Thorey I S, Muth K, Russ A P, Otte J, Reffelmann A, von Melchner H
Department of Hematology, University of Frankfurt Medical School, Frankfurt am Main, Germany.
Mol Cell Biol. 1998 May;18(5):3081-8. doi: 10.1128/MCB.18.5.3081.
A strategy employing gene trap mutagenesis and site-specific recombination (Cre/loxP) has been used to identify genes that are transiently expressed during early mouse development. Embryonic stem cells expressing a reporter plasmid that codes for neomycin phosphotransferase and Escherichia coli LacZ were infected with a retroviral gene trap vector (U3Cre) carrying coding sequences for Cre recombinase (Cre) in the U3 region. Activation of Cre expression from integrations into active genes resulted in a permanent switching between the two selectable marker genes and consequently the expression of beta-galactosidase (beta-Gal). As a result, clones in which U3Cre had disrupted genes that were only transiently expressed could be selected. Moreover, U3Cre-activating cells acquired a cell autonomous marker that could be traced to cells and tissues of the developing embryo. Thus, when two of the clones with inducible U3Cre integrations were passaged in the germ line, they generated spatial patterns of beta-Gal expression.
一种采用基因诱捕诱变和位点特异性重组（Cre/loxP）的策略已被用于鉴定在小鼠早期发育过程中瞬时表达的基因。表达编码新霉素磷酸转移酶和大肠杆菌LacZ的报告质粒的胚胎干细胞，被携带位于U3区域的Cre重组酶（Cre）编码序列的逆转录病毒基因诱捕载体（U3Cre）感染。整合到活性基因中导致Cre表达激活，从而导致两个选择标记基因之间的永久切换，进而使β-半乳糖苷酶（β-Gal）表达。结果，可以选择U3Cre破坏了仅瞬时表达的基因的克隆。此外，U3Cre激活细胞获得了一种细胞自主标记，可追踪到发育中胚胎的细胞和组织。因此，当两个具有可诱导U3Cre整合的克隆在种系中传代时，它们产生了β-Gal表达的空间模式。
