Nuclear Transplantation in Amphibia and the Importance of Stable Nuclear Changes in Promoting Cellular Differentiation
Nuclear Transplantation in Amphibia and the Importance of Stable Nuclear Changes in Promoting Cellular Differentiation
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两栖动物的核移植以及稳定的核变化在促进细胞分化中的重要性
DOI：
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发表时间：
1963
期刊：
影响因子：
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通讯作者：
J. Gurdon
中科院分区：
文献类型：
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作者：
J. Gurdon
自从首次开发出一种令人满意的将活细胞核移植到去核卵中的技术以来，两栖动物的核移植实验已经获得了多种结果。本文综述了限制细胞核发育能力的稳定变化对于促进体细胞正常分化是否重要的问题。林蛙和爪蟾的实验结果清楚地表明，一些移植细胞核的有丝分裂产物发生了稳定的变化，限制了它们的发育能力。尚未最终证明这些核变化是在正常细胞分化过程中而不是在移植后发生的。如果发现在正常细胞分化过程中至少确实出现了一些稳定的核变化，那么目前没有证据表明它们是否促进细胞分化或仅作为细胞分化的结果而出现。其他核移植实验表明，至少在某些情况下，细胞核可以支持分化的肠细胞的形成，而不会失去促进其他完全不同的细胞类型形成的能力。有人认为，其中一些结果支持以下一般结论，而另一些结果则与以下一般结论一致：（1）分化体细胞的细胞核通常不会经历任何影响遗传物质本身的限制性变化； (2)体细胞核提供的专门信息要么是遗传物质部分半稳定失活的结果，要么完全取决于染色体在任何时刻所处环境的性质。
A diversity of results has been obtained from nuclear transfer experiments in Amphibia since the time when a satisfactory technique was first developed for transplanting living cell nuclei into enucleated eggs. This article reviews the question of whether stable changes restricting the developmental capacity of cell neclei are important in promoting the normal differentiation of somatic cells. The results of experiments with Rana and Xenopus have clearly shown that the mitotic products of some transplanted cell neclei have undergone stable changes restricting their developmental capacity. It has not yet been conclusively demonstrated that these nuclear changes arise during normal cell differentiation rather than following transplantation. If it should be found that at least some stable nuclear changes do arise during normal cell differentiation, there is at present no evidence to show whether they promote cell differentiation or arise only as a consequence of it. Other nuclear transfer experiments have shown that, at least in some cases, nuclei can support the formation of differentiated intestine cells without having lost the capacity to promote the formation of other quite different cell types. It is argued that some of these results support, and that others are consistent with, the following general conclusions: (1) that the nuclei of differentiating somatic cells do not generally undergo any restrictive changes affecting the genetic material itself; and (2) that the specialized information provided by somatic cell nuclei either results from a semistable inactivation of parts of the genetic material, or else depends solely upon the nature of the environment in which the chromosomes lie at any one time.