Two gene drive approaches:
- replacement: alters a specific trait
- suppression: suppresses a gene
CRISPR breaks DNA at a targeted location; the DNA heals itself in two ways:
- nonhomologous end joining: two ends that were broken get stitched together in a random way
- eventually confuses CRISPR, which is designed to locate a specific stretch of DNA
- homology-directed repair: DNA uses a genetic template to heal
CRISPR potential:
- could stop the spread of disease
- could correct genes for inherited diseases or disabilities
- could treat or prevent disease or disability
- unlimited possibilities
CRISPR concerns:
- no way to undo a gene drive once it is released in a wild population
- uncertainty over how it may affect an ecosystem
- population would likely develop a resistance to the gene drive
- if carrier populations are edited to withstand diseases, the parasites may mutate
- can damage DNA that is far from the target location
- potential cell death after DNA editing
- p53 protein could activate from stress from CRISPR activity and thwart it
- some people may have already developed a resistance to CRISPR, which is a bacterial protein, during common bacterial infections
- use for “enhancements” that could exacerbate social inequities
Good preliminary research Jenna – I’m particularly pleased that you addressed the concerns related to CRISPR – it’s crucial in considering its role and future uses.
Thursday’s class will really allow us to unpack those ideas more explicitly in the context of ethics and human/animal/environmental impact.