Lakso M, Pichel J G, Gorman J R, Sauer B, Okamoto Y, Lee E, Alt F W, Westphal H
Laboratory of Mammalian Genes and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2790, USA.
Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):5860-5. doi: 10.1073/pnas.93.12.5860.
We describe a transgenic mouse line carrying the cre transgene under the control of the adenovirus EIIa promoter that targets expression of the Cre recombinase to the early mouse embryo. To assess the ability of this recombinase to excise loxP-flanked DNA sequences at early stages of development, we bred EIIa-cre transgenic mice to two different mouse lines carrying loxP-flanked target sequences: (i) a strain with a single gene-targeted neomycin resistance gene flanked by 1oxP sites and (ii) a transgenic line carrying multiple transgene copies with internal loxP sites. Mating either of these loxP-carrying mouse lines to EIIa-cre mice resulted in first generation progeny in which the loxP-flanked sequences had been efficiently deleted from all tissues tested, including the germ cells. Interbreeding of these first generation progeny resulted in efficient germ-line transmission of the deletion to subsequent generations. These results demonstrate a method by which loxP-flanked DNA sequences can be efficiently deleted in the early mouse embryo. Potential applications of this approach are discussed, including reduction of multicopy transgene loci to produce single-copy transgenic lines and introduction of a variety of subtle mutations into the line.
我们描述了一种转基因小鼠品系，其携带在腺病毒EIIa启动子控制下的cre转基因，该启动子将Cre重组酶的表达靶向早期小鼠胚胎。为了评估这种重组酶在发育早期切除loxP侧翼DNA序列的能力，我们将EIIa-cre转基因小鼠与两种携带loxP侧翼靶序列的不同小鼠品系进行杂交：（i）一种具有单个基因靶向新霉素抗性基因且两侧为loxP位点的品系，以及（ii）一种携带多个具有内部loxP位点的转基因拷贝的转基因品系。将这些携带loxP的小鼠品系中的任何一个与EIIa-cre小鼠交配，都会产生第一代后代，其中loxP侧翼序列已从所有测试组织（包括生殖细胞）中有效删除。这些第一代后代的杂交导致缺失在种系中有效传递给后代。这些结果证明了一种在早期小鼠胚胎中有效删除loxP侧翼DNA序列的方法。讨论了该方法的潜在应用，包括减少多拷贝转基因位点以产生单拷贝转基因品系，以及在品系中引入各种细微突变。
