December 7, 2021

I, Science

The science magazine of Imperial College

Yesterday afternoon, I went to the cinema to watch The Amazing Spider-Man. When the words “DNA” and “recombination” popped up during the film, I got excited and started thinking. I later asked myself: In reality, how close are we to creating artificial hybrid species?

Let’s briefly revisit the idea of Spider-Man, a.k.a. Peter Parker. Parker is a teenage boy who acquires the agility and proportionate strength of an arachnid after being bitten by a radioactive spider. Incidentally, Parker’s father was a scientist, who, together with his collaborator Dr Connors, did research into reptile DNA and recombinant DNA technology. Reptiles have the ability of re-growing lost limbs; a skill they wanted to use in order to incorporate the genes responsible for limb regeneration into humans, for the benefit of human amputees.

Recombinant DNA are genetic sequences formed by cutting and pasting together DNA strands from multiple sources. The result of this is potentially novel genetic information. These new sequences are important as they encode for proteins that may not have existed naturally in the host organism – proteins that have new and specific biological functions. In the case of Spider-Man, these proteins give him the ability to cling to most surfaces.

Genetic recombination happens naturally, for example when the HIV virus infects human cells and incorporates its DNA into our own. This alien DNA tricks the host cell into creating more of the virus.

In the film, Dr Connors successfully isolates the genes responsible for limb regeneration in lizards. He then places this genetic material into the genome of a lab rat. Pleased with the results, he then begins to test the theory on himself. Unfortunately, as the technique is not yet perfect, it goes wrong. He becomes a wild and dangerous creature: half-human, half-lizard.

Is this pure fiction? How plausible is the concept of creating hybrid organisms with our current recombinant DNA technology?

One of the most striking examples can be seen in the synthesis of human insulin. This involves inserting the human insulin-coding gene into bacterium DNA. Bacteria can reproduce at staggering rates, thus producing insulin very, very quickly. Another example is glow-in-the-dark fish. Such fish are genetically modified fluorescent zebrafish. These were first created in 2003 by Professor Tsai of the National Taiwan University. A jellyfish gene that codes for a fluorescent protein is extracted and subsequently inserted into the genome of the fish. These are just like the fish that Sheldon Cooper engineered in The Big Bang Theory (The Luminous Fish Effect episode). Genetically-modified crops are another impressive example. Herbicide resistant genes taken from bacteria are inserted into plants like soy beans to make them resistant to certain herbicides, thus increasing crop yields.

Recombinant DNA has been widely used for pharmaceutical and medical purposes in developing gene therapy. Genetic disorders can occur when faulty genes encode proteins that are unable to carry out their normal functions. Using recombinant DNA, it should be possible to devise a means of transport for ‘healthy genes’, using bacteria or viruses. This would incorporate these new genes into our cells, restoring them to their normal healthy state.

This definitely sounds like a step closer to incorporating foreign DNA into ours – but Spider-Man may be a way off yet.

More > What animal trait would you acquire? Comment and let us know!

Image: via Fish Lore