Phone: (413) 585-3697
Office: Sabin-Reed Hall 347
Email: mbarresi@smith.edu

Courses:

Fall

Bio 302 Developmental Biology
Bio 303 Developmental Biology Laboratory

Spring
Bio 206 Cell Physiology
Bio 207 Cell Physiology Laboratory

Research Interests:

My research interests are focused on how glial cells help wire the nervous system in the embryonic zebrafish brain. We discovered that astroglial cells provide a substrate for midline crossing axons in the forebrain. Further investigation will attempt to determine how the cellular identity of these astroglial cells is established, what molecular cues control glial cell positioning in the brain, and lastly how these astroglial cells actively participate in axon guidance. In order to address these questions we use zebrafish as a model system.

Why Zebrafish?

The zebrafish has recently become a favorite vertebrate model system to many researchers studying Neuroscience. Zebrafish can be bred in a small laboratory space and produce hundreds of embryos a day for analysis. Most importantly, zebrafish is the fastest developing vertebrate model system, going from a one-cell embryo to an embryo with a functioning nervous system in less than 24h. Additionally, zebrafish embryos are optically transparent, enabling the observation of single cell movement and tissue formation in living embryos. Experimentally, zebrafish provide the ability to use genetics, classical embryology, molecular biology, physiology, and pharmacology to answer our research questions.

Laboratory Projects:
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Glial Cell Fate - We are interested in defining the cellular identity of astroglial cells in the forebrain. By using both gene and cell markers we will attempt to determine exactly what types of glial cells exist in the forebrain during embryonic and larval development. In addition, the fate of each cell type is precisely regulated by the signaling systems present in their environment. We will use a series of zebrafish mutants that affect the Hedgehog and Fibroblast Growth Factor signaling pathways to determine if either of these signaling systems play a role in glial cell differentiation.

Glial Cell Guidance - We show that the Slit family of axon guidance repellents may play a role in determining the position of astroglia in the forebrain. By using specific knockdown techniques we will test which slit genes and their roundabout receptors are required for glial cell guidance in the forebrain.

Axon-Glial Interactions - In order to investigate the behaviors of two cells interacting we need to be able to watch those cells in their normal context. We are currently developing tools to watch both glial cells and axons in the live embryo as they contact each other during the formation of the first neural pathways. More specifically, we are generating transgenic fish lines that drive the expression of Red Fluorescent Protein specifically in glial cells and Green Fluorescent Protein in axons. These fluorescent lines will allow us conduct time-lapse microscopy to watch the behavior of labeled cells at different times.

Representative Publications:

Click Here to access PubMed Listing of these articles.

S.H. Devoto, W. Stoiber, C.L. Hammond, P. Steinbacher, J.R. Haslett, M.J.F. Barresi, S.E. Patterson, E. Adiarte, and S.M. Hughes. Submitted, 2005. Generality of vertebrate developmental patterns: evidence for a dermomyotome in fish. Evolution and Development.

Barresi MJ, Hutson LD, Chien CB, Karlstrom RO. 2005. Hedgehog regulated Slit expression determines commissure and glial cell position in the zebrafish forebrain. Development. 132(16):3643-56.

Sbrogna JL, Barresi MJ, Karlstrom RO. 2003. Multiple roles for Hedgehog signaling in zebrafish pituitary development. Dev Biol. 254(1):19-35.

Hernandez, L.P., Barresi, M.J.F., and Devoto, S.H. 2002.Functional Morphology and Developmental Biology of the Zebrafish: reciprocal illumination from an unlikely couple. Integrative and Comparative Biology, Vol 42(2):222-231.

Barresi MJ, D'Angelo JA, Hernandez LP, Devoto SH. 2001. Distinct mechanisms regulate slow-muscle development. Curr Biol. 11(18):1432-8.

Stickney HL, Barresi MJ, Devoto SH. 2000. Somite development in zebrafish. Dev Dyn. 219(3):287-303. Review.

Barresi MJ, Stickney HL, Devoto SH. 2000. The zebrafish slow-muscle-omitted gene product is required for Hedgehog signal transduction and the development of slow muscle identity . Development. 127(10):2189-99.