• Alex Taylor

Will We See Their Likes Again?

The gastric brooding frog had an...interesting way of reproducing. Sadly, this marvel of nature has been extinct for 30 years. Nevertheless, conservation has stepped in and its DNA could be used to bring it back to life.

The gastric brooding frog's DNA has been reactivated

A line adapted my country’s national anthem, Flower of Scotland, is the question I asked myself when I heard about the subject of this post. And as I discovered, the answer may well be yes.

The gastric brooding frog is a genus of ground-dwelling frogs native to Queensland in eastern Australia. The genus consists of only two species, the southern and the northern…well, it did, until both species went extinct in the 1980s. Now the gastric brooding frog is no longer.

It truly was a weird and wonderful creature. A clue in its name reveals that these two species were the only frogs to incubate their young in the female’s stomach and give birth through her mouth. Yep, you read that right.

Once the eggs were fertilised, the female swallowed them and the tadpoles developed in her stomach. They weren’t digested like items in the stomach usually are because the production of hydrochloric acid aka digestive juices in her stomach was stopped by the hormones produced by the young. In fact, while they were inside, the female’s entire digestive system shut down and her stomach turned into a womb.

Six to seven weeks later, they are ready to be born. She opens her mouth widely and dilates her oesophagus which propels her offspring from her stomach to her mouth. Then ta daa, up to 25 fully formed baby frogs emerge. Four days later, the new mother’s digestive tract goes back to normal, and she can start to feed again.

This truly unique and fascinating method of reproduction makes its extinction all the more devastating. Just as scientists were beginning to study it and people were appreciating its weirdness, it went extinct. The exact cause is unknown, but habitat loss or degradation, pollution, pathogens, parasites and over collecting may all have contributed.

However, a group of scientists under the name of the Lazarus Project have taken the first steps to bringing the frog back to life. Having located a few carcasses stored in a deep freezer, they were able to recover tissue samples. A laboratory technique called stomatic cell nuclear transfer was then used to implant the dead frog’s cell nucleus into a fresh egg from a related and very much alive frog. The reproductive process took over and an embryo was created – the reactivation of DNA from an extinct species was achieved.

The embryo did not survive for long, but in 2013 the project was named as one of the best inventions of the year. Not much more has been heard from the project since then, but the team behind it are certain that their method is a way of future-proofing a species, and potentially bringing other species back to life.

De-extinction is controversial as it distracts from conservation work that needs to be done to save species that still exist but are in serious danger of going extinct. Yet the scientists argue that bringing back the gastric brooding frog may provide insights about reproduction that lead to treatments for pregnant women who have trouble carrying babies to full term. I don’t like the fact that benefits to us humans are used as a reason to justify resurrecting other species, like their worth is only measured by how we can benefit from them. On the other hand, if it can help species whose populations become perilously close to extinction, it is useful research. Still making my mind up about this one.

#deextinction #frog

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