De Robertis E M, Gurdon J B
Proc Natl Acad Sci U S A. 1977 Jun;74(6):2470-4. doi: 10.1073/pnas.74.6.2470.
Genes that are unexpressed in somatic cells have been activated by injecting cultured cell nuclei of the frog Xenopus laevis into oocytes of the newt Pleurodeles waltlii. The genes that were activated are normally expressed in oocytes but not in cultured cells. Conversely, genes that are normally expressed in cultured cells but not in oocytes became inactive when cultured cell nuclei were injected into oocytes. These changes in gene activity were detected by two-dimensional gel electrophoresis of proteins synthesized by oocytes injected with nuclei. Controls, which included the use of alpha-amanitin, showed that these changes in protein synthesis are dependent on gene transcription. We conclude that genes that become inactive during cell differentiation can be reactivated, in the absence of cell division, by normal components of oocyte cytoplasm.
通过将非洲爪蟾培养的细胞核注射到美西螈的卵母细胞中，体细胞中未表达的基因被激活。被激活的基因通常在卵母细胞中表达，但不在培养细胞中表达。相反，当将培养细胞核注射到卵母细胞中时，通常在培养细胞中表达但不在卵母细胞中表达的基因变得不活跃。通过对注射了细胞核的卵母细胞合成的蛋白质进行二维凝胶电泳检测到了基因活性的这些变化。包括使用α-鹅膏蕈碱在内的对照表明，这些蛋白质合成的变化依赖于基因转录。我们得出结论，在细胞分化过程中变得不活跃的基因可以在没有细胞分裂的情况下，通过卵母细胞细胞质的正常成分重新激活。
