The Experts below are selected from a list of 4908 Experts worldwide ranked by ideXlab platform

Amalya Hovhannisyan - One of the best experts on this subject based on the ideXlab platform.

  • Organ Patterning in the adult stage the role of wnt β catenin signaling in liver zonation and beyond
    Developmental Dynamics, 2009
    Co-Authors: Rolf Gebhardt, Amalya Hovhannisyan
    Abstract:

    Wnt/β-catenin signaling has been found to play key roles in metabolic zonation of adult liver, regeneration, and hepatocellular carcinogenesis. In this review, recent progress in this field is summarized, in particular the rapidly growing knowledge about the various interactions of β-catenin with many transcription factors involved in controlling metabolism. These interactions may provide the basis for understanding how the wide range of activities of Wnt/β-catenin signaling is differentially interpreted. Based on these results, a three-level mode for the molecular interpretation of β-catenin activity gradients in liver is proposed favoring cell differentiation, metabolic zonation, and proliferation. While derangement of the combinatorial interplay of the various transcription factors with β-catenin at the intermediary activity level may contribute to the development of metabolic diseases, extremely high activation of β-catenin may eventually lead to initiation and progression of hepatocellular tumors. Developmental Dynamics 239:45–55, 2010. © 2009 Wiley-Liss, Inc.

  • Organ Patterning in the adult stage: The role of Wnt/β‐catenin signaling in liver zonation and beyond
    Developmental Dynamics, 2009
    Co-Authors: Rolf Gebhardt, Amalya Hovhannisyan
    Abstract:

    Wnt/β-catenin signaling has been found to play key roles in metabolic zonation of adult liver, regeneration, and hepatocellular carcinogenesis. In this review, recent progress in this field is summarized, in particular the rapidly growing knowledge about the various interactions of β-catenin with many transcription factors involved in controlling metabolism. These interactions may provide the basis for understanding how the wide range of activities of Wnt/β-catenin signaling is differentially interpreted. Based on these results, a three-level mode for the molecular interpretation of β-catenin activity gradients in liver is proposed favoring cell differentiation, metabolic zonation, and proliferation. While derangement of the combinatorial interplay of the various transcription factors with β-catenin at the intermediary activity level may contribute to the development of metabolic diseases, extremely high activation of β-catenin may eventually lead to initiation and progression of hepatocellular tumors. Developmental Dynamics 239:45–55, 2010. © 2009 Wiley-Liss, Inc.

Rolf Gebhardt - One of the best experts on this subject based on the ideXlab platform.

  • Organ Patterning in the adult stage the role of wnt β catenin signaling in liver zonation and beyond
    Developmental Dynamics, 2009
    Co-Authors: Rolf Gebhardt, Amalya Hovhannisyan
    Abstract:

    Wnt/β-catenin signaling has been found to play key roles in metabolic zonation of adult liver, regeneration, and hepatocellular carcinogenesis. In this review, recent progress in this field is summarized, in particular the rapidly growing knowledge about the various interactions of β-catenin with many transcription factors involved in controlling metabolism. These interactions may provide the basis for understanding how the wide range of activities of Wnt/β-catenin signaling is differentially interpreted. Based on these results, a three-level mode for the molecular interpretation of β-catenin activity gradients in liver is proposed favoring cell differentiation, metabolic zonation, and proliferation. While derangement of the combinatorial interplay of the various transcription factors with β-catenin at the intermediary activity level may contribute to the development of metabolic diseases, extremely high activation of β-catenin may eventually lead to initiation and progression of hepatocellular tumors. Developmental Dynamics 239:45–55, 2010. © 2009 Wiley-Liss, Inc.

  • Organ Patterning in the adult stage: The role of Wnt/β‐catenin signaling in liver zonation and beyond
    Developmental Dynamics, 2009
    Co-Authors: Rolf Gebhardt, Amalya Hovhannisyan
    Abstract:

    Wnt/β-catenin signaling has been found to play key roles in metabolic zonation of adult liver, regeneration, and hepatocellular carcinogenesis. In this review, recent progress in this field is summarized, in particular the rapidly growing knowledge about the various interactions of β-catenin with many transcription factors involved in controlling metabolism. These interactions may provide the basis for understanding how the wide range of activities of Wnt/β-catenin signaling is differentially interpreted. Based on these results, a three-level mode for the molecular interpretation of β-catenin activity gradients in liver is proposed favoring cell differentiation, metabolic zonation, and proliferation. While derangement of the combinatorial interplay of the various transcription factors with β-catenin at the intermediary activity level may contribute to the development of metabolic diseases, extremely high activation of β-catenin may eventually lead to initiation and progression of hepatocellular tumors. Developmental Dynamics 239:45–55, 2010. © 2009 Wiley-Liss, Inc.

Kieran F Harvey - One of the best experts on this subject based on the ideXlab platform.

  • control of Organ growth by Patterning and hippo signaling in drosophila
    Cold Spring Harbor Perspectives in Biology, 2015
    Co-Authors: Kenneth D Irvine, Kieran F Harvey
    Abstract:

    Abstract Control of Organ size is of fundamental importance and is controlled by genetic, environmental, and mechanical factors. Studies in many species have pointed to the existence of both Organ-extrinsic and -intrinsic size-control mechanisms, which ultimately must coordinate to regulate Organ size. Here, we discuss Organ size control by Organ Patterning and the Hippo pathway, which both act in an Organ-intrinsic fashion. The influence of morphogens and other Patterning molecules couples growth and Patterning, whereas emerging evidence suggests that the Hippo pathway controls growth in response to mechanical stimuli and signals emanating from cell-cell interactions. Several points of cross talk have been reported between signaling pathways that control Organ Patterning and the Hippo pathway, both at the level of membrane receptors and transcriptional regulators. However, despite substantial progress in the past decade, key questions in the growth-control field remain, including precisely how and when Organ Patterning and the Hippo pathway communicate to control size, and whether these communication mechanisms are Organ specific or general. In addition, elucidating mechanisms by which Organ-intrinsic cues, such as Patterning factors and the Hippo pathway, interface with extrinsic cues, such as hormones to control Organ size, remain unresolved.

Jeff A. Long - One of the best experts on this subject based on the ideXlab platform.

  • Control of Arabidopsis apical–basal embryo polarity by antagonistic transcription factors
    Nature, 2010
    Co-Authors: Zachery R. Smith, Jeff A. Long
    Abstract:

    Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and Organ Patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical–basal axis. Recent work has identified the PLETHORA ( PLT ) genes as master regulators of basal/root fate^ 1 , 2 , 3 , whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS ( TPL ) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER ( HD-ZIP III ) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles. During embryogenesis in Arabidopsis , the shoot stem cell and root stem cell populations are established at the apical and basal pole, respectively. While, it is known that the PLETHORA genes function as master regulators of root fate, the regulators of shoot fate are unknown. Zachery Smith and Jeff Long now show that the Class III homeodomain-leucine zipper ( HD-ZIP III ) transcription factors are master regulators of embryonic apical shoot fate, and that they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. During development in Arabidopsis plants, populations of shoot stem cells and root stem cells are established at the embryo's apical and basal poles, respectively. PLETHORA genes are master regulators of root fate, but the regulators of shoot fate were unknown. Here, CLASS III HOMEODOMAIN-LEUCINE ZIPPER genes are identified as master regulators of apical/shoot fate, and are shown to be sufficient to convert the embryonic root pole into a second shoot pole.

  • control of arabidopsis apical basal embryo polarity by antagonistic transcription factors
    Nature, 2010
    Co-Authors: Zachery R. Smith, Jeff A. Long
    Abstract:

    During embryogenesis in Arabidopsis, the shoot stem cell and root stem cell populations are established at the apical and basal pole, respectively. While, it is known that the PLETHORA genes function as master regulators of root fate, the regulators of shoot fate are unknown. Zachery Smith and Jeff Long now show that the Class III homeodomain-leucine zipper (HD-ZIP III) transcription factors are master regulators of embryonic apical shoot fate, and that they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. During development in Arabidopsis plants, populations of shoot stem cells and root stem cells are established at the embryo's apical and basal poles, respectively. PLETHORA genes are master regulators of root fate, but the regulators of shoot fate were unknown. Here, CLASS III HOMEODOMAIN-LEUCINE ZIPPER genes are identified as master regulators of apical/shoot fate, and are shown to be sufficient to convert the embryonic root pole into a second shoot pole. Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and Organ Patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical–basal axis. Recent work has identified the PLETHORA (PLT) genes as master regulators of basal/root fate1,2,3, whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS (TPL) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles.

  • Control of Arabidopsis apical–basal embryo polarity by antagonistic transcription factors
    Nature, 2010
    Co-Authors: Zachery R. Smith, Jeff A. Long
    Abstract:

    Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and Organ Patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical-basal axis. Recent work has identified the PLETHORA (PLT) genes as master regulators of basal/root fate, whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS (TPL) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles.

Zachery R. Smith - One of the best experts on this subject based on the ideXlab platform.

  • Control of Arabidopsis apical–basal embryo polarity by antagonistic transcription factors
    Nature, 2010
    Co-Authors: Zachery R. Smith, Jeff A. Long
    Abstract:

    Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and Organ Patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical–basal axis. Recent work has identified the PLETHORA ( PLT ) genes as master regulators of basal/root fate^ 1 , 2 , 3 , whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS ( TPL ) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER ( HD-ZIP III ) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles. During embryogenesis in Arabidopsis , the shoot stem cell and root stem cell populations are established at the apical and basal pole, respectively. While, it is known that the PLETHORA genes function as master regulators of root fate, the regulators of shoot fate are unknown. Zachery Smith and Jeff Long now show that the Class III homeodomain-leucine zipper ( HD-ZIP III ) transcription factors are master regulators of embryonic apical shoot fate, and that they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. During development in Arabidopsis plants, populations of shoot stem cells and root stem cells are established at the embryo's apical and basal poles, respectively. PLETHORA genes are master regulators of root fate, but the regulators of shoot fate were unknown. Here, CLASS III HOMEODOMAIN-LEUCINE ZIPPER genes are identified as master regulators of apical/shoot fate, and are shown to be sufficient to convert the embryonic root pole into a second shoot pole.

  • control of arabidopsis apical basal embryo polarity by antagonistic transcription factors
    Nature, 2010
    Co-Authors: Zachery R. Smith, Jeff A. Long
    Abstract:

    During embryogenesis in Arabidopsis, the shoot stem cell and root stem cell populations are established at the apical and basal pole, respectively. While, it is known that the PLETHORA genes function as master regulators of root fate, the regulators of shoot fate are unknown. Zachery Smith and Jeff Long now show that the Class III homeodomain-leucine zipper (HD-ZIP III) transcription factors are master regulators of embryonic apical shoot fate, and that they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. During development in Arabidopsis plants, populations of shoot stem cells and root stem cells are established at the embryo's apical and basal poles, respectively. PLETHORA genes are master regulators of root fate, but the regulators of shoot fate were unknown. Here, CLASS III HOMEODOMAIN-LEUCINE ZIPPER genes are identified as master regulators of apical/shoot fate, and are shown to be sufficient to convert the embryonic root pole into a second shoot pole. Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and Organ Patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical–basal axis. Recent work has identified the PLETHORA (PLT) genes as master regulators of basal/root fate1,2,3, whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS (TPL) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles.

  • Control of Arabidopsis apical–basal embryo polarity by antagonistic transcription factors
    Nature, 2010
    Co-Authors: Zachery R. Smith, Jeff A. Long
    Abstract:

    Plants, similarly to animals, form polarized axes during embryogenesis on which cell differentiation and Organ Patterning programs are orchestrated. During Arabidopsis embryogenesis, establishment of the shoot and root stem cell populations occurs at opposite ends of an apical-basal axis. Recent work has identified the PLETHORA (PLT) genes as master regulators of basal/root fate, whereas the master regulators of apical/shoot fate have remained elusive. Here we show that the PLT1 and PLT2 genes are direct targets of the transcriptional co-repressor TOPLESS (TPL) and that PLT1/2 are necessary for the homeotic conversion of shoots to roots in tpl-1 mutants. Using tpl-1 as a genetic tool, we identify the CLASS III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP III) transcription factors as master regulators of embryonic apical fate, and show they are sufficient to drive the conversion of the embryonic root pole into a second shoot pole. Furthermore, genetic and misexpression studies show an antagonistic relationship between the PLT and HD-ZIP III genes in specifying the root and shoot poles.