Summary

Nobel prize scientist Jennifer Doudna details the origins of gene editing and her lab’s discovery of CRISPR - a revolution in life sciences that allows universal, affordable, low-risk DNA editing. The book discusses the use cases for CRISPR as well as its future implications and ethical concerns. Doudna makes the argument that human germ line editing should be pursued carefully and ethically.

Key Takeaways

• Genome editing: Ability to change an organism’s DNA (CRISPR-Cas9)
• In vivo (living organism for genetic disease) vs in vitro (gene line editing)
• Applications of CRISPR: genetic defects, gene drive, human germ line editing

Notes

• Genetic modifications naturally occur randomly + slowly
• Gene editing first possible in 80s although imprecise, unreliable
• CRISPR: Contains Cas9 protein that can alter DNA
  • Found in bacteria, immune system function
• Cas: CRISPR associated system, the “cutting machine” enzyme
• Four types of CRISPR repair:
  • Non-homogenous end joining: error-prone repair by combining ends with random modifications
  • Homogenous recombination: replace cut section with provided DNA piece
  • Double cuts: cut at 2 adjacent locations, either delete or flip sequence
  • Gene regulation controller: modified Cas9 to locate gene, regulate expression without edits
• Shortcomings:
  • Off-target effects: mistaken cuts hard to control
  • Delivery vehicle: harder to deploy in vivo vs in vitro
• Two types:
  • In vivo: (in organism) harder, but doesn’t affect genome
  • In vitro: (in test tube) gene line editing, lasting effects
• Applications:
  • Curing genetic defects (in vivo)
  • Gene drive: propagates gene edit through species by altering probability of transmission
  • Human germ line editing: in vitro editing of human genome