Friday, January 28, 2022

Resurrecting Lost Genetics: Cloning Historic Horses to Increase Genetic Diversity in the Przewalski's Horse Population


    The Przewalski's horse, also known as Equus przwalskii, has been struggling with extinction for many years. At one point the Przewalski's was believed to be completely extinct in the wild, but conservation efforts have succeeded in reintroducing Przewalski's horses into protected areas in their natural habitat. More information about Przewalski's horses can be found here

    With a population of about 2,000 individuals in captive breeding programs and in protected areas, the Przewalski's horse has been classified as an endangered species, but the Przewalski's horse is beginning to face a different challenge. The Revive & Restore conservation organization, who has been involved in the conservation efforts of Przewalski's horses, explains that the Przewalski's horse population is now suffering from genetic bottlenecking. Genetic bottlenecking commonly occurs when population numbers are low, and it causes a decrease in genetic diversity in the population because of inbreeding. This lack of genetic diversity causes species to be extremely venerable to sudden environmental changes or diseases because they do not have the genetic variation that helps them to adapt to change. 

    The most common solution to this problem is brining unrelated individuals into the population to broaden the gene pool, but for the Przewalski's horse there are not unrelated individuals because all living Przewalski's horses are decedents of 12 individuals that remained when the recovery efforts began. Thanks to modern science, these unrelated individuals do not necessarily need to be living to be introduced into the population. Conservationist had saved living cells from more than a dozen Przewalski's horses and had them cryopreserved, and these cells contain genetics that are no longer found in the current Przewalski's horse population. Scientists are reintroducing these lost genetics by cloning the historic Przewalski's horses using the frozen cells. In 2020 they successfully cloned a past stallion who they have names Kurt, and once Kurt reaches sexual maturity he will be used in breeding and will help to bring more genetic diversity into the population.

    This is not only an amazing feat in science, but it also such an amazing thing to whiteness. I think the cloning of past Przewalski's horses in order to reintroduce lost genetics is spectacular. As someone in the horse community, I have heard both the advantages and disadvantages of equine cloning and the debate over cloning horses, so it brings me great joy to see this scientific advancement be used to assist the Przewalski's horses on their road of population recovery.

Link to the press release from the San Diego Zoo Global (now known as the San Diego Zoo Wildlife Alliance)

Przewalski's Horse Press Release Revive & Restore.pdf - Google Drive

No comments:

Post a Comment