The diversity of cell types within the vertebrate nervous system depends on patterning events that occur at early stages of development. The specification and patterning of neural tissue is closely coupled to the development of the other germ layers. The mesoderm and endoderm are important sources of signals that induce neural tissue and establish asymmetries within the neural plate. In this proposal, we seek to utilize the potent genetic and cellular methodologies available in the zebrafish to study patterning of the neural ectoderm. The zebrafish is well suited to this analysis. Zebrafish embryos are transparent and embryonic development occurs rapidly. These attributes foster detailed observation of normal and aberrant embryonic development. Zebrafish produce large numbers of offspring, which in addition to facilitating phenotypic characterization, enhances genetic analysis. The proposed experiments utilize several well characterized zebrafish mutations to investigate the molecular mechanisms that induce and pattern neural tissue. The general approach is to account for all the signals that generate anterior and posterior neural tissue. Models for both neural induction and patterning will be tested. A genetic screen is proposed to identify novel loci that disrupt anterior neural specification. The screen takes advantage of the ability to generate haploid zebrafish embryos in order to increases the throughput of the screen. There are two components to the screen: a morphology based approach to identify enhancers of a mutation (bozozok) which disrupts anterior neural patterning and an in situ based effort to detect alterations of the expression domains of the phox2a transcription factor. One promising mutation identified in a pilot screen alters anterior neural patterning and will be studied in detail. Because all vertebrates share fundamental similarities in the organization of their nervous systems, understanding the genetic networks that govern neural patterning in zebrafish will provide important insights into development of other species, including humans. Several zebrafish mutations have that disrupt embryonic development have anterior neural defects similar to a common human congenital abnormality, holoprosencephaly, and share similar etiologies. Deciphering the mechanisms of vertebrate axis formation may also provide insight into the causes other human developmental disorders.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
3R01HD043998-05S2
Application #
7933152
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Henken, Deborah B
Project Start
2009-09-30
Project End
2010-09-29
Budget Start
2009-09-30
Budget End
2010-09-29
Support Year
5
Fiscal Year
2009
Total Cost
$73,822
Indirect Cost
Name
State University New York Stony Brook
Department
Neurosciences
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Kok, Fatma O; Shepherd, Iain T; Sirotkin, Howard I (2010) Churchill and Sip1a repress fibroblast growth factor signaling during zebrafish somitogenesis. Dev Dyn 239:548-58
Gates, Keith P; Mentzer, Laura; Karlstrom, Rolf O et al. (2010) The transcriptional repressor REST/NRSF modulates hedgehog signaling. Dev Biol 340:293-305
Londin, Eric R; Mentzer, Laura; Gates, Keith P et al. (2007) Expression and regulation of the zinc finger transcription factor Churchill during zebrafish development. Gene Expr Patterns 7:645-50
Kok, Fatma O; Oster, Emma; Mentzer, Laura et al. (2007) The role of the SPT6 chromatin remodeling factor in zebrafish embryogenesis. Dev Biol 307:214-26
Londin, Eric R; Mentzer, Laura; Sirotkin, Howard I (2007) Churchill regulates cell movement and mesoderm specification by repressing Nodal signaling. BMC Dev Biol 7:120
Londin, Eric R; Niemiec, Jack; Sirotkin, Howard I (2005) Chordin, FGF signaling, and mesodermal factors cooperate in zebrafish neural induction. Dev Biol 279:1-19