If you thought genetically engineering a human genome was a little freaky, you’re right. If you think it’s still cool, you’d also be right.
Genetic engineering is exactly what you think it is – the engineering of genes. More specifically, it’s directly changing a genome to make a new or edited organism. This can be accomplished through molecular cloning (cloning of the desired DNA strand, and injecting the copied DNA into the organism so it replicates itself), or gene targeting (removal of a gene, adding a gene, or introducing a point mutation – like purposefully inducing a genetic mutation), but there is now a much more precise way to genetically modify an organism. It’s called CRISPR, and it is being widely regarded as a revolutionary development in science. The thing is, scientists didn’t invent it.
CRISPR stands for “Clustered regularly interspaced short palindromic repeats”, and it is naturally occurring. It consists of prokaryotic DNA with repeating base sequences, and this initially puzzled scientists, until they realized that they have “spacer DNA”, which means that all these sequences are the genetic makeup of something – it was later discovered that this “something” was viruses. Cells were found to be keeping a sort of database of the DNA of certain viruses, and using proteins (Cas – CRISPR-associated proteins) to target the virus when it entered the cell.
CRISPR takes certain sections of a virus’ DNA and turns it into RNA, which Cas then takes control of and carries it around the cell. If the protein encounters something that matches the RNA, Cas cuts it into two so it cannot replicate itself within the cell. Scientists mostly focus on Cas9, which is the associated protein of strep throat. Cas9 can recognize genetic sequences twenty bases long, so biologists can feed it the RNA of any desired gene and it can go and copy and paste it anywhere you want in the genome.
This technique has been recently used in mice. Gene engineering mostly consists of isolating genes and messing with them a bit, to see what effect they really have on an organism. Normally, to isolate a gene, scientists would have to go through three generations of mice to get the desired phenotype, but now with CRISPR, they need only insert the gene into an embryonic stem cell and it takes one generation to see the gene. It’s also being proposed to be used in fighting inherited diseases – when you inject the copy of a certain gene, but it is non-functional, embryonic stem cells will adopt the new gene and replicate that. The generation born will have a “knocked-out” version of the gene, meaning it does not work. Using CRISPR, scientists may be capable to do the same thing with much more precision and efficiency than ever before.
CRISPR is still in early development, but with more testing, it is definitely possible to witness some incredible advancement in science. However, any form of genetic engineering has always been under mass scrutiny. In 2015, scientists at major academic establishments called for the world to place a temporary ban on editing inheritable human genomes. Also, the term “genetically modified organism” has become almost synonymous with genetically modified food and crops, which are subject to ridiculous amounts of debate, mostly due to GMO-manufacturer Monsanto’s suspicious and unethical activity. CRISPR is being proposed for certain forms of gene therapy (genetic engineering in humans for clinical use), but this is even more controversial than the food. It was only in 2012 that the first form of gene therapy was permitted world-wide after the European Commission cleared the treatment, Glybera, for clinical use. (Glybera compensates for a rare genetic disease called lipoprotein lipase (LPL) deficiency, which can cause severe pancreatitis. Glybera puts the LPL gene into the cell, and it acts as a free-floating DNA strand.)
Despite obvious benefits of using CRISPR and other forms of genetic engineering, it is virtually impossible to get anything out to the public. (The biggest genetic innovation that has hit the market so far is probably GloFish or blue roses.) American laws about gene engineering haven’t been updated since 1996, and much has changed since. These regulations were written with only genetically modified bacteria in mind (genetically engineered insulin made it onto the market in 1982), and it was incomprehensible that we could edit the human genome with the simple insertion of isolated RNA. CRISPR still isn’t perfect, but more research still needs to happen. And that doesn’t just apply to this specific technique – when it comes to gene engineering, anything from genetically modified food to certain forms of cancer research are up for intense debate.
Although, it is still important to remember that we’ve come a long way, and it’s amazing what humans are capable now. The more we understand our genes, the better we can make ourselves. I’m not talking edited babies, with chosen hair and eye colour – I’m thinking more along the lines of completely taking the genes that cause negative mutations in humans, such as Alzheimer’s and blindness, out of the human gene pool.
Now imagine if Mendel could’ve seen that.