More than 730,000 pairs of bases, by far the largest phage “show up”

Is the virus life? The question has not been settled yet. The prevailing view is that viruses are not life. But U.S. scientists recently wrote in the journal Nature that they recently discovered giant phages, the largest of which have 735,000 base pairs of genomes, and these complex phages blur the line between life and non-life.

Phage is a virus specifically infected with bacteria, according to a recent report on the American Fun Science website. Phages and other viruses are not considered living organisms, but this does not mean they are harmless. Phages are the main driver of ecosystem change because they prey on bacterial populations, alter the metabolism of bacteria, spread antibiotic resistance and carry compounds that cause disease in animals and humans.

To learn more about phage, the researchers retrieved a bacteriophage DNA database with phage samples from 30 different environments around the world.

The researchers say the average phage has 50,000 base pairs, but they found that 351 phages have 200,000 base pairs, four times as many as common phages, one of which has 735,000 base pairs — compared to about 3 billion base pairs.

Jill Banfield, a senior study author and professor of Earth and planetary science at the University of California, Berkeley, said the genomes of these “megaphages” are much larger than those of many bacteria, one of the forms of life, and are “hybrids between traditional viruses and traditional biological organisms.”

The researchers also found that the phages had many special genes, some of which were part of the CRISPR-Cas9 system that bacteria use to fight the virus. In addition, some phages have genes that encode essential proteins for ribosome function. Ribosomes are cellular machines that convert genetic material into proteins. These proteins are usually not found in viruses, and they are often found in bacteria and ancient bacteria. Some of these giant phages may also use ribosomes in bacterial hosts to replicate their proteins, the researchers believe.

“The ability to translate ribosomes and proteins is one of the main characteristics that distinguish between viruses and bacteria, life and non-life,” said co-author Rohan Sahdwa, an associate professor at the University of California. Some of the newly discovered giant phages have this translation mechanism, so they blur the line between life and non-life. “

Editor-in-chief circle point

Viruses have occupied the planet long before humans appeared. For the most part, it coexists peacefully with human beings. Viruses copy themselves wholeheartedly. Is it life? Most people think not. Now, scientists’ latest findings have blurred the line between life and non-life – the genomes of viruses that can eat bacteria are so large that there is even a CRISPR/Cas system. When the bacteriophage’s genes enter the bacteria, they can intercept its CRISPR system for their own use, the virus has its own survival strategy, it is absolutely superior IQ! There are so many viruses that humans need to work hard to learn more about this ancient tiny creature.