ReTro Experiences Adulthood

    Meet ReTro. He is extraordinary because he is the first cloned Rhesus monkey to reach adulthood. In the article written about ReTro on the Scientific American website, we get a full overview of the meaning of this experiment and its success. 

    ReTro was cloned the same way as Dolly the Sheep, through a process known as somatic cell nuclear transfer (SCNT). In this process, a nucleus from a somatic cell is inserted into an egg cell whose nucleus has been removed. It is noted there are extremely low survival rates with this process, which is why ReTro is so amazing to have fully developed into an adult. They had tried this experiment in 2022, but that rhesus monkey survived 12 hours after birth. At the Chinese Academy of Sciences, they researched all the errors within the cloning process. Their outcome: 484 SCNT and 499 ICSI (intracytoplasmic sperm injection) monkeys were compared, all developing through the same stages before reaching surrogates. Only 35 SCNT embryos were successfully implanted, compared to 74 ICSI embryos successfully implanted. The SCNT placentas were deformed and thick. They found SCNT embryos had serious genetic modification, resulting in a decrease in DNA methylation. To fix these issues, they used trophoblasts from ICSI embryos to form natural placentas around a cloned fetus. Once this was completed only two of the pregnancies evolved with only one survival, which we know as ReTro. Even with this success, cloning is still highly difficult, with a very low success rate. They wanted to use these animals to study drug efficacy. 

    In my opinion, it's amazing to believe we have found the basis of cloning, but not the exact way to do it yet. If universities across the globe keep putting their best foot forward in the science of genetics, there are so many things we will be able to discover and cure. If we successfully begin cloning other species, will this evolve into a future experiment with humans? Will cloning help us test genetic medical trials for illnesses? There are so many questions revolving around the process and if it is truly something we need to do. Dolly the sheep made people begin to wonder if human cloning was the next step, and if it would be humane to study. Yet Dolly was born in 1996, almost 20 years ago!

Sources:

Naddaf M, Magazine N. 2024 Jan 17. Meet ReTro, the First Cloned Rhesus Monkey to Reach Adulthood. Scientific American. https://www.scientificamerican.com/article/meet-retro-the-first-cloned-rhesus-monkey-to-reach-adulthood/.

Dolly the sheep. National Museums Scotland. https://www.nms.ac.uk/explore-our-collections/stories/natural-sciences/dolly-the-sheep/.

Company Successfully Clones Woman's Cat

 

An article posted by The Washington Post goes into depth about a company called ViaGen: a pet company that works with veterinarians, geneticists, and other biologists to genetically preserve and eventually clone your pet. Specifically, this article talks about Kelly Anderson, a woman whose cat died in an accident in 2017.  After getting tissue samples from her cat Chai, ViaGen was able to clone her cat into a new one: Belle. Even though Belle (left picture) is not exactly the same cat, she has identical genetic material as Chai (right picture).

Cloning has been a big part of the genetics industry for about 25 years since Dolly the Sheep was successfully cloned. Since then, several people have used companies like ViaGen to have their pets recreated. This type of cloning is compared to wiping a phone: one the outside, the clones look identical, but on the inside, their behaviors and memories are completely different. These services cost at least $25,000 or more, depending on the animal, but the results are promising.

ViaGen uses tissue samples provided by the person who wants to clone their animal. This can be done while alive or after death, but ViaGen recommends obtaining a sample as soon as possible after death. An example ViaGen uses is during a dental exam for a pet; this way, tissue samples can be easily collected without any harm to the pet when alive. These samples are mixed in with specific enzymes to retrieve the DNA from the samples. Then, a donor animal is chosen in order to use an unfertilized egg to create the clone. The donor egg's nucleus is removed and replaced with the nucleus of the pet wanting to be cloned. The egg is then put into a mixture of nutrients typically found in a female's uterus and when they become embryos, they are implanted into a surrogate to create the clone. They are then inspected by veterinarians once born, and given to the customer. ViaGen has even gone to created the first cloned black-footed ferret, which is the first ever native endangered species to be cloned in the U.S.

I was not aware that pets could be successfully cloned. I had no idea that cloning was a popular process and that it could be done with ease. Having a replica of a pet is interesting and using these techniques for other species could help with de-extinction and genetic diversity among endangered species. ViaGen's website states that the process only takes a few months, and they can clone bigger animals like horses as well. I hope this company and others like it use this to help species thrive and to bring back animals that are helpful to the environment.

Related Articles:

The Importance of Dolly the Sheep

Bringing Back Extinct Species

Bones Show Dolly's Arthritis Was Normal For a Sheep Her Age

It was reported that Dolly the Sheep suffered from severe arthritis in her knees. New x-ray evidence shows that cloning was unlikely the reason for this arthritis. Other cloned sheep along with Dolly's naturally conceived daughter, Bonnie, were also x-rayed. Results revealed that Dolly had the joints of any normal sheep her age, cloned or not. Dolly had arthritis in her hips, knees, and elbows, which is common in sheep. Dolly, Bonnie, and two other cloned sheep, Megan and Morag, had their bones examined. After examination, it is suggested that Megan and Bonnie, who were older than Dolly at their time of death, had more damaged bones whereas Morag who was younger at death had less bone damage. Overall, Dolly's arthritis levels were equal to those of any normal sheep at her age, suggesting that cloning wasn't to blame. It is thought that her "creaky" joints are a result from giving birth to six lambs.

It is interesting to learn more about Dolly considering every biology student has heard about this famous sheep. I did not know the details of her health such as the arthritis but it is good to know that there is evidence supporting the cloning did not affect that aspect of her health and that it was just due to pregnancy which is common for sheep after giving birth. 

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