Finnish researchers have isolated the country's first giant virus, named Jyvaskylavirus, according to a study published in the journal eLife. The virus was discovered by an international research team from the University of Jyväskylä in central Finland.
Named after the Finnish city where it was found, the virus has a diameter of about 200 nanometers, making it roughly twice the size of the influenza or coronavirus. Identified in a compost sample, the discovery suggests giant viruses are more common in soil and water bodies – even in northern environments – than previously assumed.
The researchers mixed environmental samples with a culture of the amoeba Acanthamoeba castellanii to isolate the virus, uncovering not only Jyvaskylavirus but also other new giant viruses in the samples.
"We determined the genome and structure of Jyvaskylavirus, and it was found to be related to the 'Marseillevirus' previously isolated in France. Additionally, other new giant viruses were identified in the samples," said Professor Lotta-Riina Sundberg, as reported by Science Daily.
Giant viruses, like Jyvaskylavirus, have been discovered in recent years and can be as large as bacteria, sometimes up to 1,000 times larger than their relatives. These viruses can have genomes with up to 2.5 million base pairs in their genetic material, far exceeding the 7,000-20,000 base pairs typical of standard-sized viruses.
According to SciTechDaily, the discovery of Jyvaskylavirus highlights how much remains unknown about the structure, origin, and function of many giant viruses.
"This new discovery will help us better understand the interactions between bacteria and the role of viruses in regulating communities of all living organisms," Sundberg said.
In recent years, over 60 species of giant viruses have been documented in remote regions worldwide, including Europe, South America, North Africa, India, Japan, and Siberia. Scientists have identified giant viruses – some as large as bacteria – that infect amoebas and other microorganisms. One such virus, Tupanvirus, was discovered in 2018 in brackish swamps in Brazil.
Other giant viruses have been found in extreme environments, such as Siberia's frozen soil, where Pithovirus and Mollivirus retained their infectivity after 30,000 years. Researchers have warned that climate change could lead to the release and reactivation of additional harmful viruses as ice melts.
"Despite their intimidating name, giant viruses are not necessarily more dangerous than regular-sized species, and Jyvaskylavirus is not considered a threat to humans," the scientists reported.
The researchers hope further studies will deepen the understanding of these unique microscopic organisms. "These giant viruses play key roles in ecosystems and are more widespread than previously thought," Science Daily reported.
Giant viruses have exponentially larger genomes compared to standard-sized viruses. While many viruses measure tens of nanometers in size, Jyvaskylavirus is larger but still significantly smaller than the largest known giant virus, Pandoravirus salinas, which measures 500 nanometers.
