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Title: | The Cytostomal Apparatus of Tetramitus Rostratus |
Authors: | Allen, Linda B |
Advisor: | Dingle, A.D |
Department: | Biology |
Keywords: | microtubular, eukaryotic, tetramitus rostratus, cystomal apparatus |
Publication Date: | Oct-1987 |
Abstract: | Microtubular systems are an integral and essential element of eukaryotic cells. Many of these systems display linkages between the microtubules. The aim of this study was to investigate one such system, the cytostomal apparatus of Tetramitus rostratus. It was hoped that some insight could be gained into the nature of inter-microtubule linkages as well as investigating conditions for possible isolation via differential solubilization. The cytostomal apparatus consists of two sheaves of microtubules that originate at the basal bodies and extend through two-thirds of the length of the cell, apparently supporting the gullet. These microtubules are extremely stable: they are cold stable, calcium stable and griseofulvin/colchicine stable. They are highly cross-linked by fine filaments. These "linkers" have an average length of 107 nm. Linker width varies from the mid-portion (6 nm) to the ends (12 nm). In this and other respects they are similar to the highly contested microtrabecular lattice. The linkers were observed in positively stained samples and in thin-sections. Glutaraldehyde was found to have a very destructive effect on the linkers. A combination of paraformaldehyde and glutaraldehyde (2.25\/0.5\) was found not to have this effect over times that are normally used for primary fixation. Another component of the cytostomal apparatus is the system of longitudinal filaments that is especially wellrevealed with high salt (0.25M NaCl or KCl) extraction. Since this extraction solubilizes the microtubules, it may allow the longitudinal filaments to be isolated. These filaments may be related to the tektin filaments found in flagellar microtubules. In addition, a novel set of crossfibres is found to originate at the juncture of the two sheaves of microtubules and fan out across two-thirds of the width of the apparatus. These fibres were found to be especially stable in urea which may, again, allow for their isolation and characterization. The linkers have been investigated for motility. Linker length was measured after treatment with ATP (which successfully reactivated the flagellar dynein) and after treatment with ATP followed by treatment with calcium (which efficiently halted all reactivated movement of the flagella). The length of the ATP treated linkers was very close (5 nm) to the control linkers and their morphology was indistinguishable. The length of the calcium treated linkers was considerable shorter (20 nm) but the morphology suggested that this was artifactual rather than due to a physiological cause. |
URI: | http://hdl.handle.net/11375/22489 |
Appears in Collections: | Digitized Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Allen_Linda_B_1987Oct_Masters.pdf | 19.37 MB | Adobe PDF | View/Open |
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