Date of Award
Master of Science (MS)
Nicholas J Hobbs, Paul Twigg, Frank Kovacs
17-AAG;Drosophila Activity Monitors;Drosophila melanogaster;Heat Shock Proteins;Heat tolerance;Nora virus
The heat shock response (HSR) is highly conserved across the animal kingdom and is characterized by the activation of heat shock factors (HSF) and the subsequent induction of inducible heat shock proteins (HSP). The HSR and associated HSPs have been implicated in a variety of disease states. In this project, we explored two aspects of this response. First., we expanded the scope of the Drosophila melanogaster heat tolerance phenotype by involving an automated measure of activity. We discovered that heat hardening reduces motility during subsequent heat stress, and we provide evidence that the level of relative early motility can predict later loss of motility as a thermal limit. Specifically, we developed an automated phenotyping technique that can be used to explore multiple aspects of heat tolerance in small insects, such as D. melanogaster, utilizing the Drosophila Activity Monitor (DAM2) system from TriKinetics. Second, we explored the role of the HSR and HSPs during Drosophila melanogaster Nora virus (DmNV) infection. We showed that treatment with an HSP90 inhibitor reduces estimates of viral load in vivo. We also showed that treatment with an HSF inhibitor and exposing flies to a heat shock prior to infection changes the course of infection, such that the HSR tended to protect against infection, as did HSF treatment. However, when combined, heat shock and HSF-inhibition significantly interacted, leading to higher estimates of viral load. Finally, we showed that DmNV infection significantly upregulates the expression of HSP90 and HSP40 in vivo, substantiating a role for the HSR during viral infection in D. melanogaster. The work produced by this project offers novel insight into two aspects of the HSR. Further, the work is also methodological, in the sense that the methods are thoroughly described and validated such that they can be implemented an expanded in future investigations.
Rokusek, Blase, "The Heat Shock Response, Heat Tolerance, and Drosophila Melanogaster Nora Virus" (2023). Biology Theses, Dissertations, and Student Creative Activity. 13.