Viruses are not always loose, free-floating pieces of encapsulated DNA in the environment, unlike most kinds of bacteria. Instead, many of them spend their life cycle, as much as a virus can be said to have one, inside other organisms like the aforementioned bacteria or higher order creatures. And for the viruses in the family Retroviridae that integrate themselves into the genome of their host cell for later replication, it is significantly more difficult to tease out what is a normal part of the cell’s genes and what is actually ancient viral DNA.
A New Generation
For scientific researchers, there is a strong desire to be capable of sorting through this genetic information. Since being able to isolate and understand viruses embedded into the genomes of organisms can lead to preventative measures against them before they actively become dangerous to the species whose genome they are isolated in. Research into this was previously isolated to studying viruses in humans and certain select agricultural animals, but modern technology has enabled us to finally go beyond that and to largely study the genome of any species that is desired.
Such a newfound capability is thanks to the formation of Next Generation Sequencing (NGS), a nascent group of techniques focused on metagenomic analysis of genomes to filter out what belongs and what has been added. These methods do not require active cell cultures nor do they rely on genetic markers to be able to breakdown the parts of a genome, making them especially suited to this particular work. It is due to this that NGS has led directly to the creation of a new field of study known as paleovirology, the study of ancient viral remnants embedded within the genomes of organisms.
A Beneficial Side Effect
Researchers at Oxford University were utilizing these NGS techniques to search for old forms of the herpes virus contained within the genomes of certain primate species. When using these methods, the data discovered is commonly uploaded to a genomic database for perusal and use by scientists around the world. Thanks to this combination of factors, the researchers discovered an entirely novel use of NGS and the databases.
In the process of scanning for the herpes virus in the primate genome, they also happened upon two other viral sequences of completely unknown viruses. Intrigued by this unexpected result, they decided to see if they could have it happen again in a separate experiment involving looking for the herpes virus in fish. They yet again found a unique virus, one that was quite prolific and very old, found within the genomes of over 15 disparate fish species. It may even belong to an entirely undiscovered family of viruses.
The virus appears to be related to the alloherpesviruses, but is distinct enough and with never before seen protein coding genes that it is likely its own line. With several of its genes linked to other families, its lineage may be difficult to piece together, but the finding of it alone opens up new doors for NGS methods.
Stopping Disease Before It Starts
The scientists hope that being able to expand the known biodiversity of viruses and isolate previously unseen viral segments hiding within genomes will allow the prevention of possible disease outbreaks before they even occur. This includes investigating known risk species like bats, rodents, birds, and mosquitoes. By isolating viral components that have the potential for cross-species contamination, actions can be taken to make preventative medicines before any viral species jumps occur.
A final note on this method made by Oxford scientists. Due to its expansive interdisciplinary approach that combines evolutionary biology and the study of ancient viruses with paleovirology along with NGS techniques and genomic databases making up bioinformatics, it truly shows what science is capable of when multiple fields are used together to accomplish a goal. With continued work by people in all of those fields and more, the ongoing growth of human knowledge and the development of human medicine is assured.
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