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Show UNDERGRADUATE RESEARCH ABSTRACTS SPRING 2007 Kyle Logan Ann Katie Miller Darryl Kropf 49 The Effects of N-Butanol in Silvetia Compressa Kyle Logan, Ann Katie Miller (Darryl Kropf) Department of Biology University of Utah Microtubules (MTs) are essential for the proper development of most eukaryotic cells. It has been widely shown that dynamic rearrangements of MT’s are necessary for cytoskeletal dependent processes. The fucoid alga, Silvetia compressa, is an excellent model organism for investigating the roles of MTs during development because multiple characteristic MT arrays are formed in the early phases of the zygotes growth. MT dependent processes of the first cell division include pronuclear migration, rhizoid morphology, nuclear positioning and rotation, and mitotic division. While much is known about the physical rearrangements of MTs during the development of S. compressa, very little is known about the signaling molecules that regulate the cytoskeletal rearrangement. Recently, PA has been found to signal to MTs, actin, and endo-mombrane based processes in plants, yeast and metazoans. To examine PA signaling in S. compressa, n-butanol was used to block PA production through the PLD signaling pathway. Interestingly, the use of n-butanol was found to affect MT based processes, but not actin-based processes. To examine the effects of n-butanol on the cytoskeleton, zygotes were chemically fixed and immunolabled to visualize MT’s and condensed chromatin. Loss of PA during zygotic development inhibited centrosomal separation and resulted in cells arresting in metaphase, unable to form a bipolar mitotic spindle. Additionally, cells treated with n-butanol after metaphase were unable to form a cell plate and divide. These results indicate that PA signaling to MTs regulates cytoskeletal rearrangements at all stages of early fucoid algal development. |