title: Heritable and inducible gene knockdown in astrocytes or neurons in vivo by a combined lentiviral and RNAi approach.
abstract: Gene knockout by homologous recombination is a popular method to study gene functions in the mouse in vivo. However, its lack of temporal control has limited the interpretation of knockout studies because the complete elimination of a gene product often alters developmental processes, and can induce severe malformations or lethality. Conditional gene knockdown has emerged as a compelling alternative to gene knockout, an approach well-established in vitro but that remains challenging in vivo, especially in the adult brain. Here, we report a method for conditional and cell-specific gene knockdown in the mouse brain in vivo that combines Cre-mediated RNA interference (RNAi) with classical and lentivirus-mediated transgenesis. The method is based on the inducible expression of a silencing short hairpin RNA (shRNA) introduced in mice by lentivirus-mediated transgenesis, and on its activation by excision of a floxed stop EGFP reporter with an inducible Cre recombinase expressed in astrocytes or in neurons. This dual system should be of broad utility for comparative studies of gene functions in these two cell types in vivo.
authors.affiliation: Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology of the Swiss Federal Institute of Technology Zürich, Switzerland.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Heitz
authors.affiliation: Institute of Pharmacology and Toxicology, Medical Faculty of the University of Zürich Zürich, Switzerland.
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Johansson
authors.affiliation: Dorris Neuroscience Center, The Scripps Research Institute La Jolla, CA, USA.
authors.forename: Karsten
authors.initials: K
authors.lastname: Baumgärtel
authors.affiliation: Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology of the Swiss Federal Institute of Technology Zürich, Switzerland.
authors.forename: Rreze
authors.initials: R
authors.lastname: Gecaj
authors.affiliation: Institute of Laboratory Animal Science, University of Zürich Zürich, Switzerland.
authors.forename: Pawel
authors.initials: P
authors.lastname: Pelczar
authors.affiliation: Brain Research Institute, Medical Faculty of the University of Zürich and Department of Biology of the Swiss Federal Institute of Technology Zürich, Switzerland.
authors.forename: Isabelle M
authors.initials: IM
authors.lastname: Mansuy
keywords: Cre-lox genetics; conditional gene knockdown; in vivo gene knockdown; lentivirus-mediated transgenesis; shRNA