Research Projects

Endogenous viral elements (EVEs) are viral DNA or RNA sequences that integrate into host genomes through horizontal gene transfer (HGT). They are commonly found in eukaryotic genomes and play key roles in host evolution, influencing antiviral defense, gene regulation, and even introducing novel functions. Multiple studies have identified EVEs in mosquito genomes, which act as vectors for transmitting various arboviral diseases in humans. Most of these identified EVEs belong to Insect-Specific Viruses (ISVs) families such as Flaviviridae, Alphaviridae, and Rhabdoviridae. Typically, these elements are located within transposable elements and exhibit partial or incomplete genomes. This may be non-infectious and provide selective advantages to mosquito hosts, potentially strengthening antiviral defenses and modulating gene expression. However, some EVEs with intact viral genomes, raise concerns about replication competency and infectious potential within the host. This hypothesis is largely untested, and it is still unclear whether these elements affect the evolutionary fitness of mosquito hosts. Additionally, some studies have shown EVEs presence in transcriptomes, indicating they may be transcriptionally active and capable of expressing functional proteins. However, the impact of these transcriptional events and how EVEs affect mosquito biology remain largely unexplored. Moreover, co-transcript events, where host genes are adjacent to viral genes or fused host and viral open reading frames (ORFs), have been mostly overlooked in the existing literature, despite their potential in epigenetic regulation of host gene expression. Advancement in high-throughput sequencing technologies generates a wealth of genomic, transcriptomic, and epigenetic datasets in public databases. This data allows an excellent opportunity for us to explore the hidden diversity of EVEs in sequenced mosquito genomes and transcriptomes using computational tools. Our systematic computational screening and comparative analyses will identify EVEs within sequence datasets of mosquitoes. Furthermore, it will shed light on the unknown aspects of EVEs including their diversity, abundance, expression, distribution patterns, and potential functional roles in mosquito biology. Key findings, such as co-transcripts and replication-competent EVEs will be validated through PCR, RNA sequencing, and whole genome sequencing of mosquito samples collected from natural populations in India. By examining the role of EVEs in mosquito immunity and antiviral properties, this study aims to address pressing biological questions about the influence of EVEs on mosquito evolutionary fitness and virus-vector interactions. Ultimately, our project will enhance our understanding of the virus-host evolutionary dynamics and interactions, with potential applications in mosquito control and arbovirus prevention strategies. Notably, this study will also be the first to explore EVEs in Indian mosquito populations.