Happy Nice Mall

Known as the destroyer angel, the deadly daredevil, and the funeral bell, all three mushrooms have one thing in common: the incredibly deadly toxin alpha-Amanitin. If you eat one of these mushrooms, symptoms may not appear for several hours. But soon the toxin begins to wreak havoc on your body’s ability to copy genes. On the fourth day after consumption, your liver and kidneys begin to deteriorate. You may die in about a week.

There is a mystery at the core of this enigmatic infinity: These mushrooms belong to three distinct species, or groups of mushroom species, that are not closely related. How did they come to make the same toxin?

In An article published Monday in the Proceedings of the National Academy of SciencesBy sequencing the genomes of 15 fungal species from these three groups, scientists make an interesting claim: The genes that make up Alpha-Amanitin, rather than being inherited from a common ancestor of these groups, are probably extinct fungi that were not directly known to them.

This type of gene transfer, called horizontal gene transfer, is common among bacteria, said Hong Luo, a researcher at the Kunming Institute of Botany in China and author of the new paper. Tiny bits of DNA are passed from one microbe to another, then passed on to their offspring. However, growing evidence suggests that genes are somehow able to move between complex, multicellular organisms, perhaps with the help of pathogens. In April, another group of scientists reported: The genes had moved between snakes and frogs living in the same forest habitat, riding on common parasites.. It sounds strange, but it may help explain some surprising observations in the tree of life.

The team behind the mushroom paper already suspected horizontal gene transfer had created the same toxins in these fungi. But there were some surprises when they completed their research. They had hoped that their look at the genetics of fungi would confirm that one group had passed on the genes to the others. Instead, the gene toxin clusters all appeared equidistant from their origins.

“It surprised us,” said Dr. Luo.

In discussing this, the paper’s authors agreed that the simplest explanation was that horizontal gene transfer occurred—but not necessarily between these three groups.

“That’s when we started to think it must have been another species that probably went extinct,” said Francis Martin, a scientist at the French National Research Institute for Agriculture, Food and the Environment and author of the paper.

This long ago the fungus would have had the genetic toolkit to make the toxin and pass it on to still-living varieties in ways still unknown. The affected mushrooms are not its descendants – they are simply carriers of a small packet of genes that give mushrooms their extraordinary poisonous power, released like a message in a bottle.

Scientists will never know much about this proposed donor for the toxin genes, if any. But researchers wonder why these three groups of all fungi inherited and used it. Do toxins play a special role in the ecology of these fungi? Or are fungi particularly good at whatever mysterious techniques that bring genes from the environment into their genomes?

Perhaps some of these answers will become clearer as scientists learn more about how horizontal gene transfer works beyond bacteria.

“We know it does,” said Dr. “But we don’t know how,” Martin said.