Lecture Notes: CRISPR-Cas9 and Genome Editing by Jennifer Doudna

Introduction

• Speaker: Jennifer Doudna
• Acknowledgments: Royal Swedish Academy of Sciences, Nobel Prize Committee in Chemistry, family, colleagues, lab members.
• Lecture Focus: Science of CRISPR-Cas9 genome editing technology.

Origins of CRISPR

• Initial Research (Two Decades Ago): Bacteria might have an adaptive immune system.
• CRISPR System: Mechanism to protect against viral infection by integrating viral DNA into genome.
• Adaptation Process: Bacteria use CRISPR to detect and cleave viral DNA.

CRISPR Mechanism

• Process: Uses CRISPR associated proteins (Cas proteins) to guide detection and cleavage of viral DNA.
• Key Proteins: Cas9 with guide RNA for DNA targeting.
• Steps in CRISPR Immunity:
  • Adaptation
  • Expression
  • Interference

CRISPR-Cas9 Discovery and Function

• Collaboration: Began in 2011 with Emmanuelle Charpentier.
• Function: Cas9 as a dual RNA-guided protein;
  • Uses CRISPR RNA and tracer RNA.
• Experiment: Demonstrated CRISPR-Cas9 as a simple two-component system for DNA cutting.

Genome Editing with CRISPR-Cas9

• Eukaryotic Cell Repair: Non-homologous end joining or integration of homologous DNA.
• Mechanism: Cas9 creates double-stranded DNA breaks, allowing genome editing.
• Model: Cas9 guided by RNA for precise DNA cleavage.
• Applications:
  • Disease mutation correction (e.g., sickle cell anemia).
  • Responsible germline use and ethical considerations.

Current and Future CRISPR Applications

• Diversity of Systems: Ongoing research into various CRISPR systems.
• Phage-Encoded CRISPR: Discovery of tiny proteins like CRISPR-Casphi with DNA-cutting capabilities.
• Biochemical Activities:
  • Cas13 for RNA targeting.
  • Cas12 for DNA detection.

Diagnostic Uses

• Applications: Detection of human papillomavirus, SARS-CoV-2.
• Mechanisms: Leveraging CRISPR for rapid and specific viral detection.

Conclusion

• Future Directions:
  • Enhance delivery and control of CRISPR systems.
  • Fundamental research to drive future applications.
• Collaborations: Thanks to lab members, colleagues, and the University of California, Berkeley.
• Vision: Expanding CRISPR's role in healthcare and environmental solutions.