A pandemic among frogs has been going on worldwide for years\u2014the culprit: a fungal infection that has affected amphibians on nearly every continent.<\/p>\n
But now, the discovery of a virus that has evolved to replicate inside this fungus could be the key to saving nearly 500 species of frogs that have experienced declines due to this amphibian pandemic.<\/p>\n
Viruses are the smallest organisms we know about, and researchers at Univ. of California, Riverside weren\u2019t out looking for one when they found it embedded in the fungus DNA.<\/p>\n
The fungus Batrachochytrium dendrobatidis or Bd, wasn\u2019t prevalent until the late 1990s, when suddenly frogs just started dropping dead all over the world.<\/p>\n
\u201cWe wanted to see how different strains of fungus differ in places like Africa, Brazil, and the U.S., just like people study different strains of COVID-19,\u201d said UCR microbiology professor Jason Stajich.<\/p>\n
To do this, Stajich and colleagues used DNA sequencing technology. As they examined the data, they noticed some sequences that did not match the DNA of the fungus.<\/p>\n
\u201cWe realized these extra sequences, when put together, had the hallmarks of a viral genome,\u201d Stajich said.<\/p>\n
The team found that the virus\u2014a single-strand DNA virus which literally is the smallest known organism\u2014is integrated into the nuclear genome in some strains of Bd.<\/p>\n
Attempts to cure virus-positive isolates were unsuccessful; however, differences between naturally virus-positive and virus-negative Bd isolates suggested that this virus decreases the growth of its host in vitro, the authors write.<\/p>\n
They speculate that if the virus could be replicated and then engineered to further reduce this growth, biologists may have a method of saving amphibians like the harlequin frogs of Ecuador which have been heavily affected by Bd.<\/p>\n
The scientists say that a lot more research is needed before such a cure might be manufactured, including for questions like how this virus infects its host.<\/p>\n