Foster D N, Schmidt L J, Hodgson C P, Moses H L, Getz M J
Proc Natl Acad Sci U S A. 1982 Dec;79(23):7317-21. doi: 10.1073/pnas.79.23.7317.
Complementary DNA probes prepared from total polysomal poly(A)+RNA populations were used to identify clones of mouse DNA containing sequences whose expression is specifically enhanced after epidermal growth factor (EGF) stimulation of quiescent mouse embryo cells in culture. Three such clones were isolated and used to study changes in the levels of clone-specific poly(A)+RNA in the polysomes of cells after mitogenic stimulation by EGF. RNA complementary to sequences present in these clones increased approximately equal to 10-fold as a fraction of the total poly(A)+RNA by 6 hr after stimulation. All three clones were found by hybridization criteria to contain sequences related to the class of mouse retrovirus or transposon-like elements termed VL30. These VL30-related sequences were further found to be complementary to EGF-inducible poly(A)+RNAs and enhanced expression was detectable as early as 1 hr after EGF stimulation. In contrast, nine additional clones, including an AKR-type murine leukemia provirus DNA clone, contained no detectable VL30 sequence elements and were complementary to poly(A)+RNA species whose relative concentration was essentially constant in quiescent and EGF-stimulated cells. Therefore, VL30 sequence elements appear distinct in that they encompass members whose expression is specifically regulated in response to a defined peptide growth factor.
从总的多核糖体多聚腺苷酸（poly(A)+）RNA群体制备的互补DNA探针，用于鉴定含有在培养的静止小鼠胚胎细胞经表皮生长因子（EGF）刺激后其表达特异性增强的序列的小鼠DNA克隆。分离出三个这样的克隆，并用于研究在EGF有丝分裂原刺激后细胞多核糖体中克隆特异性多聚腺苷酸（poly(A)+）RNA水平的变化。与这些克隆中存在的序列互补的RNA在刺激后6小时作为总多聚腺苷酸（poly(A)+）RNA的一部分增加了约10倍。通过杂交标准发现所有三个克隆都含有与称为VL30的小鼠逆转录病毒或转座子样元件类别相关的序列。进一步发现这些与VL30相关的序列与EGF诱导的多聚腺苷酸（poly(A)+）RNA互补，并且早在EGF刺激后1小时就可检测到增强的表达。相比之下，另外九个克隆，包括一个AKR型鼠白血病前病毒DNA克隆，没有可检测到的VL30序列元件，并且与在静止和EGF刺激的细胞中相对浓度基本恒定的多聚腺苷酸（poly(A)+）RNA种类互补。因此，VL30序列元件显得独特，因为它们包含其表达响应于特定肽生长因子而被特异性调节的成员。
