Primary neuronal differentiation in Xenopus embryos is linked to the β subunit of the sodium pump.
168 - 182.
In amphibian embryos, activation of additional sodium pumps in neural plate cell membranes ensures that neural plate-derived neurons differentiate subsequently in the neural tube. When the sodium pump is inhibited during the mid-neural fold stages, neuronal differentiation fails. The effect is irreversible. We find that these events operate through the Na pump β subunit. When neural plate-specific Na pumps are activated, transcripts for β decline precipitately during the mid-neural fold stages, first in the neural plate and then in the dorsal mesoderm. As the neural tube closes, β returns, specifically in motor neurons and interneurons. Inhibition of the Na pump with the cardiac glycoside strophanthidin prevents the normal fall in β during neurulation: β is maintained in the neural plate until the neural tube closes, but lost from the dorsal mesoderm. Complete elimination of β transcripts from dorsal structures then occurs. Inhibiting the Na pump does not induce cell death (assessed by TUNEL staining) in the nervous system. Transcripts for X-Delta, NeuroD, and GSK3β are not affected by inhibition of the Na pump. Xotch and N-tubulin transcripts fall to very low levels and Xotch disappears permanently from the nervous system. When β transcript expression is maintained throughout neurulation, by over expression of injected mRNAs, Xotch is eliminated from the neural tube and somites and switches to the ectoderm. (C) 2000 Academic Press.
|Title:||Primary neuronal differentiation in Xenopus embryos is linked to the β subunit of the sodium pump|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Life Sciences|
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