David S. Durica
Professor, Zoology Richards Hall 300A & 216 405-325-1528 ddurica at ou dot edu http://faculty-staff.ou.edu/D/David.S.Durica-1/ Ph.D., Cell Biology - University of Connecticut, 1977Research:
In crustaceans, steroid hormones termed ecdysteroids are tied to numerous physiological programs that must be integrated in the life history of these animals: among these are adult growth and molting, reproduction, and a specialized form of growth that is superimposed on the growth cycle, limb regeneration. Ecdysteroids differ in types and concentrations during the molt cycle, and it is presently unclear how distinct circulating ecdysteroids can differentially modulate different physiological actions in time and space. We have determined that unique structural variants (isoforms) for the ecdysteroid hormone receptor complex exist. We hypothesize that different distributions of receptor isoforms, in concert with differences in receptor isoform affinities for circulating hormones, transduce specific hormonal signals and implement distinct genetic programs. To explore this hypothesis, we are characterizing components of the ecdysteroid signaling pathway with regard to their physical properties and distribution, and identifying primary response gene networks subject to hormonal control.
Selected Publications:
Hopkins, P.M., Durica, D., & Washington, T. (2008) RXR isoforms and endogenous retinoids in the fiddler crab, Uca pugilator. Comp. Biochem. Physiol. A., in press.
Durica, D.S., Kupfer, D., Najar, F., Lai, H., Tang, Y., Griffin, K., Hopkins, P.M. & Roe, B. (2006) EST library sequencing of genes expressed during early limb regeneration in the fiddler crab and transcriptional responses to ecdysteroid exposure in limb bud explants. Int. Comp. BioI. 46: 948-964.
Wu, X., Hopkins, P.M., Palli, S.R. & Durica, D.S. (2004) Crustacean retinoid-X receptor isoforms: distinctive DNA binding and receptor-receptor interaction with a cognate ecdysteroid receptor. Mol. Cell. Endocrinol., 218: 21-38.
Durica, D.S., Wu, X., Anilkumar, G., Hopkins, P.M. and Chung, A. C.-K.(2002) Characterization of Crab EcR and RXR Homologs and Expression during Limb Regeneration and Oocyte Maturation. Mol. Cell. Endocrinol., 189: 59-76.
Durica, D.S., Chung, A. C.-K., & Hopkins, P.M. (1999) Evolution of the steroid/thyroid/ retinoic acid receptors -characterization of EcR and RXR gene homologs and receptor expression during the molt cycle in the crab, Uca pugilator. Amer. ZooI., 39: 758-774.
Hopkins, P.M., Chung, A.C.-K., & Durica, D.S. (1999) Regeneration in the fiddler crab, Uca pugilator. Histological, physiological and molecular considerations. Amer. ZooI., 39: 513-526.
Chung, A.C.-K., Durica, D.S., Clifton, S.W., Roe, B.A., & Hopkins, P.M., 1998. Cloning of crustacean EcR and RXR gene homologs and elevation of RXR mRNA by retinoic acid. Mol. Cell. Endocrinol., 139: 209-227.