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Paola Bovolenta - One of the best experts on this subject based on the ideXlab platform.

  • Cdon acts as a Hedgehog decoy receptor during Proximal-Distal Patterning of the optic vesicle.
    Nature communications, 2014
    Co-Authors: Marcos Julián Cardozo, Luisa Sánchez-arrones, África Sandonís, Cristina Sánchez-camacho, Gaia Gestri, Stephen W. Wilson, Isabel Guerrero, Paola Bovolenta
    Abstract:

    Patterning of the vertebrate optic vesicle into proximal/optic stalk and distal/neural retina involves midline-derived Hedgehog (Hh) signalling, which promotes stalk specification. In the absence of Hh signalling, the stalks are not specified, causing cyclopia. Recent studies showed that the cell adhesion molecule Cdon forms a heteromeric complex with the Hh receptor Patched 1 (Ptc1). This receptor complex binds Hh and enhances signalling activation, indicating that Cdon positively regulates the pathway. Here we show that in the developing zebrafish and chick optic vesicle, in which cdon and ptc1 are expressed with a complementary pattern, Cdon acts as a negative Hh signalling regulator. Cdon predominantly localizes to the basolateral side of neuroepithelial cells, promotes the enlargement of the neuroepithelial basal end-foot and traps Hh protein, thereby limiting its dispersion. This Ptc-independent function protects the retinal primordium from Hh activity, defines the stalk/retina boundary and thus the correct proximo-distal Patterning of the eye.

  • Cdon acts as a Hedgehog decoy receptor during Proximal-Distal Patterning of the optic vesicle
    Nature Communications, 2014
    Co-Authors: Marcos Julián Cardozo, Luisa Sánchez-arrones, África Sandonís, Cristina Sánchez-camacho, Gaia Gestri, Stephen W. Wilson, Isabel Guerrero, Paola Bovolenta
    Abstract:

    Patterning of the vertebrate optic vesicle into proximal/optic stalk and distal/neural retina involves midline-derived Hedgehog (Hh) signalling, which promotes stalk specification. In the absence of Hh signalling, the stalks are not specified, causing cyclopia. Recent studies showed that the cell adhesion molecule Cdon forms a heteromeric complex with the Hh receptor Patched 1 (Ptc1). This receptor complex binds Hh and enhances signalling activation, indicating that Cdon positively regulates the pathway. Here we show that in the developing zebrafish and chick optic vesicle, in which cdon and ptc1 are expressed with a complementary pattern, Cdon acts as a negative Hh signalling regulator. Cdon predominantly localizes to the basolateral side of neuroepithelial cells, promotes the enlargement of the neuroepithelial basal end-foot and traps Hh protein, thereby limiting its dispersion. This Ptc-independent function protects the retinal primordium from Hh activity, defines the stalk/retina boundary and thus the correct proximo-distal Patterning of the eye. The Drosophila homologue of the vertebrate cell surface glycoprotein Cdon binds Hedgehog ligand and thereby prevents its diffusion. Here, the authors provide evidence for a similar mechanism during vertebrate optic vesicle Patterning, where Cdon acts as a negative regulator of Hedgehog signalling to define the boundary between the optic stalk and the retina.

James W. Truman - One of the best experts on this subject based on the ideXlab platform.

  • Juvenile hormone acts at embryonic molts and induces the nymphal cuticle in the direct-developing cricket
    Development Genes and Evolution, 2004
    Co-Authors: Deniz F. Erezyilmaz, Lynn M. Riddiford, James W. Truman
    Abstract:

    During embryogenesis of hemimetabolous insects, the sesquiterpenoid hormone, juvenile hormone (JH), appears late in embryogenesis coincident with formation of the first nymphal cuticle. We tested the role of embryonic JH by treating cricket embryos with JH III, or the JH-mimic (JHM) pyriproxifen, during early embryogenesis. We found two discrete windows of JH sensitivity. The first occurs during the formation of the first (E1) embryonic cuticle. Treatment with JHM prior to this molt produced small embryos that failed to complete the movements of katatrepsis. Embryos treated after the E1 molt but before the second embryonic (pronymphal) molt completed katatrepsis but then failed to complete dorsal closure and precociously formed nymphal, rather than pronymphal characters. This second sensitivity window was further assessed by treating embryos with low doses of JH III prior to the pronymphal molt. With low doses, mosaic cuticles were formed, bearing features of both the pronymphal and nymphal stages. The nymphal characters varied in their sensitivity to JH III, due at least in part to differences in the timing of their sensitivity windows. Unexpectedly, many of the JH III-treated embryos with mosaic and precocious nymphal cuticles made a second nymphal cuticle and successfully hatched. JH treatment also affected the growth of the embryos. By focusing on the developing limb, we found that the effect of JH upon growth was asymmetric, with distal segments more affected than proximal ones, but this was not reflected in misexpression of Distal-less or Bric-a-brac, which are involved in Proximal-Distal Patterning of the limb.

  • Juvenile hormone acts at embryonic molts and induces the nymphal cuticle in the direct-developing cricket
    Development Genes and Evolution, 2004
    Co-Authors: Deniz F. Erezyilmaz, Lynn M. Riddiford, James W. Truman
    Abstract:

    During embryogenesis of hemimetabolous insects, the sesquiterpenoid hormone, juvenile hormone (JH), appears late in embryogenesis coincident with formation of the first nymphal cuticle. We tested the role of embryonic JH by treating cricket embryos with JH III, or the JH-mimic (JHM) pyriproxifen, during early embryogenesis. We found two discrete windows of JH sensitivity. The first occurs during the formation of the first (E1) embryonic cuticle. Treatment with JHM prior to this molt produced small embryos that failed to complete the movements of katatrepsis. Embryos treated after the E1 molt but before the second embryonic (pronymphal) molt completed katatrepsis but then failed to complete dorsal closure and precociously formed nymphal, rather than pronymphal characters. This second sensitivity window was further assessed by treating embryos with low doses of JH III prior to the pronymphal molt. With low doses, mosaic cuticles were formed, bearing features of both the pronymphal and nymphal stages. The nymphal characters varied in their sensitivity to JH III, due at least in part to differences in the timing of their sensitivity windows. Unexpectedly, many of the JH III-treated embryos with mosaic and precocious nymphal cuticles made a second nymphal cuticle and successfully hatched. JH treatment also affected the growth of the embryos. By focusing on the developing limb, we found that the effect of JH upon growth was asymmetric, with distal segments more affected than proximal ones, but this was not reflected in misexpression of Distal-less or Bric-a-brac, which are involved in Proximal-Distal Patterning of the limb.

Marcos Julián Cardozo - One of the best experts on this subject based on the ideXlab platform.

  • Cdon acts as a Hedgehog decoy receptor during Proximal-Distal Patterning of the optic vesicle.
    Nature communications, 2014
    Co-Authors: Marcos Julián Cardozo, Luisa Sánchez-arrones, África Sandonís, Cristina Sánchez-camacho, Gaia Gestri, Stephen W. Wilson, Isabel Guerrero, Paola Bovolenta
    Abstract:

    Patterning of the vertebrate optic vesicle into proximal/optic stalk and distal/neural retina involves midline-derived Hedgehog (Hh) signalling, which promotes stalk specification. In the absence of Hh signalling, the stalks are not specified, causing cyclopia. Recent studies showed that the cell adhesion molecule Cdon forms a heteromeric complex with the Hh receptor Patched 1 (Ptc1). This receptor complex binds Hh and enhances signalling activation, indicating that Cdon positively regulates the pathway. Here we show that in the developing zebrafish and chick optic vesicle, in which cdon and ptc1 are expressed with a complementary pattern, Cdon acts as a negative Hh signalling regulator. Cdon predominantly localizes to the basolateral side of neuroepithelial cells, promotes the enlargement of the neuroepithelial basal end-foot and traps Hh protein, thereby limiting its dispersion. This Ptc-independent function protects the retinal primordium from Hh activity, defines the stalk/retina boundary and thus the correct proximo-distal Patterning of the eye.

  • Cdon acts as a Hedgehog decoy receptor during Proximal-Distal Patterning of the optic vesicle
    Nature Communications, 2014
    Co-Authors: Marcos Julián Cardozo, Luisa Sánchez-arrones, África Sandonís, Cristina Sánchez-camacho, Gaia Gestri, Stephen W. Wilson, Isabel Guerrero, Paola Bovolenta
    Abstract:

    Patterning of the vertebrate optic vesicle into proximal/optic stalk and distal/neural retina involves midline-derived Hedgehog (Hh) signalling, which promotes stalk specification. In the absence of Hh signalling, the stalks are not specified, causing cyclopia. Recent studies showed that the cell adhesion molecule Cdon forms a heteromeric complex with the Hh receptor Patched 1 (Ptc1). This receptor complex binds Hh and enhances signalling activation, indicating that Cdon positively regulates the pathway. Here we show that in the developing zebrafish and chick optic vesicle, in which cdon and ptc1 are expressed with a complementary pattern, Cdon acts as a negative Hh signalling regulator. Cdon predominantly localizes to the basolateral side of neuroepithelial cells, promotes the enlargement of the neuroepithelial basal end-foot and traps Hh protein, thereby limiting its dispersion. This Ptc-independent function protects the retinal primordium from Hh activity, defines the stalk/retina boundary and thus the correct proximo-distal Patterning of the eye. The Drosophila homologue of the vertebrate cell surface glycoprotein Cdon binds Hedgehog ligand and thereby prevents its diffusion. Here, the authors provide evidence for a similar mechanism during vertebrate optic vesicle Patterning, where Cdon acts as a negative regulator of Hedgehog signalling to define the boundary between the optic stalk and the retina.

Deniz F. Erezyilmaz - One of the best experts on this subject based on the ideXlab platform.

  • Juvenile hormone acts at embryonic molts and induces the nymphal cuticle in the direct-developing cricket
    Development Genes and Evolution, 2004
    Co-Authors: Deniz F. Erezyilmaz, Lynn M. Riddiford, James W. Truman
    Abstract:

    During embryogenesis of hemimetabolous insects, the sesquiterpenoid hormone, juvenile hormone (JH), appears late in embryogenesis coincident with formation of the first nymphal cuticle. We tested the role of embryonic JH by treating cricket embryos with JH III, or the JH-mimic (JHM) pyriproxifen, during early embryogenesis. We found two discrete windows of JH sensitivity. The first occurs during the formation of the first (E1) embryonic cuticle. Treatment with JHM prior to this molt produced small embryos that failed to complete the movements of katatrepsis. Embryos treated after the E1 molt but before the second embryonic (pronymphal) molt completed katatrepsis but then failed to complete dorsal closure and precociously formed nymphal, rather than pronymphal characters. This second sensitivity window was further assessed by treating embryos with low doses of JH III prior to the pronymphal molt. With low doses, mosaic cuticles were formed, bearing features of both the pronymphal and nymphal stages. The nymphal characters varied in their sensitivity to JH III, due at least in part to differences in the timing of their sensitivity windows. Unexpectedly, many of the JH III-treated embryos with mosaic and precocious nymphal cuticles made a second nymphal cuticle and successfully hatched. JH treatment also affected the growth of the embryos. By focusing on the developing limb, we found that the effect of JH upon growth was asymmetric, with distal segments more affected than proximal ones, but this was not reflected in misexpression of Distal-less or Bric-a-brac, which are involved in Proximal-Distal Patterning of the limb.

  • Juvenile hormone acts at embryonic molts and induces the nymphal cuticle in the direct-developing cricket
    Development Genes and Evolution, 2004
    Co-Authors: Deniz F. Erezyilmaz, Lynn M. Riddiford, James W. Truman
    Abstract:

    During embryogenesis of hemimetabolous insects, the sesquiterpenoid hormone, juvenile hormone (JH), appears late in embryogenesis coincident with formation of the first nymphal cuticle. We tested the role of embryonic JH by treating cricket embryos with JH III, or the JH-mimic (JHM) pyriproxifen, during early embryogenesis. We found two discrete windows of JH sensitivity. The first occurs during the formation of the first (E1) embryonic cuticle. Treatment with JHM prior to this molt produced small embryos that failed to complete the movements of katatrepsis. Embryos treated after the E1 molt but before the second embryonic (pronymphal) molt completed katatrepsis but then failed to complete dorsal closure and precociously formed nymphal, rather than pronymphal characters. This second sensitivity window was further assessed by treating embryos with low doses of JH III prior to the pronymphal molt. With low doses, mosaic cuticles were formed, bearing features of both the pronymphal and nymphal stages. The nymphal characters varied in their sensitivity to JH III, due at least in part to differences in the timing of their sensitivity windows. Unexpectedly, many of the JH III-treated embryos with mosaic and precocious nymphal cuticles made a second nymphal cuticle and successfully hatched. JH treatment also affected the growth of the embryos. By focusing on the developing limb, we found that the effect of JH upon growth was asymmetric, with distal segments more affected than proximal ones, but this was not reflected in misexpression of Distal-less or Bric-a-brac, which are involved in Proximal-Distal Patterning of the limb.

Sarah Hake - One of the best experts on this subject based on the ideXlab platform.

  • the maize mid complementing activity homolog cell number regulator13 narrow odd dwarf coordinates organ growth and tissue Patterning
    The Plant Cell, 2017
    Co-Authors: Marisa Rosa, Sarah Hake, Maria Jazmin Abrahamjuarez, Michael W Lewis, Joao Pedro Fonseca, Wang Tian, Vicente Ramirez, Sheng Luan, Markus Pauly
    Abstract:

    Organogenesis occurs through cell division, expansion, and differentiation. How these cellular processes are coordinated remains elusive. The maize (Zea mays) leaf provides a robust system to study cellular differentiation due to its distinct tissues and cell types. The narrow odd dwarf (nod) mutant displays defects at both the cellular and tissue level that increase in severity throughout growth. nod mutant leaves have reduced size due to fewer and smaller cells compared with the wild type. The juvenile-to-adult transition is delayed, and proximal distal-Patterning is abnormal in this mutant. Differentiation of specialized cells such as those forming stomata and trichomes is incomplete. Analysis of nod-1 sectors suggests that NOD plays a cell-autonomous function in the leaf. We cloned nod positionally and found that it encodes CELL NUMBER REGULATOR13 (CNR13), the maize MID-COMPLEMENTING ACTIVITY homolog. CNR13/NOD is localized to the membrane and is enriched in dividing tissues. Transcriptome analysis of nod mutants revealed overrepresentation of cell wall, hormone metabolism, and defense gene categories. We propose that NOD coordinates cell activity in response to intrinsic and extrinsic cues.

  • the dominant mutant wavy auricle in blade1 disrupts Patterning in a lateral domain of the maize leaf
    Plant Physiology, 2004
    Co-Authors: Sarah Hake
    Abstract:

    Mature maize leaves have defined cell types along the proximal distal and medial lateral axes. The Patterning events that establish these axes take place early in leaf initiation. We have identified a new dominant mutation, Wavy auricle in blade1 (Wab1), which affects Patterning in both axes in a dose-dependent manner. Wab1 leaves are narrower than normal leaves and displace proximal tissues distally. We show that the proximal distal Patterning defects are not due to misexpression of knox genes. Genetic analyses suggest that the action of dominant Wab1 alleles is localized to a lateral domain of the leaf, located between the midvein and the marginal domain that is determined by narrow sheath function. Thus, Wab1 defines a knox-independent pathway that affects specification of the proximal distal axis of the maize leaf. We suggest that failure to elaborate a normal lateral domain in the Wab1 leaf is responsible for disrupting Patterning of the proximal distal axis.