Synthesis of a photocaged tamoxifen for light-dependent activation of Cre-ER recombinase-driven gene modification.
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ABSTRACT:
SUBMITTER: Inlay MA
PROVIDER: S-EPMC3926663 | biostudies-literature | 2013 May
REPOSITORIES: biostudies-literature
Publications
Synthesis of a photocaged tamoxifen for light-dependent activation of Cre-ER recombinase-driven gene modification.
Inlay Matthew A MA Choe Veronica V Bharathi Sophia S Fernhoff Nathaniel B NB Baker James R JR Weissman Irving L IL Choi Seok Ki SK
Chemical communications (Cambridge, England) 20130501 43
We report the design of a water-soluble, quaternized tamoxifen photoprobe and demonstrate its application in light-controlled induction of green fluorescent protein expression via a Cre-ER recombinase system. ...[more]
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Project description:BackgroundStudies on osteoclasts, the bone resorbing cells, have remained limited due to the lack of transgenic mice allowing the conditional knockout of genes in osteoclasts at any time during development or adulthood.Methodology/principal findingWe report here on the generation of transgenic mice which specifically express a tamoxifen-inducible Cre recombinase in osteoclasts. These mice, generated on C57BL/6 and FVB background, express a fusion Cre recombinase-ERT2 protein whose expression is driven by the promoter of cathepsin K (CtsK), a gene highly expressed in osteoclasts. We tested the cellular specificity of Cre activity in CtsKCreERT2 strains by breeding with Rosa26LacZ reporter mice. PCR and histological analyses of the CtsKCreERT2LacZ positive adult mice and E17.5 embryos show that Cre activity is restricted largely to bone tissue. In vitro, primary osteoclasts derived from the bone marrow of CtsKCreERT2+/-LacZ+/- adult mice show a Cre-dependent ?-galactosidase activity after tamoxifen stimulation.Conclusions/significanceWe have generated transgenic lines that enable the tamoxifen-induced, conditional deletion of loxP-flanked genes in osteoclasts, thus circumventing embryonic and postnatal gene lethality and avoiding gene deletion in other cell types. Such CtsKCreERT2 mice provide a convenient tool to study in vivo the different facets of osteoclast function in bone physiology during different developmental stages and adulthood of mice.
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