University of Wisconsin–Madison
College of Agriculture and Life Sciences | School of Medicine and Public Health

Mary Halloran

Professor

mchalloran@wisc.edu

608-263-7875

307 Zoology Research

Education
Ph.D. University of Wisconsin-Madison (1994), Postdoctoral Research: University of Michigan, 1994-1999
Department
Integrative Biology
Research Interests
Our research is aimed at understanding mechanisms controlling development of the nervous system.
Research Fields
Cell Biology, Development, Neuro & Behavioral Genetics, Zebrafish

Research Description:
Our research is aimed at understanding how axons are guided to their targets during development of the nervous system. Several families of molecules have been identified that can act as axon guidance cues by either attracting or repelling the motile growth cone at the tip of the growing axon. There is still relatively little known about how axonal growth cones are guided in the complex in vivo environment, where they must integrate multiple cues. We are investigating the function of guidance molecules in vivo using the zebrafish embryo as a model system. The zebrafish is a simple vertebrate with rapidly developing, optically transparent embryos ideal for visualizing developing axons. We use genetic and molecular manipulation of potential guidance cues combined with live imaging of growing axons to determine how guidance cues function in vivo to control the formation of neural connections.

Another main research area in the lab is aimed at understanding mechanisms of neural crest cell (NCC) migration, and in particular the epithelial to mesenchymal transition (EMT) that NCCs undergo to delaminate from the neuroepithelium and begin migration. EMT is a dramatic process involving major changes in cell morphology and motility that allow cell migration and formation of new tissues. EMTs are important for many developmental processes, and are also co-opted in several pathological processes, including cancer metastasis. The mechanisms controlling cell changes during EMT remain poorly understood. Because a cell’s environment strongly influences its motility and intracellular signaling, it is extremely useful to have a model in which we can study these mechanisms while cells undergo EMT in the natural 3D environment. We are again taking advantage of the zebrafish model to combine in vivo imaging of NCC behavior during EMT with manipulation of potential signaling molecules.


Representative Publications:
Search PubMed for more publications by Mary Halloran

Andersen, E.A., Asuri, N.S. and Halloran, M.C. 2011. In vivo imaging of cell behaviors and F-actin reveals LIM-HD transcription factor regulation of peripheral versus central sensory axon development. Neural Development 6:27.

Clay, M.R. and Halloran, M.C. 2011. Regulation of cell adhesions and motility during initiation of neural crest migration. Curr Opinion Neurobiol 21(1):17-22

Clay, M.R. and Halloran, M.C. 2010. Control of neural crest cell behavior and migration: insights from live imaging. Cell Adh Migr 4(4):582-590.

Andersen, E., Asuri, N., Clay, M., Halloran, M. 2010. Live Imaging of Cell Motility and Actin Cytoskeleton of Individual Neurons and Neural Crest Cells in Zebrafish Embryos. JoVE 36. http://www.jove.com/index/details.stp?id=1726, doi: 10.3791/1726

Paulus, J.D., Willer, G.B., Willer, J.R., Gregg, R.G., and Halloran, M.C. 2009. Muscle contractions guide Rohon-Beard peripheral sensory axons. J Neurosci 29:13190-13201.

Sittaramane V., Sawant A., Wolman M.A., Maves L., Halloran M.C., Chandrasekhar A. 2009. The cell adhesion molecule Tag1, transmembrane protein Stbm/Vangl2, and Laminin-alpha1 exhibit genetic interactions during migration of facial branchiomotor neurons in zebrafish. Dev Biol 325:363-373.

Berndt, J.D., Clay, M.R., Langenberg, T., and Halloran, M.C. 2008. Rho-kinase and myosin II affect dynamic neural crest cell behaviors during epithelial to mesenchymal transition in vivo. Dev Biol 324:236-244.

Langenberg, T., Kahana, A., Wszalek, J.A., and Halloran, M.C. 2008. The eye organizes neural crest cell migration. Dev Dyn 237:1645-1652.

Wolman, M.A., Sittaramane, V.K., Essner, J.J., Yost, H.J., Chandrasekhar, A. and Halloran, M.C. 2008. Transient axonal glycoprotein-1 (TAG-1) and laminin-a1 regulate dynamic growth cone behaviors and initial axon direction in vivo. Neural Development 3:6.

Wolman, M.A., Regnery, A.M., Becker, T., Becker, C.G., and Halloran, M.C. 2007. Semaphorin3D regulates axon-axon interactions by modulating levels of L1CAM. J Neurosci 27:9653-9663.

Berndt, J.D. and Halloran, M.C. 2006. Semaphorin3D promotes cell proliferation and neural crest cell development downstream of TCF in the zebrafish hindbrain. Development. 133:3983-3992.

Sakai, J.A. and Halloran, M.C. 2006. Semaphorin3D guides laterality of retinal ganglion cell projections in zebrafish. Development. 133:1035-1044.

Paulus, J.D. and Halloran, M.C. 2006. Zebrafish bashful/Laminin-a1 mutants exhibit multiple axon guidance defects. Dev Dyn. 235:213-224.

Liu, Y. and Halloran, M.C. 2005. Central and peripheral branches from one neuron are guided differentially by Sema3D and TAG-1. J Neurosci. 25:10556-10563.

Wolman, M.A., Liu, Y., Tawarayama, H., Shoji, W. and Halloran, M.C. 2004. Repulsion and attraction of axons by Sema3D are mediated by different neuropilins in vivo. J Neurosci. 24:8428-8435.