The arrangement of microtrabecular network during chromatin migration process and immunolocalization of actin and myosin in pollen mother cells of David lily

摘要

The pollen mother cells of David lily at synizesis of meiotic propbase I were studied using the light microscope and diethylene glycol distearate (DGD) embedment-free electron microscope. The results showed that there existed clear areas in front of and behind the chromatin masses undergoing migration via cytoplasmic channels (cytomixis) under light microscope. Observations of diethylene glycol distearate embedment free electron microscopy indicated that these clear areas were actually filled with microtrabecular components. Several major arrangement changes of microtrabecular network were observed as follows: When the nucleus moved aside from the center, an area filled with cytoplasmic microtrabecular network appeared behind. Later, when chromatin underwent cytomixis via cytoplasmic channels, another area filled with nuclear microtrabecular network appeared between nuclear envelope and the rear condensed chromatin, and some thick microtrabecular filaments linked the migrating chromatin masses in front; Thereafter, most of the chromatin went into a neighboring cell and mixed into a whole. Combined with immunoelectron microscopy technique, actin and myosin were co-localized in some places in the pollen mother cells (PMCs) at synizesis. The TRITC-Ph labeling method revealed a filamentous meshwork surrounding the nuclei, and that the masses of migrating chromatin were also surrounded by F-actin. These results indicated that the microtrabecular network was involved in the chromatin migration from one cell to the neighboring, and that the actin-myosin system was probably related to this process. [References: 36]