Jorge García-Marqués

Cajal Institute · Department of Neurobiology

Abstract Astrocytes are the most abundant glial population in the central nervous system, where they fulfill multiple essential tasks. Such diverse functions require a heterogeneous population of cells, yet it is still unclear how this cellular heterogeneity emerges during development. To clarify to what extent such diversity is determined by line...

NG2-glia are the most unknown population originating in the CNS. Despite their relative abundance in the brain, fundamental questions about their function, heterogeneity, and origin remain in debate. Particularly, it is still intriguing how these cells escaped from classical in vivo clonal analyses describing other neural types. Using StarTrack lab...

Astrocytes are a heterogeneous population of glial cells with multifaceted roles in the central nervous system. Recently, the new method for the clonal analysis Star Track evidenced the link between astrocyte heterogeneity and lineage. Here, we tested the morphological response to mechanical injury of clonally related astrocytes using the Star Trac...

Astrocytes are the most numerous cell type in the brain, where they are known to play multiple important functions. While there is increasing evidence of their morphological, molecular, and functional heterogeneity, it is not clear whether their positional and morphological identities are specified during brain development. We address this problem...

The rostral migratory stream (RMS) is a well defined migratory pathway for precursors of olfactory bulb (OB) interneurons. Throughout the RMS an intense astroglial matrix surrounds the migratory cells. However, it is not clear to what extent the astroglial matrix participates in migration. Here, we have analyzed the migratory behavior of neuroblast...

During development, regulatory factors appear in a precise order to determine cell fates over time. Consequently, to investigate complex tissue development, it is necessary to visualize and manipulate cell lineages with temporal control. Current strategies for tracing vertebrate cell lineages lack genetic access to sequentially produced cells. Here...

Cell lineage defines the mitotic connection between cells that make up an organism. Mapping these connections in relation to cell identity offers an extraordinary insight into the mechanisms underlying normal and pathological development. The analysis of molecular determinants involved in the acquisition of cell identity requires gaining experiment...

During development, regulatory factors appear in a precise order to determine cell fates over time. To investigate complex tissue development, one should not just label cell lineages but further visualize and manipulate cells with temporal control. Current strategies for tracing vertebrate cell lineages lack genetic access to sequentially produced...

We present CLADES (cell lineage access driven by an edition sequence), a technology for cell lineage studies based on CRISPR–Cas9 techniques. CLADES relies on a system of genetic switches to activate and inactivate reporter genes in a predetermined order. Targeting CLADES to progenitor cells allows the progeny to inherit a sequential cascade of rep...

Reconstructing the genealogy of every cell that makes up an organism remains a long-standing challenge in developmental biology. Besides its relevance for understanding the mechanisms underlying normal and pathological development, resolving the lineage origin of cell types will be crucial to create these types on-demand. Multiple strategies have b...

The genome is the blueprint for an organism. Interrogating the genome, especially locating critical cis-regulatory elements, requires deletion analysis. This is conventionally performed using synthetic constructs, making it cumbersome and non-physiological. Thus, we created Cas9-mediated Arrayed Mutagenesis of Individual Offspring (CAMIO) to achiev...

The first meeting exclusively dedicated to the ‘High-throughput dense reconstruction of cell lineages' took place at Janelia Research Campus (Howard Hughes Medical Institute) from 14 to 18 April 2019. Organized by Tzumin Lee, Connie Cepko, Jorge Garcia-Marques and Isabel Espinosa-Medina, this meeting echoed the recent eruption of new tools that all...

We previously reported a CRISPR-mediated knock-in strategy into introns of Drosophila genes, generating an attP-FRT-SA-T2A-GAL4-polyA-3XP3-EGFP-FRT-attP transgenic library for multiple uses (Lee et al., 2018b). The method relied on double stranded DNA (dsDNA) homology donors with ~1 kb homology arms. Here, we describe three new simpler ways to edit...

We previously reported a CRISPR-mediated knock-in strategy into introns of Drosophila genes, generating an attP - FRT-SA-T2A-GAL4-polyA-3XP3-EGFP-FRT-attP transgenic library for multiple uses (Lee et al., 2018b). The method relied on double stranded DNA (dsDNA) homology donors with ~1 kb homology arms. Here, we describe three new simpler ways to ed...

Gaining independent genetic access to discrete cell types is critical to interrogate their biological functions as well as to deliver precise gene therapy. Transcriptomics has allowed us to profile cell populations with extraordinary precision, revealing that cell types are typically defined by a unique combination of genetic markers. Given the lac...

Astrocytes are organized as communicating cellular networks where each cell is connected to others via gap junctions. These connections are not pervasive and there is evidence for the existence of subgroups composed by preferentially connected cells. Despite being unclear how these are established, we hypothesized lineage might contribute to the es...

Interrogating the genome, especially locating critical cis-elements in non-protein coding regions, requires efficient deletion analysis. Conventional deletion analyses using synthetic constructs are cumbersome and nonphysiological. Here we invent CAMIO (Cas9-mediated Arrayed Mutagenesis of Individual Offspring), to achieve high-throughput organism-...

We present CLADES (Cell Lineage Access Driven by an Edition Sequence), a technology for cell lineage studies based on CRISPR/Cas9. CLADES relies on a system of genetic switches to activate and inactivate reporter genes in a pre-determined order. Targeting CLADES to progenitor cells allows the progeny to inherit a sequential cascade of reporters, co...

Delineating cell lineages is a prerequisite for understanding the genesis of cell types. Recent studies have demonstrated the feasibility of generating and reconstructing CRISPR/Cas9-coded cell lineages. However, these works have not investigated the limitations or optimality of the encoding or reconstruction processes. Here, we surveyed a multitud...

Gaining independent genetic access to discrete cell types is critical to interrogate their biological functions, as well as to deliver precise gene therapy. Transcriptome analyses have allowed us to profile cell populations with extraordinary precision, revealing that cell types are typically defined by a unique combination of genetic markers. Give...

Clonal cell analysis defines the potential of single cells and the diversity they can produce. To achieve this, we have developed a novel adaptation of the genetic tracing strategy, UbC-StarTrack, which attributes a specific and unique color-code to single neural precursors, allowing all their progeny to be tracked. We used integrable fluorescent r...

Genetic lineage tracing with electroporation is one of the most powerful techniques to target neural progenitor cells and their progeny. However, the spatiotemporal relationship between neural progenitors and their final phenotype remain poorly understood. One critical factor to analyze the cell fate of progeny is reporter integration into the geno...