Scientists Create a Living Clone Embryo from a Long-Extinct Species of Mouth-Birthing Frog

I recently asked whether or not it was a good idea to revive extinct species using cloning technology—something like Jurassic Park, minus the dinosaurs (dinosaurs, it seems have been extinct for too long to ever clone them.)

A lot of people were asking this question over the weekend because of a day-long National Geographic symposium in Washington, DC, on Friday that brought together 25 conservation and biotech experts to discuss the idea of “de-extinction.” Some of the guests made persuasive points in favor of it, others against.

Turns out the discussion, while hardly moot, is already a bit behind the curve. That’s because University of New South Wales paleontologist Mike Archer announced that his team of scientists—called “the Lazarus Project”—had already done it on the embryonic level with a species of frog that went extinct in 1983. Debate, schmebate. The Lazarus Project clones first and asks questions later.

What’s more, this isn’t any ordinary frog: The Rheobatrachus silus is a gastric-breeding frog, which means the females swallow their fertilized eggs, incubate them in its stomach, and give birth through their mouths.

The team has only created embryos so far, and the embryos only lasted a few days. But the embryos are the first of an extinct species to be resurrected using dead cells, the scientists claim. In 2009, a Pyrenian ibex was cloned and died shortly after birth, about nine years after the last living member of the species is known to have died. The difference was that live cells from the ibex’s skin were extracted and frozen while the ibex was still living, preserved for a later date.

The DNA used to build the frog embryos, by contrast, was extracted from long-dead cells taken from frogs that were frozen just before the species went extinct, according to a press release from the University of New South Wales. That DNA was transplanted into donor eggs from a Great Barred Frog (a distant relative) that had had its nuclei removed—a process known as “somatic cell nuclear transfer” (SCNT).

The egg cells created by the SCNT began dividing, forming the beginnings of an embryo. Archer and his team confirmed that the new cells contained the genes of the extinct mouth-birthing frog.

“We are watching Lazarus arise from the dead, step by exciting step,” Archer said in the release. “We’ve reactivated dead cells into living ones and revived the extinct frog’s genome in the process. Now we have fresh cryo-preserved cells of the extinct frog to use in future cloning experiments.

“We’re increasingly confident that the hurdles ahead are technological and not biological,” he continued, “and that we will succeed.”

That certainly seems possible given recent advances in this type of cloning, which has come a long way since it was used to create the first cloned animal, Dolly the Sheep. Earlier this month, Japanese scientists announced they had more or less perfected it for a living species, having successfully cloned 25 generations of healthy, fully-functioning mice from a single source—581 clones from the same mouse.