这篇文章是关于自1924年首次发表以来,人们对这个著名的组织者实验的看法。该实验涉及在两栖动物胃的背唇移植到宿主胚胎的影响下产生次生胚胎。斯派曼和他的学校的早期实验产生了一种观点,即整个早期两栖动物胚胎在决心方面“冷漠”,除了名为“组织者”的特殊区域。这主要被视为神经诱导的媒介,也有能力产生前后身体模式。分离组织者发出的因子的早期生化努力并未成功,但最终定义了存在于各种动物组织中的“神经化(N)”和“中胚层化(M)”因子。到1950年代,这种观点成为涉及N和M因素的“两梯度”模型,这解释了前后图案效应。在1970年代,中胚层诱导现象的特征是在开始原肠胚形成之前发生的过程。使用谱系标签重新调查组织者的效果,可以更精确地定义事件的顺序。自1980年代以来,使用分子生物学工具的现代研究,结合显微外科手术,解释了所涉及的大多数过程。现在应该将组织者移植物视为涉及多种相互作用的实验:受精后背腹极化,中胚层诱导,背化信号负责中胚层的神经化和背腹模式,以及导致前后模式的其他因素。
This article is about how the famous organizer experiment has been perceived since it was first published in 1924. The experiment involves the production of a secondary embryo under the influence of a graft of a dorsal lip from an amphibian gastrula to a host embryo. The early experiments of
Spemann and his school gave rise to a view that the whole early amphibian embryo was \"indifferent\" in terms of determination, except for a special region called \"the organizer\". This was viewed mainly as an agent of neural induction, also having the ability to generate an anteroposterior body pattern. Early biochemical efforts to isolate a factor emitted by the organizer were not successful but culminated in the definition of \"neuralizing (N)\" and \"mesodermalizing (M)\" factors present in a wide variety of animal tissues. By the 1950s this view became crystallized as a \"two gradient\" model involving the N and M factors, which explained the anteroposterior patterning effect. In the 1970s, the phenomenon of mesoderm induction was characterized as a process occurring before the commencement of gastrulation. Reinvestigation of the organizer effect using lineage labels gave rise to a more precise definition of the sequence of events. Since the 1980s, modern research using the tools of molecular biology, combined with microsurgery, has explained most of the processes involved. The organizer graft should now be seen as an experiment which involves multiple interactions: dorsoventral polarization following fertilization, mesoderm induction, the dorsalizing signal responsible for neuralization and dorsoventral patterning of the mesoderm, and additional factors responsible for anteroposterior patterning.