Abstract
The localizations of tubulin and calmodulin were investigated in the mouse oocyte during the second meiosis by fluorescently labeling and microinjecting these proteins prepared from porcine brain tissue. When in-jected, both tubulin and calmodulin were quickly incorporated into the pre-formed meiotic apparatus of the oocyte at metaphase. The localization of label-ed tubulin was coincident with that of birefringence. However, the localization of labeled calmodulin was somewhat different: the fluorescence of calmodulin was intense in the polar regions of the spindle. After the chromosomes began to move, followed by parthenogenetic activation upon microinjection of a calcium buffer, these two fluorescent proteins, localized in the meiotic apparatus, mov-ed to the interzonal region of the spindle during anaphase. At late anaphase and throughout telophase, calmodulin was excluded from the mid-bodylike struc-tures in the interzonal region, whereas tubulin did accumulate in these struc-tures.
