Expression of retroviral vectors in transgenic mice obtained by embryo infection.
Expression of retroviral vectors in transgenic mice obtained by embryo infection.
复制标题
逆转录病毒载体在通过胚胎感染获得的转基因小鼠中的表达。
作者：
C. Stewart;S. Schuetze;M. Vanek;E. Wagner
植入前胚胎被携带新霉素耐药（neo）基因和v - myc基因的逆转录病毒载体MMCV - neo感染。获得了三个转基因亚株（M‐TKneo 1‐3），它们稳定地传播单个完整的载体拷贝。在所有亚株中，检测到来自胸苷激酶（TK）启动子的neo基因的表达，并分析了在所有组织中表达该基因的两个亚株。在第三个亚株中，载体已整合到X染色体上，neo在不同组织间表达不同。用逆转录病毒载体SAX获得了第二系列转基因小鼠，其中人腺苷脱氨酶cDNA （ADA）受内部SV40启动子控制。分析了4个亚株（M‐SAX 1‐4）；但未检测到ADA cDNA的表达。在所有小鼠中，在病毒5 '长末端重复序列（LTRs）的控制下，没有发现这些基因的表达。在M‐TKneo亚株中，无论其表达如何，载体都是低甲基化的，而在M‐SAX小鼠中，载体是高甲基化的。这些结果首次证明TK启动子可以在成年小鼠的所有组织中明显表达一个基因，并且具有内部启动子的逆转录病毒载体可能为转基因小鼠的基因高效表达提供了一种替代DNA注射的方法。
Pre‐implantation embryos were infected with the retroviral vector MMCV‐neo, which carries the neomycin resistance (neo) gene and the v‐myc gene. Three transgenic substrains (M‐TKneo 1‐3) were derived which stably transmit a single intact copy of the vector. In all of the substrains, expression of the neo gene from the internal thymidine kinase (TK) promoter was detected, with two of the substrains expressing the gene in all tissues analysed. In the third substrain, the vector had integrated on the X chromosome and neo expression varied between different tissues. A second series of transgenic mice were obtained with the retroviral vector SAX, in which the human adenosine deaminase cDNA (ADA) is under the control of an internal SV40 promoter. Four substrains (M‐SAX 1‐4) were analysed; however, no expression of the ADA cDNA was detected. In all mice, no expression was found of the genes under the control of the viral 5′ long terminal repeats (LTRs). In the M‐TKneo substrains the vector was hypomethylated irrespective of its expression whereas in the M‐SAX mice the vector was hypermethylated. These results demonstrate for the first time that the TK promoter can apparently express a gene in all tissues of adult mice and that retroviral vectors with internal promoters may provide an alternative to DNA injection for the efficient expression of genes in transgenic mice.