The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Tamara L Western - One of the best experts on this subject based on the ideXlab platform.
-
atbxl1 encodes a bifunctional β d xylosidase α l arabinofuranosidase required for pectic arabinan modification in arabidopsis mucilage Secretory Cells
Plant Physiology, 2009Co-Authors: Andrej A Arsovski, Theodore M Popma, George W Haughn, Nicholas C Carpita, Maureen C Mccann, Tamara L WesternAbstract:Following pollination, the epidermal Cells of the Arabidopsis (Arabidopsis thaliana) ovule undergo a complex differentiation process that includes the synthesis and polar secretion of pectinaceous mucilage followed by the production of a secondary cell wall. Wetting of mature seeds leads to the rapid bursting of these mucilage Secretory Cells to release a hydrophilic gel that surrounds the seed and is believed to aid in seed hydration and germination. A novel mutant is identified where mucilage release is both patchy and slow and whose seeds display delayed germination. While developmental analysis of mutant seeds reveals no change in mucilage Secretory cell morphology, changes in monosaccharide quantities are detected, suggesting the mucilage release defect results from altered mucilage composition. Plasmid rescue and cloning of the mutant locus revealed a T-DNA insertion in AtBXL1, which encodes a putative bifunctional β-d-xylosidase/α-l-arabinofuranosidase that has been implicated as a β-d-xylosidase acting during vascular development. Chemical and immunological analyses of mucilage extracted from bxl1 mutant seeds and antibody staining of developing seed coats reveal an increase in (1→5)-linked arabinans, suggesting that BXL1 is acting as an α-l-arabinofuranosidase in the seed coat. This implication is supported by the ability to rescue mucilage release through treatment of bxl1 seeds with exogenous α-l-arabinofuranosidases. Together, these results suggest that trimming of rhamnogalacturonan I arabinan side chains is required for correct mucilage release and reveal a new role for BXL1 as an α-l-arabinofuranosidase acting in seed coat development.
-
Differentiation of Mucilage Secretory Cells of the Arabidopsis Seed Coat
Plant physiology, 2000Co-Authors: Tamara L Western, Debra J. Skinner, George W HaughnAbstract:In some plant species, including Arabidopsis, fertilization induces the epidermal Cells of the outer ovule integument to differentiate into a specialized seed coat cell type with a unique morphology and containing large quantities of polysaccharide mucilage (pectin). Such seed coat mucilage Cells are necessary for neither viability nor germination under normal laboratory conditions. Thus, the Arabidopsis seed coat offers a unique system with which to use genetics to identify genes controlling cell morphogenesis and complex polysaccharide biosynthesis and secretion. As a first step in the application of this system, we have used microscopy to investigate the structure and differentiation of Arabidopsis seed coat mucilage Cells, including cell morphogenesis and the synthesis, secretion, and extrusion of mucilage. During seed coat development in Arabidopsis, the epidermal Cells of the outer ovule integument grow and differentiate into Cells that produce large quantities of mucilage between the primary cell wall and plasma membrane. Concurrent with mucilage production, the cytoplasm is shaped into a column in the center of the cell. Following mucilage secretion the cytoplasmic column is surrounded by a secondary cell wall to form a structure known as the columella. Thus, differentiation of the seed coat mucilage Cells involves a highly regulated series of events including growth, morphogenesis, mucilage biosynthesis and secretion, and secondary cell wall synthesis.
George W Haughn - One of the best experts on this subject based on the ideXlab platform.
-
atbxl1 encodes a bifunctional β d xylosidase α l arabinofuranosidase required for pectic arabinan modification in arabidopsis mucilage Secretory Cells
Plant Physiology, 2009Co-Authors: Andrej A Arsovski, Theodore M Popma, George W Haughn, Nicholas C Carpita, Maureen C Mccann, Tamara L WesternAbstract:Following pollination, the epidermal Cells of the Arabidopsis (Arabidopsis thaliana) ovule undergo a complex differentiation process that includes the synthesis and polar secretion of pectinaceous mucilage followed by the production of a secondary cell wall. Wetting of mature seeds leads to the rapid bursting of these mucilage Secretory Cells to release a hydrophilic gel that surrounds the seed and is believed to aid in seed hydration and germination. A novel mutant is identified where mucilage release is both patchy and slow and whose seeds display delayed germination. While developmental analysis of mutant seeds reveals no change in mucilage Secretory cell morphology, changes in monosaccharide quantities are detected, suggesting the mucilage release defect results from altered mucilage composition. Plasmid rescue and cloning of the mutant locus revealed a T-DNA insertion in AtBXL1, which encodes a putative bifunctional β-d-xylosidase/α-l-arabinofuranosidase that has been implicated as a β-d-xylosidase acting during vascular development. Chemical and immunological analyses of mucilage extracted from bxl1 mutant seeds and antibody staining of developing seed coats reveal an increase in (1→5)-linked arabinans, suggesting that BXL1 is acting as an α-l-arabinofuranosidase in the seed coat. This implication is supported by the ability to rescue mucilage release through treatment of bxl1 seeds with exogenous α-l-arabinofuranosidases. Together, these results suggest that trimming of rhamnogalacturonan I arabinan side chains is required for correct mucilage release and reveal a new role for BXL1 as an α-l-arabinofuranosidase acting in seed coat development.
-
Differentiation of Mucilage Secretory Cells of the Arabidopsis Seed Coat
Plant physiology, 2000Co-Authors: Tamara L Western, Debra J. Skinner, George W HaughnAbstract:In some plant species, including Arabidopsis, fertilization induces the epidermal Cells of the outer ovule integument to differentiate into a specialized seed coat cell type with a unique morphology and containing large quantities of polysaccharide mucilage (pectin). Such seed coat mucilage Cells are necessary for neither viability nor germination under normal laboratory conditions. Thus, the Arabidopsis seed coat offers a unique system with which to use genetics to identify genes controlling cell morphogenesis and complex polysaccharide biosynthesis and secretion. As a first step in the application of this system, we have used microscopy to investigate the structure and differentiation of Arabidopsis seed coat mucilage Cells, including cell morphogenesis and the synthesis, secretion, and extrusion of mucilage. During seed coat development in Arabidopsis, the epidermal Cells of the outer ovule integument grow and differentiate into Cells that produce large quantities of mucilage between the primary cell wall and plasma membrane. Concurrent with mucilage production, the cytoplasm is shaped into a column in the center of the cell. Following mucilage secretion the cytoplasmic column is surrounded by a secondary cell wall to form a structure known as the columella. Thus, differentiation of the seed coat mucilage Cells involves a highly regulated series of events including growth, morphogenesis, mucilage biosynthesis and secretion, and secondary cell wall synthesis.
Despina Stamataki - One of the best experts on this subject based on the ideXlab platform.
-
Delta1 expression, cell cycle exit, and commitment to a specific Secretory fate coincide within a few hours in the mouse intestinal stem cell system. PLoS One. 2011; 6:e24484. [PubMed: 21915337
2016Co-Authors: Despina Stamataki, Maxine Holder, Christine Hodgetts, Rosemary Jeffery, Emma Nye, Spencer-dene Douglas J. WintonAbstract:The stem Cells of the small intestine are multipotent: they give rise, via transit-amplifying cell divisions, to large numbers of columnar absorptive Cells mixed with much smaller numbers of three different classes of Secretory Cells- mucus-secreting goblet Cells, hormone-secreting enteroendocrine Cells, and bactericide-secreting Paneth Cells. Notch signaling is known to control commitment to a Secretory fate, but why are the Secretory Cells such a small fraction of the population, and how does the diversity of Secretory cell types arise? Using the mouse as our model organism, we find that Secretory Cells, and only Secretory Cells, pass through a phase of strong expression of the Notch ligand Delta1 (Dll1). Onset of this Dll1 expression coincides with a block to further cell division and is followed in much less than a cell cycle time by expression of Neurog3 – a marker of enteroendocrine fate – or Gfi1 – a marker of goblet or Paneth cell fate. By conditional knock-out of Dll1, we confirm that Delta-Notch signaling controls Secretory commitment through lateral inhibition. We infer that Cells stop dividing as they become committed to a Secretory fate, while their neighbors continue dividing, explaining the final excess of absorptive over Secretory Cells. Our data rule out schemes in which Cells first become committed to be Secretory, and then diversify through subsequent cell divisions. A simple mathematical model shows how, instead, Notch signaling may simultaneously govern the commitment to be Secretory and the choice between alternative modes of secretor
-
delta1 expression cell cycle exit and commitment to a specific Secretory fate coincide within a few hours in the mouse intestinal stem cell system
PLOS ONE, 2011Co-Authors: Despina Stamataki, Christine Hodgetts, Rosemary Jeffery, Emma Nye, Maxine V Holder, Bradley Spencerdene, Douglas J Winton, Julian LewisAbstract:The stem Cells of the small intestine are multipotent: they give rise, via transit-amplifying cell divisions, to large numbers of columnar absorptive Cells mixed with much smaller numbers of three different classes of Secretory Cells - mucus-secreting goblet Cells, hormone-secreting enteroendocrine Cells, and bactericide-secreting Paneth Cells. Notch signaling is known to control commitment to a Secretory fate, but why are the Secretory Cells such a small fraction of the population, and how does the diversity of Secretory cell types arise? Using the mouse as our model organism, we find that Secretory Cells, and only Secretory Cells, pass through a phase of strong expression of the Notch ligand Delta1 (Dll1). Onset of this Dll1 expression coincides with a block to further cell division and is followed in much less than a cell cycle time by expression of Neurog3 – a marker of enteroendocrine fate – or Gfi1 – a marker of goblet or Paneth cell fate. By conditional knock-out of Dll1, we confirm that Delta-Notch signaling controls Secretory commitment through lateral inhibition. We infer that Cells stop dividing as they become committed to a Secretory fate, while their neighbors continue dividing, explaining the final excess of absorptive over Secretory Cells. Our data rule out schemes in which Cells first become committed to be Secretory, and then diversify through subsequent cell divisions. A simple mathematical model shows how, instead, Notch signaling may simultaneously govern the commitment to be Secretory and the choice between alternative modes of Secretory differentiation.
Mark Q Martindale - One of the best experts on this subject based on the ideXlab platform.
-
genomic analysis of the tryptome reveals molecular mechanisms of gland cell evolution
Evodevo, 2019Co-Authors: Leslie S Babonis, Joseph F Ryan, Camille Enjolras, Mark Q MartindaleAbstract:Background Understanding the drivers of morphological diversity is a persistent challenge in evolutionary biology. Here, we investigate functional diversification of Secretory Cells in the sea anemone Nematostella vectensis to understand the mechanisms promoting cellular specialization across animals.
Christophe Dunand - One of the best experts on this subject based on the ideXlab platform.
-
Arabidopsis seed mucilage Secretory Cells: Regulation and dynamics
Trends in Plant Science, 2015Co-Authors: Edith Francoz, Philippe Ranocha, Vincent Burlat, Christophe DunandAbstract:Seeds from various angiosperm species produce polysaccharide mucilage facilitating germination and, therefore, conferring major evolutionary advantages. The seed epidermal mucilage Secretory Cells (MSCs) undergo numerous tightly controlled changes of their extracellular matrixes (ECMs) throughout seed development. Recently, major progress based on the model species Arabidopsis thaliana was published, including the identification of 54 genes necessary for mucilage synthesis and release. Here, we review these genes that constitute the so-called 'MSC toolbox', within which transcription factors and proteins related to polysaccharide production, secretion, modification, and stabilization are the most abundant and belong to complex regulatory networks. We also discuss how seed coat 'omics data-mining, comparative genomics, and operon-like gene cluster studies will provide means to identify new members of the MSC toolbox.
