Direct Readout of Neural Stem Cell Transgenesis with an Integration-Coupled Gene Expression Switch

Takuma Kumamoto (1) , Franck Maurinot (1) , Raphaëlle Barry-Martinet (1) , Célia Vaslin (2) , Sandrine Vandormael-Pournin (3) , Mickaël Le (1) , Marion Lerat (1) , Dragos Niculescu (1) , Michel Cohen-Tannoudji (4) , Alexandra Rebsam (2) , Karine Loulier (1) , Stéphane Nedelec (2) , Samuel Tozer (5, 1) , Jean Livet (1)

1 Institut de la Vision
2 IFM - Inserm U1270 - SU - Institut du Fer à Moulin
3 INSERM - Institut National de la Santé et de la Recherche Médicale
4 Embryon précoce de mammifères et cellules souches
5 IBENS - Institut de biologie de l'ENS Paris

Stable genomic integration of exogenous transgenes is essential in neurodevelopmental and stem cell studies. Despite tools driving increasingly efficient genomic insertion with DNA vectors, transgenesis remains fundamentally hindered by the impossibility of distinguishing integrated from episomal transgenes. Here, we introduce an integration-coupled On genetic switch, iOn, which triggers gene expression upon incorporation into the host genome through transposition, thus enabling rapid and accurate identification of integration events following transfection with naked plasmids. In vitro, iOn permits rapid drug-free stable transgenesis of mouse and human pluripotent stem cells with multiple vectors. In vivo, we demonstrate faithful cell lineage tracing, assessment of regulatory elements, and mosaic analysis of gene function in somatic transgenesis experiments that reveal neural progenitor potentialities and interaction. These results establish iOn as a universally applicable strategy to accelerate and simplify genetic engineering in cultured systems and model organisms by conditioning transgene activation to genomic integration.

Keywords: mosaic analysis; neural stem cells; somatic transgenesis; transposon systems; lineage tracing; DNA vectors; genetic engineering; genetic switch; genomic integration

Domains: Development Biology

Takuma Kumamoto, Franck Maurinot, Raphaëlle Barry-Martinet, Célia Vaslin, Sandrine Vandormael-Pournin, et al.. Direct Readout of Neural Stem Cell Transgenesis with an Integration-Coupled Gene Expression Switch. Neuron, 2020, Online ahead of print, pp.S0896-6273(20)30407-4. ⟨10.1016/j.neuron.2020.05.038⟩. ⟨pasteur-02877084⟩