In a breakthrough discovery, scientists have identified a viral fragment that could potentially combat the fungal pathogen responsible for devastating frog and toad populations. The fungus, known as Batrachochytrium dendrobatidis (BD), has caused major declines in over 500 amphibian species, leading to 90 possible extinctions and near-extinctions.

The viral fragment, called BdDV-1, was discovered by researchers who published their findings in the journal Current Biology. During their investigation into weaknesses of the BD fungus, they found a single-stranded DNA virus trapped within the fungus's genome. Curiously, when infected with BdDV-1, certain strains of the fungus produced fewer spores compared to uninfected fungi.

However, there is a significant challenge ahead: the virus currently worsens the fungus's ability to attack frogs instead of weakening it. Timothy Y. James, professor at the University of Michigan's Department of Ecology and Evolutionary Biology, revealed that the virus even surprised researchers by not affecting the health of host frogs and fungi as expected.

Although initially discouraging, scientists are optimistic about the discovery of BdDV-1. Prior to this study, finding a virus capable of infecting the BD fungus had proven difficult. Now, researchers have not only found a virus, but one that can be kept alive in a laboratory and potentially manipulated through genetic modification.

The next step involves modifying the BdDV-1 fragment to have a positive effect on the fungus that benefits the frogs. By utilizing a process called transformation, the researchers aim to introduce the modified virus sequence into the BD strains to test its function. These efforts could potentially lead to a Trojan horse strategy to eliminate the fungus and save the frog populations.

Additionally, this research expands our understanding of mycology, the study of fungi biology. Previously, it was uncertain if mycoviruses (viruses that infect fungi) could infect them unless they were RNA viruses. The BdDV-1 is the first full-length CRESS virus of Circoviridae, a specific family of viruses, known to infect fungi. However, many questions remain unanswered regarding the mechanisms by which the virus infects the fungus.

While the experts acknowledge that it is "unclear" how this newfound knowledge will directly aid in saving frogs, they are confident that the virus can indeed infect the fungus. This opens up possibilities for using the viral backbone to deliver beneficial genes into the fungus, potentially offering a Trojan horse-like strategy to combat the fungus in the future.

The research conducted thus far brings hope to the fight against BD, which is driving one of the largest mass extinctions of our time. By harnessing the power of this newly discovered virus, scientists may be one step closer to finding a cure that can protect endangered amphibian species from the devastating effects of this deadly fungus.