NUCLEAR TRANSPLANTATION STUDIES ON THE EARLY GASTRULA (RANA-PIPIENS) .1. NUCLEI OF PRESUMPTIVE ENDODERM
NUCLEAR TRANSPLANTATION STUDIES ON THE EARLY GASTRULA (RANA-PIPIENS) .1. NUCLEI OF PRESUMPTIVE ENDODERM
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DOI：
10.1016/0012-1606(60)90008-7
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发表时间：
1960-01-01
影响因子：
2.7
通讯作者：
KING, TJ
中科院分区：
文献类型：
--
作者：
BRIGS, R;KING, TJ
以往的研究表明，与内胚层分化相关的核变化在原肠胚后期进展良好。本研究的目的是确定在发育过程中，这种核“分化”过程何时开始。将来自原肠系早期营养极区的假定内胚层核移植到去核的卵子中进行检测。为了进行比较，对来自未确定的动物胚泡极区的细胞核进行了对照转移。受精卵的发育情况如下：(1)卵裂：对照和实验移植的结果基本相同。在每一系列的移植中，大约60%的移植导致了完整囊胚的形成。(2)胚胎分化：正常发育至幼虫期的囊胚率为80%。在假定内胚层核转移的情况下，52%的囊胚发育正常。大多数剩余胚胎在神经后阶段表现出异常，未能达到幼虫期。其中一些异常胚胎在外胚层衍生物中表现出极大的缺陷。然而，在大多数情况下，这些缺陷与核的内胚层起源没有任何明显的关系。(3)幼虫发育：所有正常经过胚胎期的胚胎都被饲养到死亡或变态。在它们的幼虫发育过程中，核移植动物与它们正常受精的对照组没有什么不同。这些实验的结果(见上文2)表明，内胚层的核分化大约在原肠胚早期开始，但最初只涉及少数核。
Previous studies showed that nuclear changes associated with endodermal differentiation are well advanced at late gastrula stage. The purpose of the present investigation was to determine when in development this process of nuclear "differentiation" begins. Presumptive endoderm nuclei from the vegetal pole region of early gastrulae were tested by transplantation into enucleated eggs. For comparison, control transfers were performed with nuclei from the undetermined animal pole region of blastulae. The recipient eggs developed as follows (1) Cleavage: Control and experimental transfers gave about the same results. Approximately 60% of the transfers in each series led to the formation of complete blastulae. (2) Embryonic differentiation: 80% of the complete blastulae resulting from the control transfers developed normally to larval stages. In the case of the transfers of presumptive endoderm nuclei, 52% of the blastulae developed normally. The majority of the remaining embryos displayed abnormalities in postneurula stages and failed to attain the larval stage. A few of these abnormal embryos showed extreme deficiencies in the ectodermal derivatives. In the majority, however, the deficiencies were not related to the endodermal origin of the nuclei in any obvious fashion. (3) Larval development: All embryos which passed through the embryonic stages normally were reared until they died or reached metamorphosis. In their larval development the nuclear-transplant animals did not differ from their normally fertilized controls. The results of these experiments (see 2, above) indicate that endodermal nuclear differentiation begins at about the early gastrula stage, but involves at first only a minority of the nuclei.