Intercellular signaling plays a critical role in patterning embryonic development and in the regulation of cell proliferation and survival in embryos and adults. By temporally and spatially combining signals from different signaling pathways, organisms gain the ability to produce complex cellular decisions through the activation of target genes that respond to multiple signaling factors. How these combinatorial signals are used at the molecular and cellular level is for the most part not well understood. The central question of this proposal is: how do Bmps and Wnts work together to establish genetic hierarchies leading to the formation of the posterior mesoderm and neural crest? To examine this, three avenues will be pursued using zebrafish as a model system. (1) Transgenic zebrafish expressing Bmp and Wnt/B-catenin activators and inhibitors under heat shock control will be used to determine when and how these signals are used to regulate the formation of the posterior mesoderm and neural crest throughout development. (2) The promoters of several key target genes responding to Bmp and Wnt/B-catenin signals will be analyzed in order to understand how these signaling pathways are ultimately integrated at the transcriptional level. (3) Microarray and subtractive screens will be used to identify genes that are regulated by both Bmp and Wnt/B-catenin signals using zebrafish mutants that have defects in the Bmp and Wnt signaling pathways. A critically chosen subset of these genes, which are expressed in the posterior mesoderm and neural crest, will be selected for further study using a combination of the transgenic fish expressing inducible Bmp and Wnt activators and inhibitors, overexpression studies and morpholino antisense oligonucleotides. Finally, this analysis will provide a molecular framework for understanding how combinatorial Bmp and Wnt signals lead to the formation of specific tissues within the embryo. Since both Bmp and Wnt signaling are involved in disease processes in humans, and since these signaling pathways are highly conserved, this research will have direct relevance to understanding mechanisms of human disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Program Projects (P01)
Project #
1P01GM065469-01
Application #
6464359
Study Section
Special Emphasis Panel (ZRG1-CDF-5 (01))
Program Officer
Greenberg, Judith H
Project Start
2002-04-01
Project End
2005-03-31
Budget Start
2002-04-01
Budget End
2003-03-31
Support Year
1
Fiscal Year
2002
Total Cost
$798,511
Indirect Cost
Name
University of Washington
Department
Biochemistry
Type
Schools of Medicine
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Hogan, Benjamin M; Layton, Judith E; Pyati, Ujwal J et al. (2006) Specification of the primitive myeloid precursor pool requires signaling through Alk8 in zebrafish. Curr Biol 16:506-11
Cooper, Mark S; Szeto, Daniel P; Sommers-Herivel, Greg et al. (2005) Visualizing morphogenesis in transgenic zebrafish embryos using BODIPY TR methyl ester dye as a vital counterstain for GFP. Dev Dyn 232:359-68
Pyati, Ujwal J; Webb, Ashley E; Kimelman, David (2005) Transgenic zebrafish reveal stage-specific roles for Bmp signaling in ventral and posterior mesoderm development. Development 132:2333-43
Weidinger, Gilbert; Thorpe, Chris J; Wuennenberg-Stapleton, Katrin et al. (2005) The Sp1-related transcription factors sp5 and sp5-like act downstream of Wnt/beta-catenin signaling in mesoderm and neuroectoderm patterning. Curr Biol 15:489-500
Ragland, Jared W; Raible, David W (2004) Signals derived from the underlying mesoderm are dispensable for zebrafish neural crest induction. Dev Biol 276:16-30
Lewis, Jessica L; Bonner, Jennifer; Modrell, Melinda et al. (2004) Reiterated Wnt signaling during zebrafish neural crest development. Development 131:1299-308
Szeto, Daniel P; Kimelman, David (2004) Combinatorial gene regulation by Bmp and Wnt in zebrafish posterior mesoderm formation. Development 131:3751-60