Efficient in vivo Manipulation of Mouse Genomic Sequences at the Zygote Stage

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 93; no. 12; pp. 5860 - 5865
• Main Authors: Lakso, Merja, Pichel, José G., Gorman, James R., Sauer, Brian, Okamoto, Yo, Lee, Eric, Alt, Frederick W., Westphal, Heiner
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 11.06.1996; National Acad Sciences; National Academy of Sciences
• Subjects: Alleles; Animals; DNA - genetics; DNA Nucleotidyltransferases - genetics; Embryos; Eye Neoplasms - genetics; Female; Fiber cells; Genes; Genetic loci; Genetics; Genome; Germ cells; Integrases; Lens, Crystalline - pathology; Male; Mice; Mice, Transgenic; Polymerase chain reaction; Rodents; Transgenes; Transgenic animals; Viral Proteins; Zygote; Zygotes
• ISSN: 0027-8424; 1091-6490
• 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 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 loxP 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 germ line.