Mary Halloran

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.

Selected Publications

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 (invited review)

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. (invited review)

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. [Highlighted in the “In this issue” section]

Halloran, M.C. and Wolman, M.A. (2006) Repulsion or adhesion: receptors make the call. Current Opinion Cell Biology18:533-540

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

Stevens, C.B. and Halloran, M.C. (2005) Developmental expression of Sema3G, a novel zebrafish semaphorin. Gene Expr Patterns 5:647-653. Erratum-name change to Sema3H.

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

Liu, Y., Berndt, J.D., Su, F., Tawarayama, H., Shoji, W., Kuwada, J.Y., and Halloran, M.C. (2004). Semaphorin3D guides retinal axons along the dorsoventral axis of the tectum. J Neurosci 24:310-318

Halloran, M.C. and Berndt, J.D. (2003). Current progress in neural crest motility and migration and future prospects for the zebrafish model system. Dev Dyn 228:497-513