Fixing The Errors Within My Code
Disclaimer* For full understanding of the concept, you must understand the meaning of the following words.
DNA — Deoxyribonucleic acid, a self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
RNA — Ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the gen.
Enzyme — A substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.
Transcriptase — An enzyme that catalyzes the formation of RNA from a DNA template during transcription. Also called RNA polymer.
Both prime editing and CRISPR are tools for editing an organisms genomes. However, the instruments used to edit the genes are very complex and require particular detail.
CRISPER
Humans shed about 600,000 particles of skin every hour. This can be caused by unhealthy DNA or unhealthy cells. Thanks to an invention first used in 2013, called CRISPR we can edit those cells and and our DNA! CRISPR can be used to delete, add, or change minimal damage to a DNA strand. It does this by mimicking a natural occurrence in the cell’s system. Within the bacteria cells, tiny snippets of DNA are being taken from invading viruses to create CRISPR arrays. The arrays are A DNA sequence made from the process. The arrays then help the cells remember the viruses including similar ones. Once the cell gets attacked it will release RNA segments as a result of the CRISPR arrays to target the viral DNA. A protein called Cas9 is then used to cut the DNA. A guide sequence is now necessary to bind specific parts of the DNA. Combined with Cas9, It will cut the DNA at the targeted location. This method can be used on a wide variety of organisms. It is also cheaper than prime editing (another method) and gives accurate results. With this method precision is needed; any cells that are left unedited can still attribute to disease progression and mosaic effects.
Prime Editing
Prime editing is different from CRISPR because prime writes genetic information into specified DNA. This is made possible due to the use of catalytically impaired Cas9 endonuclease fused to an engineered reverse transcriptase. Prime editing focuses on a DNA strand where genetic information will be replaced. This allows it to facilitate insertions, deletions, and conversions. It can do this without breaking strands of DNA or using DNA templates. In the process, the PBS allows the DNA to hybridize to RNA (peg-RNA). At the same time the reverse transcriptase template sequences will be used for the genetic sequence that will be edited. In order to specifically nick (nickase) a strand, a fusion protein of two enzymes is needed. Cas9 H840A nickase is the first enzyme that is being used. The Cas9 enzyme has a formula for substitution. Instead of a double stranded cut, this will only merely cause a single strand to break. The second enzyme is known as M-MLV (Moloney Murine Leukemia Virus). A second sgRNA directs the fusion protein to the DNA strand to be edited. The first step to Prime editing is the peg-RNA plus the fusion protein targeting the cell. The fusion protein will now nick the cell’s DNA during the target sequence. That will then initiate the reverse transcription of the template sequence in peg-RNA. There is both an unedited and edited strand of DNA. The unedited is being removed for a replacement of a newly edited strand to anneal it back to double stranded DNA. A mismatch in the base pairs of the strands will now be present, which will have two outcomes. Intrinsic DNA system will be incorporate changes into the nucleotide order into the cell. The chances of by-products from this operation will be reduced, which is a desired feature in many gene editing techniques. Prime editing is highly precise and is very flexible to its needs.
The Importance and Future of Prime Editing
As you should know, prime editing sparked in late 2019. Just as we were getting used to CRISPR, a new gene editing tool came into the market. Because of the accuracy of prime editing it can be used to kill diseases. Instead of getting injected with drugs you can get your genes edited to be specific to that disease. Your genes are the blueprint of your everything. Being able to edit ourselves is a huge step for humanity and its progression. Also we will be able to get rid of genetic diseases that runs through families. Prime editing will be useful as well as important in our near future.
