The processes which drive morphogenesis during Drosophila development are well studied. However, the mechanisms employed to preserve the structures formed as a result of these events are poorly understood. The work of this thesis examines the role of localised cell signalling in effecting the morphogenesis of epithelial tissues. The Drosophila embryonic hindgut is a curved epithelial tube which undergoes elongation and rotation to form a shepherd's crook shaped organ which breaks with the symmetry of the embryo. Work within this thesis describes how asymmetric JAK/STAT signalling, on the inside of the curve, positively regulates protein levels of the homophilic adhesion molecule Fasciclin III (FasIII). Increased levels of FasIII lead it to become asymmetrically distributed throughout the lateral cell membrane. Loss of either JAK/STAT signalling or FasIII leads to a reduction in the magnitude of the hindgut curve. Furthermore, preliminary data indicates that the spatial regulation of JAK/STAT signalling, and lateral FasIII, is also required for correct directional control of hindgut rotation. Secondly, this thesis describes a role for localised JAK/STAT signalling and lateralised FasIII in maintaining the shape of folds within the prospective hinge of the 3rd instar larval wing disc. Further investigation of these folds indicates that their development is required for correct wing posture within the adult. This thesis confirms FasIII as a mediator of cell-cell adhesion. It is therefore hypothesised that the lateralised FasIII domain increases tissue stability within the hindgut curve and the wing disc folds. Loss of this intrinsic support results in these structures being unable to maintain their form during development.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:557569 |
| Date | January 2012 |
| Creators | Wells, R. E. |
| Contributors | Zeidler, M. P. ; Strutt, D. I. |
| Publisher | University of Sheffield |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.whiterose.ac.uk/2658/ |
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