Timothy J. Bradley

picture of Timothy J. Bradley

Professor, Ecology & Evolutionary Biology
School of Biological Sciences Phone: (949) 824-7038
Fax: (949) 824-2181
Email: tbradley@uci.edu

University of California, Irvine
5238, 5354 Bio Sci II
Mail Code: 2525
Irvine, CA 92697
Research Interests
Comparative physiology of ion transport epithelia
Academic Distinctions
National Merit Scholarship Finalist, 1966
Careers '75 Research Scholarship from the Province of British Columbia, 1974
NIH Postdoctoral Fellowship, 1978 1980
Fellow of the American Association for the Advancement of Science, Elected 1992
Excellence in Teaching Award, School of Biological Sciences, 1999
Daniel G. Aldrich, Jr. Distinguished University Service Award, 2009
Research Abstract
My laboratory is engaged in studies of physiological ecology, the evolution of physiological processes, the physiology of respiration and energy metabolism, and conservation biology at salt lakes.

Control of Respiration in Insects
A discontinuous gas exchange cycle (DGC) is observed in a variety of insects under a number of environmental circumstances. Insect physiologists have been puzzled and intrigued by this complex respiratory pattern. Two explanations had previously been put forward to explain this behavior; 1) that the pattern serves to reduce respiratory water loss, and 2) that the pattern may have initially evolved in underground insects as a way of dealing with hypoxic/hypercapnic conditions. We have argued that the cyclical open and closed pattern demonstrated by insects at rest is a necessary consequence of the need to rid the respiratory system of accumulated carbon dioxide followed by a closed period needed to reduce oxygen toxicity. More recently, we have been investigating the respiratory patterns displayed by insects at higher levels of activity. We have described a respiratory control model for insects that explains the patterns of respiration expressed in insects under all conditions of activity and environmental variability observed in nature.

Osmoregulation in Insects
A major area of study in my laboratory has been the characterization and elucidation of the mechanisms of osmoregulation in saline-water and blood-feeding insects. Saline-water insects are of interest from an ecological and physiological standpoint because of their capacities to osmoregulate in extreme aquatic habitats (environmental salinities up to three times seawater, pH 10, or water rich in magnesium or sulfate). Bloodfeeding insects must deal with extraordinary rates of diuresis (excreting up to five times their previous body volume in two hours). Both groups have an unusual problem for insects, namely excreting large amounts of sodium. All of these ecological peculiarities present very interesting physiological problems and these have been the subject of my studies.


Salton Sea Initiative
The University of California, Irvine (UCI) is a land grant institution with internationally recognized expertise in many sustainability-related domains. UCI seeks to harness its research, teaching, and service resources to address sustainability challenges facing the Salton Sea region We view addressing the challenges at Salton Sea as multi-faceted, long term, and critical to Southern California’s future. We also believe that, as desertification and salinity crises expand globally, the solutions pioneered at the Sea could inform actions of similarly situated communities across the globe. We have also initiated collaborations with faculty at a number of public and private universities. While our initial task is to continue to build relationships in the desert, we are also actively researching processes that may be helpful in addressing broader engineering, biological, legal and planning issues. Topics being investigated include: desalination, biological remediation, nutrient removal, public health issues, land use, regional planning, and water allocation. In this work, rather than advocate for any one particular path forward, we seek to use our campus strengths to provide technical assistance through our research expertise, to open up public discourse, and to strengthen the capacity of relevant stakeholders to engage the resources necessary to address these problems.
Publications
Bradley, T.J. Animal Osmoregulation. Oxford University Press. Oxford. 165 pp. 2009.
 
Selected publications (out of a total of 125)
 
Heinrich, E., E. Gray, A. Ossher, S. Meigher, F. Grun, T.J. Bradley (2017) Aerobic function in mitochondria persists beyond death by heat stress in insects. J. Thermal Biol. 69: 267-274.
 
Kezos JN, L.G. Cabral, B.D. Wong, B.K. Khou, A. Oh, J.F. Harb, D. Chiem, T.J. Bradley, L.D. Mueller, M.R. Rose (2017) Starvation but not locomotion enhances heart robustness in Drosophila. J Insect Physiol. 99:8-14.
 
Curtis, C.; G.N. Landis, D. Folk, N.B. Wehr, N. Hoe, M. Waskar, D. Abdueva, D. Skvortsov, D. Ford, A. Luu, A. Badrinath, R.L. Levine, T.J. Bradley, S. Tavare, J. Tower (2016) Transcriptional profiling of MnSOD-mediated lifespan extension in Drosophila reveals a species-general network of aging and metabolic genes. Genome Biology. Vol. 17, Article 93. DOI: 10.1186/s13059-016-0959-3
 
Curtis, C.; G.N. Landis, D. Folk, N.B. Wehr, N. Hoe, M. Waskar, D. Abdueva, D. Skvortsov, D. Ford, A. Luu, A. Badrinath, R.L. Levine, T.J. Bradley, S. Tavare, J. Tower (2016) Transcriptional profiling of MnSOD-mediated lifespan extension in Drosophila reveals a species-general network of aging and metabolic genes. Genome Biology. Vol. 17, Article 93. DOI: 10.1186/s13059-016-0959-3
 
Contreras, H.L., E.C. Heinrich & T.J. Bradley (2014) Hypotheses regarding the discontinuous gas exchange cycle (DGC) in insects. Curr. Opinion Insect Sci. 4:4853.
 
Heinrich , E.C. & T.J. Bradley (2014) Temperature–dependent variation in respiratory pattern and spiracular control in Rhodnius prolixus. J. Exp. Biol. 217:2752-2760.
 
Bradley, T.J. (2012) Wildlife management: bringing research to the field. In: Wildlife Conservation and Habitat Management: a Joint US/Iran Workshop. Pp. 9-11. National Research Council of the U.S. National Academies.
 
Heinrich, E.C., M.J. McHenry & T.J. Bradley (2013) Coordinated ventilation and spiracle activity produce unidirectional airflow in the hissing cockroach, Gromphadorhina portentosa. J. Exp. Biol. 216:4473-4482.
 
Vorhees, A.S., E.M. Gray & T.J. Bradley (2013) Thermal resistance and performance correlate with climate in populations of a widespread mosquito. Physiol. Biochem. Zool. 86: 73-81.
 
Vorhees, A. S. & T.J. Bradley (2012) Comparison of critical thermal maxima and mortality across developmental stages of Tenebrio molitor. J. Exp. Biol. 215:2319-2326.
 
Albers, M.A. & T.J. Bradley (2011) On the evolution of saline tolerance in the larvae of mosquitoes in the genus Ochlerotatus. Physiol. Biochem. Zool. 84:258-267.
 
Contreras, H.L. & T.J. Bradley (2011) The effect of ambient humidity and metabolic rate on the gas exchange pattern of the semi-aquatic insect, Aquarius remigis. J. Exp. Biol. 214:1086-1091.
 
Contreras, H.L. & T.J. Bradley (2011) The effect of ambient humidity and metabolic rate on the gas exchange pattern of the semi-aquatic insect, Aquarius remigis. J. Exp. Biol. 214:1086-1091.
 
Contreras, H.L. & T.J. Bradley (2010) Transitions in insect respiratory patterns are controlled by changes in metabolic rate. J. Insect Physiol. 6:522-528.
 
Bradley, T.J., A.D. Briscoe, S.G. Brady, H.L. Contreras, B.N. Danforth, R. Dudley, D. Grimaldi, J.F. Harrison, A. Kaiser, C. Merlin, S.M. Reppert, J.M. VandenBrooks, S.P. Yanoviak (2009) Episodes in insect evolution. Integrative Comp. Biol. 49(5):590-606.
 
Bahadori, S; J. Cho, T Lo, H. Contreras, H.O. Lawal, D.E. Krantz, T.J. Bradley, D.W. Walker (2009) Neuronal expression of a single-subunit yeast NADHubiquinone oxidoreductase (Ndi1) extends Drosophila lifespan. Aging Cell 9:191-202.
 
Bradley, T.J. (2008) Active transport in insect recta. J. Exp. Biol. 211:835-836.
Contreras, H.L. & T.J. Bradley (2009) Metabolic rate controls respiratory pattern in insects. J. Exp. Biol. 212: 424-428
 
Bradley, T.J. (2008) Saline-water insects: Ecology, physiology and evolution. In: Aquatic Insects: Challenges to Populations. J. Lancaster & R.A. Briers, eds. CAB International. UK.
 
Bradley, T.J. (2008) Control of the respiratory pattern in insects. Adv. in Med. & Biol. 618: 211-220. Reprinted in Hypoxia and the Circulation. R. Roach. P Wagner & P. Hackett, eds. Springer Science, NY.
 
Curtis, C.; G.N. Landis, D. Folk, N.B. Wahr, N. Hoa, M. Wasker, D. Abdueva, D. Ford, A. Luu, A. Badrinath, R.L. Levine, T.J. Bradley, S. Tavare, & J. Tower (2007) Transcriptional profiling of MnSOD-mediated lifespan extension in Drosophila reveals a species-specific network of aging and metabolic genes. Genome Biology 8:R264.
 
Archer, M.A., T.J. Bradley, L.D. Mueller & M.R. Rose (2007) Using experimental evolution to study the physiological mechanisms of desiccation resistance in Drosophila melanogaster. Physiol. Biochem. Zool. 80:386-398.
 
Gray, E.M. & T.J. Bradley (2006) Evidence from mosquitoes suggests that cyclic gas exchange and discontinuous gas exchange are two manifestations of a single respiratory pattern. J. Exp. Biol. 209:1603-1611.
 
Bradley, T.J. (2006) Discontinuous ventilation in insects: protecting tissues from O2. Resp Physiol. Neurobiol. 154:30-36.
 
Albers, M. & T.J. Bradley (2006) Fecundity in Drosophila following desiccation is dependent on nutrition and selection regime. Physiol. Biochem. Zool. 79:857-865.
 
Gray, E.M. & T.J. Bradley (2005) Malarial infection in Aedes aegypti: Effects on feeding, fecundity and metabolic rate. J. Parasitology 132:169-176.
 
Gray, E. M. & T. J. Bradley (2005) The physiology of desiccation resistance in Anopheles gambiae and Anopheles arabiensis. Amer. J. Trop. Med & Hyg. 73(3):553-559.
 
Folk, D.G. & T.J. Bradley . (2005) Adaptive evolution in the lab: unique phenotypes in fruit flies comprise a fertile field of study. Int. Comp. Biol. 45:492-499.
 
Mueller, L.D.; D.G. Folk, N. Nguyen, P. Nguyen, P. Lam, M.R. Rose & T. Bradley. (2005) Evolution of larval foraging behavior in Drosophila and its effects on growth and metabolic rates. Physiol. Entomol. 30:262-269.
 
Hetz, S. & T.J. Bradley (2005) Insects breathe discontinuously to avoid oxygen toxicity, Nature. 433:516-519.
 
Albers, M.A. & T.J. Bradley (2011) On the evolution of saline tolerance in the larvae of mosquitoes in the genus Ochlerotatus. Physiol. Biochem. Zool. 84:258-267.
 
Folk, D.G. & T.J. Bradley . (2005) Adaptive evolution in the lab: unique phenotypes in fruit flies comprise a fertile field of study. Int. Comp. Biol. 45:492-499.
 
Folk, D.G. & T.J. Bradley (2004) The evolution of recovery from desiccation stress in laboratory-selected populations of Drosophila melanogaster. J. exp. Biol. 207(15): 2671-2678.
 
Albers, M. & T.J. Bradley (2004) Osmotic regulation in adult Drosophila melanogaster during dehydration and rehydration. J. exp. Biol. 207: 2313-2321.
 
Williams, A.E., M.R. Rose & T.J. Bradley. (2004) The respiratory pattern in Drosophila melanogaster selected for desiccation resistance is not associated with the observed evolution of decreased locomotory activity. Physiol. Biochem. Zool. 77(1):10-17.
 
Yanega, G.M., A Reyes, T.J. Bradley (2014) The Salton Sea Initiative. Desert Report, March 2014, 18-19.
 
Gray, E. & T.J. Bradley. (2003) Metabolic rate in female Culex tarsalis (Diptera: Culicidae) : Age, size, activity and feeding effects. J. Med. Entomol. 40(6) 903-911.
Graduate Programs
Comparative Physiology

Last updated
10/30/2017