CRISPR: The Gene Editing Revolution

Introduction

• All living organisms are defined by their genes.
• DNA acts as an instruction manual, composed of four bases in specific sequences.
• Recent advancements in gene editing allow scientists to modify fundamental features of organisms rapidly.

Applications of Gene Editing

• Development of drought-resistant crops
• Creation of apples that don’t brown
• Prevention of infectious outbreaks
• Cures for genetic diseases
• CRISPR is the most efficient gene editing tool available today.

Origin of CRISPR

• CRISPR functions as a natural bacterial immune system.
• Found in bacteria and archaea, protects against invading viruses.
• Two main components:
  • CRISPRs: Short repetitive DNA sequences.
  • Cas proteins: CRISPR-associated proteins that cut DNA (molecular scissors).

Mechanism of CRISPR

1. Viral Infection Response:
   • Cas proteins cut viral DNA and incorporate it into the bacterium’s CRISPR region.
   • Captures a chemical snapshot of the infection.
   • Viral codes are copied into RNA.
2. Role of RNA:
   • RNA binds to Cas9 protein, acting as a scout.
   • Searches for matching viral DNA.
3. Recognition and Defense:
   • If the virus invades again, the complex recognizes it and Cas9 destroys the viral DNA.

CRISPR as a Gene Editing Tool

• In 2012, scientists adapted CRISPR to edit nearly any DNA.
• Process in the Lab:
  1. Design