Show simple item record

dc.contributor.advisorAntin, Parker B.en_US
dc.contributor.authorBales, Mark
dc.creatorBales, Marken_US
dc.date.accessioned2013-04-11T08:43:43Z
dc.date.available2013-04-11T08:43:43Z
dc.date.issued2002en_US
dc.identifier.urihttp://hdl.handle.net/10150/280000
dc.description.abstractThe signaling pathways that regulate the fate of cells located in the anterior lateral (AL) region of the vertebrate embryo are not well understood. Mesodermal cells in this region will assume the heart muscle phenotype while adjacent endoderm gives rise to foregut tissues such as the liver. The AL endoderm supplies key signaling molecules to promote the survival and differentiation of the precardiac mesoderm. These AL endoderm factors are know to up-regulate transcription factors, such as Nkx2--5, that regulate cardiac genes. However, little is known about how the AL endoderm is patterned and the exact mechanism by which the cardiac transcription factors function within the mesoderm. Therefore, two projects were pursued to understand the developmental pathways that promote early heart development. One project looks at defining the mechanism by which the Nkx2 homeobox genes regulate cardiac gene expression in mouse embryonic stem cells. Unfortunately, this project was plagued with difficulties. Mouse ES cells were used as a model system to study cardiac differentiation. However, these cells were found to contain a potent genome protection mechanism that prevented the stable integration of transcription factors. This phenomenon is addressed and discussed within the thesis. The second project defines the role of retinoids in patterning the AL endoderm. In this study, the homeobox gene cHex, a gene required for hepatocyte development, was used as an AL endoderm marker. It was found that retinoids act directly on the cHex gene promoter to reduce its activity and restrict its expression domain to the AL endoderm.
dc.language.isoen_USen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectBiology, Molecular.en_US
dc.subjectBiology, Cell.en_US
dc.titleMolecular regulation of gene expression in anterior mesendoderm of vertebratesen_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.identifier.proquest3053864en_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineCell Biology and Anatomyen_US
thesis.degree.namePh.D.en_US
dc.identifier.bibrecord.b42811508en_US
refterms.dateFOA2018-05-29T12:18:54Z
html.description.abstractThe signaling pathways that regulate the fate of cells located in the anterior lateral (AL) region of the vertebrate embryo are not well understood. Mesodermal cells in this region will assume the heart muscle phenotype while adjacent endoderm gives rise to foregut tissues such as the liver. The AL endoderm supplies key signaling molecules to promote the survival and differentiation of the precardiac mesoderm. These AL endoderm factors are know to up-regulate transcription factors, such as Nkx2--5, that regulate cardiac genes. However, little is known about how the AL endoderm is patterned and the exact mechanism by which the cardiac transcription factors function within the mesoderm. Therefore, two projects were pursued to understand the developmental pathways that promote early heart development. One project looks at defining the mechanism by which the Nkx2 homeobox genes regulate cardiac gene expression in mouse embryonic stem cells. Unfortunately, this project was plagued with difficulties. Mouse ES cells were used as a model system to study cardiac differentiation. However, these cells were found to contain a potent genome protection mechanism that prevented the stable integration of transcription factors. This phenomenon is addressed and discussed within the thesis. The second project defines the role of retinoids in patterning the AL endoderm. In this study, the homeobox gene cHex, a gene required for hepatocyte development, was used as an AL endoderm marker. It was found that retinoids act directly on the cHex gene promoter to reduce its activity and restrict its expression domain to the AL endoderm.


Files in this item

Thumbnail
Name:
azu_td_3053864_sip1_m.pdf
Size:
3.179Mb
Format:
PDF

This item appears in the following Collection(s)

Show simple item record