For the first time, South Korean scientists created dogs — two adorable Beagles, to be specific — from cloned, CRISPR-edited skin cells.
This new gene-editing technique possibly eliminates harmful genetic traits such as disease-causing mutations from purebred dogs, reports New Scientist.
CRISPR-Editing and Cloning
The researchers announced their achievement in BMC Biotechnology. They described how CRISPR gene-editing technology was used to manipulate a particular trait in the pair of pooches.
New Scientist defines CRISPR, predicted to “likely change the world,” as a way of finding a specific bit of DNA inside a cell. The next step in CRISPR gene editing is usually to alter that piece of DNA. However, CRISPR is also capable of other things, such as turning genes on or off without altering their sequence.
In the past, CRISPR-edited dogs have been created by altering fertilized eggs. However, this is the first time they have been created by cloning, which is the process of creating organisms that are genetically identical. These organisms are identical twins and are, to some degree, copies of each other. The creation of embryos by fusing egg cells with body cells, known as somatic cell nuclear transfer (SCNT), was first used back in 2005 with the creation of an Afghan hound called Snuppy. The technique has since “been used not only for pet cloning but also for propagating elite working dogs, including sniffing dogs and rescue dogs,” the researchers wrote.
“Because breeding programs with a limited number of founder dogs are strictly selective, purebred dogs have a greater risk of genetic disorders than any other species,” they continued. Scientists believe this new technique may correct specific flaws without affecting any other traits.
Cloning Pros and Cons
Cloning specialists face technical problems. For instance, there is evidence that cloned animals die unusually young. And there are ethical issues. Some pet parents have had their loved ones cloned to order. When their original dog dies, the clone replaces them. But the clone won’t be completely identical, as the new pooch will have different life experiences. Some scientists claim the gene-editing tool causes unwanted mutations that may prove dangerous. Some say the practice is ‘much less safe’ than once thought. Moreover, cloning could theoretically create ‘designer babies’ by allowing parents to choose their hair color, height, or even personality traits such as intelligence.
This new cloning approach has advantages over the editing-eggs approach, Okjae Koo at biotech company ToolGen told New Scientist. South Korean scientists used CRISPR gene-editing to prevent hip dysplasia in two Labrador dogs, Gene and Geny. They attempted to correct a mutation linked to the common hip disorder. Pedigree dogs are often susceptible to genetic diseases because of years of inbreeding. For example, Spaniels having brains too big for their skulls and Boxers suffering from epilepsy.
Some optimistic scientists say that cloning can help critically endangered species by adding clones to their populations. Even more futuristic plans include cloning to resurrect extinct animals such as mammoths by using preserved tissue. But the jury is still out on whether cloning is an ethical practice.
Currently, the 22-month-old Beagles are healthy and without any abnormalities. They might still experience issues as they get older, say the researchers, adding that they are “continuously monitoring” the dogs and will provide more details about their long-term wellbeing in future studies.
