Developmental and Structural Section
Betzelberger, Amy M. , Doty, Karen F. , Cook, Martha E. .
Cell Growth in the Green Algal Order Coleochaetales (Charophyceae).
Two types of cell growth have been described in plants and in charalean green algae: diffuse growth, in which growth occurs along the cell length, and tip growth, in which growth occurs in a small portion of the cell. These types of growth have been shown to be associated with particular cytoskeletal patterns. Among the most complex of these patterns are those reported in the charalean algae. Here we look at cell growth in the Coleochaetales, the sister group to the clade composed of charalean algae and plants. The morphologically diverse order Coleochaetales presents a unique opportunity for studying the evolution of cell growth. Both Chaetosphaeridium and Coleochaete produce thalli composed of complex branched filaments that (unlike those of charalean algae) grow flat against a substrate. Furthermore, Chaetosphaeridium has been shown to undergo a unique type of vegetative cell growth in which the newly formed cell bulges laterally to re-orient itself into an adjacent position. Our study looks at cell growth in Chaetosphaeridium and three morphologically diverse species of Coleochaete to determine whether these forms might grow by means of diffuse or tip growth as described in charalean algae and plants. We used differential interference contrast (DIC) microscopy and the fluorescent cellulose stain calcofluor, along with fluorescent labeling of the cytoskeleton, to study growth patterns. Correlated cell wall and cytoskeletal studies increase our understanding of growth phenomena in the Coleochaetales and may shed light on the evolution of plant cell growth processes.
1 - Illinois State University, Department of Biological Sciences, Campus Box 4120, Normal, Illinois, 61790-4120, USA
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM