Giant viruses dating back 1.5 billion years were found in Yellowstone’s geothermal springs, which scientists say could reveal the conditions under which life emerged on Earth.
The viruses are labeled ‘gigantic’ because they have extremely large genomes compared to regular viruses and pose no risk to humans, but could explain what conditions were like on Earth when single-celled organisms formed.
Researchers from Rutgers University found that the viruses were bacteria, while others belonged to archaea – a single-celled organism similar to bacteria – that requires extreme environments to reproduce and eukaryotic, which is found in fungi.
Previous theories suggested the viruses were more recent because hot springs come and go over time, but the latest study found they have lived at least as long as cellular organisms.
Giant viruses with ancient origins dating back 1.5 billion years were found in Yellowstone’s geothermal springs
Initially, the researchers thought that the giant viruses would not be very old because the hot springs form and disappear, meaning the viruses would have to form again under higher temperatures in the newly developed hot spring.
Hot springs are located on dormant volcanoes whose magma heats the groundwater, causing the steam and less dense hot water to rise through fissures in the earth, creating geysers and hot springs.
Yellowstone’s hot springs formed at least 15,000 years ago after the last glaciers in the region melted, allowing the geysers to rise – but the bacteria had already flourished more than a billion years before that.
However, the findings showed that “the connections between the viruses and (the hot springs) are ancient,” Bhattacharya shared. Science.
The viruses thrive in temperatures above 200 degrees Fahrenheit, high pressure or excessive salt concentrations, and researchers believe they reproduce by infecting red algae in the hot springs.
Researchers analyzed DNA in Lemonade Creek – an acidic hot spring in Yellowstone that reaches temperatures of about 111 degrees Fahrenheit.
They took samples from the thick green mat that covered the creek bottom, called Rhodophyta or red algae, and from the nearby soil and area between rocks that were near the creek bed.
The researchers found that the DNA contained sequences from archaea, algae (eukaryote) and bacteria that harbored 3,700 potential viruses – about two-thirds were giant viruses not known to infect humans.
Eukaryotic cells are found in fungi, plants, animals and other single-celled organisms
About 51 percent of the viruses found came from bacteria that have evolved to adapt to increasingly higher temperatures
Archaea make up 40 percent of the microbes that live in the ocean and are also found in the intestines of people and animals, as well as in hot springs such as Yellowstone, where each pool contains a different mineral content, salinity and temperature.
Archaea make up 40 percent of the microbes that live in the ocean and are also found in the intestines of people and animals, as well as in hot springs such as Yellowstone, where each pool contains a different mineral content, salinity and temperature.
The team used computer analysis to narrow down the official viruses to 25 different types that they believe used red algae to reproduce.
This association likely began 1.5 billion years ago, when viruses first evolved by borrowing each other’s genes to acclimatize to the heat and toxins such as arsenic found in hot springs.
The viruses had to adapt to the changing climate as glaciers melted and hot springs emerged. Therefore, the bacteria and archaea borrowed genes from each other to survive under extreme conditions.
From there, bacteria and archaea reformed into eukaryotes – which are single-celled organisms found in plants and fungi.
By developing and trading genes, “the viruses probably play an important role in the long-term stability of the hot spring communities,” Andreas Weber, a biochemist at Heinrich Heine University Düsseldorf, who was not involved in the study, told Science.
The DNA samples contained 921 unique genome candidates that likely jumped from one host to another.
“This work supports the concept that viruses are present wherever cellular life exists, that viruses exist at least as long as cellular life,” Mark Young, an emeritus environmental virologist at Montana State University who was also not involved in the work, told me. was, to Science.
Young was part of the research team that first discovered the giant viruses in Yellowstone’s Midway Geyser Basin and identified many of the archaea as thermophiles, meaning they thrive in hot, acidic conditions like those in the park.
“Wherever there is life, we expect viruses,” Young said Montana State University (MSU) in 2004, and then-park geologist Hank Heasler added, “This is a great example of why we need places that are protected so scientists can come in and look for new discoveries.”
Although these viruses don’t make people sick, scientists are still studying them to better understand their role in evolution and how they move their genes from one organism to another.
“They’re not just a passenger,” Young told MSU at the time. ‘They are the most important source of biological material on this planet. They play a major role in the movement of genes.’