Modelling genetic mosaicism of neurodevelopmental disorders in vivo by a Cre-amplifying fluorescent reporter
Francesco Trovato, Riccardo Parra, Enrico Pracucci, Silvia Landi, Olga Cozzolino, Gabriele Nardi, Federica Cruciani, Vinoshene Pillai, Laura Mosti, Andrzej Cwetsch, Laura Cancedda, Laura Gritti, Carlo Sala, Chiara Verpelli, Andrea Maset, Claudia Lodovichi, Gian Michele Ratto
Abstract
Genetic mosaicism, a condition in which an organ includes cells with different genotypes, is frequently present in monogenic diseases of the central nervous system caused by the random inactivation of the X-chromosome, in the case of X-linked pathologies, or by somatic mutations affecting a subset of neurons. The comprehension of the mechanisms of these diseases and of the cell-autonomous effects of specific mutations requires the generation of sparse mosaic models, in which the genotype of each neuron is univocally identified by the expression of a fluorescent protein in vivo. Here, we show a dual-color reporter system that, when expressed in a floxed mouse line for a target gene, leads to the creation of mosaics with tunable degree. We demonstrate the generation of a knockout mosaic of the autism/epilepsy related gene PTEN in which the genotype of each neuron is reliably identified, and the neuronal phenotype is accurately characterized by two-photon microscopy.