Abstract
dc:description.abstractDuring cell division, chromosome segregation takes place on bipolar, microtubulebased spindles. Here, C. elegans is used to analyze spindle organization under both mitotic and meiotic conditions. First, the role of SAS-4 in organizing centrosome structure was analyzed. Partial depletion of SAS-4 in early embryos results in structurally defective centrioles. The study of this protein sheds light on the poorly understood role of the centrioles in dictating centrosome size. Second, the ultrastructure of wild-type mitotic spindle components was analyzed by electron tomography. This 3-D analysis reveals morphologically distinct microtubule end morphologies in the mitotic spindle pole. These results have structural implications for models of microtubule interactions with centrosomes Third, spindle assembly was studied in female meiosis. Specifically, the role of the microtubule severing complex katanin in spindle organization was analyzed. Electron tomography reveals fragmentation of spindle microtubules and suggests a novel katanin-dependent mechanism of meiotic spindle assembly. In this model, relatively long microtubules seen near the meiotic chromatin are converted into numerous short fragments, thus increasing the total number of polymers in an acentrosomal environment. Taken together, these results provide novel insights into the three-dimensional organization of microtubules during spindle assembly.
Degree
thesis:*- Level thesis:degree_level
- thesis.habilitation
- Grantor dc:publisher
- Technische Universität Dresden
- Year
- 2006
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Müller-Reichert, Thomas
- Contributors dc:contributor
-
- Rödel, Gerhard
- Hyman, Anthony
- Schliwa, Manfred