Schwartz M S, Brumbaugh J A
Exp Cell Res. 1982 Nov;142(1):155-68. doi: 10.1016/0014-4827(82)90419-0.
Pigmented B-16 mouse melanoma cells were fused with chick embryo fibroblasts or fibroblast cytoplasts and maintained as heterokaryons or non-dividing cybrids, respectively. These single cells were examined ultrastructurally for evidence or pigment gene expression using a cytochemical test for dopa oxidase, the initial enzyme in the conversion of dopa to melanin. Heterokaryons showed significantly less enzyme activity than control cells, whereas non-dividing cybrids showed no significant difference. Therefore, the presence of the intact nuclear membranes in the heterokaryons did not serve as a barrier to the interactions resulting in extinction of differentiated function(s). However, the presence of the fibroblast nucleus was necessary to elicit continued response.
将色素沉着的B - 16小鼠黑色素瘤细胞与鸡胚成纤维细胞或成纤维细胞质体融合，分别作为异核体或不分裂的胞质杂种进行培养。利用多巴氧化酶的细胞化学试验，对这些单细胞进行超微结构检查，以寻找色素基因表达的证据，多巴氧化酶是多巴转化为黑色素过程中的起始酶。异核体的酶活性明显低于对照细胞，而不分裂的胞质杂种则无显著差异。因此，异核体中完整核膜的存在并不是导致分化功能消失的相互作用的障碍。然而，成纤维细胞核的存在是引发持续反应所必需的。
