In developing vertebrates, neural tube closure (NTC) – the formation of the neural tube from a sheet of neural ectoderm – requires both neural ectoderm and non-neural ectoderm. But, whereas cell shape changes, cell rearrangement and cell division in the neural ectoderm are essential for NTC, the cellular changes in the non-neural ectoderm that contribute to NTC are unclear. Now, on p. 1417, Naoto Ueno and co-workers use digital scanned laser light sheet fluorescence microscopy to examine the movements of non-neural ectoderm cells in Xenopus embryos during NTC. The researchers show that the collective movement of deep-layer non-neural ectoderm cells towards the dorsal midline helps to drag along the superficial non-neural ectoderm during NTC. Inhibition of this movement by deletion of integrin β1 function, they report, blocks NTC completion. By contrast, oriented cell division, cell shape changes and cell rearrangement in the non-neural ectoderm have little or no role in NTC. Together, these results suggest that a global reorganisation of embryonic tissues is involved in NTC.
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