David Julian, Ph.D
I am a comparative, ecological
physiologist with an interest in the cellular responses and adaptations
of animals to environmental stressors. To an ecological physiologist, a
stressor is any environmental condition that threatens an organism’s
survival by pushing it outside its normal homeostatic boundaries; that
is, any condition that limits an organism’s ability to regulate its
physiological processes. The core focus of my lab is on the adaptations
that allow some marine and aquatic animals to thrive in seemingly
inhospitable “extreme” environments. Animals in the most extreme
environments, such as those at deep-sea hydrothermal vents and under
Antarctic ice sheets, are referred to as extremophiles. However, animals
in many environments that are more familiar to us also face
comparatively extreme conditions. Such environments include the mud of
tidal marshes and mangroves (which have very low oxygen and high
hydrogen sulfide concentrations), exposed
Hance JM, Andrzejewski JE, Predmore BL, Dunlap KJ, Misiak KL, Julian D. Cytotoxicity from sulfide exposure in a sulfide-adapted marine invertebrate. Journal of Experimental Marine Biology and Ecology (in press).
de Castro e Paula LA, Andrzejewski J, Julian D, Spicer LJ and Hansen PJ (2008). Effect of heat stress on oxygen and steroid concentrations in preovulatory follicles of lactating cows exposed to acute heat stress. Theriogenology 69: 805-813.
Wohlgemuth SE, Julian D, Akin DE, Fried J, Toscano K, Leeuwenburgh C and Dunn WA (2007). Autophagy in the aging heart and liver and the effect of calorie restriction. Rejuvenation Research 10(3):281-92.
Wohlgemuth SE, Arp AJ, Bergquist DC and Julian D (2007). Rapid induction and disappearance of electron-dense organelles following sulfide exposure in the marine annelid Branchioasychis americana. Invertebrate Biology, 126(2): 163-172.
Joyner-Matos J, Chapman LJ, Downs CA, Hofer T, Leeuwenburgh C and Julian D (2007). Stress response of a freshwater clam along an abiotic gradient: Too much oxygen may limit distribution. Functional Ecology 21: 344-355 (erratum in vol. 21: 619).
Joyner-Matos JL, Downs CA and Julian D (2006). Increased expression of stress proteins in the surf clam Donax variabilis following hydrogen sulfide exposure. Comparative Biochemistry and Physiology, Part A, 145: 245-257.
Julian D, April KL, Patel S, Stein JR and Wohlgemuth SE (2005). Mitochondrial depolarization following hydrogen sulfide exposure in erythrocytes from a sulfide-tolerant marine invertebrate. Journal of Experimental Biology 208: 4109-4122.