A fungus on almost every continent may be the Achilles heel of frogs and toads. Scientists have discovered a virus that infects fungi, and it may be engineered to guard amphibians.
The fungus, or Bd, destroys the skin of frogs and toads, and eventually causes heart failure. To date it has contributed to the decline of greater than 500 amphibian species, and 90 potential extinctions, including the yellow-legged mountain frog within the Sierras and the golden frog of Panama.
A brand new paper within the journal documents the invention of a virus that infects Bd, and which may be engineered to manage the fungal disease.
The UC Riverside researchers who found the virus are excited in regards to the implications of their discovery. In addition to helping them find out about how fungal pathogens grow and spread, it offers hope for ending what they call a worldwide amphibian pandemic.
“Frogs control spoilage insects, crop pests and mosquitoes. If their populations are wiped out worldwide, it could be catastrophic,” said Mark Yacob, a doctoral student in microbiology at UCR and the paper's writer. said
“They're also the canary in the coal mine of climate change. As temperatures warm, UV light gets stronger, and water quality deteriorates, frogs respond. If they die out, So we lose an important environmental signal,” Yaqub said.
Bd wasn't prevalent before the late Nineties, but then, “all of a sudden the frogs started dying,” Yacoob said.
When they found the virus that causes BD, Jacob and UCR microbiology professor Jason Stejch were working on the population genetics of BD, hoping to search out out where it got here from and the way it's changing. Was hoping to get a greater understanding of it.
“We wanted to see how different strains of the fungus differed in places like Africa, Brazil, and the Americas, just like people study different strains of COVID-19,” Stejch said. To do that, the researchers used DNA sequencing technology. When they examined the info, they noticed some sequences that didn't match the DNA of the fungus.
“We realized that these additional sequences, when put together, were characteristic of the viral genome,” Stejch said.
Previously, researchers have searched for Bd virus but haven’t found it. The fungus itself is difficult to check since it requires complex procedures to maintain it alive within the laboratory.
“It's a tricky fungus to even track because they have a life stage where they're motile, they have a flagella, which resembles a sperm tail, and They float.”
Additionally, finding viruses that infect Bd was difficult because essentially the most well-known viruses that infect fungi, generally known as mycoviruses, are RNA viruses. However, this virus is a single-stranded DNA virus. By studying the DNA, the researchers could see the virus embedded within the genome of the fungus.
It appears that just some strains of the fungus contain viruses of their genomes. But those affected appear to behave otherwise than those that don't. “When these strains have the virus, they produce fewer spores, so they spread more slowly. But they can also be more virulent, killing frogs more quickly,” Stejch said.
Right now, the virus is essentially stuck contained in the fungal genome. The researchers would eventually prefer to clone the virus and see if a manually infected strain of Bd also produces fewer spores.
“Since some strains of the fungus are susceptible and others are not, this highlights the importance of studying multiple strains of the fungus species,” Yacoub said.
Going forward, researchers are on the lookout for insights into how the virus works. “We don't know how the virus infects the fungus, how it gets into the cells,” Yacoub said. “If we're going to engineer viruses to help amphibians, we need answers to questions like these.”
In some locations, it seems that some amphibian species have acquired resistance to Bd. “With COVID, there's also a slowing of immunity. We're hoping to help nature,” Yacoob said.