Seibutsu Butsuri

Show abstractHide abstract

Current models on the movement of chromosomes in cell division were presented briefly in the introductory remark and possible involvement of dynein and calmodulin in the mitotic process was mentioned.
Immunocytochemical evidence on the presence of dynein in the mitotic apparatus was presented subsequently. Mitotic spindles and their poles in cells from various speciesincluding vertebrates and invertebrates are stained intensely by indirect immunofluorescence either with an antibody against a tryptic fragment of dynein 1 of sea urchin axonemes or with another antibody against dynein 1. These antidyneins inhibit the ATPase activity of dynein 1. From studies involving preabsorption of antidyneins with dynein 1, tubulin, high molecular weight microtubule-associated proteins, or calmodulin, it was concluded that the fluorescence in the mitotic apparatus is due to the presence of dynein 1. Immunoelectron microscopy has revealed that dynein is localized on the kinetochore spindle fibers and at the pericentriolar region, dynein in these regions being mostly associated with microtubules. It remains to be solved whether dynein is bound also to nonkinetochore microtubules.
Biochemical studies on the presence of dynein in the mitotic apparatus were considered. Brief reviews were also made of the researches concerning binding of exogenous dynein to the spindle microtubules and intertubule cross-bridges in the spindle. In addition, possible involvement of dynein in the chromosome movement was discussed.
A survey was made of studies on the presence of calmodulin in the mitotic apparatus and its possible role in the chromosome movement.

View full abstract

Download PDF (3594K)

Register with J-STAGE for free!