The University of Iowa
College of Liberal Arts and Sciences
The Department of Biology

Faculty Information

Bridget Lear

Bridget Lear

Assistant Professor
Ph.D., University of Chicago 2001
450C BB
(319) 335-3079
bridget-lear@uiowa.edu
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Neural and genetic basis of circadian behavior in Drosophila

I am interested in understanding the neural mechanisms that regulate circadian rhythms, the daily patterns of physiology and behavior that are prominent in many species. My lab studies the model organism Drosophila melanogaster, which exhibits robust daily rhythms in several behaviors, including locomotor activity (Figure 1). Genetic approaches in Drosophila have led to the identification of a number of key circadian rhythms genes, including several with conserved function in mammals.

Much of the focus in circadian rhythms research has gone towards understanding the molecular circadian clock, the cell-autonomous transcriptional feedback loops and post-translational modifications that generate ~24 hour molecular oscillations. In Drosophila and mammals, the central circadian clocks that control rhythmicity are located in neuronal groups within the brain. Yet, little is known about how the molecular clock regulates the output of these neurons to promote rhythmicity. My lab is interested in understanding the processes that occur downstream of the molecular clock to mediate circadian neuron function. I have previously demonstrated that a putative sodium leak channel, narrow abdomen (na), is an important component of circadian neuronal output in Drosophila. We are now using this system to further characterize the function and regulation of this unique channel, with a particular interest in determining whether NA is subject to circadian regulation. In addition, my lab is utilizing the molecular and genetic tools of Drosophila in order to identify new circadian rhythms genes, with a focus on genes likely to function in circadian neuronal output.

I currently have openings in my lab for both students and postdocs.

Click on a thumbnail to view image and description:
Actogram.jpg
Figure 1


Selected Publications


Zhang, L., B.Y. Chung, B.C. Lear, V.L. Kilman, Y Liu, G Mahesh, R.A. Meissner, P.E. Hardin, and R. Allada. “DN1p Circadian Neurons Coordinate Acute Light and PDF Inputs to Produce Robust Daily Behavior in Drosophila.” Current Biology 20(7): 591-599. http://dx.doi.org/10.1016/j.cub.2010.02.056

Pfeiffenberger, C., B.C. Lear, K.P. Keegan, and R. Allada. “Sleep and circadian behavior monitoring in adult Drosophila.” In: Drosophila Neurobiology: A Laboratory Manual, eds. B. Zhang, M.R. Freeman, and S. Waddell, Cold Spring Harbor Press. 483-504.

Zhang, L., B.C. Lear, A. Seluzicki, and R. Allada (2009). “The Cryptochrome photoreceptor gates PDF neuropeptide signaling to set circadian network hierarchy in Drosophila.” Current Biology 19: 2050-2055. http://dx.doi.org/10.1016/j.cub.2009.10.058

Lear, B.C., L. Zhang, and R. Allada (2009). “The neuropeptide PDF acts directly on evening pacemaker neurons to regulate multiple features of circadian behavior.” PLoS Biology 7 (7): e1000154. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000154

Lear, B.C., J.M. Lin, J.R. Keath, J.J. McGill, I.M. Raman, and R. Allada (2005). “The ion channel Narrow Abdomen is critical for neural output of the Drosophila circadian pacemaker.” Neuron 48: 965-976. http://dx.doi.org/10.1016/j.neuron.2005.10.030

Lear, B.C., C.E. Merrill, J.M. Lin, A. Schroeder, L. Zhang, and R. Allada (2005). “A G-protein coupled receptor, groom-of-PDF, is required for PDF neuron action in circadian behavior.” Neuron 48: 221-227. http://dx.doi.org/10.1016/j.neuron.2005.09.008

Fujioka, M., B.C. Lear, M. Landgraf, G.L. Yusibova, J. Zhou, K.M. Riley, N.H. Patel, and J.B. Jaynes (2003). “Even-skipped, acting as a repressor, regulates axonal projections in Drosophila,” Development 130: 5385-5400. http://dx.doi.org/10.1242/dev.00770

Nash, H.A., R.L. Scott, B.C. Lear, and R. Allada (2002). “An unusual cation channel mediates photic control of locomotion in Drosophila,” Current Biology 12: 2152-2158. http://cell.com/current-biology/retrieve/pii/S0960982202013581

Lear, B.C., J.B. Skeath, and N.H. Patel (1999). “Neural cell fate in rca1 mutants: the roles of intrinsic and extrinsic factors in asymmetric division in the Drosophila CNS,” Mechanisms of Development 88: 207-219. http://dx.doi.org/10.1016/S0925-4773(99)00190-2