Bruce McEwen Laboratory
Welcome to Dr. McEwen's laboratory at the Wadsworth Center!
Here we use a comprehensive structural approach to study kinetochore function, chromosome motion, and axoneme structure. These studies are accomplished through electron tomography, cryo-electron tomography, light microscopy, serial section electron microscopy, and computer based image processing.
This figure shows how we can use electron tomography to analyze cell division. (a) An immuno-fluorescent light microscopy image of a mammalian cell during cell division. (b) Electron microscopy image of a kinetochore from the same cell type. The kinetochore is the region of the chromosome that attaches to the mitotic spindle. (c) Single 2D slice from the 3D electron tomographic reconstruction of the kinetochore illustrated in (b). Note how much sharper microtubules are in the tomographic reconstruction. (d) Single microtubule extracted from the tomographic reconstruction. (e) A 3D model created by tracing and color coding (green) the microtubule in (d). (f) Same model as in (e) showing kinetochore components (red) that are attached to the microtubule.
Credit: From B. F. McEwen, Electron Tomography, in the McGraw-Hill Yearbook of Science and Technology, 2003
This image shows the location of centromere protein E (CENP-E) in human lung cells. CENP-E is required during cell division for normal attachment of chromosomes to the mitotic spindle, though its exact function is unknown. Cells in the middle and bottom center are in the first stages of cell division, when chromosomes (blue) are attaching to the microtubules (green) of the mitotic spindle. During this stage, CENP-E (red) is located in the kinetochore, a specialized region where chromosomes are attached. When all chromosomes are attached and aligned at the spindle equator, they split apart with duplicated copies migrating to opposite spindle poles. At this stage, CENP-E leaves the kinetochore for the spindle equator, as illustrated by the cell in the upper left. Between cell divisions, the protein either is absent or diffusely located in the cytoplasm.
Credit: Dr. Bruce F. McEwen and Rita M. Barnard. This immuno-fluorescent staining image was published in Molecular Biology of the Cell, September 2001, and is on the cover of the American Society for Cell Biology's latest brochure.
Questions, problems or comments about this website material should be directed to Bruce McEwen or David A. Smith.