Instituto de Biologia Molecular e Celular, Rua do Campo Alegre, 823, Porto P-4150-180, Portugal.
EMBO Rep. 2013 Aug;14(8):696-703. doi: 10.1038/embor.2013.85. Epub 2013 Jun 18.
Cytokinesis is asymmetric along the apical-basal axis of epithelial cells, positioning the midbody near the apical domain. However, little is known about the mechanism and purpose of this asymmetry. We use live imaging of Drosophila follicle cell division to show that asymmetric cytokinesis does not result from intrinsic polarization of the main contractile ring components. We show that adherens junctions (AJs) maintain close contact with the apical side of the contractile ring during cytokinesis. Asymmetric distribution of AJ components within follicle cells and in the otherwise unpolarized S2 cells is sufficient to recruit the midbody, revealing that asymmetric cytokinesis is determined by apical AJs in the epithelia. We further show that ectopic midbody localization induces epithelial invaginations, shifting the position of the apical interface between daughter cells relative to the AB axis of the tissue. Thus, apical midbody localization is essential to maintain epithelial tissue architecture during proliferation.
细胞分裂是沿着上皮细胞的顶端-基底轴不对称进行的，将中体定位在顶端区域附近。然而，对于这种不对称性的机制和目的知之甚少。我们使用果蝇滤泡细胞分裂的实时成像来表明，不对称的细胞分裂不是由于主要收缩环成分的内在极化引起的。我们表明，在细胞分裂过程中，黏着连接（AJs）与收缩环的顶端侧保持紧密接触。滤泡细胞内 AJ 成分的不对称分布以及在非极化的 S2 细胞中，足以募集中体，表明不对称的细胞分裂是由上皮细胞中的顶端 AJ 决定的。我们进一步表明，异位中体定位诱导上皮内陷，使子细胞之间的顶端界面相对于组织的 AB 轴发生移位。因此，顶端中体定位对于在增殖过程中维持上皮组织的结构是必不可少的。
