Description
Endogenous viral elements (EVEs) are integrations of full or partial viral genomes in their host nuclear genome. Endogenous retroviruses are widespread in eukaryote genomes, but other non-retroviral viruses have been shown to generate EVEs, albeit more rarely. These genomic imprints can shed light on the deep evolutionary history of viruses, ancestral host ranges, and ancient viral-host interactions. EVEs are thus ‘genomic fossils’ that we can use to compensate for the absence of physical fossil traces of viruses.In this presentation, I will use viruses from the Flaviviridae family as an example. This viral family contains important members, including well-known human pathogens, such as Zika, dengue, and hepatitis C viruses. The first EVEs derived from Flaviviridae have been identified in mosquitoes, but recent studies have extended the host range to include other invertebrates and some vertebrates such as fish.
However, none had been detected in mammals, even though the family encompasses numerous mammal-infecting members. Through a comprehensive in silico screening of a large dataset of available mammalian genomes, our study identified two novel Flaviviridae-like EVEs, derived from the genus Pestivirus, in the reference genome of the Indochinese shrew (Crocidura indochinensis), a first in mammals. Homologs of these novel EVEs were subsequently detected in other shrew species, especially within the Crocidurinae subfamily and one in the Soricinae subfamily on different continents. Based on this wide distribution, we estimate that the integration event occurred before the last common ancestor of the subfamily, about 10.8 million years ago, attesting to an ancient origin of pestiviruses and supporting a deep-evolutionary history of flavivirids in general.
| Period | 24-Oct-2022 |
|---|---|
| Event title | viruses in silico: the EVBC lectures |
| Event type | Seminar |
| Organiser | European Virus Bioinformatics Center (EVBC) |
| Location | Jena, GermanyShow on map |
| Degree of Recognition | International |