What if your parents told the scientists to ‘edit’ your DNA before your birth to give you the face and the body your parents imagined? CRISPR is the fast track lane to accomplish this! CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. This type of technology had a massive breakthrough and is experimented furthermore.
An experiment was done by the Harvard Medical School and the Technion Institute of Technology which had a rectangular shaped box(like a bathtub) and they put a jelly or food bacteria that could grow. They divided the box into 9 small vertical boxes or in simpler terms made it into a football field. The scientists also added the antibiotics from the sides of the boxes and increased the number of antibiotics to the center. Then, they let the jelly/food bacteria grow from the sides. The objective of this experiment was to see whether the jelly will adapt to the antibiotics and come in the middle. Slowly the jelly grew more and came towards the middle. This is how we, humans, came into existence on Earth. Evolution is the answer to everything. But the difference between the experiment and the evolution of humans is that we took more time to evolve. CRISPR will play a huge role in the evolution of living organisms.
Before we even knew about CRISPR, it functioned as the Bacterial Immune System which has adaptive immunity towards viruses that invade our body. But there is also Cas 9 which is CRISPR Associated Protein. These are known as molecular scissors since it cuts the DNA. When Cas 9 binds with Single Guide RNA, it forms a complex which identifies and cuts a specific section of DNA. Before ‘gene-editing’ CRISPR was used to kill viruses.
As we know that Single Guide RNA and Cas 9 form a complex that can cut a specific gene, this complex then searches for the virus. When the virus is spotted, Cas 9 immediately kills the virus.
Other bacterias that have this defense mechanism
Halophiles, E.Coli, and Clostridium
According to Andrea M. Henle, in 2012, scientists found a way to ‘hijack’ a gene through CRISPR. This means that Cas protein could target any specific gene in our body and alter it. For example, Cas 9 fused to Deaminase. Deaminase mutates specific DNA bases. As there are four bases called, Adenine, Cytosine, Guanine, and Thymine. Eventually, the mutation results in the replacing of Cytidine(ribose ring attached with Cytosine) with thymidine(ribose ring attached with Thymidine.
This power to change a very specific DNA in our genome could cure many sorts of diseases that still don’t have a cure.
Scientists first have to design a guide RNA which should resemble the genetic code they want to edit in the DNA. Then the guide RNA is linked with Cas 9. The guide RNA helps to target the genetic code they targeted. This helps to edit any gene in our genome.
Implications of gene-editing
When the DNA is edited, there will cell repairing the gene editing. But the fixing of genes is called Nonhomologous End Joining and it is error-prone. ‘Error-prone’ means that there could be missing or more bases. According to the Ted-Ed video, the resulting gene is often “unusable.” But this implication could be resolved if the researchers and scientists could design a DNA template strand(used to attach complementary bases). The DNA template strand would help repair a defective gene or position a new gene.
Since we have not seen CRISPR’s long term insinuations, it is “unethical” to use it at laboratories, farms, and hospitals. But it also erases these genetic disorders and diseases in our population. These statements raise serious concerns about whether it is good or bad for humanity.
Wonders of CRISPR
CRISPR could help treat and even cure genetic disorders and diseases like hearing loss, Huntington’s disease, Angelman syndrome, Spinocerebellar ataxia, Cystic fibrosis, Turner syndrome, Muscular dystrophy, Sickle cell, blindness, and Gaucher disease.
Pros and Cons of Gene-editing
Let’s discuss the pros and cons of gene editing. According to Explore Biotech, these are some of the pros and cons.
Pros: Erases diseases, speed up drug research, extend lifespan, growth in food production and the quality, and pest-resilient crops.
Cons: Erase diversity, ethical dilemma, safety concerns(long-term implications), the rich could only afford since gene therapy is expensive and not affordable for everyone.
Originally published at https://medicalblogs.wixsite.com on January 2, 2021.