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Tatsumi Hirata - One of the best experts on this subject based on the ideXlab platform.

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    Summary The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium. Video Abstract

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium.

Ikuo K Suzuki - One of the best experts on this subject based on the ideXlab platform.

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    Summary The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium. Video Abstract

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium.

Takashi Gojobori - One of the best experts on this subject based on the ideXlab platform.

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    Summary The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium. Video Abstract

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium.

Takahiko Kawasaki - One of the best experts on this subject based on the ideXlab platform.

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    Summary The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium. Video Abstract

  • the temporal sequence of the mammalian neocortical neurogenetic program drives mediolateral pattern in the chick pallium
    Developmental Cell, 2012
    Co-Authors: Ikuo K Suzuki, Takahiko Kawasaki, Takashi Gojobori, Tatsumi Hirata
    Abstract:

    The six-layered neocortex permits complex information processing in all mammalian species. Because its homologous region (the pallium) in nonmammalian amniotes has a different architecture, the ability of neocortical progenitors to generate an orderly sequence of distinct cell types was thought to have arisen in the mammalian lineage. This study, however, shows that layer-Specific Neuron subtypes do exist in the chick pallium. Deep- and upper-layer Neurons are not layered but are segregated in distinct mediolateral domains in vivo. Surprisingly, cultured chick neural progenitors produce multiple layer-Specific Neuronal subtypes in the same chronological sequence as seen in mammals. These results suggest that the temporal sequence of the neocortical neurogenetic program was already inherent in the last common ancestor of mammals and birds and that mammals use this conserved program to generate a uniformly layered neocortex, whereas birds impose spatial constraints on the sequence to pattern the pallium.

Oliver Hobert - One of the best experts on this subject based on the ideXlab platform.

  • an atlas of caenorhabditis elegans chemoreceptor expression
    PLOS Biology, 2018
    Co-Authors: Berta Vidal, Ulkar Aghayeva, Chen Wang, Lori Glenwinkel, Emily A Bayer, Oliver Hobert
    Abstract:

    One goal of modern day neuroscience is the establishment of molecular maps that assign unique features to individual Neuron types. Such maps provide important starting points for Neuron classification, for functional analysis, and for developmental studies aimed at defining the molecular mechanisms of Neuron identity acquisition and Neuron identity diversification. In this resource paper, we describe a nervous system-wide map of the potential expression sites of 244 members of the largest gene family in the C. elegans genome, rhodopsin-like (class A) G-protein-coupled receptor (GPCR) chemoreceptors, using classic gfp reporter gene technology. We cover representatives of all sequence families of chemoreceptor GPCRs, some of which were previously entirely uncharacterized. Most reporters are expressed in a very restricted number of cells, often just in single cells. We assign GPCR reporter expression to all but two of the 37 sensory Neuron classes of the sex-shared, core nervous system. Some sensory Neurons express a very small number of receptors, while others, particularly nociceptive Neurons, coexpress several dozen GPCR reporter genes. GPCR reporters are also expressed in a wide range of inter- and motorNeurons, as well as non-Neuronal cells, suggesting that GPCRs may constitute receptors not just for environmental signals, but also for internal cues. We observe only one notable, frequent association of coexpression patterns, namely in one nociceptive amphid (ASH) and two nociceptive phasmid sensory Neurons (PHA, PHB). We identified GPCRs with sexually dimorphic expression and several GPCR reporters that are expressed in a left/right asymmetric manner. We identified a substantial degree of GPCR expression plasticity; particularly in the context of the environmentally-induced dauer diapause stage when one third of all tested GPCRs alter the cellular Specificity of their expression within and outside the nervous system. Intriguingly, in a number of cases, the dauer-Specific alterations of GPCR reporter expression in Specific Neuron classes are maintained during postdauer life and in some case new patterns are induced post-dauer, demonstrating that GPCR gene expression may serve as traits of life history. Taken together, our resource provides an entry point for functional studies and also offers a host of molecular markers for studying molecular patterning and plasticity of the nervous system.

  • a map of terminal regulators of Neuronal identity in caenorhabditis elegans
    Wiley Interdisciplinary Reviews-Developmental Biology, 2016
    Co-Authors: Oliver Hobert
    Abstract:

    Our present day understanding of nervous system development is an amalgam of insights gained from studying different aspects and stages of nervous system development in a variety of invertebrate and vertebrate model systems, with each model system making its own distinctive set of contributions. One aspect of nervous system development that has been among the most extensively studied in the nematode Caenorhabditis elegans is the nature of the gene regulatory programs that specify hardwired, terminal cellular identities. I first summarize a number of maps (anatomical, functional, and molecular) that describe the terminal identity of individual Neurons in the C. elegans nervous system. I then provide a comprehensive summary of regulatory factors that specify terminal identities in the nervous system, synthesizing these past studies into a regulatory map of cellular identities in the C. elegans nervous system. This map shows that for three quarters of all Neurons in the C. elegans nervous system, regulatory factors that control terminal identity features are known. In-depth studies of Specific Neuron types have revealed that regulatory factors rarely act alone, but rather act cooperatively in Neuron-type Specific combinations. In most cases examined so far, distinct, biochemically unlinked terminal identity features are coregulated via cooperatively acting transcription factors, termed terminal selectors, but there are also cases in which distinct identity features are controlled in a piecemeal fashion by independent regulatory inputs. The regulatory map also illustrates that identity-defining transcription factors are reemployed in distinct combinations in different Neuron types. However, the same transcription factor can drive terminal differentiation in Neurons that are unrelated by lineage, unrelated by function, connectivity and neurotransmitter deployment. Lastly, the regulatory map illustrates the preponderance of homeodomain transcription factors in the control of terminal identities, suggesting that these factors have ancient, phylogenetically conserved roles in controlling terminal Neuronal differentiation in the nervous system. WIREs Dev Biol 2016, 5:474-498. doi: 10.1002/wdev.233 For further resources related to this article, please visit the WIREs website.

  • direct conversion of c elegans germ cells into Specific Neuron types
    Science, 2011
    Co-Authors: Baris Tursun, Tulsi Patel, Paschalis Kratsios, Oliver Hobert
    Abstract:

    The ability of transcription factors to directly reprogram the identity of cell types is usually restricted and is defined by cellular context. Through the ectopic expression of single Caenorhabditis elegans transcription factors, we found that the identity of mitotic germ cells can be directly converted into that of Specific Neuron types: glutamatergic, cholinergic, or GABAergic. This reprogramming event requires the removal of the histone chaperone LIN-53 (RbAp46/48 in humans), a component of several histone remodeling and modifying complexes, and this removal can be mimicked by chemical inhibition of histone deacetylases. Our findings illustrate the ability of germ cells to be directly converted into individual, terminally differentiated Neuron types and demonstrate that a Specific chromatin factor provides a barrier for cellular reprogramming.

  • differential sulfations and epimerization define heparan sulfate Specificity in nervous system development
    Neuron, 2004
    Co-Authors: Hannes E Bulow, Oliver Hobert
    Abstract:

    Heparan sulfate proteoglycans (HSPG) are components of the extracellular matrix through which axons navigate to reach their targets. The heparan sulfate (HS) side chains of HSPGs show complex and differentially regulated patterns of secondary modifications, including sulfations of distinct hydroxyl groups and epimerization of an asymmetric carbon atom. These modifications endow the HSPG-containing extracellular matrix with the potential to code for an enormous molecular diversity. Attempting to decode this diversity, we analyzed C. elegans animals lacking three HS-modifying enzymes, glucuronyl C5-epimerase, heparan 6O-sulfotransferase, and 2O-sulfotransferase. Each of the mutant animals exhibit distinct as well as overlapping axonal and cellular guidance defects in Specific Neuron classes. We have linked individual HS modifications to two Specific guidance systems, the sax-3/Robo and kal-1/Anosmin-1 systems, whose activity is dependent on different HS modifications in different cellular contexts. Our results demonstrate that the molecular diversity in HS encodes information that is crucial for different aspects of Neuronal development.