The most common organism in the ocean grows a virus in its DNA. Scientists came to this conclusion by studying the marine bacteria SAR11. The findings of the researchers are published in the journal Nature Microbiology.
SAR11 are tiny drifting organisms similar to jelly beans. However, such “crumbs” managed to evolve well, practically displacing other bacteria. This was possible due to the fact that Pelagibacter, another name for these organisms, contains a unique virus. Oceanographers from the University of Washington found that this virus spends most of its time at rest in the host’s DNA but sometimes erupts to infect other cells, transferring part of its host’s genetic material.
“Many bacteria have viruses that exist in their genomes. But today we managed to find them in the most common organisms in the ocean, ”said research co-author Robert Morris, professor of oceanography. “We suspect that this is probably common or more common than we thought before”.
The two-part survival strategy for this virus differs from the similar strategies of other organisms. The virus lurks in the host’s DNA and is copied as the cells divide, but for reasons that are still poorly understood, it also multiplies and is released from other cells.
A new study shows that as many as 3% of SAR11 cells can have a virus that multiplies and cleaves, or lyses a cell, which is a much higher percentage than most viruses that inhabit the host genome. This produces a large number of free viruses and may be the key to its survival.
“The ocean has 10 times more viruses than bacteria”, Morris adds. – Understanding how these large numbers are supported is very important. How does the virus survive? If he kills his master, then how does he find another master before he degrades”.
Research can help with basic research that can help clarify the interaction between the host and the virus in other settings.
Researchers have found that the virus complicates the task of sequencing the genome. Then they discovered that the virus was not only in this single strain. The authors of the study believe that bacterial genes that become infected with viruses can help other SAR11 maintain their competitive advantage in malnutrition.