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dc.contributor.authorMurphy, Fiona Lauraen
dc.date.accessioned2019-02-15T14:38:24Z
dc.date.available2019-02-15T14:38:24Z
dc.date.issued2014en
dc.identifier.urihttp://hdl.handle.net/1842/35438
dc.description.abstracten
dc.description.abstractPrevious studies have identified the Notch signalling pathway as an important regulator of haematopoietic development. However its role in definitive haematopoietic stem cell (dHSC) development is still unclear mainly due to the fact that Notch mutants die around mid- gestation before the emergence of the first dHSC. Here I investigated the role of the Notch signalling pathway in dHSC development focusing on the ligand Jaggedl and the receptor Notchl. I carried out a detailed characterisation of the expression pattern of Notchl and Jaggedl in the aorta-gonad-mesonephros (AGM) region, where dHSCs first emerge in the embryo, by immunocytochemistry and immunohistochemistry. I then determined, by sorting cells from the AGM region based on their level of Notchl, that Notchl was highly expressed in endothelial cells, precursors of dHSCs (called pre -HSC) and dHSCs, and its expression then decreases in haematopoietic progenitors.en
dc.description.abstractI also generated a Jaggedl dtTomato knock -in reporter mouse using a combination of recombineering and traditional cloning to produce a targeting vector, followed by targeting a B16 ES cell line, and producing a mouse line from a correctly targeted ES cell clonal line. This mouse line allowed me to visualise Jagged1 expression during dHSC development. With the line I showed that pre-HSCs express both Jagged1 and Notch1 and that Jagged1⁺Notch1⁺ cell surface marker phenotype can enrich the pre-HSC population 1 in 8.en
dc.description.abstractTo further investigate the implication of Jagged1 in dHSC development the gene was conditionally deleted in the HSC lineage using a CD41-Cre. Our result indicated that Jagged1 is not required for HSC development in a cell autonomous manner. Furthermore, I carried out experiments with a conventional Jagged1 knock -out mouse line. It has previously been shown that Jagged1 null embryos die around E10.5 and contain fewer intra-haematopoietic progenitors. I used an explant culture system to culture E10.5 AGM regions from Jagged1⁻/⁻ embryos past the point of embryo lethality and in culture HSCs were produced. This result indicates that Jagged1⁻/⁻ embryos contain pre-HSCs that can mature efficiently into dHSC in vitro.en
dc.publisherThe University of Edinburghen
dc.relation.ispartofAnnexe Thesis Digitisation Project 2019 Block 22en
dc.relation.isreferencedbyen
dc.titleJagged1 and notch1 involvement in haematopoietic stem cell developmenten
dc.typeThesis or Dissertationen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD Doctor of Philosophyen


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