Fougère C, Ruiz F, Ephrussi B
Proc Natl Acad Sci U S A. 1972 Feb;69(2):330-4. doi: 10.1073/pnas.69.2.330.
Hybrids between Syrian hamster melanoma cells and mouse fibroblasts, containing one genome (1s) of each parent, produce neither melanin nor DOPA-oxidase ("extinction"). Attempts to induce loss of the fibroblast chromosomes by irradiation of the fibroblasts before fusion with melanoma cells resulted in the formation of colonies comprising pigmented hybrid cells, which contained 2s melanoma and 1s fibroblast chromosome-complements suggesting that extinction or re-expression of melanogenesis is a function of genic balance. This interpretation was confirmed by crosses between 2s melanoma cells with unirradiated 1s fibroblasts, which produced both pigmented and unpigmented hybrids. No correlation has thus far been established between karyotype and phenotype of the hybrid cells, but analysis of the karyological data suggests that the fibroblast chromosomes responsible for extinction cannot be numerous.
叙利亚仓鼠黑色素瘤细胞与小鼠成纤维细胞的杂种细胞，含有每个亲本的一个基因组（1s），既不产生黑色素也不产生多巴氧化酶（“灭绝”）。在与黑色素瘤细胞融合之前，通过照射成纤维细胞来诱导成纤维细胞染色体丢失的尝试，导致形成了由色素沉着的杂种细胞组成的菌落，这些细胞包含2s黑色素瘤和1s成纤维细胞染色体组，这表明黑色素生成的“灭绝”或重新表达是基因平衡的一种功能。2s黑色素瘤细胞与未照射的1s成纤维细胞之间的杂交证实了这一解释，该杂交产生了色素沉着和无色素的杂种细胞。到目前为止，杂种细胞的核型与表型之间尚未建立相关性，但对核型数据的分析表明，导致“灭绝”的成纤维细胞染色体数量不会很多。
