Ostertag W, Pragnell I B
Proc Natl Acad Sci U S A. 1978 Jul;75(7):3278-82. doi: 10.1073/pnas.75.7.3278.
The Friend spleen focus-forming virus (SFFV) complex released by Friend virus-transformed erythroid cells has been analyzed with respect to changes in the genome composition that may occur during induction of erythropoiesis with dimethyl sulfoxide. It is shown that: (a) There are three types of virus particles, one with buoyant density 1.20 g/ml, one with density 1.17 g/ml (the density of the cloned lymphatic leukemia virus helper component of the complex), and a major fraction that has a density of 1.14 g/ml. (b) Three RNA subunits-35S, 32S, and 30S-have previously been shown to be detectable in the Friend virus complex. The 1.20-g/ml particles contain only 30S RNA, whilst the 1.14- to 1.17-g/ml particles contain a mixture consisting of predominantly 30S and 32S RNA and about 5-10% 35S RNA. (c) Induction of differentiation results in an increase in the 1.14-g/ml particles and 32S RNA. The amount of 30S RNA does not change. (d) Hybridization of the different genomic viral RNAs with full-length virus cDNA shows that the 30S RNA (of induced and uninduced Friend virus) is more closely related to the 32S RNA of the induced Friend virus than to the 32S RNA of the constitutively released Friend virus. (e) The 30S RNA contains SFFV-specific sequences. (f) A hypothesis is presented in which the induction of the new 32S RNA species is related to the increase of SFFV activity and to a specific function of the SFFV during induction of erythropoiesis.
对由弗氏病毒转化的红系细胞释放的弗氏脾灶形成病毒（SFFV）复合物，就其在用二甲基亚砜诱导红细胞生成过程中可能发生的基因组组成变化进行了分析。结果表明：（a）存在三种病毒颗粒，一种浮力密度为1.20 g/ml，一种密度为1.17 g/ml（该复合物中克隆的淋巴白血病病毒辅助成分的密度），以及主要部分密度为1.14 g/ml。（b）先前已证明在弗氏病毒复合物中可检测到三种RNA亚基——35S、32S和30S。密度为1.20 g/ml的颗粒仅含有30S RNA，而密度为1.14至1.17 g/ml的颗粒含有主要由30S和32S RNA以及约5 - 10%的35S RNA组成的混合物。（c）分化诱导导致密度为1.14 g/ml的颗粒和32S RNA增加。30S RNA的量不变。（d）不同基因组病毒RNA与全长病毒cDNA的杂交表明，（诱导和未诱导的弗氏病毒的）30S RNA与诱导的弗氏病毒的32S RNA的关系比与组成性释放的弗氏病毒的32S RNA的关系更密切。（e）30S RNA包含SFFV特异性序列。（f）提出了一种假说，其中新的32S RNA种类的诱导与SFFV活性的增加以及SFFV在红细胞生成诱导过程中的特定功能有关。
