By Will Dunham
WASHINGTON, May 22 (Reuters) - A U.S. company said more than two dozen healthy baby chickens have hatched from an artificial egg platform it has developed in what it calls a pivotal step in its plan to bring back the South Island Giant Moa, a large flightless bird from New Zealand that went extinct centuries ago.
The announcement was made this week by Colossal Biosciences, a company dedicated to "de-extinction" - resurrecting vanished species. The moa is one of two birds - the dodo being
the other - among the six species in its portfolio to revive, guided by ancient DNA. The company said last year that it had genetically engineered the dire wolf, an extinct Ice Age predator.
"Using our system we have hatched 26 chicks and we are now actively monitoring these birds as they grow up," Colossal CEO and co-founder Ben Lamm told Reuters.
The chicks hatched at Colossal's Dallas headquarters, Lamm said.
The artificial egg platform involves a bioengineered silicone-based membrane placed inside a rigid outer structure. The membrane was made to mimic an eggshell's gas-exchange function - permitting the embryonic bird to breathe oxygen by regulating the movement of gases and moisture.
"The technology is designed to closely replicate the conditions of a natural egg to produce healthy animals with normal development, fertility and longevity. This is especially important for species like the moa, whose eggs were far larger than those of any living bird, making traditional surrogate approaches impractical," Lamm said.
Through cloning, embryos in the dire wolf project were created from edited gray wolf cells, and these were implanted in surrogate domesticated dog mothers. But no extant avian species is sufficiently large to lay a South Island Giant Moa egg, about the size of a soccer ball.
The moa, which stood up to about 12 feet (3.6 meters) tall, went extinct roughly 500 years ago, largely due to hunting by people. The emu, a large flightless bird from Australia that can reach about six feet (1.8 meters) tall, is its closest living relative.
"In order to hatch a South Island Giant Moa, Colossal needs a way to gestate the embryo. There is no living surrogate large enough to lay a South Island Moa egg, as they are around eight times larger than an emu egg," Lamm said.
Lamm described how the artificial egg process works.
"The process begins with a fertilized avian embryo, similar to the earliest stages of development inside a natural egg. The embryo and yolk are then transferred into Colossal's artificial egg platform, which is designed to replicate the key functions of a natural eggshell and incubation environment, including gas exchange, moisture regulation, temperature stability and developmental support," Lamm said.
"As the embryo develops, the system provides continuous environmental control and supplementation where needed - for example, calcium support during skeletal growth, which would normally come from the natural shell. Because the embryo develops visibly on top of the yolk, researchers can monitor development in real time throughout embryogenesis," Lamm said, the process in which a fertilized egg develops into an embryo.
For the 26 chicks, the total development time from embryo transfer to hatching was approximately 21 days, consistent with normal development for the species, Lamm said.
This artificial egg platform, Lamm said, could be useful in conservation of endangered bird species. It also is an important step toward bringing back the moa, Lamm said.
"Other hurdles include the need to reconstruct an accurate moa genome from ancient DNA, identify the genetic basis of key moa traits and engineer those traits into a closely related living species such as the emu," Lamm said.
"At Colossal, the project is currently in the genome-sequencing phase," Lamm said, focused on building high-quality genomes for this and the eight other extinct moa species. "So far, the team has identified multiple strong ancient DNA sources, including samples from the South Island Giant Moa."
(Reporting by Will Dunham; Editing by Daniel Wallis)
