Sanger J W, Sanger J M
Cell Tissue Res. 1980;209(2):177-86. doi: 10.1007/BF00237624.
Rat kangaroo cells (PtK2) were studied with scanning and transmission electron microscopy in order to correlate shape changes during the cell cycle with the presence or absence of microvilli andd stress fibers. During interphase, bundles of actin are prominent in the cytoplasm, and microvilli are localized over and around the centrally positioned nucleus. As mitosis begins, the interphase bundles of actin and the microvilli disappear, but the mitotic cells maintain a flattened shape. At metaphase the cell is still so flat that both the chromosomes and spindle apparatus are visible through the intact cell membrane. Microvilli reappear in late anaphase above the chromosomes and poles. Before cleavage begins, microvilli increase in number until they cover the apical surface of the cell. At the same time, the cell increases in height so that the chromosomes and mitotic apparatus can no longer be detected through the cell membrane. During cleavage, microvilli continue to cover the cell in a uniform manner but become greatly diminished in number after cytokinesis is completed and the cells flatten and enter interphase. It is suggested that the microvilli organize a network of actin filaments which interact with cortical myosin to produce the cell rounding porior to cleavage.
为了将细胞周期中的形态变化与微绒毛和应力纤维的存在与否联系起来，对袋鼠细胞（PtK2）进行了扫描电子显微镜和透射电子显微镜研究。在间期，肌动蛋白束在细胞质中很突出，微绒毛位于中央位置的细胞核上方和周围。随着有丝分裂开始，间期的肌动蛋白束和微绒毛消失，但有丝分裂细胞保持扁平形状。在中期，细胞仍然很扁平，以至于通过完整的细胞膜可以看到染色体和纺锤体。微绒毛在后期染色体和纺锤体极上方重新出现。在分裂开始前，微绒毛数量增加，直到覆盖细胞的顶面。与此同时，细胞高度增加，以至于通过细胞膜无法再检测到染色体和有丝分裂装置。在分裂过程中，微绒毛继续均匀地覆盖细胞，但在胞质分裂完成后数量大大减少，细胞变平并进入间期。有人提出，微绒毛组织了一个肌动蛋白丝网络，该网络与皮质肌球蛋白相互作用，在分裂前产生细胞变圆。
