A hidden reservoir of red wolf DNA has been found in southwestern Louisiana coyotes — and it could be used to help the endangered wolves grow their wild population
June 29, 2022
A genetic reservoir of red wolf “ghost DNA” has been found hidden in coyote-wolf hybrids in southwestern Louisiana. The long-lost genes represent genetic diversity that experts believed had disappeared when the last 14 wild red wolves were captured and bred in the 1970s.
red wolves (Canis rufus) are seriously threatened. Just over 200 live in captivity and only one population was reintroduced to the wild in North Carolina in 1987. In 2012, that population reached 120 individuals, but today only 20 remain.
The re-wild wolves are genetically homogeneous and therefore more vulnerable to harmful genetic mutations, changing environments and extinction. The genetically diverse coyote-wolf hybrids may hold the keys to the survival of the species.
“It’s hard for me to be anything but optimistic,” said Bridgett vonHoldt of Princeton University in New Jersey.
She and her colleagues sequenced the genome of more than 30 coyotes from southwestern Louisiana, where red wolves last lived in the wild and where they mixed and mated with coyotes. They found that up to 69 percent of the genomes came from red wolves.
The canine chimeras look like intermediates between the two species, but vonHoldt says they behave more like wolves. “I think we shouldn’t call it a coyote anymore,” she says. “If it looks like a wolf, and it acts like a wolf, maybe we should just call it a wolf.”
The wolf-like coyotes may hold the key to conservation. She says that when more red wolves are ready to be reintroduced into the wild, they should be placed close to hybrid carriers of this ghost DNA. Natural pairings between the two could increase the genetic diversity of the dwindling gene pool.
In addition, the researchers are developing biobanks — what vonHoldt calls “frozen zoos” — of coyote cells that can be cloned to revive genetic diversity in the natural population. The biobank could also be used to bring red wolf genes back into captive populations, but vonHoldt remains skeptical about that approach.
Samantha Wisely of the University of Florida, who was not involved in the study, says biobanking “can definitely save a species,” indicating successful cloning of endangered black-footed ferrets and Przewalski horses.
The study fundamentally challenges how we think about hybrids and conservation. “The U.S. Fish and Wildlife Service has no policy on endangered species hybrids,” said Ben Novak of Revive & Restore, a U.S. biotechnology company. “The red wolves could be pioneering in that.”
Wisely agrees that preserving ghost genes from hybrids is groundbreaking. “It’s an innovative approach that really pushes the US Fish and Wildlife Service to action,” she says. Protecting the coyote-wolf hybrids is well within their regulatory power, even if they don’t designate them as an endangered species, she says. “I’m not sure if people have ever talked about conservation in this way.”
Now vonHoldt is working with nonprofits and government agencies to translate these findings into policy. “There’s a lot to do,” she says, “but the future is bright.”
Reference magazine: scientific progressDOI: 10.1126/sciaadv.abn7731
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