Gene editing

Question 1

Describe roles of CRISPR

Answer 1

• Guide RNA cuts specific sections of DNA
• Guide RNA binds to CRISPR and forms Cas9. This finds the PAM and unwinds part of the sequence and it can then be cut at the correct location
• Cell repair introduces mutations which impair the gene, therefore knocking out the genes.
• Can replace specific molecules in the sequence
• Can also be used to promote gene transcription
• Can be used to block gene transcription
• Can also be used to visualise the location of structures in the DNA sequence

Question 2

Promise and challenge of therapeutic genome editing (12th Feb 2020)

Answer 2

• Potential for use in sickle cell as it is the result of a single base mutation
• Sickle cell could have gene editing of cells taken out the body rather than inside the body
• Duchenne muscular dystrophy is another condition with potential for treatment
• Treatment of sickle cell by gene editing and using bone marrow transplant to reintroduce the cells eliminating the need for a donor
• Delivery: viral, electroporation, direct application of pre-assembled CRISPR-Cas RNPs

Question 3

Gene editing and CRISPR in the clinic: current and future perspectives (April 09 2020)

Answer 3

• Hyperaccurate CRISPR systems are being developed
• Base editors remove the need for double stranded breaks
• ## RNA targeting