We use the zebrafish as an experimental system, working toward two broad research goals: to uncover conserved basic mechanisms that regulate the generation and organization of tissues in the vertebrate embryo and to understand the primary roles of molecular and genetic pathways that are disturbed in congenital birth defects.
Current research projects include:
1) the role of regulated calcium mobilization in muscle and neural disease and normal development;
2) transcription regulation of the pluripotent state of neural crest precursor cells; and
3) the mechanism be which T-box transcription factors interact to assign tissue identities in the early embryo.
We want to understand regulation of cell identity and differentiation in the early vertebrate embryo. We work with zebrafish because of the precision with which tissue development can be monitored in the nearly transparent, rapidly developing zebrafish embryo, and the ease with which gene expression can be perturbed and mutants can be isolated. Three major projects in the lab are aimed at understanding: 1) the role of intracellular calcium mobilization in tissue patterning events, 2) factors that confer identity to the stem cell-like precursors of the neural crest, and 3) how the mesoderm germ layer is subdivided into groups of tissue precursors that occupy specific regions of the embryo.
The current studies of calcium mobilization began with our search for a conceptual framework for thinking about the origin of a series of congenital myopathies. Like many birth defects, congenital muscle diseases are often first recognized and characterized at times far removed from the onset of the disorder, making it difficult to identify the initial biochemical or cellular defects that trigger the disease process. Our studies of zebrafish embryos and diseased tissue have shown that different genetic disorders associated with congenital myopathies directly disrupt mobilization of intracellular calcium.
Our work indicates intracellular calcium release is required to orchestrate tissue patterning in many contexts and is required specifically for cell differentiation events that require transmission of Hedgehog growth factor signaling. In ongoing studies, we are analyzing the roles of calcium mobilization in mediating many kinds of intercellular signaling events, including those required for neuronal patterning, muscle differentiation, and left-right patterning. In addition, we are investigating the mechanisms by which calcium release is regulated, including the roles of Selenoproteins in regulating calcium release channel activity.
A second project is aimed at uncovering the genetic program that leads to formation of the neural crest. We identified a mutation that blocks formation of the neural crest, and found the mutant gene encodes PAF-1, a component of a transcription regulatory complex required in many types of stem cells. Current work focuses on identifying the molecular function of PAF-1 and the downstream genes whose expression is needed for neural crest identity.
A third project is to understand how groups of T-box genes, which encode related transcription factors, coordinate development of multiple neighboring tissues. T-box gene mutations cause congenital defects of the heart, limb, and other organ systems. Each syndrome appears to be composed of multiple cellular defects, as if the relevant T-box gene has different functions in different cell types. To explain this recurrent phenomenon, we proposed that individual T-box transcription factors indeed have different functions in different cells because the target genes regulated by any individual factor are determined by the combination of T-box transcription factors co-expressed in a cell. Our work aims to identify the primary cellular and molecular targets of T-box transcription factors and to understand how combinations of T-box factors interact to assign cell identity.
References to Publications:
Bai, X., Kim, J., Yang, Z., Jurynec, M.J., Lee, J., LeBlanc, J., Sessa, A., Akie, T.E., Jiang, H., Grunwald, D.J., Lin, S., Cantor, A.B., Orkin, S.H. and Zon, L.I. (2010). TIFy controls erythroid cell fate by regulating transcription elongation. Cell. 142, 133-143. PMID20603019
Jurynec, M. J. and Grunwald, D. J. (2010). SHIP2 modulates FGF signaling in the establishment of the dorsoventral axis in zebrafish. Disease Models and Mechanisms. 3, xxx-xxx. PMID20616095
Jurynec, M. J., Xia, R., Mackrill, J. J., Gunther, D., Crawford, T., Flanigan, K. M., Abramson, J. J., Howard, M. T., and Grunwald, D. J. (2008). Selenoprotein N is required for Ryanodine Receptor calcium release channel activity in human and zebrafish muscle. Proceedings of the National Academy of Sciences (USA), 105,12485-90. PMID18713863
Vasquez, S. X., Hansen, M. S., Bahadur, A. N., Hockin, M. F., Kindlemann, G., Nevell, L., Wu, I. Q., Grunwald, D. J., Jones, G. M., Johnson, C. R., VandeBerg, J. L., Cappechi, M. R. and Keller, C. (2008). Volumetric Computed Tomography for Skeletal Analysis of Model Genetic Organisms. Anatomical Record, 291, 475-487. PMID18286615
Lee, J. E., Wu, S. F., Goering, L. M. & Dorsky, R. I. (2006). Canonical Wnt signaling through Lef1 is required for hypothalamic neurogenesis. Development 133, 4451-61. PMID17050627
Lamason, R. L., et al. (2005). SLC24A5, a putative cation exchanger, affects pigmentation in zebrafish and man. Science 310, 1782-1786. PMID16357253
Goering, L. M., Hoshijima, K., Hug, B., Bisgrove, B., Kispert, A., and Grunwald, D. J. (2003). An interacting network of T-box genes directs gene expression and fate in the zebrafish mesoderm. Proceedings of the National Academy of Sciences (USA), 100, 9410-9415. PMID12883008
Hoshijima, K., Metherall, J. E., and Grunwald, D. J. (2002). A protein disulfide isomerase expressed in the embryonic midline is required for left/right asymmetries. Genes Dev 16, 2518-2529. PMID12368263
Grunwald, D. J., and Eisen, J. S. (2002). Headwaters of the zebrafish — emergence of a new model vertebrate. Nat Rev Genet 3, 717-724. PMID12209146
Korzh, V., and Grunwald, D. (2001). Nadine Dobrovolskaia-Zavadskaia and the dawn of developmental genetics. Bioessays 23, 365-371. PMID11268043
Dorsky, R. I., Snyder, A., Cretekos, C. J., Grunwald, D. J., Geisler, R., Haffter, P., Moon, R. T., and Raible, D. W. (1999). Maternal and embryonic expression of zebrafish lef1. Mech Dev 86, 147-150. PMID10446273
Cretekos, C. J., and Grunwald, D. J. (1999). alyron, an insertional mutation affecting early neural crest development in zebrafish. Dev Biol 210, 322-338. PMID10357894
Appel, B., A. Fritz, M. Westerfield, D.J. Grunwald, J. Eisen, and B.B. Riley. (1999). Delta-mediated specification of midline cell fates in zebrafish embryos. Curr Biol 9, 247-256. PMID10074451
Schier, A. F., Neuhauss, S. C., Helde, K. A.,Talbot, W. S., Driever, W. (1997). The one-eyed pinhead gene functions in mesoderm and endoderm formation in zebrafish and interacts with no tail. Development 124, 327-42. PMID9053309
Liao, W., Bisgrove, B. W., Sawyer, H., Hug, B., Bell, B., Peters, K., Grunwald, D. J., and Stainier, D. Y. (1997). The zebrafish gene cloche acts upstream of a flk-1 homologue to regulate endothelial cell differentiation. Development 124, 381-389. PMID9053314
Hug, B., Walter, V., and Grunwald, D. J. (1997). tbx6, a Brachyury-related gene expressed by ventral mesendodermal precursors in the zebrafish embryo. Dev Biol 183, 61-73. PMID9119115
Bisgrove, B. W., Raible, D. W., Walter, V., Eisen, J. S., and Grunwald, D. J. (1997). Expression of c-ret in the zebrafish embryo: potential roles in motoneuronal development. J Neurobiol 33, 749-768. PMID9369149
Weinberg, E. S., Allende, M. L., Kelly, C. S., Abdelhamid, A., Murakami, T., Andermann, P., Doerre, O. G., Grunwald, D. J., and Riggleman, B. (1996). Developmental regulation of zebrafish MyoD in wild-type, no tail and spadetail embryos. Development 122, 271-280. PMID8565839
Grunwald, D. J. (1996). A fin-de siecle achievement: charting new waters in vertebrate biology. Science 274, 1634-1635. PMID8984632
Riley, B. B., and Grunwald, D. J. (1996). A mutation in zebrafish affecting a localized cellular function required for normal ear development. Dev Biol 179, 427-435. PMID8903357
Riley, B. B., and Grunwald, D. J. (1995). Efficient induction of point mutations allowing recovery of specific locus mutations in zebrafish. Proceedings of the National Academy of Sciences (USA) 92, 5997-6001. PMID7597068
Wilson, E. T., Cretekos, C. J., and Helde, K. A. (1995). Cell mixing during early epiboly in the zebrafish embryo. Dev Genet.17, 6-15. PMID7554496
Helde, K. A., Wilson, E. T., Cretekos, C. J., and Grunwald, D. J. (1994). Contribution of early cells to the fate map of the zebrafish gastrula. Science 265, 517-520. PMID8036593
Wilson, E. T., Helde, K. A., and Grunwald, D. J. (1993). Something’s fishy here–rethinking cell movements and cell fate in the zebrafish embryo. Trends Genet 9, 348-352. PMID8273149
Stachel, S. E., Grunwald, D. J., and Myers, P. Z. (1993). Lithium perturbation and goosecoid expression identify a dorsal specification pathway in the pregastrula zebrafish. Development 117, 1261-1274. PMID8104775
Grunwald, D. J., and Streisinger, G. (1992). Induction of recessive lethal and specific locus mutations in the zebrafish with ethyl nitrosourea. Genet Res 59, 103-116. PMID1628817
Grunwald, D. J., and Streisinger, G. (1992). Induction of mutations in the zebrafish with ultraviolet light. Genet Res 59, 93-101. PMID1628821
Streisinger, G., Coale, F., Taggart, C., Walker, C., and Grunwald, D. J. (1989). Clonal origins of cells in the pigmented retina of the zebrafish eye. Dev Biol 131, 60-69. PMID2909409
Grunwald, D. J., Kimmel, C. B., Westerfield, M., Walker, C., and Streisinger, G. (1988). A neural degeneration mutation that spares primary neurons in the zebrafish. Dev Biol 126, 115-128. PMID3342929
David Grunwald Ph.D.
Post Doc Members
Tim Dahlem, Ph.D.
Department of Human Genetics
University of Utah
15 N 2030 E rm. 5160
Salt Lake City, Utah 84112-5330