Vertebrate cranial neural crest cells (CNCCs) contribute not only to ectodermal lineages like neurons, glia and pigment but also to "ectomesenchymal" lineages like cartilage and bone. Whereas studies have established that in zebrafish the CNCCs are lineage restricted at the neural tube, the molecular bases for regulation of the cell lineage remains unknown. In this thesis work, I will discuss my studies on the role of Bmp signaling from the ectoderm in restricting the ectomesenchyme potential of the CNCC. I will provide evidence for functions of Id2a and Twist1 proteins in specification of the ectomesenchyme. We show that although twist1 genes are expressed in the CNCC starting at pre-migratory stages, presence of Id2a in these cells prevents Twist1 from functioning, and that a loss of Id2a in the migratory CNCCs over time in development facilitates specification of the ectomesenchyme lineage. Furthermore I will discuss a detailed characterization of the roles of Twist1 in specification of the ectomesenchyme lineage in zebrafish. We propose that Twist1 functions as a master-regulator in specification of the ectomesenchyme lineage via regulating induction of early ectomesenchyme genes and repressing the non-ectomesenchyme.
|Commitee:||Lien, Ellen, Lu, Wange, Maxson, Robert, Sucov, Henry M.|
|School:||University of Southern California|
|Department:||Genetic, Molecular, and Cell Biology|
|School Location:||United States -- California|
|Source:||DAI-B 73/11(E), Dissertation Abstracts International|
|Keywords:||Ectomesenchyme, Neural crest cells|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be