It’s Chinese New Year, so brace yourselves for about a dozen puns on rabbits in the year of the rabbit. Rabbits? Furry creatures, perhaps. Not always white, with long ears; big glossy eyes and button noses, with long whiskers. Long teeth. Hop around. Glow in the dark.
Let’s backtrack. Glow in the dark?
Modern day science has brought about knowledge and inventions to do the seemingly impossible, to interfere and manipulate nature; to, as in this case, modify organisms genetically. These organisms that have had their DNA altered in some way are also known as GMOs, genetically modified organisms.
An example of this: the aforementioned rabbit. The green fluorescent protein (GFP), extracted from jellyfish, is inserted into the genetic makeup of the rabbit embryo—usually not as the main goal but rather as a sign that the organism has been successfully genetically engineered, a selectable marker. Scientists have also succeeded with animals such as cats, pigs, and sheep, all of which have shown no signs of ill health or erratic behaviour. But how, exactly? Let us… go down the rabbit hole.
The discovery and isolation of restriction enzymes and bacterial plasmids make possible the manipulation of individual genes.
Restriction enzymes are a protein produced by bacteria that cleaves DNA at specific sites along the molecule, which can be isolated and used to manipulate fragments of DNA, allowing for genetic engineering (more on that later). Meanwhile, plasmids are small rings of DNA in bacteria that are able to reproduce and synthesise protein—meaning that by incorporating foreign DNA into a plasmid, researchers can obtain an almost limitless amount of copies of the inserted gene. Additionally, if the gene is operative, this will be indicated by the modified bacterium producing the protein specified by the foreign DNA; hence the use of GFP as a visible indicator of success.
To put it briefly, the process of genetic engineering can be split into about three key steps.
One must find and isolate the target gene / gene of interest, the gene they want to insert.
Restriction digestion occurs when the same restriction enzyme, ‘scissors’, cleaves the target gene and plasmid. They are then so-called glued together by DNA ligase, ‘glue’, in a process known as ligation, to form what is known as a recombinant plasmid (a modified plasmid containing the inserted gene).
The recombinant plasmid is transformed into an appropriate bacterial host cell, where it then reproduces and gene cloning occurs, now with the target gene.
There is the how, so here comes the what and why. Let’s hop into it!
Glow in the dark animals enable scientists to clearly observe cells of organisms such as worms, and study diseases, e.g. feline immunodeficiency virus (FIV) in cats, similar to the human immunodeficiency virus (HIV) in humans.
Yet glowing in the dark isn’t the only thing GMOs can do. Some organisms such as plants are modified to be resistant to certain pests, eliminating the use of pesticide in farming, which can harm wildlife. Crops can have increased nutrients, yield; enhanced taste, quality. Hence, food security is increased. There are also ongoing studies to use genetic technology to treat medical conditions such as human heart disease, asthma, diabetes, cancer.
Isn’t it hare-raising to think about the possibilities GMOs could bring? The hope for treatment, for positive environmental impact. Although nothing in this world comes without cost…
Gene editing is still imprecise. There are many ways it could go wrong; in recklessly attempting to fix a certain problem, we might create ten more. The long-term effects and safety of genetic engineering are yet to be known as well; species might inadvertently be affected or eliminated, ecosystems damaged beyond repair.
Social and political concerns are highlighted. Mutations will not be confined to geographical borders and genetic drives to combat diseases might need agreements among countries. The Director-General of WHO established a new advisory committee on developing global standards for governance and oversight of human genome editing, who agreed that it would be irresponsible at this time for anyone to proceed with the clinical application of human germline editing. Furthermore, the fact that genetic engineering is so expensive means not all will be able to benefit as well, or at least for now—the 721 on-going gene therapy trials will treat 1000 rare diseases, implying that only a small number of patients will benefit and that the price is out of reach for the majority.
Then comes the ethics. There is of course the age-old debate on animal testing, especially in the unpredictable case of genetic engineering. Some people are hopping mad and question the tackling of genetics in the first place with regard to environment-caused diseases. There are also those who ask whether we have the ‘right’ to interfere with nature at all, if there is such a thing. Technology such as CRISPR-Cas9 has even attempted to alter human genomes in human embryos, and beg the question of just how far genetic engineering can go, or if it will reach the point where somewhere in the future, parents will be paying for their kids to have blue eyes, green eyes, black hair, blond hair, greater height, greater intelligence.
And you? What do you think?
Do you think this warrants concern—sorry, warrens concern? Or do you think we should just press forward; onward; push the limits?
Whatever the case, I look forward to seeing where the future takes us, together.
Written by Benecia Kang
Illustrated by Chua Jia Qi