CRISPR: Five weird projects pushing the boundaries of gene editing
Over the past few years, targeted gene editing has gone from complicated and error-prone niche applications to easy and efficient mainstream technology. All this thanks to CRISPR, a new and easy-to-use gene-editing tool that is spreading in the scientific community like wildfire.
To date, CRISPR has mainly been used in the medical field, from uncovering causes of disease to developing new therapies. However, researchers can be a quirky and peculiar bunch, and some have spotted alternative applications for this technique. Let’s just say some uses can be a little off the wall…
CRISPR: Hercules, the super-dog
With double the amount of muscle, Hercules is the world’s first genetically engineered super-dog. Together with his sister Tiangou, the duo were created by Chinese scientists by switching off a gene called myostatin. This gene regulates the amount of muscle fibres produced and, without this break, the body just doesn’t know when to stop.
According to Xiang Gao, one of the scientists involved in the study, this gene was selected simply because it would be easy to see the result. “We believe the protocol we developed solves the major problems for dog genome modification (including transgenic). It is as efficient as CRISPR/Cas9 in other laboratory animals, such as mice and rats,” he explains.
These scientists are planning to use CRISPR to take advantage of the dog’s proximity to humans to study human diseases, but it’s easy to see how biotech companies may have different ideas. Now that the door to designer pets is firmly open, it probably won’t be long until we can “customise” our pet in terms of size, colour, as well as strength or intelligence.
There’s even a precedent for this situation, as a different research institute in China is already offering miniature pigs no bigger than a beagle. These micropigs, also created by gene-editing techniques, are selling like hot cakes with a $1,600 price tag.
CRISPR: Fluorescent beetles
Fluorescence is known to occur in many living organisms, but normally flour beetles are not among them. Until now.
A team of French researchers created a glowing beetle by adding a green fluorescent protein to its genome. Just like with Hercules, this was the first time CRISPR was applied to beetles, and the researchers just looked for something easy to spot.
Now that it’s working, the team sees immense potential in exploring this technique to study how specific types of cells change during development. “A way of doing that is to introduce a fluorescent protein that allows you to observe specific cells. If you want to label muscle cells, for example, you can use CRISPR to insert a fluorescent protein into a muscle-expressed gene and observe what happens. CRISPR provides a faster and cleaner approach to do this,” biologist Michalis Averof of the Institute of Functional Genomics in Lyon tells me. Fans of weird and uncommon species used in the lab, the same team also works with small crustaceans and is aiming to create a fluorescent version to study leg regeneration after injuries and amputations.
In Australia, embryo chicks have also been ‘CRISPRed’ with a fluorescent tag, but in this case, it was actually done with a specific application in mind. Typically, in the egg industry, male embryos have no value and
In Australia, embryo chicks have also been ‘CRISPRed’ with a fluorescent tag, but in this case, it was actually done with a specific application in mind. Typically, in the egg industry, male embryos have no value andare usually culled immediately after hatching. To avoid this procedure, researchers from the Commonwealth Scientific and Industrial Research Organisation introduced a fluorescent protein in males, allowing for embryos to be sexed before hatching. In theory, male embryos can then be removed and potentially used for alternative purposes, such as vaccine production.
CRISPR: Turning males into females
Females that turn to males and males that turn to females – it’s all in a day’s work in a lab in Blacksburg, Virginia. They first had to identify the gene responsible for gender determination, but afterwards it was actually easy to use CRISPR and other genetic tools to play around with the gender in mosquito populations. “We identified a gene which we called Nix,” explains Zach Adelman. “When we knocked it out all mosquitoes became female mosquitos, and when we added it in, the mosquitos became male mosquitoes.”
It may sound amusing, but this work actually has a very serious motivation. In mosquitoes, it’s only the female that can bite and transmit diseases, so they’re trying to build large populations of non-biting sterile males to release into the wild. Malaria, Dengue and now Zika are just some of the many diseases transmitted by mosquitoes, and many groups are hard at work to develop ways to control the spread of these small and dangerous insects.
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