilsack targeted for his Pro-GMOs stand - November 7th, 2009 [November 7th, 2009]
- Call for technology to produce cellulosic ethanol - November 7th, 2009 [November 7th, 2009]
- Kenyan scientists weigh on GMOs - November 7th, 2009 [November 7th, 2009]
- Indian researcher makes a case for biotechnology - November 7th, 2009 [November 7th, 2009]
- Michigan smoothens the way for alternative energy investors - November 7th, 2009 [November 7th, 2009]
- Link of ethanol use to high food prices questioned - November 7th, 2009 [November 7th, 2009]
- EU challenges France on GM Maize - November 7th, 2009 [November 7th, 2009]
- POET rolls out cellulosic ethanol plant - November 7th, 2009 [November 7th, 2009]
- There’s a bright future for cellulosic ethanol investment - November 7th, 2009 [November 7th, 2009]
- Cellulosic ethanol can considerably reduce gasoline use by 2030 - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - Background - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - History - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - Methods - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - Uses - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - Controversy - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - In popular culture - November 7th, 2009 [November 7th, 2009]
- Human genetic engineering - An Introduction - November 7th, 2009 [November 7th, 2009]
- Human Genetic Engineering - A Very Hot Issue! - November 7th, 2009 [November 7th, 2009]
- What are the risks of genetic engineering in humans? (human genetic engineering) - November 7th, 2009 [November 7th, 2009]
- What are the benefits of human genetic engineering? (human genetic engineering) - November 7th, 2009 [November 7th, 2009]
- Genetic Engineering - Ethics and Controversy - November 7th, 2009 [November 7th, 2009]
- Genetic Engineering Ethics In Science Fiction - November 7th, 2009 [November 7th, 2009]
- Genetic Engineering Ethics - November 7th, 2009 [November 7th, 2009]
- Welcome to Pest Control Exterminator Network - December 13th, 2009 [December 13th, 2009]
- OMD - Genetic Engineering - August 27th, 2011 [August 27th, 2011]
- X-Ray Spex - Genetic Engineering - August 27th, 2011 [August 27th, 2011]
- Ancient Alien Nephilim, Giants, Mutants, Genetic Engineering, and Hybrids (2-6) - August 28th, 2011 [August 28th, 2011]
- Human-Plant Hybrid (Genetic Engineering at Home) - August 28th, 2011 [August 28th, 2011]
- Ancient Alien Nephilim, Giants, Mutants, Genetic Engineering, and Hybrids (1-6) - August 29th, 2011 [August 29th, 2011]
- 3. Genetic Engineering - August 29th, 2011 [August 29th, 2011]
- Genetic engineering nightmare - August 31st, 2011 [August 31st, 2011]
- Ancient Alien Nephilim, Giants, Mutants, Genetic Engineering, and Hybrids (3-6) - August 31st, 2011 [August 31st, 2011]
- Future of genetic engineering - by Futurist Dr Patrick Dixon. Genetic mutations and genetic disorders. Gene science by conference keynote speaker - September 2nd, 2011 [September 2nd, 2011]
- Genetic engineering: The world's greatest scam? - September 3rd, 2011 [September 3rd, 2011]
- Watch Fed Up! Genetic Engineering, Industrial Agriculture and Sustainable Alternatives Full Movie Online Part 1/15 - September 3rd, 2011 [September 3rd, 2011]
- Ancient Alien Nephilim, Giants, Mutants, Genetic Engineering, and Hybrids (5-6) - September 5th, 2011 [September 5th, 2011]
- Genetic Engineering, Humans with Animals. - September 6th, 2011 [September 6th, 2011]
- Is Genetic Engineering Good for the Environment? - September 7th, 2011 [September 7th, 2011]
- Open Source Food and Genetic Engineering - Michael Pollan - September 10th, 2011 [September 10th, 2011]
- Ancient Alien ( demons ) Nephilim Giants, Mutants Genetic Engineering and Hybrids.avi - September 11th, 2011 [September 11th, 2011]
- MUST SEE : Genetic Engineering Corn Grows in Sand ! For Those That Appreciate Nature ! - September 12th, 2011 [September 12th, 2011]
- Designing Humanity - Genetic Engineering - September 14th, 2011 [September 14th, 2011]
- Genetic Modification | QUEEN ANNE SCIENCE CAFE - September 14th, 2011 [September 14th, 2011]
- Genetic Engineering in California Agriculture - September 15th, 2011 [September 15th, 2011]
- Genetic Engineering Animation - September 15th, 2011 [September 15th, 2011]
- Proof Of Ancient Genetic Engineering - September 15th, 2011 [September 15th, 2011]
- Joad Cressbeckler Fears Genetic Modification Causes 'Wrath-Minded Taters' - September 16th, 2011 [September 16th, 2011]
- Ethical Concerns With Genetic Engineering - September 16th, 2011 [September 16th, 2011]
- Scientists under Attack - Genetic Engineering in the magnetic Field of Money TRAILER - September 17th, 2011 [September 17th, 2011]
- Genetic Modification - September 18th, 2011 [September 18th, 2011]
- Genetic Engineering Not a New Science - Pamela Ronald - September 23rd, 2011 [September 23rd, 2011]
- The Island of Dr. Moreau prt. IV - September 28th, 2011 [September 28th, 2011]
- Ancient Alien Nephilim, Giants, Mutants, Genetic Engineering, and Hybrids (4-6) - September 30th, 2011 [September 30th, 2011]
- 4. Genetic Engineering (cont.) - October 2nd, 2011 [October 2nd, 2011]
- Ancient Alien Nephilim, Giants, Mutants, Genetic Engineering, and Hybrids (6-6) - October 4th, 2011 [October 4th, 2011]
- Islands at Risk (Part 3) - Genetic Engineering in Hawai'i - October 4th, 2011 [October 4th, 2011]
- Morgellons Is Genetic Engineering , A Silent Superbug - October 4th, 2011 [October 4th, 2011]
- Islands at Risk (Part 2) - Genetic Engineering in Hawai'i - October 4th, 2011 [October 4th, 2011]
- The Ethics of Genetically Engineering Children - Arthur Caplan - October 4th, 2011 [October 4th, 2011]
- Disney Geneticists Debut New Child Stars - October 4th, 2011 [October 4th, 2011]
- Genetic Engineering and Society, Lecture 1a, Honors Collegium 70A, UCLA - October 4th, 2011 [October 4th, 2011]
- OMD - Genetic Engineering (312mm Version) (Audio Only) - October 4th, 2011 [October 4th, 2011]
- The difference between normal and genetically modified food - October 4th, 2011 [October 4th, 2011]
- Bioethics Of Human Genetic Engineering - Documentary Video - October 6th, 2011 [October 6th, 2011]
- Islands at Risk (Part 1) - Genetic Engineering in Hawai'i - October 6th, 2011 [October 6th, 2011]
- Coast To Coast AM: Genetic Engineering 3-24-2011 Download Link - October 6th, 2011 [October 6th, 2011]
- Lloyd Pye - Ancient Genetic Engineering - October 13th, 2011 [October 13th, 2011]
- X RAY SPEX - ROUNDHOUSE LONDON GENETIC ENGINEERING - Video - October 13th, 2011 [October 13th, 2011]
- OMD - Genetic Engineering 1983 - Video - October 14th, 2011 [October 14th, 2011]
- OMD - GENETIC ENGINEERING - Video - October 14th, 2011 [October 14th, 2011]
- Mechanism of Recombination - Video - October 15th, 2011 [October 15th, 2011]
- Harvard Prof. Michael Sandel on Human Genetic Modification, Berkeley, CA, 7 May 2007 - Video - October 15th, 2011 [October 15th, 2011]
- Genetic Engineering [Medical Ethics Series] - (excerpt) - Video - October 15th, 2011 [October 15th, 2011]
- Genetic Engineering and Society, Lecture 1b, Honors Collegium 70A, UCLA - Video - October 24th, 2011 [October 24th, 2011]
- Genomics: genetic modification (genetic engineering) and the human gene project - Video - October 26th, 2011 [October 26th, 2011]
- Genetically Engineering Intelligent Babies - Horizon: Are We Still Evolving? Preview - BBC Two - Video - October 27th, 2011 [October 27th, 2011]
- "GENETIC ENGINEERING" GERMAN REGIME feat THIRSTIN HOWL THE3RD - Video - October 28th, 2011 [October 28th, 2011]
- Science 360: Genetic Engineering - Video - October 31st, 2011 [October 31st, 2011]
- UFOTV Presents... - Bad Seed: Danger of Genetically Modified Food - Video - November 8th, 2011 [November 8th, 2011]