NSF PRFB FY23: Heritable viruses as hidden drivers of host phenotypes: Densoviruses and aphid wing plasticity

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Insects are the most abundant and diverse animal group, and like all living organisms, they evolved around viral infections. Understanding the impact viruses have on the lifecycles of insects is critical to maintaining healthy ecosystems throughout wildlands, agriculture, and urban environments. This project uses aphids, which are small insects that feed on plants, as a model organism. Aphids are found throughout ecosystems on many types of host plants and contain many different viruses. These viruses can impact the health and activity of both the insect and the host plants in ways that are still unknown. For this reason, this research aims to learn how inherited aphid viruses are passed on through generations while influencing the development of physical characteristics such as wings. This research also improves our ability to lessen the negative impacts of insects on agriculture while also promoting positive impacts on society. In addition, this project will engage students and agricultural communities on how interactions between viruses and insects contribute to healthy food webs and food security. This fellowship further addresses the impacts that virus-host interactions have on society by exploring the understudied role that viruses have in insect evolution. Specifically, this project uses single-stranded DNA viruses (Densovirinae) and viruses integrated into the aphid genomes (endogenous viral elements) as a tractable model system to study heritable virus-host interactions. RNA sequencing of field-collected aphids will be used to measure virus heritability, viral diversity, and the extent to which viral infection correlated with aphid wing production. CRISPR-targeted mutagenesis will be used to better understand the role of viruses integrated into host genomes. This research develops a comprehensive picture of the factors shaping heritable virus-host dynamics and the potential links to wing development while potentially uncovering previously unrecognized insect-specific viruses circulating in natural populations. This project will also promote undergraduate engagement in scientific research and generate outreach activities at local farm extension networks to improve the understanding of aphid biology and insect agricultural impact. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.