Report

Apical Abscission Alters Cell Polarity and Dismantles the Primary Cilium During Neurogenesis

Science  10 Jan 2014:
Vol. 343, Issue 6167, pp. 200-204
DOI: 10.1126/science.1247521

You are currently viewing the abstract.

View Full Text
As a service to the community, AAAS/Science has made this article free with registration.

Developing Neurons Make the Cut

Neurons in the developing central nervous system of vertebrates derive from cells adjacent to the ventricles that then proliferate and differentiate to populate the brain. As one of these cells begins to differentiate, the cell nucleus migrates toward its new residence, away from the ventricle surface, and the cell stretches out. At some point, like any maturing adolescent, the cell has to leave home. Das and Storey (p. 200; see the Perspective by Tozer and Morin) show that instead of letting go and drawing the trailing process up into the migrating cell, the cell cuts off and discards its first roots. The abscission process leaves behind the primary cilium and any signaling systems localized to the cilium.

Abstract

Withdrawal of differentiating cells from proliferative tissue is critical for embryonic development and adult tissue homeostasis; however, the mechanisms that control this cell behavior are poorly understood. Using high-resolution live-cell imaging in chick neural tube, we uncover a form of cell subdivision that abscises apical cell membrane and mediates neuron detachment from the ventricle. This mechanism operates in chick and mouse, is dependent on actin-myosin contraction, and results in loss of apical cell polarity. Apical abscission also dismantles the primary cilium, known to transduce sonic-hedgehog signals, and is required for expression of cell-cycle-exit gene p27/Kip1. We further show that N-cadherin levels, regulated by neuronal-differentiation factor Neurog2, determine cilium disassembly and final abscission. This cell-biological mechanism may mediate such cell transitions in other epithelia in normal and cancerous conditions.

View Full Text