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Happy short work week to those of you in the U.S.! I want to take a minute to highlight again this amazing accomplishment in #geneticRescue, and also correct a mistake that I made in my first post 1/12 https://twitter.com/bonesandbugs/status/1302628586461962240?s=20
Firstly, although I would find this cool if anyone had accomplished it, I'm extra excited about this work because one of the key players is @Revive_Restore, an amazing tech-oriented conservation nonprofit for which I am on the Board of Directors. 2/12
https://reviverestore.org/
https://reviverestore.org/
In my excitement to share their good news, however, I tweeted that Kurt is a "one month old purebred Przewalski's horse." The issue is with my use of the word "purebred."
While Kuporovich, the stallion whose cryopreserved cells were used to clone Kurt, is listed in the PH studbook, his pedigree shows that 16.25% of his nuclear makeup is from a domestic mare. 4/12
The admixture of domestic horse DNA into the Przewalski’s horse preservation herd (from which Kurt is descended) happened around 1908. 5/12
After its only PH stallion died, one breeding station used the hybrid offspring of that stallion and a domestic mare to breed to its PH mare. This was the first documented introgression into PH from a domestic horse in the history of the management under human care. 6/12
So why is bringing Kuporovich’s genetic variation back into the PH gene pool good for Przewalski’s horses? Intriguingly, it is because of this admixture event. 7/12
I Issues surrounding pure v mixed ancestry have fraught PH management strategies for decades, as many breeders embraced the idea that they needed to use only "pure" individuals if they wanted to retain wild horse variation. 8/12
Because so many Przewalski’s horses were admixed, however, this resulted in the loss of quite a lot of wild horse variation that wasn’t present in those “pure” lineages This is where Kurt comes in! 9/12
The variation in Kuporovich’s genome (and therefore Kurt’s genome) includes some of that lost variation! Reintroducing this lost variation will enrich the Przewalski horse breeding program and aid their management into the future. 10/12
I should also say that Kurt's birth is the first step of a long-term project to revive P-horse diversity. @Revive_Restore @sandiegozoo and @ViaGenPets_ will sequence more DNA, explore viability of more cell lines, and, hopefully, resurrect more extinct P-horse diversity 11/12
Many thanks to @frozenzoo for talking me through the history of Przewalksi's horse management & helping me to understand this better! I know also that there is a manuscript coming soon that describes this work in detail. Here's to more successes! 12/12 https://time.com/5886467/clone-endangered-przewalskis-horse-zoo/
