What Is Cas9 Protein?
What is Cas9?
This point of this article to reach out to a wide general audience and educate them a little on the recent scientific breakthroughs that is Genome editing. The topic we will discuss is that of Cas9 known as (CRISPR associated protein 9). This is an RNA guided DNA endonuclease enzyme associated with the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) adaptive immunity system in Streptococcus pyogenes, among other bacteria.
Apart from its original function in bacterial immunity, the Cas9 protein has been heavily utilized as a genome engineering tool to induce site directed double strand breaks in DNA. These breaks can lead to gene inactivation or the introduction of heterologous genes through nonhomologous end joining and homologous recombination respectively in many laboratory model organisms. Alongside zinc finger nucleases and TALEN proteins, Cas9 is becoming a prominent tool in the field of genome editing.
For many years scientists throughout the world have had a common goal. They wanted to develop efficient and reliable ways to make precise, targeted changes to the genome of living cells. There have been several attempts to manipulate gene function over the last few years and recently a new tool was discovered based on a bacterial CRISPRassociated Protein9 nuclease ( cas9 for short). This breakthrough has been cause for much excitement as scientists have found that Cas9 has an almost limitless potential. We will cover some of the most common questions that many people have about what Cas9 means for the human race and our way of living. The primary functions of CRISPR ( Clustered Regularly Interspaced Short Palindromic Repeats ) and CRISPRassociated (Cas) genes are essential in adaptive immunity in select bacteria and archaea , enabling t he organisms to respond to and ultimately eliminate invading genetic material.
These repeats were initially discovered in the 1980s in E. coli (9), but their function wasn’t confirmed until 2007 by Barrangou and colleagues, who demonstrated that S. thermophilus can acquire resistance against a bacteriophage by integrating a genome fragment of an infectious virus into its CRISPR locus (10). There are Three types of CRISPRS mechanisms that have been identified, and so far type II is the one that has received the most study. The study involves invading DNA from viruses or plasmids that is cut into small fragments and incorporated into a CRISPR locus surrounded by a series of short repeats ( approx 20 bps ). The next step is to transcribe the loci, and process the transcripts that generate small RNA’s (crRNACRISPR RNA ), which in turn are then used to steer effector endonucleases that target invading DNA based on sequence complimentary. Basically to summarize, the discovery of CRISPRS will enable scientists to more easily and effectively target DNA in cells. As mentioned earlier, the potential is limitless, a massive new tool that will be useful in everything from agricultural industries to gene therapy for human disease.
A Little Of What Cas9 Can Do:
There are many things the use of Cas9 can do and create, too many to list in this article, so we will touch base on a few of the most talked about and questioned. The power of evolutionary changes both in humans and even nature is at the fingertips of some of the most predominant scientists throughout the world. The biggest most exciting aspect of this is the elimination of disease, by the altering of DNA. Cas9 is compatible with many different organisms, including forms of bacteria, yeasts, plants, algae and human cells. Another great benefit to CRISPRCas9 is the low cost, making it an affordable and easy way to move any living genes around, in bacteria or people. Using Cas9 researchers have already reversed mutations that cause blindness, stopped cancer cells from multiplying, and made cells impervious to the virus that causes AIDS, Cystic Fibrosis, Muscular Distrophy and Sickle Cell Anemia with more cures for others possible.
Agronomists have rendered wheat invulnerable to killer fungi like powdery mildew, hinting at engineered staple crops that can feed a population of 9 billion on an ever-warmer planet. Bioengineers have even used Crispr to alter the DNA of yeast so that it consumes plant matter and excretes ethanol, promising an end to reliance on petrochemicals!
There have even been talks of altering DNA in certain animals and scientists have found that there is a probability of being able to create a dragon using gene editing! If the genes of a Komodo dragon were edited it’s quite possible it could be turned into a winged and possibly larger version of itself! There are possible uses for CRISPR that have been discussed involving the creation and resurrection of beast and mammals that roamed the earth 70,000 years ago. CRISPR could be added to an Asian Elephant which would add the genes of wooly mammoth-like animal. The infamous glowing plants you undoubtedly saw in the record breaking box office movie Avatar are something of a reality a this has already been achieved.
There is another side I will briefly touch base on, that is called Eugenics. For those of you that are Star Trek fans the 1982 movie Star Trek Wrath of Khan and 2012 remake Star Trek Into Darkness both covered the story about genetically engineered beings, having the strength of Ten men, incredible senses and perfect immunity to disease. This is also an area that isn’t out of reach for scientists with CRISPR.
Benefits & Drawbacks:
There are many benefits to CRISPR research and the use of Cas9. Obviously the removal of disease from the human race, and the possibility of wiping out disease from family lines forever is a tantalizing thought. I’m sure many who have lost a relative or have someone suffering currently living with a life threatening, incurable illness will be very excited about CRISPR. The possibility of living in a world free from hunger, with enough food for everyone by using these breakthroughs, there would be potential of unlimited energy, and even eradicating pollution which would help save our planet for future generations.
But with any positive scientific advances there will always be risks as well as negative feedback from as many people who are for it as there are against. Some will call it Unethical, or that people were not intended to “ play god “. There could be unpredictable and possibly harmful effects for future generations. It is feared by some that the temptation to stray away from the original plan, and that the research could be exploited for non therapeutic modifications. The chance that in the future we could have a breed of super humans with gene editing, who could be used as “weapons” will no doubt worry many.
The future is now
To summarize, the discovery of Cas9 makes it possible to genetically engineer pretty much any organism inexpensively ( we have very competitive pricing here ), which has already opened many doors for research and biotechnology. In short, Cas9 seems to be the genetic engineering silver bullet that biologists in many fields have been waiting generations for. Whether you are for or against these scientific advances, the truth of the matter is they are happening. It’s no longer a case of the if’s but’s and maybe’s, or “hypothetically speaking” , and certainly not years into the future in another lifetime. Right NOW as you read this more and more scientific breakthroughs are occurring in a lab somewhere. Be prepared to be a part of, to see, hear and live in these historical times and watch the future of the human race unfold before us.
