Vorticella convallaria has a contractile stalk that arises from the aboral pole of the cell. The myonemes from the body converge at this pole and pass into the stalk to form a large contractile bundle called the spasmoneme. When contracted the stalk coils into a helix. The spasmoneme is partially encased in an extension of the pellicle and a thin layer of cytosol that is enclosed with plasma membrane. An additional secreted sheath surrounds the stalk. TEM taken on 4/6/72 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 7,500X. Bar = 1?m. The negative was printed to paper and the image was scanned to Photoshop. This digitized image is available for qualitative analysis. There is a high resolution version of this image in the library (CIL:39517) which is available for quantitative analysis. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).
Biological Process: Contractile system, Macronucleus organization, Plasma membrane organization
Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).
Author: Richard Allen (University of Hawaii)
Source: The Cell: An Image Library