CRISPR- Cas9 is one of the newest genome technology editing tools. CRIPS has until now mostly been used for research, but it may seem unlimited, due to the technic being applicable to all living organisms. The predicted possibilities for Crisp may seem endless in the future from eliminating diseases by identifying single defected genes, editing genetic features at embryonic stage creating “designer babies” or preventing aging. In this essay I will explain the background of CRISPR showing how the technique is used, medical use and ethical issues.
The first interaction with what we today call CRISPR was in 1987 when scientist Yoshizumo Ishino was studying genomes in archaea and bacteria, and accidentally cloned CRISPR together with his target of interest. The function of CRISPR was not known at the time, but today scientists explain it as a natural defense mechanism in bacteria. CRISPR is an acronym for clustered regularly interspaced short palindromic repeats. CRISPR are segments of DNA containing repetitive base sequences where each sequence is followed by short segments of spacer DNA. This spacer DNA has proven to be a unique segment of genome that matches the segment of DNA from a virus attack. This meaning that if the bacterium survives a virus attack, it can copy a part of the viruses’ genome so that in futuristic infections it will be able to recognize and eliminate the same virus. It can be simplified by saying that spacers are RNA copies of a virus, and history of previous infections to prevent new invading viruses. The last part the CRISPR system is made of are CAS genes, these generate what is called a CAS protein. Cas proteins are both helicases meaning they can unwind DNA and nucleases meaning they can cut DNA.
So what happens if a virus invades a bacterium? The virus would embed its DNA in the genome and make bacteriophages who will eventually kill the cell. The CRISPR system allows the bacteria to make cas proteins and transcribe spacer DNA to locate and remove the virus, including coping the virus DNA making it possible to prevent later attacks.
In 2012 scientist Jennifer Doudna and Emmanuelle Chapertier discovered a way to build a system that can detect and edit parts of the genome by altering sections of DNA, the CRISPR- CAS9 system, based on the evolutionary defense mechanism known as CRISPR.
The CRISPR- CAS9 system relies on two RNA pieces and one Cas protein called Cas9. One of the RNA strands, known as crispr RNA, contains complementary base sequences changed to match the target DNA. The second RNA strand creates a structure that binds to the protein called Cas9, better known as tracr RNA. These RNA pieces are often combined to a dual-function RNA, called guide RNA. The guide RNA can together with the Cas9 protein be injected into a cell where the cells genome can be cut at a desired place and cause a disruption of the genome. This disruption leads to cell repairs and mutations, or we can incorporate new genetic information, e.g. switching a defect cancer gene with a healthy gene. This can be done by adding host DNA that binds to the genome with help from ligase enzymes, and the cell’s DNA fixes the rest. This CRISPR-cas9 system is becoming a great tool removing, recombining and editing DNA.
Crispr has been proven to be more effective, cheaper and more accurate, and has been said to be able to prevent and interfere with diseases such as cystic fibrosis or cancer. Crispr is a newly developed technology, meaning that there are fewer conducted trials then with other genome editing. However, scientist have through CRISPR-CAS9 a big possibility of further advances in improving human health and well-being.
A medical prediction for the future is that embryonic alterations using the CRISPR-CAS9 system can be used to remove and create a permanent resolution for genetic diseases allowing the generation being treated to live a healthy life. Scientists can use this research to find the answer to questions like: why some people miscarry or why some people struggle to get pregnant. On the other hand, these alterations are done without consent of the humans produced through germline gene therapy, an important ethical concern.
One of the most controversial issues surrounding CRISPR is connected to embryonic change, the possibility of being able to create desirable genetic characteristics through so called “designer babies”. Designer babies make it possible for parents to enchant traits seen as advantageous in life such as higher intelligence or better physic. This could lead to an unrealistic idea of what perfection is, creating a society where human flaws are unacceptable, and possibly changing our views on the value of a human life. This also leads to another issue: who can afford this technology? CRISPR-CAS9 is said to be cheaper than other gene editing tools, but at the same time it will be a technique only people with a certain wealth will be able to enjoy. CRISPR- CAS9 can therefore lead to a larger gap between rich and poor, the technology is not disturbed equally. Some people and groups may therefore experience injustice, discrimination and disadvantage.
Although there are many safety percussions taken with use of the CRISPR- CAS9 system, there are still potential risks. We don’t know a lot about this technology, and if it is not used correctly it may cause unintended mutations and effects due to off targeting DNA alterations. These might lead to irreversible changes that can be passed on in future generations, or even a highly unwanted result: death. Professor of bioengineering, Gang Bao, stated in an interview for Stat news:” Even if on-target gene editing is accurate, the off-target effects could influence the function of many genes, possibly posing serious health problems.”
To make a short conclusion we can say that CRISPR-CAS9 is a newly developed gene technology based on a bacterial defense mechanism, using a cas 9 protein to cut and edit genes. The system has caused a lot of controversy in media, through predictions such as designer babies and embryo editing, but is also said to be a futuristic way of removing disease and