{"id":{"repo_id":"columbia-diss","oai_identifier":"oai:academiccommons.columbia.edu:10.7916/D81J9HQW"},"canonical_url":"https://search.dev.ndltd.org/etd/columbia-diss/oai:academiccommons.columbia.edu:10.7916/D81J9HQW","repository":{"repo_id":"columbia-diss","name":"Columbia University","base_url":"https://academiccommons.columbia.edu/oai"},"display":{"title":"Temporal control of vulval precursor cell fate patterning in Caenorhabditis elegans","abstract":"Development of a multicellular organism requires precise coordination of temporal and spatial cues to ensure that developmental events occur at the correct time and place. C. elegans vulval development offers a convenient experimental system for investigating the temporal and spatial regulation of multiple developmental decisions in response to different patterning signals. In this thesis, I present my studies on the temporal control of Vulval Precursor Cell (VPC) fate patterning through analyses of VPC development defects in heterochronic mutants. I show that loss of the miRNA lin-4 inhibits LIN-12/Notch activity through persistence of LIN-14, but not LIN-28 or HBL-1. Persistent lin-14 blocks LIN-12 activity without interfering with the key events of LIN-12/Notch signal transduction, and lin-14 activity in the second larval stage is sufficient to prevent premature LIN-12 activation. I also present evidence that persistent lin-14 activity impedes extension of the VPC apical domains, and that ectopic Wnt signaling prevents the daughters of uninduced VPCs from fusing with the major hypodermal syncytium in lin-4 null mutants. Finally, through characterization of heterochronic mutants that exhibit precocious or delayed vulval induction, I provide clues to possible mechanisms underlying the temporal control of vulval induction.","abstract_html":"Development of a multicellular organism requires precise coordination of temporal and spatial cues to ensure that developmental events occur at the correct time and place. C. elegans vulval development offers a convenient experimental system for investigating the temporal and spatial regulation of multiple developmental decisions in response to different patterning signals. In this thesis, I present my studies on the temporal control of Vulval Precursor Cell (VPC) fate patterning through analyses of VPC development defects in heterochronic mutants. I show that loss of the miRNA lin-4 inhibits LIN-12/Notch activity through persistence of LIN-14, but not LIN-28 or HBL-1. Persistent lin-14 blocks LIN-12 activity without interfering with the key events of LIN-12/Notch signal transduction, and lin-14 activity in the second larval stage is sufficient to prevent premature LIN-12 activation. I also present evidence that persistent lin-14 activity impedes extension of the VPC apical domains, and that ectopic Wnt signaling prevents the daughters of uninduced VPCs from fusing with the major hypodermal syncytium in lin-4 null mutants. Finally, through characterization of heterochronic mutants that exhibit precocious or delayed vulval induction, I provide clues to possible mechanisms underlying the temporal control of vulval induction.","abstract_has_math":false,"creators":["Li, Ji"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011","date_published":"2011","updated_at":"2026-07-24T01:44:11Z","subjects":["Developmental biology","Genetics","Caenorhabditis elegans--Genetics","Vulva"],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.7916/D81J9HQW","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Li, Ji"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011"]},{"key":"dc:type","label":"Dc Type","values":["Theses"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Developmental biology","Genetics","Caenorhabditis elegans--Genetics","Vulva"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://doi.org/10.7916/D81J9HQW"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Development of a multicellular organism requires precise coordination of temporal and spatial cues to ensure that developmental events occur at the correct time and place. C. elegans vulval development offers a convenient experimental system for investigating the temporal and spatial regulation of multiple developmental decisions in response to different patterning signals. In this thesis, I present my studies on the temporal control of Vulval Precursor Cell (VPC) fate patterning through analyses of VPC development defects in heterochronic mutants. I show that loss of the miRNA lin-4 inhibits LIN-12/Notch activity through persistence of LIN-14, but not LIN-28 or HBL-1. Persistent lin-14 blocks LIN-12 activity without interfering with the key events of LIN-12/Notch signal transduction, and lin-14 activity in the second larval stage is sufficient to prevent premature LIN-12 activation. I also present evidence that persistent lin-14 activity impedes extension of the VPC apical domains, and that ectopic Wnt signaling prevents the daughters of uninduced VPCs from fusing with the major hypodermal syncytium in lin-4 null mutants. Finally, through characterization of heterochronic mutants that exhibit precocious or delayed vulval induction, I provide clues to possible mechanisms underlying the temporal control of vulval induction."]},{"key":"dc:title","label":"Title","values":["Temporal control of vulval precursor cell fate patterning in Caenorhabditis elegans"]}]}],"canonical_facts":{"dc:creator":["Li, Ji"],"dc:date":["2011"],"dc:description":["Development of a multicellular organism requires precise coordination of temporal and spatial cues to ensure that developmental events occur at the correct time and place. C. elegans vulval development offers a convenient experimental system for investigating the temporal and spatial regulation of multiple developmental decisions in response to different patterning signals. In this thesis, I present my studies on the temporal control of Vulval Precursor Cell (VPC) fate patterning through analyses of VPC development defects in heterochronic mutants. I show that loss of the miRNA lin-4 inhibits LIN-12/Notch activity through persistence of LIN-14, but not LIN-28 or HBL-1. Persistent lin-14 blocks LIN-12 activity without interfering with the key events of LIN-12/Notch signal transduction, and lin-14 activity in the second larval stage is sufficient to prevent premature LIN-12 activation. I also present evidence that persistent lin-14 activity impedes extension of the VPC apical domains, and that ectopic Wnt signaling prevents the daughters of uninduced VPCs from fusing with the major hypodermal syncytium in lin-4 null mutants. Finally, through characterization of heterochronic mutants that exhibit precocious or delayed vulval induction, I provide clues to possible mechanisms underlying the temporal control of vulval induction."],"dc:identifier":["https://doi.org/10.7916/D81J9HQW"],"dc:language":["English"],"dc:subject":["Developmental biology","Genetics","Caenorhabditis elegans--Genetics","Vulva"],"dc:title":["Temporal control of vulval precursor cell fate patterning in Caenorhabditis elegans"],"dc:type":["Theses"]},"updated_at":"2026-07-24T01:44:11Z"}