Roth Michaela, Roubinet Chantal, Iffländer Niklas, Ferrand Alexia, Cabernard Clemens
Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel, Switzerland.
1] Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel, Switzerland [2] Imaging Core Facility (IMCF), Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056 Basel, Switzerland.
Nat Commun. 2015 Mar 20;6:6551. doi: 10.1038/ncomms7551.
Precise cleavage furrow positioning is required for faithful chromosome segregation and cell fate determinant distribution. In most metazoan cells, contractile ring placement is regulated by the mitotic spindle through the centralspindlin complex, and potentially also the chromosomal passenger complex (CPC). Drosophila neuroblasts, asymmetrically dividing neural stem cells, but also other cells utilize both spindle-dependent and spindle-independent cleavage furrow positioning pathways. However, the relative contribution of each pathway towards cytokinesis is currently unclear. Here we report that in Drosophila neuroblasts, the mitotic spindle, but not polarity cues, controls the localization of the CPC component Survivin. We also show that Survivin and the mitotic spindle are required to stabilize the position of the cleavage furrow in late anaphase and to complete furrow constriction. These results support the model that two spatially and temporally separate pathways control different key aspects during asymmetric cell division, ensuring correct cell fate determinant segregation and neuroblast self-renewal.
精确的分裂沟定位对于准确的染色体分离和细胞命运决定因子分布是必需的。在大多数后生动物细胞中,收缩环的定位由有丝分裂纺锤体通过中央纺锤体复合物调控,并且可能还受染色体乘客复合物(CPC)调控。果蝇神经母细胞,即不对称分裂的神经干细胞,以及其他细胞都利用纺锤体依赖和纺锤体非依赖的分裂沟定位途径。然而,目前尚不清楚每条途径对胞质分裂的相对贡献。在这里我们报告,在果蝇神经母细胞中,有丝分裂纺锤体而非极性线索控制CPC组分Survivin的定位。我们还表明,Survivin和有丝分裂纺锤体是后期稳定分裂沟位置并完成沟缢缩所必需的。这些结果支持这样一种模型,即两条在空间和时间上分开的途径控制不对称细胞分裂过程中的不同关键方面,确保正确的细胞命运决定因子分离和神经母细胞自我更新。