Jennifer Doudna: We can now edit our DNA. But let's do it wisely

Summary

CRISPR-Cas9 is a groundbreaking genetic editing technology that allows precise DNA changes in cells. Developed by Jennifer Doudna and Emanuel Shantier, it originated from bacteria's immune system to combat viral infections. The technology has immense potential for curing genetic diseases, but its applications, especially in human embryos, raise ethical concerns. While the scientific community is excited, there is a need for a global conversation to responsibly manage its use. Doudna calls for a pause in human genome editing until ethical and societal implications are thoroughly discussed.

Takeaways

• 😀 CRISPR-Cas9 is a genome-editing technology invented by Jennifer Doudna and Emanuel Shantier, which allows precise modifications to DNA to potentially cure genetic diseases.
• 😀 CRISPR technology was originally discovered in bacteria as a defense mechanism against viral infections, enabling them to ‘remember’ and target viral DNA.
• 😀 The CRISPR system works by inserting viral DNA fragments into the bacterial genome, allowing bacteria to recognize and destroy the virus upon future encounters.
• 😀 The CRISPR-Cas9 system involves a protein called Cas9 that can be programmed to target specific DNA sequences, acting as molecular scissors to cut and modify DNA.
• 😀 The potential for CRISPR-Cas9 extends to gene editing in humans, animals, and plants, offering possibilities such as curing genetic disorders like cystic fibrosis and sickle cell anemia.
• 😀 CRISPR can create precise DNA changes, but the technology also raises significant ethical concerns, particularly regarding its use in human embryos and potential genetic enhancements.
• 😀 The technology has already been used in animal models, and some scientists have even attempted to apply it to human embryos, which raises profound ethical questions.
• 😀 While CRISPR's efficiency and simplicity make it appealing, it also presents potential risks, such as unintended genetic alterations or misuse for non-therapeutic purposes like 'designer humans.'
• 😀 Doudna and colleagues have called for a global conversation and pause on the clinical use of CRISPR in human embryos to carefully consider its ethical and societal impacts.
• 😀 The conversation surrounding CRISPR technology is complex, with differing opinions on whether its potential benefits outweigh the ethical risks, and some scientists advocate for cautious testing and regulation.

Q & A

What is CRISPR-Cas9, and how does it work?

CRISPR-Cas9 is a gene-editing technology that allows scientists to make precise changes to DNA. It works by using a protein called Cas9, which functions as molecular scissors to cut DNA at specific sites, enabling targeted genetic alterations. The technology was originally discovered as part of bacteria's immune system to defend against viral infections.

How did Jennifer and her colleague, Emanuel Shantier, come up with the idea for CRISPR-Cas9?

Jennifer and Emanuel Shantier developed CRISPR-Cas9 based on their research into how bacteria protect themselves from viruses. They discovered the CRISPR system, which allows bacteria to store viral DNA and use a protein (Cas9) to cut and destroy viral DNA. This led them to recognize the potential for using CRISPR for genome editing in other organisms.

What are the primary applications of CRISPR technology so far?

CRISPR technology has been used to edit the DNA in various organisms, including mice, monkeys, and human cells. Some key applications include studying genetic diseases, removing HIV from infected human cells, and editing human embryos. The technology holds promise for curing genetic diseases like cystic fibrosis and sickle cell anemia.

What ethical concerns arise from using CRISPR technology in humans?

The ethical concerns mainly revolve around the potential for genetic enhancement, such as creating 'designer humans' with enhanced traits like stronger bones or altered eye color. There is also concern about unintended genetic modifications and the long-term consequences of altering human embryos. Jennifer calls for a global pause to discuss these issues.

What is the mechanism behind the CRISPR system in bacteria?

In bacteria, the CRISPR system records viral DNA sequences and stores them in the form of short, repeated DNA sequences known as 'CRISPR.' When the bacteria are infected by a virus again, the system uses RNA to guide the Cas9 protein to the matching viral DNA, where Cas9 cuts the DNA and destroys it, preventing further infection.

How does CRISPR technology compare to older genome engineering methods?

Older genome engineering technologies were either inefficient or too complex for widespread use. CRISPR, on the other hand, is simpler to program and can be precisely controlled using RNA molecules. This makes it more accessible and effective for genome editing, offering a major leap in genetic research and potential therapies.

What are some potential therapeutic applications of CRISPR technology?

Therapeutic applications include correcting genetic mutations that cause diseases like cystic fibrosis, sickle cell anemia, and Huntington's disease. It may also be used to remove diseases like HIV from infected cells or even potentially treat various cancers by editing immune cells.

Why is there a need for a global pause on CRISPR in human embryos?

Jennifer advocates for a global pause to allow time for a thoughtful and global discussion on the ethical, societal, and safety concerns of using CRISPR in human embryos. She believes that rushing forward without careful consideration could have unintended consequences for future generations.

What is the role of RNA in the CRISPR-Cas9 system?

In the CRISPR-Cas9 system, RNA acts as a guide that matches specific DNA sequences. Once the RNA binds to the target DNA, it directs the Cas9 protein to make a precise cut in the DNA at the desired location. This is a critical aspect of the system's precision.

What is the potential for CRISPR to be used in 'designer humans'?

While the genetic information for traits like eye color or height is not fully understood, CRISPR provides a tool that could one day allow for genetic enhancements in humans. This raises concerns about the ethical implications of modifying humans for non-therapeutic purposes, such as selecting desirable traits.