Nyman U, Lanfranchi G, Bergman M, Ringertz N R
J Cell Physiol. 1984 Aug;120(2):257-62. doi: 10.1002/jcp.1041200221.
Reactivation of dormant chick erythrocyte (CE) nuclei was studied by fusing chick red cells with rat myoblasts, HeLa cells, and chick fibroblasts. Heterokaryons representing different stages of nuclear reactivation were fixed and examined for nuclear antigens using polyclonal patient autoantisera reacting with mammalian (human, mouse, and rat) nuclear envelope, nucleoplasm, and chromatin (DNA) antigens. Reactivation of CE nuclei was associated with marked changes in nuclear antigenicity. In rat myoblast and HeLa heterokaryons the CE nuclei acquired mammalian nucleoplasmic and nuclear envelope antigens in the corresponding nuclear subcompartments. Drastic changes in nuclear antigenicity were noted also in heterokaryons stained with DNA antisera. The compact chromatin of nuclei in mature chick erythrocytes showed little binding of DNA antibodies. Isolated nuclei on the other hand gave a strong immunofluorescence. CE nuclei in heterokaryons were strongly positive during the early stages of nuclear reactivation but then exhibited decreased reactivity. An unexpected finding was a marked reduction in the capacity of mammalian nuclei in heterokaryons to bind DNA-antibodies. This observation is discussed in relation to the previous finding that in CE-heterokaryons these nuclei often show reduced transcription and replication. The present results indicate that in heterokaryons both types of nuclei exchange macromolecules of regulatory importance via the common cytoplasm.
通过将鸡红细胞与大鼠成肌细胞、HeLa细胞和鸡成纤维细胞融合，研究了休眠鸡红细胞（CE）细胞核的重新激活。代表核重新激活不同阶段的异核体被固定，并使用与哺乳动物（人、小鼠和大鼠）核膜、核质和染色质（DNA）抗原反应的多克隆患者自身抗血清检测核抗原。CE细胞核的重新激活与核抗原性的显著变化有关。在大鼠成肌细胞和HeLa异核体中，CE细胞核在相应的核亚区获得了哺乳动物核质和核膜抗原。在用DNA抗血清染色的异核体中也注意到了核抗原性的剧烈变化。成熟鸡红细胞中细胞核的致密染色质与DNA抗体的结合很少。另一方面，分离的细胞核产生强烈的免疫荧光。异核体中的CE细胞核在核重新激活的早期阶段呈强阳性，但随后反应性降低。一个意外的发现是异核体中哺乳动物细胞核结合DNA抗体的能力显著降低。结合之前在CE-异核体中这些细胞核经常显示转录和复制减少的发现，对这一观察结果进行了讨论。目前的结果表明，在异核体中，两种类型的细胞核都通过共同的细胞质交换具有重要调节作用的大分子。
