Croce C M, Koprowski H
Proc Natl Acad Sci U S A. 1975 May;72(5):1658-60. doi: 10.1073/pnas.72.5.1658.
Somatic cell hybrid clones between either C57BL/6 or Balb/c mouse peritoneal macrophages and two different simian virus 40 (SV40)-transformed human cell lines deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase) were obtained in hypoxanthine-aminopterin-thymidine selective medium. All the hybrid cell clones contained the human chromosome 7, which carries the SV40 genome, and were SV40 tumor (T)-antigen positive. No hybrid cell clones studied displayed the density-dependent inhibition of cell growth characteristic of normal cells; all clones had a high saturation density and gave origin to cell colonies when plated in soft agar. Since the expression of the transformed phenotype was always associated with the presence of the human chromosome 7, which carries the SV40 genome, it is concluded that this chromosome contains gene(s) [Tr gene(s)] coding for "transforming factor(s)."
在次黄嘌呤 - 氨基蝶呤 - 胸腺嘧啶核苷选择培养基中，获得了C57BL / 6或Balb / c小鼠腹膜巨噬细胞与两种不同的次黄嘌呤磷酸核糖转移酶（EC 2.4.2.8；IMP：焦磷酸磷酸核糖转移酶）缺陷的猿猴病毒40（SV40）转化的人细胞系之间的体细胞杂交克隆。所有杂交细胞克隆都含有携带SV40基因组的人类7号染色体，并且SV40肿瘤（T）抗原呈阳性。所研究的杂交细胞克隆均未表现出正常细胞特有的细胞生长密度依赖性抑制；所有克隆都具有高饱和密度，并且接种于软琼脂中时可形成细胞集落。由于转化表型的表达总是与携带SV40基因组的人类7号染色体的存在相关，因此得出结论，该染色体包含编码“转化因子”的基因（Tr基因）。
