Discover the origin of the fungus that kills amphibians

According to new research, a poisonous fungus has devastated amphibian populations around the world that are likely to originate in East Asia.

A study in Science supported the idea that the pet trade helped spread the killer lines of chytrid mushrooms around the world.

This fungus is the main cause of significant decline in frogs, toads, newts and salamanders.

There are still no effective measures to control this disease.

The authors of the report emphasize the need to tighten biosecurity along the national border, including a ban on trade in amphibians as pets.

According to the study co-author, Dr. Simon O'Hanlon from Lon Don International School, chytrid n , also has the scientific name Batrachochytrium dendrobatidis, or Bd , was first confirmed to be a problematic problem. in the 1990s.

American frogs are more or less immune to chytrid fungi, but it helps spread the disease to other susceptible amphibians - (Photo from Dirk S).

He explained: 'Up to now, we have not been able to determine exactly where it came from. In the study, we solved this problem and pointed out that it is possible to trace the damage caused by this strain back to East Asia. '

Bd causes a disease called chytridiomycosis , which attacks the skin of animals, interfering with the ability to regulate water levels and electrolytes (salts and minerals needed for important biological functions) of species. this. This can lead to heart failure.

Some species are more affected than other species: while the American amphibian (Rana catesbeiana) seems to be quite immune, other amphibians have nearly 100% mortality.

The team collected mushroom samples from around the world and arranged the genomes of these samples. They combined this information with data from previous Bd genome studies, forming a set of 234 specimens.

Starting point

The members of the research team then observed the relationship between different forms of fungi. They identified four main gene lines, three of which appeared to be globally distributed.

But the fourth category is restricted to the Korean peninsula.

This form of Korean mushroom seems familiar to this area and shows many genetic overlaps with the general population of chytrid fungi than any other strain. Named as BdASIA-1 , it resembles the ancestors of the most current Bd types.

Chytrid fungi have a strong impact on the extremely endangered Corroboree frog, a local species in South Tablelands of Australia.

Later, the researchers used genome data to estimate when the killer fungus flowed from its most recent common ancestor.

Instead of dating thousands of years ago, as predicted earlier, the disease appears to have appeared in the early 20th century, coinciding with the trade of amphibians.

Co-author Professor Matthew Fisher, also from the London School of International Studies, said: 'Our research not only shows East Asia as the starting point of this deadly source of fungal disease, but also reveals the initiation. head of chytrid mushroom diversity in Asia. So, until the trade of sick amphibians ends, we will continue to risk putting global irreplaceable amphibian diversity in danger. '

A study published in Science earlier this year showed that some frogs may have developed disease resistance. But the researchers also warned that it was too early to celebrate any sign of recovery.