Competence, specification and commitment in otic placode induction.
Competence, specification and commitment in otic placode induction.
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DOI：
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发表时间：
2000-08
期刊：
影响因子：
4.6
通讯作者：
A. Groves;M. Bronner‐Fraser
中科院分区：
文献类型：
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作者：
A. Groves;M. Bronner‐Fraser
内耳是由邻近后脑的颅外胚层诱导而来。尽管经过近一个世纪的研究，内耳感应的分子机制仍然不清楚。我们已经鉴定出在内耳原基（耳基板）中很早就表达的四个基因。 Pax-2、Sox-3、BMP-7 和 Notch 均在 4-5 体节期 (ss) 以后的基板外胚层中表达，早在耳基板在 12-14ss 形态上可见之前。我们使用这四种分子标记来表明，颅外胚层在 4-6ss 时被指定形成耳基板，并且该外胚层在 10ss 时被确定为基板命运。我们还证明，如果在足够早的时候使用，大部分胚胎外胚层都有能力产生耳基板。我们已经沿着胚胎的头尾轴绘制了耳基板诱导活动的位置，并确定这种活动至少持续到 10ss。四种分子耳基板标记的使用表明鸟类耳基板的诱导发生比之前想象的更早，并且以一系列独立调控的步骤进行。
The inner ear is induced from cranial ectoderm adjacent to the hindbrain. Despite almost a century of study, the molecular mechanisms of inner ear induction remain obscure. We have identified four genes expressed very early in the anlage of the inner ear, the otic placode. Pax-2, Sox-3, BMP-7 and Notch are all expressed in placodal ectoderm from the 4-5 somite stage (ss) onwards, well before the otic placode becomes morphologically visible at the 12-14ss. We have used these four molecular markers to show that cranial ectoderm becomes specified to form the otic placode at the 4-6ss, and that this ectoderm is committed to a placodal fate by the 10ss. We also demonstrate that much of the embryonic ectoderm is competent to generate an otic placode if taken at a sufficiently early age. We have mapped the location of otic placode-inducing activity along the rostrocaudal axis of the embryo, and have determined that this activity persists at least until the 10ss. Use of the four molecular otic placode markers suggests that induction of the otic placode in birds occurs earlier than previously thought, and proceeds in a series of steps that are independently regulated.