Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA.
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Dev Cell. 2013 Dec 23;27(6):648-55. doi: 10.1016/j.devcel.2013.11.006. Epub 2013 Dec 5.
Cell-shape change demands cell-surface growth, but how growth is fueled and choreographed is still debated. Here we use cellularization, the first complete cytokinetic event in Drosophila embryos, to show that cleavage furrow ingression is kinetically coupled to the loss of surface microvilli. We modulate furrow kinetics with RNAi against the Rho1-GTPase regulator slam and show that furrow ingression controls the rate of microvillar depletion. Finally, we directly track the microvillar membrane and see it move along the cell surface and into ingressing furrows, independent of endocytosis. Together, our results demonstrate that the kinetics of the ingressing furrow regulate the utilization of a microvillar membrane reservoir. Because membranes of the furrow and microvilli are contiguous, we suggest that ingression drives unfolding of the microvilli and incorporation of microvillar membrane into the furrow. We conclude that plasma membrane folding/unfolding can contribute to the cell-shape changes that promote embryonic morphogenesis.
细胞形状的改变需要细胞表面的生长，但生长是如何提供动力和协调的仍存在争议。在这里，我们利用果蝇胚胎中第一次完整的胞质分裂事件——细胞化，表明分裂沟内陷与表面微绒毛的丧失在动力学上是耦联的。我们通过 RNAi 来调节 Rho1-GTPase 调节剂 slam 的动力学，表明沟内陷控制着微绒毛耗竭的速度。最后，我们直接跟踪微绒毛膜，并观察到它沿着细胞表面移动并进入内陷的沟中，这与内吞作用无关。总的来说，我们的结果表明，内陷沟的动力学调节了微绒毛膜储备的利用。由于沟和微绒毛的膜是连续的，我们推测内陷驱动微绒毛的展开，并将微绒毛膜纳入沟中。我们得出结论，质膜的折叠/展开可以促进胚胎形态发生的细胞形状变化。
