Department: Biochemistry and Molecular Biology
Academic Unit: College of Agriculture and Biotechnology
Title: Associate Professor
Professional degrees (Degree, year, Institution): Ph.D., 1995, Queen’s University
Mail Stop: 330
Pine bark beetles, while physically very small, can kill vast areas of coniferous forest during outbreak conditions. The increased forest fire risk and loss of timber are significant economic costs associated with bark beetle activity. Research in my lab focuses on understanding various aspects of the bark beetles’ biochemistry in order to better develop targeted control strategies. Our long term goal is to specifically regulate bark beetle populations, at least in an urban setting, without harming non-target organisms. There are two broad subject areas under study:
Pheromone Biosynthesis: Bark beetle outbreaks are mediated by aggregation pheromones, many of which are monoterpenes. Since de novo monoterpene synthesis in the Metazoa is rare, the pheromone biosynthetic pathway is an attractive target for eventual control strategies. Monoterpenoid pheromone components are synthesized in the midgut via the mevalonate (isoprenoid) pathway, with carbon likely being shunted away from the mevalonate pathway and into the pheromone pathway at geranyldiphosphate.
Phloem Detoxification: Pine trees are full of toxic resin, which discourages animals from eating them. The resin contains mostly monoterpenoid solvents --turpentine and Pinesol are produced from pine trees-- and considering that drinking a medium-sized glass of turpentine is enough to kill most humans (not recommended, don’t try it!), it is remarkable that bark beetles can thrive in their environment. Since different beetle species are more or less restricted to their host tree species, their detoxification processes are probably “tuned” to their host tree. We are trying to understand the biochemical mechanisms the beetles use to survive constant monoterpene ingestion, focusing primarily on functional characterization of various cytochrome P450 enzymes.
Current Graduate Students
Guizhi (Minmin) Song
Other lab members:
Sharon Young (the best technician on the planet)
Showell Busby (undergrad)
Heidi Pak (undergrad)
Leah Plaugher (undergrad)
Aw, T., K. Schlauch, C.I. Keeling, S. Young, J.C. Bearfield, G.J. Blomquist, and C. Tittiger, 2010. Functional genomics of mountain pine beetle (Dendroctonus ponderosae) midguts and fat bodies. BMC Genomics 11(1):215.
A.B. Gilg, C. Tittiger, and G.J. Blomquist, 2009. Unique animal prenyltransferase with monoterpene synthase activity. Naturwissenschaften 96: 731-735.
P. Sandstrom, M.D. Ginzel, J.C. Bearfield, W.H. Welch, G.J. Blomquist, and C. Tittiger, 2008. Myrcene hydroxylases do not determine enantiomeric composition of pheromonal ipsdienol in Ips spp. J. Chem. Ecol. 34:1584-1592.
J.C. Bearfield, C.D. Box, C.I. Keeling, S. Young, G.J. Blomquist and C. Tittiger 2008, "Isolation, endocrine regulation and transcript distribution of a putative primary JH-responsive gene from the pine engraver, Ips pini (Coleoptera: Scolytidae)" Insect Biochem. Molec. Biol. 38: 256-267 Read More...
P. Sandstrom, M.D. Ginzel, J.C. Bearfield, W.H. Welch, G.J. Blomquist, and C. Tittiger 2008, "Myrcene hydroxylases do not determine enantiomeric composition of pheromonal ipsdienol in Ips spp." J. Chem. Ecol. 34:1584-1592. Read More...
M. D. Ginzel, J. C. Bearfield, C. I. Keeling, C. C. McCormack, G. J. Blomquist and C. Tittiger 2007, "Antennally-mediated negative-feedback regulation of pheromone production in the pine engraver beetle, Ips pini." Naturwissenschaften. 91:61-64. Read More...
C. I. Keeling, J. C. Bearfield, S. Young, G. J. Blomquist and C. Tittiger 2006, "Effects of juvenile hormone on gene expression in the pheromone-producing midgut of the pine engraver beetle, Ips pini" Insect Molec. Biol. 15, 207-216 Read More...
P. Sandstrom, W. H. Welch, G. J. Blomquist and C. Tittiger 2006, "Functional expression of a bark beetle cytochrome P450 that hydroxylates myrcene to ipsdienol" Insect Biochem. Molec. Biol. 36, 835-845 Read More...
J. C. Bearfield, C. I. Keeling, S. Young, G. J. Blomquist and C. Tittiger 2006, "Isolation, endocrine regulation, and mRNA distribution of the 3-hydroxy-3-methylglutaryl coenzyme A synthase (HMG-S) gene from the pine engraver, Ips pini" Insect Molec. Biol. 15, 187-195 Read More...
Taban, A. H., J. Fu, J. Blake, A. Awano, C. Tittiger and G. J. Blomquist 2006, "Site of pheromone biosynthesis and isolation of HMG-CoA reductase cDNA in the cotton boll weevil, Anthonomus grandis" Arch. Insect Biochem. Biophys. 62, 153-163 Read More...
A. B. Gilg, J. C. Bearfield, C. Tittiger, W. H. Welch and G. J. Blomquist, 2005. Isolation and functional expression of the first animal geranyl diphosphate synthase and its role in bark beetle pheromone biosynthesis. Proc. Nat. Acad. Sci. U.S.A. 102, 9760-9765. 2005, "Isolation and functional expression of the first animal geranyl diphosphate synthase and its role in bark beetle pheromone biosynthesis" Proc. Nat. Acad. Sci. U.S.A. 102, 9760-9765 Read More...
Faculty by research area
- Mastick, C
- Mastick C.
- Mastick G.
- Van der Linden
- von Bartheld
- von Bartheld