Source: UNIVERSITY OF TENNESSEE submitted to NRP
FUNCTIONAL CHARACTERIZATION OF VIRUS-LIKE PARTICLES PRODUCED BY THE FRUIT FLY PARASITOID, FOPIUS ARISANUS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
Reporting Frequency
Annual
Accession No.
1032017
Grant No.
2022-67012-42170
Cumulative Award Amt.
$91,332.49
Proposal No.
2024-03079
Multistate No.
(N/A)
Project Start Date
Mar 31, 2024
Project End Date
Mar 30, 2026
Grant Year
2024
Program Code
[A1112]- Pests and Beneficial Species in Agricultural Production Systems
Recipient Organization
UNIVERSITY OF TENNESSEE
2621 MORGAN CIR
KNOXVILLE,TN 37996-4540
Performing Department
(N/A)
Non Technical Summary
Tephritid fruit flies represent some of the most destructive pests of soft fruits and vegetables worldwide. The Hawaiian Islands, in particular, have suffered from invasive fly damages to commercial fruit production for over a century, and biological control efforts are a large priority for the control of these agricultural pests. One of the most successful cases of biological control on Hawaii has been the release of the parasitoid wasp Fopius arisanus to suppress destructive fruit fly populations. F. arisanus is one of few fruit fly parasitoid species that has become established on the islands and is the dominant wasp species found to parasitize several major fruit fly pests. While the general biology, ecology, and behavior of F. arisanus has been well studied, there is a fundamental gap in knowledge pertaining to the molecular dynamics between F. arisanus and its fruit fly hosts that lead to prolific parasitism rates by this wasp at the expense of fly survival. Recent sequencing of the F. arisanus genome revealed several clusters of viral genes dispersed throughout that were later demonstrated to produce high densities of virus-like particles (VLPs) within the ovaries of female wasps. This discovery is the most recent of several known viral elements produced by agriculturally important parasitoid wasp lineages. Other heritable parasitoid viruses provide a highly beneficial function for the wasps that produce them by manipulating the physiology of the host insect. In this project, I will use a combination of molecular biology, manipulative genetics, and genomic sequencing techniques to characterize the function of F. arisanus VLPs and investigate the genetic underpinnings that facilitate VLP function within fruit fly hosts. Understanding molecular factors, such as VLPs, that likely contribute to fruit fly impairment during parasitism will provide novel avenues for future biological control initiatives against fruit fly pests.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21531101040100%
Knowledge Area
215 - Biological Control of Pests Affecting Plants;

Subject Of Investigation
3110 - Insects;

Field Of Science
1040 - Molecular biology;
Goals / Objectives
I will continue to benefit from project funding in my new role as a faculty member as I aim to make further progress on the goals outlined in the original postdoctoral fellowship. Support from the original award allowed me to successfully participate in several career development opportunities that broadened my scientific network and ultimately enabled me to secure a permanent job as an academic research scientist. I will therefore prioritize the remaining project funding to complete the original award's research program and communicate my findings to various communities of interest, including stakeholders and the broader scientific community.Continued funding from this grant will allow me to complete the research objectives set out in the original award Project Plan as part of the "Execute a research program" goal and publish my results in peer-reviewed journals. The following aims outline the remaining work needed to complete this work and lay the foundation for our understanding of F. arisanus VLPs:Characterize the progression of VLP production in F. arisanus ovariesDetermine the function of individual VLP genes involved in VLP productionBased on my prior work throughout project funding, I now have the genetic and molecular tools in place to expand our knowledge of the VLPs produced by F. arisanus and how they are formed in female wasp ovaries. Therefore, I will utilize a combination of manipulative genetics, genomic sequencing, and proteomics techniques to assess the transcriptional and protein dynamics of VLPs throughout wasp development. The results from this work will continue to inform us of the molecular factors that enable F. arisanus to be one of the dominant biological control agents of tephritid fruit fly pests worldwide. Furthermore, downstream applications of this work could lead to innovative pest control strategies that leverage knowledge of these fly-targeting viruses toward suppression of fly pest populations.
Project Methods
The methods for this project include many research techniques in the realms of molecular biology, manipulative genetics, and genomic sequencing.The approach for the first research aim, "Characterize the progression of VLP production in F. arisanus ovaries", will be to track the activity of VLP genes in female wasp ovaries throughout development using quantitative PCR (qPCR), RNA sequencing (RNA-seq), and transmission electron microscopy (TEM) technologies. F. arisanus ovaries will be dissected during multiple stages of pupal development and adulthood and subjected to qPCR, RNA-seq, and TEM analyses. Expression of VLP genes will be analyzed at each sampled stage with qPCR and/or RNA-seq to group genes into those that are expressed early in wasp development, those that are expressed at an intermediate stage, and those that are expressed late in the wasp life cycle. These results will be coupled with TEM images to align VLP gene expression with the stages of VLP production. Results from this study are expected to show that viral genes are activated in a stage-specific manner to produce VLPs during wasp development that is similar to the viral gene expression patterns observed in other parasitoid wasp-virus systems.The approach for the second research aim, "Determine the function of individual VLP genes involved in VLP production ", will be to investigate whether VLP gene function is conserved with related, pathogenic viruses using RNA interference (RNAi) technology. The expression of individual VLP genes will be knocked down with RNAi during wasp development, and resulting phenotypic changes will be assessed using qPCR, RNA-seq, and TEM methods, similar to the first aim. I expect the results to show that genes, such as the viral RNA polymerase subunits, still function to control the expression of other viral genes, which has been shown in other parasitoid-virus systems. I also expect that knock down of viral genes with putative roles in virus particle formation will inhibit or disrupt the production of VLPs, which will be detected with TEM images of wasp ovaries.Engagement with stakeholders from the public is essential for adoption and successful implementation of new IPM tactics and strategies. I will use my current network, based in Hawaii and Tennessee, to interface with the public throughout the research period, including growers and laypeople, to familiarize stakeholders with the ideas and concepts of using microbial symbionts to improve biological control methods. Many stakeholders are environmentally-conscious, and emphasis will be placed on the low environmental impact and increased sustainability of biological control-based IPM tactics. I will also engage with stakeholders on an international scale by giving invited scientific research presentations to globally apprise researchers on my work with parasitoid wasp-virus-fruit fly interactions.Additional efforts will be made throughout the project, including mentoring activities. My mentoring experiences throughout the original project thus far have immensely benefited my career development. I have mentored undergraduate students and laboratory technicians, as well as co-advised a master's student during the project. I taught these mentees important skills involved in experimental design, the scientific process, and scientific writing and presentation of results.Major milestones for the research objectives will be evaluated by the timeliness and quality of data I produce, which in turn, will reflect the success of the research project. The results of this research will be disseminated to the scientific community via publications in peer-reviewed journals and invited presentations at Rutgers University, the American Society for Virology annual meeting in Columbus, Ohio,the International Congress of Entomology meeting in Kyoto, Japan, and the Entomology 2024 meeting in Phoenix, Arizona. Publications will include a first-author manuscript that will be submitted before the end of the funding period. Collaborators will be updated on project findings and accomplishments quarterly via teleconference meetings. Career progress during and after the funding period will be documented on my ResearchGate account. My success as a mentor will be determined by the completion of an Individual Development Plan (IDP) created with each mentee at the start of the mentorship, which outlines the professional and research goals for the mentee during the mentorship period. An ongoing open dialogue will be maintained with quarterly meetings with mentees to assess the progress of the IDP.

Progress 03/31/24 to 03/30/25

Outputs
Target Audience:The target audiences for this project during the past year included several different groups of people. First, the project served fellow scientists and researchers across academic, government, and private industry sectors. The integrative nature of this research wasof widescale appeal to scientists of both agriculture and evolutionary biology disciplines as it concerns an important biological control agent, as well as a complex symbiotic relationship at its focus. Additionally, I expanded my advisory group that has been served by the project to include faculty members at the University of Tennessee with expertise in integrated pest management strategies.I continuedto benefit from current advisory group members, including USDA scientistson Hawaii Island who work on tephritid fruit fly and parasitoid wasp biology, as well as colleagues within the field of entomology that work on insect-microbe interactions. The advisory group was kept abreast of the completion of project milestones and was tapped for their thoughts on the scientific merits of the research as it progresses, as well asinsights they could provide regarding unexpected results. In addition, this project served regulatory agencies by promoting basic research that will lead to innovative and sustainable pest control strategies in the future. This project also served different groups of students, including university graduate and undergraduate students that were mentored by me this past year. Finally, the general public was served by this project through science communication outlets that I published in during the last year. Changes/Problems:The project timeline has been extended by one year due to administrative delays associated with transitioning to a new university procurement system, which was implemented in the past year. These systematic changes resulted in unexpected delays in purchasing critical equipment necessary for completing planned experiments. With these issues now resolved, the additional time will ensure that all research objectives--particularly those involving molecular analyses--can be fully completed as originally proposed. What opportunities for training and professional development has the project provided?Over the past year, project activities supported several impactful training and professional development opportunities for both undergraduate and graduate students. As a new faculty member, I provided one-on-one mentorship as the major advisor for to a new M.S. student in my lab, guiding him through the development of a comprehensive thesis research plan. This mentorship included hands-on training in experimental design, molecular biology techniques, bioinformatics protocols, and scientific communication, with the goal of building his independent research capacity and professional skill set. Additionally, I served as a faculty mentor for two undergraduate students in the UTK Department of Entomology & Plant Pathology's REEU summer research program. Through this program, the students received individualized instruction in handling a microsatellite sequencing dataset, learned to analyze genomic signatures of fire ant hybridization, and gained exposure to scientific communication and career pathways in genomics research. The program culminated in the students creating a research poster and presenting it as part of a university-wide symposium for undergraduate research. My professional development was further enriched through participation in national and international conferences and seminar series as an invited speaker. In the last year, I delivered seven invited talks at multiple institutions, including the University of Illinois, Mississippi State University, and Rutgers University. I also participated in symposia at major scientific meetings such as the International Congress of Entomology (Kyoto, Japan), the American Society for Virology Annual Meeting, and Entomology 2024 (Phoenix, AZ). These engagements provided critical opportunities to expand my scientific network, stay current in the field, and bring new ideas back to my research group and collaborators. How have the results been disseminated to communities of interest?Over the past year, I actively disseminated project results to a range of communities of interest, including academic researchers, professional stakeholders, and members of the public who are traditionally less engaged with scientific research. Dissemination to the scientific community occurred through multiple invited and peer-reviewed presentations at national and international meetings. These included talks at the International Congress of Entomology in Kyoto, the American Society for Virology Annual Meeting, and Entomology 2024, where I shared findings on the genomic and functional evolution of mutualistic viruses in parasitoid wasps. These venues allowed me to connect with entomologists, virologists, and biological control practitioners across disciplines and global regions. To extend the impact of this research beyond the scientific community, I also engaged in multiple science communication efforts aimed at the general public. Notably, I authored a piece for The Conversation titled "In Hawaii, parasites and viruses team up in the battle against fruit flies" (Oct 2024), which explained the applied significance of our findings in accessible language and reached a broad, non-specialist readership. This article was further syndicated by other media outlets and sparked public interest in biological control and symbiotic virus research. In addition, I was interviewed for Knowable Magazine in a feature titled "The wasps that tamed viruses" (May 2024), which highlighted the broader implications of mutualistic virus evolution for global agriculture and pest management. These public-facing efforts were designed to enhance understanding of emerging topics in insect virology and to foster greater appreciation for the role of science in addressing real-world challenges. I also gave an outreach talk at the Alabama Regenerative Growers Conference (Nov 2024), presenting "Parasitoid wasps: nature's hidden allies" to a diverse audience of farmers, educators, and sustainable agriculture advocates. This event helped bridge the gap between basic research and applied practice, encouraging stakeholder engagement with biocontrol innovations rooted in symbiosis research. Together, these dissemination and outreach efforts contributed to increasing public understanding of insect-microbe interactions and underscored the broader societal value of fundamental science that this project supports. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, I will focus on completing the final research objectives outlined in the original project plan to deepen our understanding of virus-like particle (VLP) production and function in Fopius arisanus. Specifically, I will (1) finalize temporal and spatial characterization of VLP development in the wasp ovary and (2) experimentally determine the role of individual viral genes using gene knockdown and transcriptomic profiling approaches. These experiments will build on the genomic and molecular tools already developed in earlier stages of the project. In parallel, I plan to prepare and submit at least one additional manuscript for publication in a peer-reviewed journal, summarizing key findings related to viral gene function and its relevance to parasitoid reproductive biology. I will also continue disseminating results through upcoming conference presentations and seminar invitations, including an invitedtalk for the USDA-APHIS-PPQ Science & Technology, Domestic and Emergency Scientific Support (DESS) community in May 2025 and an invited presentation at the Entomological Society of America meeting in November 2025. To support the development of early-career scientists, I will continue mentoring two graduate students, a postdoctoral researcher, and new undergraduate students, integrating them into project activities such as sample preparation, data analysis, and figure generation. This hands-on training will provide essential experience in molecular biology, entomology research, and scientific communication. Lastly, I plan to expand public outreach efforts by developing new science communication content about parasitoid-virus mutualisms, and seek opportunities to present at community-oriented events or through media partnerships, continuing to enhance awareness of beneficial insect-microbe relationships and their relevance to agriculture and pest management.

Impacts
What was accomplished under these goals? I continued to benefit from project funding in my first year as a faculty member and made substantial progress on the goals outlined in the Project Plan. Support from the award enabled me to successfully participate in several career development opportunities that broadened my scientific network and ultimately helped me lay the foundations for my newly established research program. I prioritized the remaining project funding to complete the original award's research program and to communicate my findings to various communities of interest, including stakeholders and the broader scientific community. Funding from this grant this past year allowed me to make progress on several research objectives outlined in the original award Project Plan under the goal to "Execute a research program" and to prepare two manuscripts for submission to peer-reviewed journals. Over the past year, I focused on two main aims that laid the foundation for our understanding of F. arisanus virus-like particles (VLPs): Characterizethe progression of VLP production in F. arisanus ovaries. Determine the function of individual VLP genes involved in VLP production. Building on the tools and knowledge developed earlier in the project, I used molecular biology and genomic sequencingtechniques to assess the transcriptional dynamics of VLPs during wasp development. The results from this work have continued to inform our understanding of the molecular mechanisms that contribute to the success ofF. arisanusas a dominant biological control agent of tephritid fruit fly pests worldwide. Additionally, these findings have opened new avenues for futuredevelopment of innovative pest control strategies that harness viral mechanisms to suppress fly pest populations.

Publications

  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Coffman KA, Kauwe AN, Gillette NE, Burke GR, Geib SM. Host range of a parasitoid wasp is linked to host susceptibility to its mutualistic viral symbiont. Molecular Ecology. 2024;33: e17485. https://doi.org/10.1111/mec.17485
  • Type: Peer Reviewed Journal Articles Status: Published Year Published: 2025 Citation: Coffman KA. The roles of viruses in tephritid pest multitrophic interactions and an outlook for biological control. Current Opinion in Insect Science. 2025;68: 101333. https://doi.org/10.1016/j.cois.2025.101333