Next November 2nd at 12:00 am it will take place the seminar "Temporal labelling and manipulation of vertebrate cell lineages with a new CRISPR/Cas9 system" by Dr. Isabel Espinosa-Medina from Janelia Research Campus (HHMI), VA, US at Ramon y Cajal room (PPBB).

Abstract

During development, regulatory factors appear in a precise order to help determine each cell’s fate. To investigate the cellular origins and fating mechanisms of complex tissues, it is critical to not just label cell lineages, but to visualize and manipulate cells with temporal control. Current strategies for tracing vertebrate cell lineages lack genetic access to sequentially produced cells. Here we present TEMPO (Temporal Encoding and Manipulation in a Predefined Order), an imaging-readable genetic tool allowing differential labelling and manipulation of consecutive cell generations in vertebrates. TEMPO is based on CRISPR; a cascade of gRNAs drives activation/inactivation of reporters/effectors in a predefined order. Using TEMPO to visualize zebrafish and mouse neurogenesis, we recapitulated birth-order-dependent neuronal fates. Temporally manipulating cell-cycle regulators in mouse cortex progenitors altered the proportion and distribution of neurons and glia, revealing the interactions between cells arising from perturbed versus unperturbed windows in a single sample. Thus, TEMPO enables sequential manipulation of molecular factors, crucial to study cell-type specification.