Experimental separation of cell division and silica shell formation in Cyclotella cryptica

Badour, S. S.

doi:10.1007/bf00407050

“…6 also indicate that a significant portion of the center of the forming valve is oriented along the long axis of the cell, and not in the final valve plane. Previous work on Cyclotella cryptica indicated that when cytokinesis was inhibited, valves were also formed along the side of the cell (Badour, 1968). …”

Section: Discussionmentioning

confidence: 99%

3D imaging of diatoms with ion-abrasion scanning electron microscopy

Hildebrand

¹

,

Kim

²

,

Shi

³

et al. 2009

Journal of Structural Biology

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Ion-abrasion scanning electron microscopy (IASEM) takes advantage of focused ion beams to abrade thin sections from the surface of bulk specimens, coupled with SEM to image the surface of each section, enabling 3D reconstructions of subcellular architecture at ~ 30 nm resolution. Here, we report the first application of IASEM for imaging a biomineralizing organism, the marine diatom Thalassiosira pseudonana. Diatoms have highly patterned silica-based cell wall structures that are unique models for the study and application of directed nanomaterials synthesis by biological systems. Our study provides new insights into the architecture and assembly principles of both the "hard" (siliceous) and "soft" (organic) components of the cell. From 3D reconstructions of developmentally synchronized diatoms captured at different stages, we show that both micro-and nanoscale siliceous structures can be visualized at specific stages in their formation. We show that not only are structures visualized in a whole-cell context, but demonstrate that fragile, early-stage structures are visible, and that this can be combined with elemental mapping in the exposed slice. We demonstrate that the 3D architectures of silica structures, and the cellular components that mediate their creation and positioning can be visualized simultaneously, providing new opportunities to study and manipulate mineral nanostructures in a genetically tractable system.

show abstract

“…6 also indicate that a portion of the forming valve is oriented along the long axis of the cell, and not in the final valve plane. Previous work on Cyclotella cryptica indicated that when cytokinesis was inhibited, valves were also formed along the side of the cell (Badour, 1968).…”

Section: Discussionmentioning

confidence: 99%

3D Imaging of Diatoms with Ion Abrasion Scanning Electron Microscopy

Hildebrand

¹

,

Kim

²

,

Shi

³

et al. 2008

View full text Add to dashboard Cite

Ion-abrasion scanning electron microscopy (IASEM) takes advantage of focused ion beams to abrade thin sections from the surface of bulk specimens, coupled with SEM to image the surface of each section, enabling 3D reconstructions of subcellular architecture at ~ 30 nm resolution. Here, we report the first application of IASEM for imaging a biomineralizing organism, the marine diatom Thalassiosira pseudonana. Diatoms have highly patterned silica-based cell wall structures that are unique models for the study and application of directed nanomaterials synthesis by biological systems. Our study provides new insights into the architecture and assembly principles of both the "hard" (siliceous) and "soft" (organic) components of the cell. From 3D reconstructions of developmentally synchronized diatoms captured at different stages, we show that both micro-and nanoscale siliceous structures can be visualized at specific stages in their formation. We show that not only are structures visualized in a whole-cell context, but demonstrate that fragile, early-stage structures are visible, and that this can be combined with elemental mapping in the exposed slice. We demonstrate that the 3D architectures of silica structures, and the cellular components that mediate their creation and positioning can be visualized simultaneously, providing new opportunities to study and manipulate mineral nanostructures in a genetically tractable system. 3

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“…The high MPSi : TDV ratio may have been caused by Si incorporation by diatoms in excess of that required for growth. It is reported that Si uptake continues even after cell division has been inhibited (Badour 1968). Since A. granulata, the dominant species during these periods, possesses a thick cell wall (Horn and Goldman 1983) and requires a large amount of Si (Kilham et al 1986), the Si content of this species may be high when silicification is not disturbed.…”

Section: Resultsmentioning

confidence: 98%