University of North Florida

Dr. Gregory Ahearn
Professor

Ph.D: Arizona State University (1970)
Post-Doctoral: University of Copenhagen
Professor of Zoology, University of Hawaii, 1986-2001.

Phone: 904-620-1806
Office: 3/2203
Email: gahearn@unf.edu

TEACHING: Physiology, Anatomy & Physiology.

RESEARCH INTERESTS: My laboratory is using electrophysiology, membrane vesicle techniques, cell culture, dissociated tissue cell suspensions, and molecular biology to investigate the physiology of molecular transport by epithelial cell membranes of fish and crustacean gastrointestinal and renal organs. Over the past 25 years we have used a variety of experimental techniques to investigate membrane transport processes in the crustacean gasdtrointestinal tract and antennal glands for nutrients, ions, and heavy metals. For the past 12 years, we have investigated the mechanisms of sugar, amino acid, and vitamin transport in the fish intestine as a scientific cooperative exchange program with the University of Lecce, Italy. Recently we have focused our work on investigating ion transport processes of crustacean epithelial cells and have discovered a novel 2Na+/1H+ transport protein in crustacean cell membranes which significantly differs physiolgically from its mammalian counterpart. We are currently investigating this interesting invertebrate protein with molecular biology techniques which will allow us to identify the gene that codes for the protein and compare it to the DNA sequences responsible for analogous proteins in vertebrates. In addition, we have recently shown that this transporter is involved in heavy metal uptake from the environment and are currently investigating the interaction of this carrier system with epithelial detoxification processes for a variety of heavy metals.

RECENT PUBLICATIONS

Ahearn, G. A., Mandal, P. K., and Mandal, A. (2005) Organelle-specific zinc ATPases in crustacean ER and lysosomal membranes. Intern. Congress Ser., Proc. 3rd Intern. Confr. Comp. Physiol. Biochem., (Ed. S. Morris and A. Vosloo), Vol. 1275C: 114-125.
J Exp Zool. 292(6):507-22.

Capo, J. A., Mandal, P. K., Eyyunni, S., and Ahearn, G. A. (2005) 65Zn2+ transport by lobster hepatopancreatic basolateral membrane vesicles. J. Comp. Physiol. Part B: 175: 13-20.

Mandal, P. K., Mandal, A., and Ahearn, G. A. (2005) Physiological characterization of 45Ca2+ and 65Zn2+ transport by lobster hepatopancreatic endoplasmic reticulum. J. Exp. Zool. 303A:515-526.

Conrad, E. M. and Ahearn, G. A. (2005) 3H-L-histidine and 65Zn2+ are co-transported by a dipeptide transport system in lobster (Homarus americanus) intestine. J. Exp. Biol. 208: 287-296.

Gerencser, G. A., Robbins, F., Zhang, J., and Ahearn, G. A. (2004) Electrogenic proton-regulated oxalate/chloride exchange by lobster hepatopancreatic brush border membrane vesicles. J. Exp. Biol. 207(4): 571-578.

Mandal, A., Verri,T., Mandal, P. K., Storelli, C., and Ahearn, G. A. (2003) Expression of Na+/D-glucose cotransport in Xenopus laevis oocytes by injection of poly(A)+ RNA isolated from lobster (Homarus americanus) hepatopancreas. Comp. Biochem. Physiol. Part A 135(3): 467-475.

Chavez-Crooker, P., Pozo, P., Castro, H., Dice, M. S., Boutet, I., Tanguy, A., Moraga, D., and Ahearn, G. A. (2003) Cellular localization of calcium, heavy metals, and metallothionein in lobster (Homarus americanus) hepatopancreas. Comp. Biochem. Physiol. Part C 136(3): 213-224.

Peppler, J. E. and Ahearn, G. A. (2003) Effect of heavy metals on the uptake of 3H-L-histidine by the polychaete Nereis succinea. Comp. Biochem. Physiol. Part C 136(2): 181-189.