Also found in: Dictionary, Thesaurus, Medical.



tubular formations in animals and plant cells. The diameter of microtubules, or threads, is 150–290 angstroms (Å), rarely up to 400 Å; the inner diameter is 100–200 Å. The wall of aomicrotubule consists of 7–15, more often 12–13, threads 30–40 Å in diameter, constructed of globular protein subparticles approximately 35 Å in size.

There are two basic kinds of microtubules: cytoplasmic microtubules and those of the spindle of cell division. Cytoplasmic microtubules support the cell and ensure intracellular transport, cell movement, and contraction of the cell and its components. According to some data, cytoplasmic microtubules are active in the construction of microtubules of the spindle of cell division.

References in periodicals archive ?
In the next laboratory step, these travelling protein microtubules, microns in length, encounter relatively large polymer spheres, tens of microns in diameter, inserted by the researchers.
All of these routes to spindle formation appeared to be dependent on Augmin - a protein complex responsible for amplifying the number of microtubules in the cell.
Based on their observations, the team derived a simple mathematical model describing the relationship between the size and shape of the spindle apparatus and the density and amount of microtubules.
Quadilobing in certain liverworts is preceded by pre-meiotic bands of microtubules marking the future cytokinetic planes before the nucleus enters prophase I (Fig.
To study the binding of the kinetochore to microtubules in more detail, we now propose to reconstitute the full-length NDC80 complex with additional recombinantly expressed kinetochore components, including CENP-C, the MIS12 complex, the SKA complex and the KNL1 complex.
When Smith and colleagues quickly stretched brain cells growing on a silicone membrane, the microtubules inside the axons immediately buckled and broke, spilling their contents.
By now, a role for microtubules in spindle movements has been found in many systems.
For example, students took a mid-term exam which included topics on microtubule polymerization and cell division covered in lecture.
to bind to and stabilize microtubules correlates inversely with its degree of phosphorylation.
Our interest here draws upon the role that soliton dynamics can play in neurobiology/neurophysiology in a particular situation; namely, we survey how such effects theoretically related to systems such as the sine--Gordon and the class of evolutionary equations considered in Davydov (1982, 1991), might influence the mechanisms of dendritic and axonal microtubules, subneuronal processing of information, and synaptogenesis in cerebral architecture.
Oral daily treatment with ENMD-1198 in an orthotopic MDA MB 231 breast cancer model led to a reduction in tumor burden equivalent to the positive control cyclophosphamide, disruption of microtubules within tumor cells, and a substantial decrease in HIF-1alpha.

Full browser ?