An embryo goes from a single cell to a complex organism containing thousands of cells of multiple types. These cells assemble into tissues and organs with a precise architecture. The complexity of this architecture is at its most extreme in the group of animals that includes humans, the vertebrates. Research proposed here will use one of the closest invertebrate relatives of the vertebrates, the ascidian. Ascidians are primitive marine chordates that have the same basic architecture, or body plan, as the vertebrates, but as embryos have much fewer cells, and are under the control of a much smaller genome. Experiments proposed here will exploit developmental mutants to investigate two processes: the morphogenesis of the notochord and the patterning of the non-neural ectoderm. The notochord is one of the defining characteristics of the chordates, and the notochord is an important experimental paradigm for understanding tissue morphogenesis, specific experiments will focus on the role of a laminin gene product in organizing and directing the cells of the notochord to form a coherent tissue. In the absence of this gene product the notochord cells wander endlessly through the body. Experiments will explore how the laminin gene product interacts with previously characterized cell-signaling pathways known to be important in directing notochord cell motility. A second type of mutant that will be investigated disrupts the patterning of the trunk ectoderm of the ascidian larva. In this mutant various malformations are evident, the most interesting being the lack-of specific ectodermal thickenings that appear to be similar to vertebrate placodes. In the absence of these placode-like structures, the development of other tissues, in particular the pharyngeal endoderm, is abnormal.
Specific aims are targeted at identifying the gene responsible for generating this phenotype, and understanding its normal function.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD038701-10
Application #
7800912
Study Section
Development - 1 Study Section (DEV)
Program Officer
Mukhopadhyay, Mahua
Project Start
2000-04-01
Project End
2011-03-31
Budget Start
2010-04-01
Budget End
2011-03-31
Support Year
10
Fiscal Year
2010
Total Cost
$248,110
Indirect Cost
Name
University of California Santa Barbara
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
094878394
City
Santa Barbara
State
CA
Country
United States
Zip Code
93106
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