Poster: Cytoskeleton structure & dynamics
Abs #
691: Interphase microtubule arrays at high resolution
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Presenter: |
Barton, Deborah A., dbarton@bio.usyd.edu.au |
Authors | Barton, Deborah A. (A) Overall, Robyn L. (A) | | Affiliations: |
(A): School Biological Sciences, The University of Sydney
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During interphase, microtubules of plant cells are aligned into arrays just beneath the cell membrane. To date, no techniques have been available to image individual microtubules as part of a three-dimensional array. Using immunofluorescence it is difficult to determine if a fluorescent line is composed of individual or bundled microtubules. On the other hand, while individual and bundled microtubules are easily distinguished using transmission electron microscopy, it is difficult to image three -dimensional arrays in the thin sections used. Field emission scanning electron microscopy (FESEM) has been used successfully to visualise individual microtubules within plant cells.(Vesk et al(1996) Protoplasma 195: 168-182). We have extended this to image large areas of microtubule arrays at high resolution in Tradescantia leaf epidermal peels. We have modified the technique to exclude pre-extraction of cytoplasm or taxol-induced stabilisation of the microtubules prior to fixation. Individual microtubules within arrays were clearly resolved and often co-aligned in bundles. Some bundles were arranged at disparate angles, meeting or crossing over at various locations. In addition crosslinkers between individual microtubules were commonly seen. Immunolabelling microtubules with a fluoronanogold secondary antibody allowed microtubules within the same cell to be investigated by both confocal microscopy and FESEM. Often, individual lines of fluorescence correlated to several microtubules and even a number of microtubule bundles in FESEM images. In addition, there were a small number of individual microtubules seen in FESEM images that were not readily visible in the corresponding fluorescence images. We are continuing to explore the microtubule arrays at high
