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Conservation of boundary extension mechanisms between plants and animals.

Mathur J - J. Cell Biol. (2005)

Bottom Line: Locomotion clearly sets plants and animals apart.However, recent studies in higher plants reveal cell-biological and molecular features similar to those observed at the leading edge of animal cells and suggest conservation of boundary extension mechanisms between motile animal cells and nonmotile plant cells.

View Article: PubMed Central - PubMed

Affiliation: Molecular Cell Biology Lab, Department of Plant Agriculture, University of Guelph, Guelph, Ontario N1G 2W1, Canada. jmathur@uoguelph.ca

ABSTRACT
Locomotion clearly sets plants and animals apart. However, recent studies in higher plants reveal cell-biological and molecular features similar to those observed at the leading edge of animal cells and suggest conservation of boundary extension mechanisms between motile animal cells and nonmotile plant cells.

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Schematic depiction of similar intracellular zonation at the leading edge of animal and plant cells. (A) A generalized motile animal cell with a rear end and leading edge. Enlarged view of the lamellipodium displays an organelle-free area near the absolute edge, followed by an actin-rich zone with dynamic, rapidly polymerizing actin. The microtubular zone usually lies behind the actin-packed zone, though pioneering microtubules make their way into the actin zone. Arrow shows the direction of membrane extension. (B) A seedling depicting two of the regions where “diffuse”-growing cells, such as hypocotyl cells and “tip”-growing cells such as root hairs are found. (C) Plant cells exhibiting diffuse growth have large expanding vacuoles that press the cytoplasm into a thin layer against the plasma membrane. A fine F-actin meshwork lying below the plasma membrane is followed by cytoplasmic microtubules on its inner side. Plant cell–specific cortical microtubule arrays have not been shown. Arrows suggest the multidirectional, diffuse nature of cell expansion. (D) Plant cells that extend by tip-focused growth are characterized by an apical accumulation of vesicles in an organelle-free zone. A fine actin meshwork with its distal region interspersed by dynamic microtubules follows. A vacuole occupies the rest of the nongrowing, mature part of the tubular cell. Arrow shows the direction of membrane extension. Note that the conserved region (blue speckled) of Rho-GTPase/actin interaction leading to a fine F-actin mesh in each cell type has been based on the localization of Rac in live animal cells (Kraynov et al., 2000) and AtROP localizations for different plant cells (Fu et al., 2001, 2002; Molendijk et al., 2001; Jones et al., 2002).
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fig1: Schematic depiction of similar intracellular zonation at the leading edge of animal and plant cells. (A) A generalized motile animal cell with a rear end and leading edge. Enlarged view of the lamellipodium displays an organelle-free area near the absolute edge, followed by an actin-rich zone with dynamic, rapidly polymerizing actin. The microtubular zone usually lies behind the actin-packed zone, though pioneering microtubules make their way into the actin zone. Arrow shows the direction of membrane extension. (B) A seedling depicting two of the regions where “diffuse”-growing cells, such as hypocotyl cells and “tip”-growing cells such as root hairs are found. (C) Plant cells exhibiting diffuse growth have large expanding vacuoles that press the cytoplasm into a thin layer against the plasma membrane. A fine F-actin meshwork lying below the plasma membrane is followed by cytoplasmic microtubules on its inner side. Plant cell–specific cortical microtubule arrays have not been shown. Arrows suggest the multidirectional, diffuse nature of cell expansion. (D) Plant cells that extend by tip-focused growth are characterized by an apical accumulation of vesicles in an organelle-free zone. A fine actin meshwork with its distal region interspersed by dynamic microtubules follows. A vacuole occupies the rest of the nongrowing, mature part of the tubular cell. Arrow shows the direction of membrane extension. Note that the conserved region (blue speckled) of Rho-GTPase/actin interaction leading to a fine F-actin mesh in each cell type has been based on the localization of Rac in live animal cells (Kraynov et al., 2000) and AtROP localizations for different plant cells (Fu et al., 2001, 2002; Molendijk et al., 2001; Jones et al., 2002).

Mentions: Though descriptions vary from cell to cell, the generalized leading edge of an amoeboid cell comprises a 2–5-μm-wide veil-like, organelle free, cytoplasmic extension called the lamellipodium. The leading edge has an actin-rich zone comprising of a fine F-actin mesh followed by a microtubule-rich region (Etienne-Manneville, 2004) (Fig. 1 A). A few pioneering microtubules do extend into the F-actin mesh (Small et al., 2002b; Raftopoulou and Hall, 2004).


Conservation of boundary extension mechanisms between plants and animals.

Mathur J - J. Cell Biol. (2005)

Schematic depiction of similar intracellular zonation at the leading edge of animal and plant cells. (A) A generalized motile animal cell with a rear end and leading edge. Enlarged view of the lamellipodium displays an organelle-free area near the absolute edge, followed by an actin-rich zone with dynamic, rapidly polymerizing actin. The microtubular zone usually lies behind the actin-packed zone, though pioneering microtubules make their way into the actin zone. Arrow shows the direction of membrane extension. (B) A seedling depicting two of the regions where “diffuse”-growing cells, such as hypocotyl cells and “tip”-growing cells such as root hairs are found. (C) Plant cells exhibiting diffuse growth have large expanding vacuoles that press the cytoplasm into a thin layer against the plasma membrane. A fine F-actin meshwork lying below the plasma membrane is followed by cytoplasmic microtubules on its inner side. Plant cell–specific cortical microtubule arrays have not been shown. Arrows suggest the multidirectional, diffuse nature of cell expansion. (D) Plant cells that extend by tip-focused growth are characterized by an apical accumulation of vesicles in an organelle-free zone. A fine actin meshwork with its distal region interspersed by dynamic microtubules follows. A vacuole occupies the rest of the nongrowing, mature part of the tubular cell. Arrow shows the direction of membrane extension. Note that the conserved region (blue speckled) of Rho-GTPase/actin interaction leading to a fine F-actin mesh in each cell type has been based on the localization of Rac in live animal cells (Kraynov et al., 2000) and AtROP localizations for different plant cells (Fu et al., 2001, 2002; Molendijk et al., 2001; Jones et al., 2002).
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Related In: Results  -  Collection

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fig1: Schematic depiction of similar intracellular zonation at the leading edge of animal and plant cells. (A) A generalized motile animal cell with a rear end and leading edge. Enlarged view of the lamellipodium displays an organelle-free area near the absolute edge, followed by an actin-rich zone with dynamic, rapidly polymerizing actin. The microtubular zone usually lies behind the actin-packed zone, though pioneering microtubules make their way into the actin zone. Arrow shows the direction of membrane extension. (B) A seedling depicting two of the regions where “diffuse”-growing cells, such as hypocotyl cells and “tip”-growing cells such as root hairs are found. (C) Plant cells exhibiting diffuse growth have large expanding vacuoles that press the cytoplasm into a thin layer against the plasma membrane. A fine F-actin meshwork lying below the plasma membrane is followed by cytoplasmic microtubules on its inner side. Plant cell–specific cortical microtubule arrays have not been shown. Arrows suggest the multidirectional, diffuse nature of cell expansion. (D) Plant cells that extend by tip-focused growth are characterized by an apical accumulation of vesicles in an organelle-free zone. A fine actin meshwork with its distal region interspersed by dynamic microtubules follows. A vacuole occupies the rest of the nongrowing, mature part of the tubular cell. Arrow shows the direction of membrane extension. Note that the conserved region (blue speckled) of Rho-GTPase/actin interaction leading to a fine F-actin mesh in each cell type has been based on the localization of Rac in live animal cells (Kraynov et al., 2000) and AtROP localizations for different plant cells (Fu et al., 2001, 2002; Molendijk et al., 2001; Jones et al., 2002).
Mentions: Though descriptions vary from cell to cell, the generalized leading edge of an amoeboid cell comprises a 2–5-μm-wide veil-like, organelle free, cytoplasmic extension called the lamellipodium. The leading edge has an actin-rich zone comprising of a fine F-actin mesh followed by a microtubule-rich region (Etienne-Manneville, 2004) (Fig. 1 A). A few pioneering microtubules do extend into the F-actin mesh (Small et al., 2002b; Raftopoulou and Hall, 2004).

Bottom Line: Locomotion clearly sets plants and animals apart.However, recent studies in higher plants reveal cell-biological and molecular features similar to those observed at the leading edge of animal cells and suggest conservation of boundary extension mechanisms between motile animal cells and nonmotile plant cells.

View Article: PubMed Central - PubMed

Affiliation: Molecular Cell Biology Lab, Department of Plant Agriculture, University of Guelph, Guelph, Ontario N1G 2W1, Canada. jmathur@uoguelph.ca

ABSTRACT
Locomotion clearly sets plants and animals apart. However, recent studies in higher plants reveal cell-biological and molecular features similar to those observed at the leading edge of animal cells and suggest conservation of boundary extension mechanisms between motile animal cells and nonmotile plant cells.

Show MeSH
Related in: MedlinePlus