Limits...
Rac-GTPases Regulate Microtubule Stability and Axon Growth of Cortical GABAergic Interneurons.

Tivodar S, Kalemaki K, Kounoupa Z, Vidaki M, Theodorakis K, Denaxa M, Kessaris N, de Curtis I, Pachnis V, Karagogeos D - Cereb. Cortex (2014)

Bottom Line: We show that in the absence of both Rac proteins, the embryonic migration of medial ganglionic eminence-derived interneurons is further impaired.In addition, Rac1/Rac3-deficient interneurons show gross cytoskeletal defects in vitro, with the length of their leading processes significantly reduced and a clear multipolar morphology.We propose that in the absence of Rac1/Rac3, cortical interneurons fail to migrate tangentially towards the pallium due to defects in actin and microtubule cytoskeletal dynamics.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece.

No MeSH data available.


Related in: MedlinePlus

Morphological defects of Rac1/Rac3-deficient MGE-derived cells. The morphology of control (A; C, C′) and double-mutant (B; D, D′) interneurons was visualized by scanning electron microscopy (SEM) and YFP/Phalloidin immunohistochemistry in MGE explant cultures. These assays revealed the splitting of the leading process and the increase in neurite numbers in YFP+ double-mutant cells. Cortactin and YFP immunostaining of control (E, E′) and double-mutant (F, F′) interneurons revealed the absence of lamellipodia in the YFP+ double-mutant cells. MGE-derived cells cultured for 5 DIV from control (G, G′) and double-mutant (H, H′) E13.5 embryos were immunostained with anti-GFP and anti-Tau1 antibodies (G–H′). Tau1 immunostaining (G′, H′) shows signal in all neurites of double-mutant cells in contrast to the single neurite of control cells. Scale bars: A and B: 5 μm; C and D: 50 μm; C′ and D′: 10 μm; E, F, E′, and F′: 20 μm; G, H, G′, and H′: 75 μm.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4537417&req=5

BHU037F5: Morphological defects of Rac1/Rac3-deficient MGE-derived cells. The morphology of control (A; C, C′) and double-mutant (B; D, D′) interneurons was visualized by scanning electron microscopy (SEM) and YFP/Phalloidin immunohistochemistry in MGE explant cultures. These assays revealed the splitting of the leading process and the increase in neurite numbers in YFP+ double-mutant cells. Cortactin and YFP immunostaining of control (E, E′) and double-mutant (F, F′) interneurons revealed the absence of lamellipodia in the YFP+ double-mutant cells. MGE-derived cells cultured for 5 DIV from control (G, G′) and double-mutant (H, H′) E13.5 embryos were immunostained with anti-GFP and anti-Tau1 antibodies (G–H′). Tau1 immunostaining (G′, H′) shows signal in all neurites of double-mutant cells in contrast to the single neurite of control cells. Scale bars: A and B: 5 μm; C and D: 50 μm; C′ and D′: 10 μm; E, F, E′, and F′: 20 μm; G, H, G′, and H′: 75 μm.

Mentions: To further study the morphological defects of Rac1/Rac3-deficient interneurons and their intrinsic or extrinsic nature, we grew ventrally aggregated YFP+ cells from the MGE on collagen-coated coverslips. We processed these cultures either for scanning electron microscopy (SEM) analysis or for immunostaining for various cytoskeletal markers. High magnification analysis of these cultures using SEM strongly indicated the presence of morphological defects in the absence of both Rac proteins (Fig. 5A,B). These morphological defects included an increased number of neurites per cell, splitting of the leading processes and absence of an obvious axonal growth cone. Immunostaining for YFP and Phalloidin to visualize the actin cytoskeleton in similar cultures (Fig. 5C–D′), revealed extensive splitting of the leading processes of double mutant cells after 2 DIV, a phenotype that is not frequently observed in control or single Rac1 conditional mutants (Fig. 5C′,D′ and Fig. 6A).Figure 5.


Rac-GTPases Regulate Microtubule Stability and Axon Growth of Cortical GABAergic Interneurons.

Tivodar S, Kalemaki K, Kounoupa Z, Vidaki M, Theodorakis K, Denaxa M, Kessaris N, de Curtis I, Pachnis V, Karagogeos D - Cereb. Cortex (2014)

Morphological defects of Rac1/Rac3-deficient MGE-derived cells. The morphology of control (A; C, C′) and double-mutant (B; D, D′) interneurons was visualized by scanning electron microscopy (SEM) and YFP/Phalloidin immunohistochemistry in MGE explant cultures. These assays revealed the splitting of the leading process and the increase in neurite numbers in YFP+ double-mutant cells. Cortactin and YFP immunostaining of control (E, E′) and double-mutant (F, F′) interneurons revealed the absence of lamellipodia in the YFP+ double-mutant cells. MGE-derived cells cultured for 5 DIV from control (G, G′) and double-mutant (H, H′) E13.5 embryos were immunostained with anti-GFP and anti-Tau1 antibodies (G–H′). Tau1 immunostaining (G′, H′) shows signal in all neurites of double-mutant cells in contrast to the single neurite of control cells. Scale bars: A and B: 5 μm; C and D: 50 μm; C′ and D′: 10 μm; E, F, E′, and F′: 20 μm; G, H, G′, and H′: 75 μm.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4537417&req=5

BHU037F5: Morphological defects of Rac1/Rac3-deficient MGE-derived cells. The morphology of control (A; C, C′) and double-mutant (B; D, D′) interneurons was visualized by scanning electron microscopy (SEM) and YFP/Phalloidin immunohistochemistry in MGE explant cultures. These assays revealed the splitting of the leading process and the increase in neurite numbers in YFP+ double-mutant cells. Cortactin and YFP immunostaining of control (E, E′) and double-mutant (F, F′) interneurons revealed the absence of lamellipodia in the YFP+ double-mutant cells. MGE-derived cells cultured for 5 DIV from control (G, G′) and double-mutant (H, H′) E13.5 embryos were immunostained with anti-GFP and anti-Tau1 antibodies (G–H′). Tau1 immunostaining (G′, H′) shows signal in all neurites of double-mutant cells in contrast to the single neurite of control cells. Scale bars: A and B: 5 μm; C and D: 50 μm; C′ and D′: 10 μm; E, F, E′, and F′: 20 μm; G, H, G′, and H′: 75 μm.
Mentions: To further study the morphological defects of Rac1/Rac3-deficient interneurons and their intrinsic or extrinsic nature, we grew ventrally aggregated YFP+ cells from the MGE on collagen-coated coverslips. We processed these cultures either for scanning electron microscopy (SEM) analysis or for immunostaining for various cytoskeletal markers. High magnification analysis of these cultures using SEM strongly indicated the presence of morphological defects in the absence of both Rac proteins (Fig. 5A,B). These morphological defects included an increased number of neurites per cell, splitting of the leading processes and absence of an obvious axonal growth cone. Immunostaining for YFP and Phalloidin to visualize the actin cytoskeleton in similar cultures (Fig. 5C–D′), revealed extensive splitting of the leading processes of double mutant cells after 2 DIV, a phenotype that is not frequently observed in control or single Rac1 conditional mutants (Fig. 5C′,D′ and Fig. 6A).Figure 5.

Bottom Line: We show that in the absence of both Rac proteins, the embryonic migration of medial ganglionic eminence-derived interneurons is further impaired.In addition, Rac1/Rac3-deficient interneurons show gross cytoskeletal defects in vitro, with the length of their leading processes significantly reduced and a clear multipolar morphology.We propose that in the absence of Rac1/Rac3, cortical interneurons fail to migrate tangentially towards the pallium due to defects in actin and microtubule cytoskeletal dynamics.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece.

No MeSH data available.


Related in: MedlinePlus