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An audacious collaboration between geneticists and conservationists plans to bring back the extinct dodo and reintroduce it to its once-native habitat in Mauritius.
US-based biotechnology and genetic engineering company Colossal Biosciences, which is pursuing the “de-extinction” of multiple species, including the woolly mammoth, has entered a partnership _____ the Mauritian Wildlife Foundation to find a suitable location for the large flightless birds.
The dodo has been extinct since 1681; a combination of predation by humans and animals introduced by humans led to its downfall, turning it into a textbook case for extinction. But according to the partners, its return to Mauritius could benefit the dodo’s immediate environment and other species.
Colossal first announced its intention to resurrect the dodo in January 2023. Exactly when it will be able to do so remains unclear, but fresh details regarding how it plans to recreate the species have been revealed.
The full genome of the dodo has been sequenced by Beth Shapiro, lead paleogeneticist at Colossal. In addition, the company says it has now sequenced the genome of the solitaire, an extinct relative of the dodo from Rodrigues Island, close to Mauritius, and the Nicobar pigeon, the dodo’s closest living relative, which resides on islands in Southeast Asia spanning the Indian and Pacific Oceans.
Geneticists at Colossal have found cells that act as a precursor for ovaries or testes in the Nicobar pigeon can grow successfully in a chicken embryo. They are now researching to see if these cells (called primordial germ cells, or PGCs) can turn into sperm and eggs.
This is a vital step in creating hybridized animals through reproduction. Scientists have previously introduced PGCs to create a chicken fathered by a duck – for which a duck embryo was injected with chicken PGCs, producing an adult duck with the sperm of a rooster. It then bred with a hen, which gave birth to a chick.
Colossal plans to go down a similar route. First, it will compare the dodo and solitaire genomes to the Nicobar pigeon’s to identify how they differ. Then it will edit the PGCs of a Nicobar so it expresses the physical traits of a dodo.
The edited PGCs will then be inserted into the embryos of a sterile chicken and rooster. With the introduction of the edited PGCs, the chicken and rooster will be capable of reproducing, and, in theory, their offspring will resemble the dodo thanks to the hybridized pigeon DNA in their reproductive systems.
“Physically, the restored dodo will be indiscernible from what we know of the dodo’s appearance,” said Matt James, Colossal’s chief animal officer, in an email.
James described the project as “an amazing engine of innovation for avian genetics, genomics, and cell biology,” in part because “most of the technologies that we use for cloning in mammals does not exist in birds today.” However, he declined to put a timeline on when the first embryo will be created.
