The interpretation of position in a morphogen gradient as revealed by occupancy of activin receptors
The interpretation of position in a morphogen gradient as revealed by occupancy of activin receptors
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DOI：
10.1016/s0092-8674(00)81185-x
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发表时间：
1998-05-15
期刊：
影响因子：
64.5
通讯作者：
Gurdon, JB
中科院分区：
文献类型：
--
作者：
Dyson, S;Gurdon, JB
非洲爪蟾囊胚细胞激活不同的中胚层基因作为浓度依赖性的反应，激活素，其行为像一个形态。为了了解细胞如何识别形态原浓度，我们将天然标记的激活素与细胞结合，并将其与基因激活的选择相关。我们发现，增加单一受体类型的占有率可以导致细胞转换基因表达。细胞通过每个细胞被占据的受体的绝对数量来感知配体浓度（100和300分子的结合激活素分别诱导Xbra和Xgsc，即，2%和6%的总受体），而不是通过被占据受体与未被占据受体的比率。长时间的占用解释了先前描述的棘轮效应。我们的研究结果提出了一个新的概念，形态梯度的形成和解释，特别适合于早期发展的需要。
Xenopus blastula cells activate different mesodermal genes as a concentration-dependent response to activin, which behaves like a morphogen. To understand how cells recognize morphogen concentration, we have bound naturally labeled activin to cells and related this to choice of gene activation. We find that the increasing occupancy of a single receptor type can cause cells to switch gene expression. Cells sense ligand concentration by the absolute number of occupied receptors per cell (100 and 300 molecules of bound activin induce Xbra and Xgsc, respectively, i.e., 2% and 6% of the total receptors) and not by a ratio of occupied to unoccupied receptors. The long duration of occupancy explains a previously described ratchet effect. Our results suggest a new concept of morphogen gradient formation and interpretation that is particularly well suited to the needs of early development.