Email: w.smith@neu.edu

Phone: 617.373.2600
Fax: 617.373.3724

Location: 433 Richards Hall
Mail: NU/Biology
         134 Mugar Life Sciences
         360 Huntington Avenue
         Boston, MA 02115 USA

Research Description

Research in my laboratory centers on cellular and biochemical changes that regulate insect growth and development. Within this broad interest, I have focused on the action of molt-stimulating and growth-regulating hormones produced by the insect brain. I use caterpillars of the sphinx moth, Manduca sexta, as my experimental animals as they are large and easy to maintain in the laboratory. I am currently working on the cellular action of insulin-like hormones in insects; insect insulins appear to serve as important regulators of insect embryonic development and later regulate maturation of the reproductive organs. Information about the action of insect growth-regulating hormones is of interest for two reasons. First, the functions and cellular actions of vertebrate and invertebrate hormones have been remarkably conserved,thus, what we learn about insect peptides may enhance our understanding of hormonal regulatory processes in general. Second, by understanding the ways in which insect hormones work to regulate development, we may be able to devise safe and specific agents to disrupt the insect life cycle and thus to control agricultural pests and disease vectors. Recent work in the lab has focused on isolation of cDNA encoding the Manduca insulin receptor, investigation of the sites and times during development when receptor is maximally expressed, using RT-PCR, in situ hybridization, or antibodies directed against the receptor or downstream effector signals, as appropriate. This work develops essential tools with which to conduct future experiments on the functions and intracellular modes of action of a growth factor like receptor in specific insect target tissues.

Larval-Pupal Metamorphosis in Manduca sexta

Priester, J., and Smith, W. A. (2005). Inhibition of tyrosine phosphorylation blocks hormone-stimulated calcium influx in an insect steroidogenic gland. Molec. Cell. Endocrinol. 229: 185-192.

Smith, W., Priester, J., and Morais, J. (2003) PTTH-stimulated ecdysone secretion is dependent upon tyrosine phosphorylation in the prothoracic glands of Manduca sexta. Insect Biochem. Mol. Biol. 33: 1317-1325.

Gilbert, L.I., Rybczynski, R., Song, Q., Mizoguchi, A., Morreale, R., Smith, W. A., Matubayahsi, H., Shionoya, M., Nagata, S., and Kataoka, H. (2000) Dynamic regulation of prothoracic gland ecdysteroidogenesis: Manduca sexta recombinant prothoracicotropic hormone and brain extracts have identical effects. Insect Biochem. Molec. Biol. 30: 1079-1089.

Smith, W. A., Koundinya, M., McAllister, T., and Brown, A. (1997) An insulin receptor-like tyrosine kinase in the tobacco hornworm, Manduca sexta. Arch. Insect Biochem. Physiol. 35: 99-110.

Watson, R. D., Ackerman-Morris, S., Smith, W. A., Watson, C., and Bollenbacher, W. E. (1996) Involvement of microtubules in prothoracicotropic homone-stimulated ecdysteroidogenesis by insect (Manduca sexta) prothoracic glands. J. Experimental Zool. 276: 63-69.

Girgenrath, S., and Smith, W. A. (1996) Investigation of presumptive mobilization pathways for calcium in the steroidogenic action of big PTTH. Insect Biochem. Molec. Biol. 26: 455-463.

Smith, W. A., Varghese, A. H., Healy, M. S., and Lou, K. J. (1996) Cyclic AMP is a requisite messenger in the action of big PTTH in the prothoracic glands of pupal Manduca sexta. Insect Biochem. Molec. Biol. 26: 161-170.

Smith, W. A. (1995) Regulation and consequences of cellular changes in the prothoracic glands of Manduca sexta during the last larval instar: A review. Arch. Insect Biochem. Physiol. 30: 271-293.

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