Oliver Ryder says the successful cloning of a Przewalski’s horse from living cells collected more than four decades ago shows how far genetic preservation has advanced. The work builds on efforts to use cloning to support endangered species, including the black-footed ferret in the United States, and to increase their genetic diversity.
Ryder, who helped establish a frozen-cell collection at the San Diego Zoo, says the prospect of cloning mammoths from DNA found in Siberian permafrost is exciting but also unsettling. Asked about the idea, he raised a basic question: what would be the purpose? He added that the power these technologies offer makes him uneasy.
His work began with a focus on molecular biology and the causes of extinction. At the San Diego Zoo, Ryder was able to collect skin samples, take biopsies and freeze living cells for later study. He worked with zoos holding Przewalski’s horses, whose population had descended from a small number of animals captured in the early 20th century, leaving the species with reduced genetic diversity.
The zoos formed a cooperative, sending Ryder skin samples from horses that died. The effort helped launch a frozen genetic bank, and Ryder says the San Diego Zoo now holds living frozen samples from 12,000 animals. His biobank preserves material from more than 1,300 animal species.
After the 1996 cloning of Dolly the sheep, Ryder and colleagues explored how cloning could assist conservation. The first cloned Przewalski’s horse, Kurt, was born in 2020 using cells frozen in 1980. A second clone, named Ollie after Ryder, has also been produced. Ryder says Kurt is growing into a potential leader of the herd and is already producing sperm.
Sources: La Vanguardia.