Novel viruses of unusual organisms
Three new viruses were discovered by the team of virologists from the Biology centre inside fungus Sodiomyces alkalinus. Not only they comprise a rather unusual combination of viruses, these three are also the first viruses found in filamentous fungi growing in an extremely alkaline environment.
From the smallest bacteria to the largest mammal - virtually every organism on Earth has its own virus, and very often not just one. With the development of the next generation sequencing, it has become apparent that the number of viruses we know so far (about 12 to 13 thousand species) is probably much smaller than the usually mentioned tip of an iceberg. Moreover, most of known viruses today come from organisms that live in the “normal” environment. Very little is known about the viruses infecting organisms which live in extreme conditions – so far only dozens of such viruses have been discovered.
An addition to the latter has been made by Lenka Hrabáková, Igor Koloniuk, Tatiana Sarkisová a Karel Petrzik from the Department of Virology at the IPMB, who – together with their Dutch colleagues – discovered three new RNA viruses in the newly described fungus Sodiomyces alkalinus. This fungus is found on Earth on strongly alkaline soils (pH = 10-11) around some salt lakes in Asia and Africa. The finding of the same three viruses within the samples from four, almost 3,000 kilometers distant areas, is very unusual. It is likely that these viruses have been spreading together for a longer time, even if we do not know any possible evolutionary advantage they could provide to their hosts. No negative effects on fungus health were detected, yet all three viruses are transmitted by spores of fungi.
Since the same team has previously discovered a special case of "nude" fungi viruses and is searching for new viruses intensively, it looks like we can expect further discoveries in the future, revealing the world of viruses of unusual organisms.
Hrabáková L., Grum-Grzymailo Alexey, Koloniuk I., Debets Alfons, Sarkisová T., Petrzik K. (2017) The alkalophilic fungus Sodiomyces alkalinus hosts beta- and gammapartitiviruses together with a new fusarivirus PLoS ONE 12 (11): e0187799. DOI: 10.1371/journal.pone.0187799