Research Project
10114895
PROJECT SUMMARY: While vertebrate monitoring is an established field, researchers working with invertebrates have limited tools for physiological monitoring. As an example, in the tobacco hornworm model much is still unknown about respiration ? one of the most fundamental biological processes! As hornworms grow their respiratory system doesn't keep pace. However, we don't have the tools to actually monitor oxygenation like we do with vertebrates. The tools that vertebrate model systems use are often not applicable to invertebrate model systems, limiting the ability to continuously profile fundamental physiology. Without advances in the development of sensors that can monitor these invertebrate model systems we cannot hope to fully metabolically profile and understand them. Our long-term goal is the development of nanosensors and accessible imaging systems capable of in vivo and in vitro metabolic monitoring of invertebrate model systems to help understand fundamental physiology. Our overall objective of this work is to answer two key questions in tobacco hornworm respiration: 1) does hypoxia increase during the 4th instar as measured by tissue oxygenation? 2) does hypoxia lead to electrolyte dysregulation in the hemolymph? Our central hypothesis is that at the end of the 4th and 5th instars oxygen concentration is lower in the hornworm, but electrolyte balances remain constant over the entire instar. Our hypothesis results from transcription studies of hypoxia related proteins in hornworms suggesting functional hypoxia during this growth cycle, and work from vertebrates showing that during hypoxia electrolyte homeostasis is maintained. The rationale for the proposed research is that development of nanosensors for invertebrate monitoring will enable answering these (and other) questions concerning metabolism not addressable with the current approaches for monitoring. To test our hypothesis and achieve our objective, we propose the following specific aims: Aim 1: Develop nanosensors for co-monitoring oxygen, pH, and electrolytes. Aim 2: Quantify in vivo and in vitro imaging approaches using consumer photography equipment. Aim 3: Monitor functional hypoxia in vivo to determine how growth impacts organism chemistry. As the overall outcome of this work we will have a nanosensor system capable of monitoring physiology of invertebrates similar to the tools available for vertebrates. We will be able to, in real time, measure hemolymph chemistry (oxygen, electrolytes) during growth and hypoxia to determine if functional hypoxia is present. The positive impact from this will be new tools and approaches to measure analyte concentrations in systems where there aren't currently viable approaches. Importantly, these will work for invertebrates, vertebrates, and a range of other in vitro systems. For AREA eligible institutions without vertebrate research, this will open up physiological monitoring to researchers who can't currently use it. We aim to bring pulse-oximetry like tools to the invertebrate research world.
