If you are
familiar with the new age technology being developed in genetics labs, you
would probably have heard the name CRISPR before. It all begins when a
virus infects a bacterium, it injects its own viral DNA into the bacterial
genome. The virus uses the host DNA replicating machinery to replicate. In
effect, the newly synthesized DNA is a combination of host DNA and viral DNA. The
CRISPR mechanism is an adaptive immune response that originated in these
bacteria. They use endonucleases that target and cleave the viral DNA out of
their own genome. As a result, they are able to protect themselves from viral
infection.
CRISPR stands for
Clustered Regularly Interspaced Short Palindromic Repeats. It refers to a
family of DNA sequences that are commonly found in prokaryotic genomes such as
those of bacteria and archaea. They are in fact, DNA fragments of viruses that
have attacked the prokaryote. These DNA sequences can be used to destroy the parent
virus and other such similar pathogens. As such, CRISPR represents a huge leap in
genetic engineering.
The specific
technology is called the CRISPR/Cas9 System. It consists of: CRISPR, the stretches of short,
palindromic DNA that are interspersed with spacer DNA. Usually, right next to
CRISPR sequences are Cas9 (for CRISPR-associated 9) genes. Cas9 is an enzyme
that cuts specific DNA pieces that are complementary to the CRISPR genes. Together
they form CRISPR Cas9.
The implications
of this cutting-edge technology is exciting. In its essence, CRISPR Cas9 can be
used in genetic engineering to edit the genome just in the same way that an Archaean
might edit viral DNA out of its own genome. We can use it to tweak the genome
of humans, animals, plants and bacteria. And when you control the genome, you
control everything. CRISPR Cas9 technology can be used to fend ourselves from
disease, treat cancer, improve food production and improve chances of pregnancy
via IVF. Ongoing research suggests that CRISPR Cas9 can be used to cut out the
genes that mosquitos need to spread malaria. They would be creating mosquitos that
are resistant to malaria!
Despite the
potential that this tool could have, we must not ignore the ethical dilemmas
that surface. One particular concern is regarding editing the human germline.
When we edit out certain genes for traits our population might not deem
suitable or desirable, the resultant genome is passed down to our generations.
This could have staggering long term effects on our species. Some scientists
and geneticists argue that we should hold off on tweaking the genome for reproductive
purposes but continue to work on using CRISPR Cas 9 for gene therapy and
treatment of disease. CRISPR Cas 9 is a scientific marvel; but it can be chaos
as much as calm.
Posted by Priya
Bikkani (1)
I have heard of CRISPR but not the specific CRISPR Cas9 system. I agree that the development of this system could in the future lead to an array of ethical issues in the future but its fascinating the good that it is able to do. I read about cutting the gene needed to spread malaria; do you know how far they've gone in that research? Also, did it mention research in cutting genes associated with diseases or is it still just a proposal and if so, what diseases are they referring to? Because I think that would be a great benefit in aiding those afflicted by the disease and in helping scientists and researchers to discover more about the genetics of the diseases.
ReplyDelete-Maddie Powers
Hi Maddie,
DeleteThey have tested this on mosquitos and according to the article link that I have included, it successfully reduced the mosquitoes proclivity to infection by Plasmodium, however there were additional side-effects for the mosquitoes like low reproductive rate.
https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006898
^^
Delete- Posted by Priya Bikkani
This new genome editing technology may cause new ethical issues. And the side-effects of CRISPR Cas9 should also be considered, because editing and changing the genes may have unpredictable effects on the individual. And it is my first time knowing about the mechanism of CRISPR Cas9. I think many of the scientists may concern more about its possible negative effects.
ReplyDeletePosted by Muchen Liu
Yes, I don't think CRISPR human trials have begun as of yet, however, we must be on the lookout for potential side-effects.
DeleteMosquitos went under CRISPR trials to prevent against malaria infection, and they discovered some side-effects with those trials.
- Posted by Priya Bikkani
As someone who's interested in healthcare and medicine, CRISPR is absolutely incredible. Discoveries like these remind us of the importance of all this research happening. It's crazy to think that there are probably many more biological processes that will lead to massive breakthroughs in science and life, but we just haven't looked in the right spots yet. I think CRISPR is going to play an extremely important role in future healthcare and am excited because I get to witness it all unfold.
ReplyDelete-Matt Murdoch
Yes, absolutely Matt. It really is a ground-breaking project. Sometimes I think we should consider ourselves very lucky to be born in a generation where we can witness great breakthroughs in medicine and science. But I am also concerned that the use of CRISPR could go the other way and turn unethical; potentially disastrous for future generations if we tamper with the germ-line cells.
Delete- Posted by Priya Bikkani
CRISPR-Cas9 is so fascinating! This seems like it has so much potential for so many different fields of research. I do see the ethical concerns behind it though and definitely think that something like that may need time to be more widely accepted and perhaps certain regulations in place to prevent the idea of editing our genome from getting out of hand. Overall, though, I'm excited to see what comes of this in the future!
ReplyDeletePosted by Alexandra Rios
Yes Alexandra, CRISPR shows great potential in the application of genetic engineering. You should check out a movie called 'Gattaca' which is a science fiction film based on the premise of gene editing, something like CRISPR.
Delete- Posted by Priya Bikkani
From an environmental standpoint, if this system is able to create an environment where mosquitos are resistant to malaria, this is a win-win situation. Humans will not be infected with malaria by mosquitos and the mosquitos can then still play their integral role in the ecosystem. Is there any idea as to how long this could take, or even if the idea is remotely possible?
ReplyDeletePosted by "Lauren Hiller"
That is a very good question Lauren. In fact they have tested this on mosquitos and according to the article link that I have included, it successfully reduced the mosquitoes proclivity to infection by Plasmodium, however there were additional side-effects for the mosquitoes like low reproductive rate.
Deletehttps://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006898
- Posted by Priya Bikkani
Crispr Cas9 has always interested me since I have heard about it in a previous genetics class. The possibilities that it can bring are huge and the research on it is still very new and expansive. What are some cases where crisps cas9 has been used to treat therapy has there been specific experiments done as of yet and if so what are the outcome and results of those experiments?
ReplyDeletePosted by "Edwin Montecinos"
Edwin, as far as I am aware, human trials with CRISPR have not yet commenced. But they have tested it on mosquitos to combat malaria, and on yeast to make biofuels.
Delete- Posted by Priya Bikkani