Viruses share genes with other organisms

According to a new study published in the Frontiers in Microbiology viruses share some genes with cells that do not come from their hosts, adding to evidence that viruses swap genes with other cellular organism making them agents of diversity. Viruses can share cells from the single celled microbes known as archaea, bacteria, and eukarya, a group which includes plants, fungi, animals, and all living things, the 3 super kingdoms of life.

The study investigated protein structures in viruses as well as in across all the super kingdoms and domains of life and found that viruses can form partnerships with other organisms and can live in communities. Researchers used a bioinformatics approach to go about studying the genomes of organisms and the viruses that infect them. They studied functional compounds of the proteins, called folds, of which there are over 1400 of across all domains of life, each having a unique structure that performs a specific action, and remain stable as the coding for the sequence changes as a result of mutations and other processes.

Researchers found that hundreds of folds are present in all types of viruses and across all the super kingdoms of life, suggesting that they came from an ancient ancestor of all life forms. The DNA from humans also contains trace remnants of viruses. Some folds only occur in one super kingdom and the viruses that infect it, suggesting a genetic material transfer between that group of viruses and their host.

The data also points to other still unknown mechanisms that allow the viruses to exchange some genetic materials with cells. Researchers also found a subset of virus specific protein folds that weren’t present in any cellular genomes, which suggests that viruses have the ability to create new genes and possibly transfer them to cellular organisms.