节点流与左右不对称性的产生

Nodal flow and the generation of left-right asymmetry.

作者信息

Hirokawa Nobutaka, Tanaka Yosuke, Okada Yasushi, Takeda Sen

机构信息

Department of Cell Biology & Anatomy, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan.

出版信息

Cell. 2006 Apr 7;125(1):33-45. doi: 10.1016/j.cell.2006.03.002.

DOI:10.1016/j.cell.2006.03.002

PMID:16615888

Abstract

The establishment of left-right asymmetry in mammals is a good example of how multiple cell biological processes coordinate in the formation of a basic body plan. The leftward movement of fluid at the ventral node, called nodal flow, is the central process in symmetry breaking on the left-right axis. Nodal flow is autonomously generated by the rotation of cilia that are tilted toward the posterior on cells of the ventral node. These cilia are built by transport via the KIF3 motor complex. How nodal flow is interpreted to create left-right asymmetry has been a matter of debate. Recent evidence suggests that the leftward movement of membrane-sheathed particles, called nodal vesicular parcels (NVPs), may result in the activation of the non-canonical Hedgehog signaling pathway, an asymmetric elevation in intracellular Ca(2+) and changes in gene expression.

摘要

哺乳动物左右不对称性的建立是一个很好的例子，说明了多个细胞生物学过程如何在基本身体结构的形成中协同作用。腹侧节点处液体的向左流动，称为节点流，是左右轴上对称性破缺的核心过程。节点流由腹侧节点细胞上向后倾斜的纤毛旋转自主产生。这些纤毛通过KIF3运动复合体运输构建而成。节点流如何被解读以产生左右不对称性一直是一个有争议的问题。最近的证据表明，被称为节点囊泡包裹体（NVPs）的膜包裹颗粒的向左移动，可能导致非经典刺猬信号通路的激活、细胞内Ca(2+)的不对称升高以及基因表达的变化。