Scientists have discovered remnants of the genome left behind by giant ancient creatures. virus It is in the DNA of single-celled organisms that complex organisms like us humans share a common ancestor.
The discovery suggests that viruses may have played a larger role in our evolution than we realized, donating genes to cells like our symbiotic eukaryotic ancestors. Amoebidium Advantage for survival.
The new study comes from a team led by evolutionary biologist Alex de Mendoza Soler of Queen Mary, University of London.
“It’s like, Amoebidium “DNA,” he said. To tell“These viral insertions are potentially harmful, but Amoebidium It seems like we are suppressing them by chemically silencing them.”
“Here we show how a single-celled eukaryote closely related to animals undergoes an iterative process that mixes its genome with that of a larger eukaryote. virus The authors say the following about the predators: write.
Such a violent attack on the very blueprint of the self AmoebidiumBut microbes seem to have found a way to cope by altering one of the four letters of their DNA alphabet to silence foreign genes. 5-Methylcytosine (5mC).
The base cytosine, or “C,” is modified by an enzyme called . DNMT1is present in all multicellular organisms. Researchers wanted to find the enzyme’s pre-animal origins. One Protists It is called Amoebidium appalachense, Which First discovered hiding in the exoskeleton of a freshwater insect.
They discovered that these single-celled organisms not only produce DNMT1, but also use it to maintain surprising amounts of genetic material from giant viruses that have been lost throughout history.
“These findings call into question our understanding of the relationship between viruses and their hosts.” To tell de Mendoza Soler.
Viruses are traditionally thought of as invaders, but the team’s research suggests a more complex story, he says.
The researchers propose that this coping mechanism allows microbes to not only survive an influx of giant viral DNA, but also to incorporate it into their own lineage.
To see if this phenomenon could be more widespread, the researchers tested a variety of isolated Amevidia. They found high levels of diversity across the viral material, suggesting that the process is continuous and dynamic.
“Viral insertions could have played a role in the evolution of complex organisms by contributing new genes, and this is possible by chemically controlling the DNA of these invaders,” says Mendoza Soler. To tell.
and, Apalachiense Although they are animal relatives, these discoveries may help us better understand similar phenomena occurring within our bodies.
The DNA of humans and other mammals also contains the remains of ancient viruses. Called endogenous retroviruses, they are thought to be the remains of viruses that failed to kill humans.
Once thought to be merely the spoils of a failed invasion, More and more thought is being given to Many of them may have provided some benefit and are still stored in our DNA.
This study Scientific advances.
