I used the zebrafish embryo to investigate the morphogenesis of the developing somite and the behaviour of its different compartments in vivo via 3D confocal time-lapse microscopy. I demonstrated that the epaxial and hypaxial somite regions show distinct morphogenesis that lead to the chevron-shape of the somite. Evidence is presented that shows that the somite volume does not significantly change during its morphological transition, which suggests that growth does not contribute to somite shape morphogenesis. In vivo cell tracking revealed that cellular dynamics during somite morphogenesis constitute a potential force, capable of driving somite shape changes. Tracked anterior border cells (abc) were observed migrating to the lateral somite surface were they are though to form the dermomyotome. The observation of different abc migration behaviours led to the hypothesis that abc's could be a heterogeneous population of cells which segregate into different behaviour groups, depending on their later fate. Furthermore, slow muscle fibres were observed in vivo to migrate collectively as a chain of slow muscle cells that reaches from somite to somite along the anteroposterior body axis. The slow muscle cells maintain interdigitating contacts to adjacent slow muscle fibres from neighbouring somites and are polarized anteroposteriorly and mediolaterally and gravitate towards the anterior somite half during their migration. Somite borders are shown to be not necessary for slow muscle fibre migration but for slow muscle fibre polarisation and maintenance of the specific cell alignment during migration. Both, abc migration and slow muscle fibre migration are discussed as contributing factors of the observed shape change of the somite.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:628016 |
| Date | January 2011 |
| Creators | Koth, Jana |
| Publisher | King's College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://kclpure.kcl.ac.uk/portal/en/theses/cell-migration-and-morphogenesis-during-formation-and-repair-of-zebrafish-skeletal-muscle(7ead12b2-66d7-4924-8a3a-c5d1a8543240).html |
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