Guerrero I, Villasante A, Corces V, Pellicer A
Proc Natl Acad Sci U S A. 1985 Dec;82(23):7810-4. doi: 10.1073/pnas.82.23.7810.
Young mice injected with the carcinogen N-nitroso-N-methylurea develop thymic lymphomas 2-4 months later. We previously have shown that these tumors frequently contain an activated N-ras gene that can transform rodent fibroblasts in vitro. We report here the intron/exon structure of such an activated N-ras gene and the sequence of its four coding exons. A single nucleotide change is responsible for the transforming alteration, a C----A transversion in the first base of codon 61. Through the use of synthetic oligonucleotides as hybridization probes, we show that this tumor lacks the normal allele of the N-ras gene. The implications of this finding for oncogene dominance are discussed.
注射致癌物质N-亚硝基-N-甲基脲的幼鼠在2至4个月后会患上胸腺淋巴瘤。我们之前已经表明，这些肿瘤经常含有一个活化的N-ras基因，该基因在体外能够转化啮齿动物成纤维细胞。我们在此报告这样一个活化的N-ras基因的内含子/外显子结构及其四个编码外显子的序列。一个单核苷酸变化导致了转化改变，即密码子61第一个碱基处的C到A的颠换。通过使用合成寡核苷酸作为杂交探针，我们表明该肿瘤缺乏N-ras基因的正常等位基因。讨论了这一发现对癌基因显性的影响。
