College of Veterinary Medicine

Research in IPN

Stacia Moffett, Ph.D.

Stacia Moffett, Ph.D.

Associate Professor
Phone: (509) 335-3290

We are studying function and control of the mosquito gut in larvae, pupae and adults of Aedes aegypti, the yellow fever mosquito. Ionic transport in the aquatic larvae produces an extreme alkalinization (above pH 10) which serves the dual purpose of eliminating many pathogens and releasing nutrients bound to tannins. The transport also regulates ionic and osmotic movement across the gut and the exchange of nutrients and wastes. The focus on the basic biology of this species may allow control of a disease vector in a manner that is environmentally safe.

The mosquito gut is modified along its length, and gut processes in the different regions, including transport and motility, are regulated by neurotransmitters such as serotonin and a large number of peptide hormones. We study this system by isolating the gut and monitoring the voltage in specific regions of the tubular epithelium while exposing the blood and lumen sides to salines containing transmitters, peptides and blockers of known transport systems. Transepithelical recordings are combined with intracellular penetrations used for voltage and ion specific measurements, and pH sensitive dyes reflect functional changes that are videotaped. Electron microscopy is being used to characterize the epithelial, regenerative and muscular cell types in the gut at different life stages. Future directions will involve the mapping and testing of receptors for the regulatory systems, with the aim of generating new blockers specific to the vital transport systems.

This work represents a change from my previous studies of nervous system regeneration in a snail that has a remarkable capacity for nervous system repair. The operations on very small animals is a technical parallel with the challenges of that work, and I have focused on the process of metamorphosis as a parallel with regeneration, as stem cells form the basis of new structures under the control of hormones in the mosquitoes.

Biographical Information

Stacia B. Moffett, Associate Professor of Biological Sciences, did doctoral research on crab reflexes at the University of Miami, Coral Gables, Florida. Postdoctoral research in Biomedical Engineering at Duke University focused on effects of temperature on the nervous system of the gastropod Aplysia.

Selected Publications

Moffett, S. 1997. Nervous System Regeneration in the Invertebrates. Springer-Verlag, Zoophysiology Series Vol. 34.

Moffett, S. (2000) Regeneration as an Application of Gastropod Neural Plasticity. In: Microscopical Research and Techniques, Topical Issue: Gastropod Nervous Systems. 49:579-588.

Griffis,B., Moffett, S.B., Cooper, R.L. (2000). Muscle phenotype remains unaltered after limb autotomy and unloading. J. Exp. Zool. 287

Bale, S.D., Howard, T.A., and Moffett, S.B. (2001). Neuronal and non-neuronal responses to nerve crush in a pulmonate snail, Melampus bidentatus. Invert. Neurosci. 4: 105-117.

Onken, H. Moffett, S.B., and Moffett D.F. (2004). The transepithelial voltage of the isolated anterior stomach of mosquito larvae (Aedes aegypti): pharmacological characterization of the serotonin-stimulated cells. J. Exp. Biol. 207: 1779-1787.

Onken, H., S. B. Moffett, and D. F. Moffett (2004). The anterior stomach of larval mosquitoes (Aedes aegypti): effects of neuropeptides on transepithelial ion transport and muscular motility. J. Exp. Biol. 207: 3731-3739.

Moffett, S.B. and Moffett, D.F. (2005). Comparison of immunoreactivity to serotonin, FMRFamide and SCPb in the gut and visceral nervous system of larvae, pupae and adults of the yellow fever mosquito, Aedes aegypti. Journal of Insect Science (online).

Clark, T.M., Hutchinson, M.J., Huegel, K.L., Moffett, S.B., Moffett, D.F. (2005). Additional morphological and physiological heterogeneity within the midgut of larval Aedes aegypti (Diptera:Culicidae) revealed by histology, electrophysiology, and effects of Bacillus thuringiensis endotoxin. Tissue and Cell 37: 457-468.

Onken, H., Moffett, S. B. & Moffett, D. F. (2006). The isolated anterior stomach of larval mosquitoes (Aedes aegypti): voltage-clamp measurements with a tubular epithelium. Comp. Biochem. Physiol. 143A:24-34.

Last Edited: Apr 09, 2013 10:18 AM   

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