The primary and most widely used method for altering DNA is CRISPR gene editing, a precise technology that functions like a molecular "find and replace" tool for the genetic code. [1, 2]
How
CRISPR Works
- Guide RNA: Scientists
program a short piece of RNA with the exact "address" or
sequence of the target DNA they want to change.
- Cas9 Enzyme: This protein
acts as molecular scissors to attach to the target site and cut through
the DNA strands.
- Cellular Repair: The cell
detects the broken DNA and triggers its natural repair process to fix the
gap. [1,
2, 3, 4]
Types
of DNA Repair and Modification
- Disruption (NHEJ): The cell mends the cut without a template, often introducing a
small deletion that turns a faulty gene off.
- Insertion or Correction (HDR): Scientists supply a new DNA template alongside the scissors,
allowing the cell to copy and paste a healthy sequence into the genome.
- Base Editing: A newer
variation chemically changes one single DNA letter to another without
cutting the double-stranded helix. [1, 2, 3, 4]
Other
Methods
- Older Nucleases: Tools like
Zinc Finger Nucleases (ZFNs) and TALENs were used before CRISPR to make
targeted cuts, though they are harder to design and more expensive.
- Viral Vectors: Viruses are
often modified and used as delivery trucks to carry healthy genes into
human cells during gene therapy. [1,
2]
Source and references:
AI Google
https://www.youtube.com/watch?v=XPDb8tqgfjY&t=1
https://www.youtube.com/watch?v=2pp17E4E-O8&t=10
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