CYTOPLASMIC ACTIVATION OF HUMAN NUCLEAR GENES IN STABLE HETEROCARYONS
CYTOPLASMIC ACTIVATION OF HUMAN NUCLEAR GENES IN STABLE HETEROCARYONS
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DOI：
10.1016/0092-8674(83)90300-8
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发表时间：
1983-01-01
期刊：
影响因子：
64.5
通讯作者：
WEBSTER, C
中科院分区：
文献类型：
--
作者：
BLAU, HM;CHIU, CP;WEBSTER, C
在人非肌肉细胞中诱导肌肉特异性基因的稳定表达。用聚乙二醇将正常二倍体人骨髓基质细胞与分化的小鼠肌细胞融合。融合产物是一种稳定的异核体，其中亲本细胞核保持不同，不进行分裂并保留完整的染色体。这与典型的种间杂种（合核体）形成鲜明对比，其中亲本细胞核结合，染色体在细胞分裂过程中逐渐丢失。在异核体中检测到人肌肉蛋白、肌球蛋白L链1和2、MB和MM [同工酶]肌酸激酶以及功能性小鼠-人杂合MM酶分子。这些蛋白质的合成在融合后24小时是明显的，并且此后以时间依赖性的方式增加。分化的小鼠肌肉细胞核可以明显地激活正常情况下不表达的细胞类型的细胞核中的人类肌肉基因，并且这种激活通过细胞质发生。活化剂仍然存在于已经开始分化的细胞中，被另一种物种的细胞核识别，并且不在未融合的细胞之间扩散。重编程的稳定异核体的巨噬细胞核提供了一个独特的系统，在其中研究细胞特化过程中的基因表达调控机制。
The stable expression of muscle-specific genes was induced in human nonmuscle cells. Normal diploid human amniocytes were fused with differentiated mouse muscle cells by using polyethylene glycol. The fusion product, a stable heterokaryon in which the parental cell nuclei remained distinct, did not undergo division and retained a full complement of chromosomes. This is in contrast with typical interspecific hybrids (synkaryons), in which the parental nuclei are combined and chromosomes are progressively lost during cell division. The human muscle proteins, myosin L chains 1 and 2, MB and MM [isozyme] creatine kinase and a functional mouse-human hybrid MM enzyme molecule were detected in the heterokaryons. Synthesis of these proteins was evident 24 h after fusion and increased in a time-dependent manner thereafter. Differentiated mouse muscle nuclei can apparently activate human muscle genes in the nuclei of a cell type in which they are not normally expressed, and that this activation occurs via the cytoplasm. The activators are still present in cells which have already initiated differentiation, are recognized by nuclei of another species, and do not diffuse between unfused cells. The reprogrammed amniocyte nuclei of stable heterokaryons provide a unique system in which to study the mechanisms regulating gene expression during cell specialization.