Science Writing

Edit Your Genes

There is a novella by Becky Chambers called To Be Taught If Fortunate. It is one of the most beautiful books I have ever read and I believe every person should read it as I can only imagine it enriching their life.

Without going into too much detail, the story revolves around a crew sent to explore exoplanets. Not an uncommon premise, however, the difference in this story is the way the crew is prepared for the mission. Instead of altering the planet so humans can survive there, they alter themselves.

Before arriving on each planet/moon, the crew undergoes genetic changes to better prepare themselves for the unique challenges of each new world. It’s not mentioned in detail how this is done, and that got me thinking if it was possible at all, or merely science fiction.

CRISPR Cas-9 is the answer.

And it’s here today, albeit in a more limited form.

Clusters of Regularly Interspaced Short Palindromic Repeats, or CRISPR, evolved millions of years ago in bacteria as a defensive mechanism against bacteriophages. If a bacteria gets attacked by a bacteriophage it hasn’t come across before, and it survives the encounter, the bacteria will hold onto a chunk of that bacteriophages DNA.

These bacteriophage remnants are held in ‘spaces’ within CRISPR, in between repeated sequences of nucleotides. CRISPR’s are the bacteria’s memory bank and defense mechanism. If the bacteria is attacked by the bacteriophage again, the CRISPR structure will spit out a single stranded RNA that is complimentary to the bacteriophages DNA it had in storage. It then picks up the other half of this incredible immune response, Cas 9.

With the enzyme Cas 9 in tow, CRISPR scans invading DNA until it finds a match, then it hooks onto the bacteriophages DNA. Cas 9 attaches to the invading DNA and cuts both strands at once, thus making the virus ineffectual.

The process is far more complicated than that and I will link to articles below if you would like to read further.

What does that mean for genetic engineering?

Essentially, CRISPR-Cas 9 has proven to be incredibly specific and efficient at cutting out a 20-base pair long section of DNA. And it was found that after a section has been cut away, the cell will replace it in one of two ways. Either by sticking the two new ends of the strand together, or it will seek a replacement to fill in the gap.

And that is what makes CRISPR an incredible tool for gene editing. It can snip out and replace a section of DNA with essentially anything. Obviously, not everything will work, but it allows for extremely targeted replacement or removal of DNA in a target cell.

Where does this leave us on the question of Becky Chambers novella?

Essentially, this opens the door for humans to become…anything. There is a caveat to that, however, if you are already born, CRISPR can only do so much for you. It can be targeted to cure cancer, autoimmune diseases, retroviruses. Don’t get me wrong, it is still an incredibly powerful tool, however, to get the full effects of cascading change, the genes must be edited in gametes, which means that only children born after gene editing will see the huge effects that science fiction loves so much.

Enceladus is one of Saturns moons and it is completely covered by ice. The surface temperature sits around -200 degrees Celsius. Do you want to walk on that moon? Easy, we can insert anti-freeze genes from organisms found in Antarctica into your cells. Would you like to swim on Europa or even in the depths of the Mariana Trench on Earth? No problem, gills for you, and increased bone density for you.

It is not as easy as I have made it sound in that last paragraph, but the reality isn’t as far away from that as you might think.

But when you kick open the door of gene-editing, even if it is to cure a disease, or to create a hardier crop, you unleash a torrent of possibilities and not all of them are good.

Imagine a race of super humans. Intelligent beyond belief, strong, barely needing food, able to do everything a human can but infinitely better.

Like swimming in the depths of the ocean, this dystopia is not far out of reach.

Gene editing is a powerful tool, perhaps the most powerful thing humans have discovered. It has the potential to irreparably change the human genome for the rest of the time our species exists.

It needs to be respected, and the consequences of gene editing tools like CRISPR-Cas 9 have to be considered.

Humans have been genetically engineering things for thousands of years. Selectively breeding dogs, for example, or cultivating certain strains of food that serve their purposes better. The idea of genetic engineering isn’t new, but CRISPR takes something that was once difficult and prohibitively expensive and makes it cheap and efficient.

I dearly hope that one day humans will be able to edit themselves to walk on planets other than Earth. I believe it is one of the best ways to equip humanity for the arduous journey of space travel.

However, the potential for abuse with CRISPR is immense and more research needs to be done.

I’m hopeful that CRISPR will benefit humanity and not destroy it.

Further Reading/References:

To Be Taught, If Fortunate: A Novella by Becky Chambers – Books – Hachette Australia

What Is CRISPR? | Live Science

Genome engineering using the CRISPR-Cas9 system | Nature Protocols

A brilliant summary of CRIPSR Cas9 and the potential consequences. Credit: Kurzgesagt on YouTube.

2 comments on “Edit Your Genes

  1. I need to come visit this blog more often! Your content is amazing 🙂

    Liked by 1 person

    • I have no idea how I missed this and I’m very sorry it took 15 days for me to realise it was there! Thank you so much for your kind words. It means a lot to hear that from a successful blogger such as yourselves!


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