{"id":{"repo_id":"wustl","oai_identifier":"oai:openscholarship.wustl.edu:etd-1159"},"canonical_url":"https://search.dev.ndltd.org/etd/wustl/oai:openscholarship.wustl.edu:etd-1159","repository":{"repo_id":"wustl","name":"Washington University in St. Louis","base_url":"https://openscholarship.wustl.edu/do/oai/"},"display":{"title":"The Role of Pax6 in Lens Placode Formation","abstract":"THE ROLE OF PAX6 IN LENS PLACODE FORMATION by Jie Huang Washington University in St. Louis, 2010 Professor David Beeebe, Chairperson Although placodes are ubiquitous precursors of tissue invagination, the mechanism of placode formation and its importance for invagination are unclear. We tested the \"restricted expansion hypothesis\" of lens placode formation by conditionally deleting the transcription factor, Pax6, or the matrix component, Fn1. Deletion of Pax6 from the lens-forming ectoderm prevented placode formation without altering cell proliferation or volume. <italic>Pax6<super>CKO</super> </italic>ectoderm expanded, rather than being constrained to a constant area, as normally occurs during lens placode formation, and expressed lower levels of transcripts encoding several extracellular matrix components. Deletion of Fn1, which is required to organize the extracellular matrix, prevented lens placode formation. Consistent with the \"restricted expansion hypothesis,\" <italic>Fn1<super>CKO </super> </italic> ectoderm expanded, rather than being constrained. Ectoderm cells of <italic>Fn1<super>CKO</super> </italic> embryos expressed markers of lens induction, reorganized their cytoskeleton as in wild type ectoderm, but did not invaginate. These results suggest that placode formation establishes the minimal mechanical requirements for tissue invagination.","abstract_html":"THE ROLE OF PAX6 IN LENS PLACODE FORMATION by Jie Huang Washington University in St. Louis, 2010 Professor David Beeebe, Chairperson Although placodes are ubiquitous precursors of tissue invagination, the mechanism of placode formation and its importance for invagination are unclear. We tested the &quot;restricted expansion hypothesis&quot; of lens placode formation by conditionally deleting the transcription factor, Pax6, or the matrix component, Fn1. Deletion of Pax6 from the lens-forming ectoderm prevented placode formation without altering cell proliferation or volume. &lt;italic&gt;Pax6&lt;super&gt;CKO&lt;/super&gt; &lt;/italic&gt;ectoderm expanded, rather than being constrained to a constant area, as normally occurs during lens placode formation, and expressed lower levels of transcripts encoding several extracellular matrix components. Deletion of Fn1, which is required to organize the extracellular matrix, prevented lens placode formation. Consistent with the &quot;restricted expansion hypothesis,&quot; &lt;italic&gt;Fn1&lt;super&gt;CKO &lt;/super&gt; &lt;/italic&gt; ectoderm expanded, rather than being constrained. Ectoderm cells of &lt;italic&gt;Fn1&lt;super&gt;CKO&lt;/super&gt; &lt;/italic&gt; embryos expressed markers of lens induction, reorganized their cytoskeleton as in wild type ectoderm, but did not invaginate. These results suggest that placode formation establishes the minimal mechanical requirements for tissue invagination.","abstract_has_math":false,"creators":["Huang, Jie"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Biology and Biomedical Sciences: Developmental, Regenerative and Stem Cell Biology","degree_department":null,"school":null,"contributors":["David Beebe"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-01-01T08:00:00Z","date_published":"2010-01-01T08:00:00Z","updated_at":"2026-07-24T06:12:41Z","subjects":["Morphology","Cellular Biology","Molecular Biology","Extracellular Matrix","Fibronectin","Lens Placode","Mice","Microarray","Pax6"],"languages":["English (en)"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7J964C5"],"render_values":[{"text":"https://doi.org/10.7936/K7J964C5","href":"https://doi.org/10.7936/K7J964C5","code":true}]}]},"links":{"outbound_url":"https://openscholarship.wustl.edu/etd/160","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["David Beebe"]},{"key":"dc:creator","label":"Author","values":["Huang, Jie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2010-01-01T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology and Biomedical Sciences: Developmental, Regenerative and Stem Cell Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Morphology","Cellular Biology","Molecular Biology","Extracellular Matrix","Fibronectin","Lens Placode","Mice","Microarray","Pax6"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/etd/160"]},{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7J964C5"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["THE ROLE OF PAX6 IN LENS PLACODE FORMATION by Jie Huang Washington University in St. Louis, 2010 Professor David Beeebe, Chairperson Although placodes are ubiquitous precursors of tissue invagination, the mechanism of placode formation and its importance for invagination are unclear. We tested the \"restricted expansion hypothesis\" of lens placode formation by conditionally deleting the transcription factor, Pax6, or the matrix component, Fn1. Deletion of Pax6 from the lens-forming ectoderm prevented placode formation without altering cell proliferation or volume. <italic>Pax6<super>CKO</super> </italic>ectoderm expanded, rather than being constrained to a constant area, as normally occurs during lens placode formation, and expressed lower levels of transcripts encoding several extracellular matrix components. Deletion of Fn1, which is required to organize the extracellular matrix, prevented lens placode formation. Consistent with the \"restricted expansion hypothesis,\" <italic>Fn1<super>CKO </super> </italic> ectoderm expanded, rather than being constrained. Ectoderm cells of <italic>Fn1<super>CKO</super> </italic> embryos expressed markers of lens induction, reorganized their cytoskeleton as in wild type ectoderm, but did not invaginate. These results suggest that placode formation establishes the minimal mechanical requirements for tissue invagination."]},{"key":"dc:title","label":"Title","values":["The Role of Pax6 in Lens Placode Formation"]}]}],"canonical_facts":{"dc:contributor":["David Beebe"],"dc:creator":["Huang, Jie"],"dc:date.available":["2010-01-01T08:00:00Z"],"dc:description.abstract":["THE ROLE OF PAX6 IN LENS PLACODE FORMATION by Jie Huang Washington University in St. Louis, 2010 Professor David Beeebe, Chairperson Although placodes are ubiquitous precursors of tissue invagination, the mechanism of placode formation and its importance for invagination are unclear. We tested the \"restricted expansion hypothesis\" of lens placode formation by conditionally deleting the transcription factor, Pax6, or the matrix component, Fn1. Deletion of Pax6 from the lens-forming ectoderm prevented placode formation without altering cell proliferation or volume. <italic>Pax6<super>CKO</super> </italic>ectoderm expanded, rather than being constrained to a constant area, as normally occurs during lens placode formation, and expressed lower levels of transcripts encoding several extracellular matrix components. Deletion of Fn1, which is required to organize the extracellular matrix, prevented lens placode formation. Consistent with the \"restricted expansion hypothesis,\" <italic>Fn1<super>CKO </super> </italic> ectoderm expanded, rather than being constrained. Ectoderm cells of <italic>Fn1<super>CKO</super> </italic> embryos expressed markers of lens induction, reorganized their cytoskeleton as in wild type ectoderm, but did not invaginate. These results suggest that placode formation establishes the minimal mechanical requirements for tissue invagination."],"dc:identifier":["https://openscholarship.wustl.edu/etd/160"],"dc:identifier.doi":["https://doi.org/10.7936/K7J964C5"],"dc:language":["English (en)"],"dc:subject":["Morphology","Cellular Biology","Molecular Biology","Extracellular Matrix","Fibronectin","Lens Placode","Mice","Microarray","Pax6"],"dc:title":["The Role of Pax6 in Lens Placode Formation"],"thesis:degree_discipline":["Biology and Biomedical Sciences: Developmental, Regenerative and Stem Cell Biology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T06:12:41Z"}