So far, the promise of genetic engineering to cure disease has been a bit of a dud. Up until now scientists could only read our genomes – now they can write. A gene-editing tool found in bacteria, called CRISPR, is poised to achieve that goal.
As well as read, the old technology allowed the ability to add says Dr. Elizabeth Simpson at the University of British Columbia on CBC Radio’s Quirks and Quarks. She’s begun to use CRISPR in her work on aniridia, a genetic eye disease.
“In the older technology we would add the missing gene, not insert it into the genome to make the eye function properly. We had a lot of trouble making the addition produce the right amount of protein at the right time. With CRISPR, all the natural regulation is still there and can be used by the eye to heal itself. We don’t have to be as clever and it’s a faster way to go.”
CRISPR (Clustered regularly-interspaced short palindromic repeats) is part of a natural bacterial defense. Scientists have known about these sections in bacterial DNA for years but they didn’t know what they were for or how they got there.
Then they discovered that these repeated clusters were sections of DNA gathered from attacking viruses: the bacteria had literally incorporated the enemy’s DNA into theirs. Still, their function remained a mystery.
Dr. Sylvain Moineau, Professor at the University of Laval, was one of the researchers to find out. He discovered that some yogurt bacteria weren’t susceptible to viral attack and some were. The ones that weren’t used the embedded viral DNA, described above, as a natural defense. These successful bacteria compared the embedded viral DNA with sections in the attacking viruses, and then cut that section out. As you can image, viruses don’t work well with gaping holes in their midsections: a pretty good defense.
While cut up viruses don’t work well, human DNA has the ability can stitch itself back up. That allows CRISPR technology to remove parts of our DNA that cause disease and replace it with functioning parts.
That’s the wonder of CRISPR. It cuts out the bad parts and inserts the good parts. Think of it as the search and replace function in word processors says Dr. Feng Zhang at the Massachusetts Institute of Technology who was key in transforming the natural CRISPR system into a gene editing tool. For example, if I’ve misspelled CRISPR throughout this whole article, I can use the search and replace function in Word to replace all incorrect instances of CRISTR with CRISPR.
Powerful tools in the hands of the wrong people can be disastrous. It would be wonderful to cure muscular dystrophy and Huntington’s disease. And since permanent genetic changes can be passed on through generations, malaria could be wiped out forever by making mosquitoes resistant to the parasite.
But In the hands of bio-hackers and unethical corporations, CRISPR could wreak havoc in areas of agriculture, biology, pharmaceuticals, ecology and wildlife preservation.
Ethical debates must take place before the technology becomes widespread. It’s another reason that we need strong government regulation.
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