کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2173999 1093770 2010 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Initiation of neuronal differentiation requires PI3-kinase/TOR signalling in the vertebrate neural tube
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Initiation of neuronal differentiation requires PI3-kinase/TOR signalling in the vertebrate neural tube
چکیده انگلیسی

Regulated neuron production within the vertebrate nervous system relies on input from multiple signalling pathways. Work in the Drosophila retina has demonstrated that PI3-kinase and downstream TOR signalling regulate the timing of photoreceptor differentiation; however, the function of such signals during vertebrate neurogenesis is not well understood. Here we show that mutant mice lacking PKB activity downstream of PDK1, the master kinase of the PI3-kinase pathway, exhibit deficient neuron production. We further demonstrate expression of PI3-kinase signalling components and active PKB and TOR signalling in the chick spinal cord, an early site of neurogenesis. Neuron production was also attenuated in the chick neural tube following exposure to small molecule inhibitors of PI3-kinase (LY294002) or TOR (Rapamycin) activity. Furthermore, Rapamycin repressed expression of early neuronal differentiation genes, such as Ngn2, but did not inhibit expression of Sox1B genes characteristic of proliferating neural progenitors. In addition, some cells expressing an early neuronal marker were mis-localised at the ventricular surface in the presence of Rapamycin and remained aberrantly within the cell cycle. These findings suggest that TOR signalling is necessary to initiate neuronal differentiation and that it may facilitate coordination of cell cycle and differentiation programmes. In contrast, stimulating PI3-kinase signalling did not increase neuron production, suggesting that such activity is simply permissive for vertebrate neurogenesis.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Developmental Biology - Volume 338, Issue 2, 15 February 2010, Pages 215–225
نویسندگان
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