Fig. 1

Recombinant AAV vectors can induce Cre-LoxP recombination. a Schematic representation of the strategy to induce Cre-LoxP recombination using rAAVs. R26^mTmG heterozygous zygotes derived from breeding R26^mTmG homozygous and wild-type mice were placed in a drop of KSOM media containing rAAV particles, rinsed, cultured in KSOM, and analyzed for fluorescence after 3 days in culture or were transferred into pseudopregnant females after 1 day in culture and allowed to develop to term. b Schematic representation of the R26^mTmG fluorescence reporter. R26^mTmG embryos express the membrane-targeted tdTomato gene (mT) and fluoresce red. Cre-mediated recombination drives expression of membrane-targeted EGFP (mG), making recombined cells fluoresce green. c Fluorescence analysis of compacted morulae transduced with rAAV6-Cre. Maternal mT protein is present in both non-treated (top row) and treated (bottom row) embryos, making them fluoresce red. Transduction with rAAV6-Cre leads to green fluorescent embryos (bottom row), indicative of Cre-mediated recombination. Inset is a merged image of the embryo marked by arrows to highlight mosaicism evident by the absence of green fluorescence in some cells. Scale bar equals 50 μm. d Fluorescence analysis of pups derived from zygotes transduced with rAAV6-Cre in culture and transferred into pseudopregnant females. Two pups show complete Cre-lox recombination (1 and 2), two are mosaic (3 and 4), and one (5) did not undergo recombination. e Schematic representation of the strategy to test for germline transmission of the recombined R26^mG allele obtained after rAAV6-Cre treatment of R26^mTmG/+ zygotes in culture. f R26^mG/+ mother and her offspring derived from a cross to a wild-type male; two R26^mG/+ pups are visible