Rubin R W, Warren R H, Lukeman D S, Clements E
J Cell Biol. 1978 Jul;78(1):28-35. doi: 10.1083/jcb.78.1.28.
The amount of actin and total protein per cell in normal rat kidney (NRK) cells in culture is initially high in very low density cultures, but rapidly decreases as the cells come into contact in higher density cultures. In a viral transformant of NRK (442), the level of actin and total protein does not change significantly from low to high density cultures. NRK cells, which are flattened against the substrate, have prominent bundles of actinlike microfilaments in the basal cytoplasm adjacent to the substrate. 442 cells, which adhere poorly and are more spherical in shape, lack well-organized basal microfilament bundles, but may display microfilament bundles in cytoplasmic processes extending from the cell body. The percentage of insoluble actin is less than 20% in both cell lines, and 442 cells consistently contain smaller amounts than NRK cells.
培养的正常大鼠肾（NRK）细胞中，每细胞的肌动蛋白和总蛋白量在极低密度培养时最初很高，但随着细胞在更高密度培养中接触，其迅速下降。在NRK的病毒转化株（442）中，从低密度培养到高密度培养，肌动蛋白和总蛋白水平没有显著变化。贴附在底物上扁平的NRK细胞，在与底物相邻的基底细胞质中有突出的肌动蛋白样微丝束。442细胞贴附性差且形状更呈球形，缺乏组织良好的基底微丝束，但在从细胞体延伸出的细胞质突起中可能显示有微丝束。两种细胞系中不溶性肌动蛋白的百分比均小于20%，且442细胞始终比NRK细胞含有更少的量。
