UCF Biology: David W. Borst (Chair)

David W. Borst
Ph.D., UCLA
Phone: 407-823-1460
Email: dborst@mail.ucf.edu
Web Page: http://biology.ucf.edu/~dborst/

Research Interests

Dr. Borst’s research is focused on comparative endocrinology, with specific interests in arthropod development, growth, and reproduction and his lab studies these topics using biochemical, cellular and molecular biology techniques. Hormones have important roles in the regulation of many physiological, developmental, and behavioral processes. Perhaps nowhere is this regulation more critical than during molting and reproduction. Molting is critical for the continued growth and survival of the individual. Similarly, the production of offspring is critical for the survival of the species. Both processes must be adjusted to meet rapid changes in the environment. This lab is studying the physiological and cellular mechanisms used by arthropods to regulate their molting and reproduction. They are particularly interested in the role(s) of the juvenile hormones (JH) and methyl farnesoate (MF) in regulating these processes in grasshoppers and lobsters, respectively. To this end, they have developed sensitive methods (RIA, HPLC, ELISA) to measure hemolymph levels of several compounds, including JH, MF, and vitellogenin (yolk protein precursor). Some of the projects in my laboratory are outlined below:

Background

Hormones have important roles in the regulation of many physiological, developmental, and behavioral processes. Perhaps nowhere is this regulation more critical than during molting and reproduction. Molting is critical for the continued growth and survival of the individual. Similarly, the production of offspring is critical for the survival of the species. Both processes must be adjusted to meet rapid changes in the environment. My lab is studying the physiological and cellular mechanisms used by arthropods to regulate their molting and reproduction. We are particularly interested in the role(s) of the juvenile hormones (JH) and methyl farnesoate (MF) (see Figure 1) in regulating these processes in grasshoppers and lobsters, respectively. To this end, we have developed sensitive methods (RIA, HPLC, ELISA) to measure hemolymph levels of several compounds, including JH, MF, and vitellogenin (Vg, the yolk protein precursor).

Projects with crustaceans: In one project (supported by the NSF) we are isolating neuroendocrine peptides that regulate MF production in lobsters and other crustaceans. These peptides will then be used to modify endogenous levels of MF in these animals. In addition, we have characterized and cloned some of the enzymes involved in the production of MF, including farnesoic acid O-methyl transferase and HMG-CoA reductase to better understand how this compound is produced. Finally, we have recently obtained a partial clone for vitellogenin (the precursor of yolk protein) and are using it to investigate the regulation of reproduction.

Projects in insects: In a second NSF-supported project, we are studying how nutrition affects grasshopper molting and reproduction. We have measured the levels of JH, ecdysteroids, Vg, and storage proteinss in the hemolymph during molting and reproduction. In addition, we have partially cloned the cDNAs for both vitellogenin and the storage proteins. We are using this information to investigate how the synthesis of these two proteins is regulated by JH and by other compounds.

Selected Publications

D.L. Lovett, C.A. Tanner, K. Glomski, T.M. Ricart, and D.W. Borst 2006. The effect of seawater composition and osmolality on hemolymph levels of methyl farnesoate in the green crab Carcinus maenas. Comp. Biochem Physiol. A143: 67-77.

Henry, R. P. and Borst, D.W. 2006. Effects of eyestalk ablation on carbonic anhydrase activity in the euryhaline blue crab, Callinectes sapidus: neuroendocrine control of enzyme expression. J. Exp. Zool. 305A: 23-31.

Li, S. Ouyang, Y. C., Ostrowski, E., and Borst, D. W. 2005. Regulation of juvenile hormone synthesis by the corpora allata from the lubber grasshopper, Romalea microptera. Peptides. 26: 63–72.

Mutun, S. and Borst, D. W. 2004. Intraspecific mitochondrial DNA variation and historical biogeography of the lubber grasshopper, Romalea microptera. Annals of the Entomol. Soc. of America 97: 681-696.

Li, S., Friesen, J. A., Fei, H., Ding, X., and Borst, D. W. 2004. The lobster mandibular organ produces soluble and membrane-bound forms of 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Biochem J. 381:831-40.

Holford, K. C., Edwards, K. A., Bendena, W. G., Tobe, S. S, Wang, W., and Borst, D. W. 2004. Purification and characterization of a mandibular organ protein from the American lobster, Homarus americanus: a putative farnesoic acid O-methy-transferase. Insect Biochem. Mol. Biol. 34:785-98.

Hatle, J. D., Miller, W. A., and Borst, D. W. 2003. Canalization of development and ecdysteroid timing during the last instar in lubber grasshoppers. J. Insect Physiol. 49: 73-80

Borst, D W., G. Wainwright, and H. H. Rees. 2002. In vivo regulation of the mandibular organ in the edible crab, Cancer pagurus. Proc.Royal Soc.: Biol. Sci. 269: 483-490.

Lovett, D.L., Verzi, M.P., Clifford, P.D. and Borst, D.W. 2001. Hemolymph levels of methyl farnesoate increase in response to osmotic stress in the green crab, Carcinus maenas. Comp. Biochem. Physiol. A:128:299-306.