Institution: | 1. Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, PL1 2PB UK;2. Station Biologique de Roscoff, 29680 Roscoff, France
Contribution: ?Investigation (equal), Resources (equal);3. Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, 28403-591 USA
Contribution: ?Investigation (equal), Methodology (equal);4. Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, 28403-591 USA
Contribution: ?Investigation (equal), Supervision (equal), Writing - review & editing (equal);5. Plymouth Electron Microscopy Centre, University of Plymouth, Plymouth, PL4 8AA UK
Contribution: Methodology (equal);6. Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, PL1 2PB UK
School of Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH UK
Contribution: Supervision (equal), Writing - review & editing (equal) |
Abstract: | The calcite platelets of coccolithophores (Haptophyta), the coccoliths, are among the most elaborate biomineral structures. How these unicellular algae accomplish the complex morphogenesis of coccoliths is still largely unknown. It has long been proposed that the cytoskeleton plays a central role in shaping the growing coccoliths. Previous studies have indicated that disruption of the microtubule network led to defects in coccolith morphogenesis in Emiliania huxleyi and Coccolithus braarudii. Disruption of the actin network also led to defects in coccolith morphology in E. huxleyi, but its impact on coccolith morphology in C. braarudii was unclear, as coccolith secretion was largely inhibited under the conditions used. A more detailed examination of the role of actin and microtubule networks is therefore required to address the wider role of the cytoskeleton in coccolith morphogenesis. In this study, we have examined coccolith morphology in C. braarudii and Scyphosphaera apsteinii following treatment with the microtubule inhibitors vinblastine and colchicine (S. apsteinii only) and the actin inhibitor cytochalasin B. We found that all cytoskeleton inhibitors induced coccolith malformations, strongly suggesting that both microtubules and actin filaments are instrumental in morphogenesis. By demonstrating the requirement for the microtubule and actin networks in coccolith morphogenesis in diverse species, our results suggest that both of these cytoskeletal elements are likely to play conserved roles in defining coccolith morphology. |