Crouse C A, Pauley R J
Department of Microbiology and Immunology, University of Miami School of Medicine, FL 33101.
Virus Res. 1989 Feb;12(2):123-37. doi: 10.1016/0168-1702(89)90059-2.
The vertically transmitted Mtv-1 provirus is the primary causative factor of mammary neoplasia in certain C3Hf strains that lack the horizontally transmitted mouse mammary tumor virus (MMTV). The studies here report the molecular cloning of the germ line 4.5 kb Mtv-1 3' EcoRI fragment and sequencing of the 3' Mtv-1 LTR. The Mtv-1 LTR sequence is closely related to the 5' Mtv-11 LTR sequence also reported here, as well as to known Mtv-8 and MMTV LTR sequences in the portion of MMTV and Mtv-8 LTRs previously demonstrated to contain transcriptional regulatory sequences. A 91 bp unique sequence region, Mtv-1 bp 862 to 952, exists in the Mtv-1 LTR, which is upstream of the sequence homology with the MMTV transcriptional regulatory domain. The Mtv-1 unique sequence region is distinct from a 117 bp sequence, bp 862 to 978, in the Mtv-11 LTR sequence as well as reported Mtv-8 and MMTV LTR sequences, and is present in the germ line Mtv-1 5' and 3' LTR-containing restriction fragments. S1 nuclease mapping experiments of C3Hf/Se mammary tumor poly(A) RNA with the cloned Mtv-1 and Mtv-11 LTRs exhibited a specific set of S1 protected fragments demonstrating that Mtv transcripts which accumulate in C3Hf spontaneous mammary tumors are encoded by the Mtv-1 provirus.
垂直传播的Mtv-1前病毒是某些缺乏水平传播的小鼠乳腺肿瘤病毒（MMTV）的C3Hf品系中乳腺肿瘤形成的主要致病因素。本文的研究报告了生殖系4.5 kb Mtv-1 3'EcoRI片段的分子克隆及3'Mtv-1 LTR的测序。Mtv-1 LTR序列与本文报道的5'Mtv-11 LTR序列密切相关，也与MMTV和Mtv-8 LTRs先前已证明含有转录调控序列的部分中已知的Mtv-8和MMTV LTR序列密切相关。在Mtv-1 LTR中存在一个91 bp的独特序列区域，即Mtv-1的862至952碱基对，该区域位于与MMTV转录调控域序列同源性的上游。Mtv-1独特序列区域与Mtv-11 LTR序列中的117 bp序列（862至978碱基对）以及报道的Mtv-8和MMTV LTR序列不同，并且存在于含有生殖系Mtv-1 5'和3'LTR的限制性片段中。用克隆的Mtv-1和Mtv-11 LTR对C3Hf/Se乳腺肿瘤多聚腺苷酸RNA进行S1核酸酶作图实验，显示出一组特定的S1保护片段，表明在C3Hf自发性乳腺肿瘤中积累的Mtv转录本由Mtv-1前病毒编码。
