Actin Distribution in Mitotic Apparatus of Somatic Embryo Cells of Norway Spruce

F-actin distribution was studied in mitotic cells of embryogenic suspension culture of Norway spruce [Picea abies (L.) Karst.]. Actin was present in dividing cells of embryo head during whole mitosis. Transient co-localization of actin microfilaments with preprophase band of microtubules was observed. Weak actin staining occurred with non-kinetochor microtubular fibers in metaphase spindle. F-actin was not localized with kinetochore microtubular fibres in metaphase as well as with shortening kinetochore fibres in late anaphase. On the other hand, abundant actin microfilaments array was formed in the area of late anaphase spindle in equatorial level of the cell between separating chromatids. F-actin was also present in phragmoplast area in telophase.