Genome editing Techniques

Genome editing can be done by various techniques that enable scientists to modify DNA in a precise and targeted manner. Let’s find out some key Genome editing techniques:

CRISPR- Cas9 Technology

CRISPR stands for “Clustered Regularly Interspaced Short Palindromic Repeats,” and Cas9 refers to the associated enzyme. This was first discovered by Jennifer Doudna and Emanuella Charpentier in 2012. They were awarded the Nobel Prize in Chemistry in the year 2020.

CRISPR technique works by using a natural defense mechanism by which Bacteria and archaea fight viral infection. CRISPR Modifications involves the following steps:

• To identify the target DNA
• Design Guide RNA
• Combine guide RNA with CRISPR cas 9 enzyme complex
• Introducing the complex to the cell
• Target identification by gRNA, binding
• Modification
• Repair

In this technique, a segment called guide RNA is synthesized which is complementary to the target gene where the modifications are to be made. Cas 9 enzyme works as molecular scissors capable of cutting the target DNA. The Guide RNA is combined with the Cas9 enzyme and forms a CRISPR-Cas9 complex that can specifically bind and modify the segment of DNA required. Once this Cut is made body’s natural DNA repair mechanism works either in 2 ways Non-Homologous end joining or homology-directed repair and causes the deletion of the target gene or alterations.

Transcription Activator Like Effector Nucleases (TALEN)

It is another method of Genome editing that helps scientists to specifically modify DNA sequences. Here a TALE sequence is designed and combined with a nuclease enzyme called FokI and this will specifically target the DNA base pair and can be made a double strand cut in DNA to be modified and then Repaired by normal mechanism. TALEN is a highly specific mechanism.

Zinc Finger Nucleases (ZFNs)

Zinc finger Nucleases is another important tool used to cause alteration in target DNA. Zinc finger motifs are DNA-binding regions in Proteins. In ZFNs, they are modified by introducing an endonuclease. These engineered proteins can bind to specific DNA sequences. They introduce targeted breaks in the DNA, prompting the cell’s natural repair mechanisms to modify the genetic material during the repair process.

Base Editing

In Base editing, a single DNA base can be altered. It uses a specialized Cas9 enzyme that doesn’t cause double-strand cuts in DNA. It consists of a deaminase enzyme that causes a change in a single base.

Prime Editing

Prime editing is a recent advancement in CRISPR-based Genome editing where a reverse transcriptase enzyme is added.

Genome editing is an important tool of Genetic Engineering. It is the most promising technique of current and future importance as it can be used to edit, modify, alter, or make changes in the DNA or Silencing a gene. Genome editing is the latest technology where genetic material or genes of an organism can be modified, added, deleted or any alterations can be made to create desirable characters.

It is the most important scientific advancement that has the potential to act as therapeutic, genetic engineering, transgenics, etc. It is the most recent focus of medical research and Agriculture. This article will focus on what is Genome editing, the different methods, applications, and ethical perspectives of Genome editing.