Project description:Bats are natural hosts for a wide diversity of viruses. While many of these viruses are highly pathogenic in humans, most do not appear to cause major symptoms in bats. These modern bat-specific characteristics are the result of past virus-host (co)evolution and virus-driven host adaptations. Innate immunity is the first line of defense against viruses in mammals, we aim at characterizing bat innate immunity in response to viruses. Using genome-wide and gene candidate evolutionary analyses, we found that many bat antiviral genes have undergone multiple duplication events in a lineage-specific manner, specifically in the Myotis bat lineage. We focus on Myotis yumanensis as a model in the Myotis lineage. We performed transcriptomic analyses and observed the upregulation of most mammalian genes implicated in the different steps of the innate immune response from sensing to interferon-stimulated genes (ISGs), showing the conservation of the core innate immunity. Our study will contribute to identifying adaptations that shaped bat innate immunity. These adaptations may contribute to the bat-virus specificity and influence viral emergence to another mammalian host
Project description:While employing deep sequencing and de novo assembly to characterize the mRNA transcript profile of a cell line derived from the microbat Myotis velifer incautus, we serendipitously identified mRNAs encoding proteins with a high level of identity to herpesviruses. Next generation sequencing and de novo assembly of the viral genome from supernatants from Vero cells yielded a single contig of approximately 130 kilobases with at least 80 ORFs, predicted microRNAs and a gammaherpesvirus genomic organization. Phylogenetic analysis of the envelope glycoprotein (gB) and DNA polymerase (POLD1) revealed similarity to multiple gammaherpesvirus, including those from as yet uncultured viruses of the Rhadinovirus genus that were obtained by deep sequencing of bat tissues. Cumulatively, this study provides the first isolation and characterization of a replication competent bat gammaherpesvirus.