Fischinger P J, Nomura S, Peebles P T
Bibl Haematol. 1975(40):537-43. doi: 10.1159/000397571.
Mouse cells transformed by the Moloney murine sarcoma virus (MSV) native to the species can give rise to revertants which are supersusceptible to a second cycle of transformation. The MSV retransformed cells can give rise to several complex functional states even after several cycles of cloning: a) Formation of sarcoma positive, leukemia negative (S+Lminus) type cells of which some sublines may be inducible for MSV by halogenated pyrimidines; b) detection of initially SminusLminus cells which spontaneously become transformed and S+Lminus; c) the derivation of flat murine leukemia virus positive (MuLV+) cells which have an atypical MuLV and may become MSV+ as well as MuLV+; d) the release of free MSV from some cell clones with an apparent absence of MuLV. A general feature of all the above variants is a failure of detection of spontaneous reversion occurring after the second cycle of transformation. The nature of MuLV spontaneously released is that of a poorly replicating MuLV which exhibits cross-interference with other MuLV pseudotypes of MSV and the envelope which is most similar to that of Moloney leukemia virus (MLV). The examination for spontaneous reversion in human S+Lminus cells transformed by the same type of genome capable of good frequency of reversion in mouse cells, did not yield human revertant cells.
由该物种天然的莫洛尼鼠肉瘤病毒（MSV）转化的小鼠细胞可产生回复体，这些回复体对第二轮转化超级敏感。即使经过几个克隆周期，MSV重新转化的细胞也可产生几种复杂的功能状态：a）形成肉瘤阳性、白血病阴性（S+L-）型细胞，其中一些亚系可能可被卤代嘧啶诱导产生MSV；b）检测到最初为S-L-的细胞，它们会自发转化为S+L-；c）衍生出扁平的鼠白血病病毒阳性（MuLV+）细胞，这些细胞具有非典型的MuLV，并且可能同时变为MSV+和MuLV+；d）从一些细胞克隆中释放出游离的MSV，明显没有MuLV。上述所有变体的一个共同特征是，在第二轮转化后未检测到自发回复。自发释放的MuLV的性质是一种复制能力较差的MuLV，它对MSV的其他MuLV假型以及与莫洛尼白血病病毒（MLV）最相似的包膜表现出交叉干扰。在能够在小鼠细胞中以较高频率回复的同一类型基因组转化的人S+L-细胞中进行自发回复检测，未产生人回复细胞。
