Cultured epithelial cell undergoing division. This cell is in prophase of mitosis. Microtubules are shown in green, actin is in red and mitotic chromosomes are colored blue.

• 以上两图为正处于有丝分裂前期的动物上皮细胞。绿色的是微丝，红色为肌动蛋白，染色质高度螺旋成为粗短的染色体（蓝色），核膜核仁逐渐解体，染色体不规则地分布于细胞内。