scholarly journals Chemokine-biased robust self-organizing polarization of migrating cells in vivo

2021 ◽  
Vol 118 (7) ◽  
pp. e2018480118
Author(s):  
Adan Olguin-Olguin ◽  
Anne Aalto ◽  
Benoît Maugis ◽  
Aleix Boquet-Pujadas ◽  
Dennis Hoffmann ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Leading Edge ◽  
Cell Polarization ◽  
In Vivo Model ◽  
Chemokine Signaling ◽  
Cell Front ◽  
Definition Of ◽  
Migrating Cells

To study the mechanisms controlling front-rear polarity in migrating cells, we used zebrafish primordial germ cells (PGCs) as an in vivo model. We find that polarity of bleb-driven migrating cells can be initiated at the cell front, as manifested by actin accumulation at the future leading edge and myosin-dependent retrograde actin flow toward the other side of the cell. In such cases, the definition of the cell front, from which bleb-inhibiting proteins such as Ezrin are depleted, precedes the establishment of the cell rear, where those proteins accumulate. Conversely, following cell division, the accumulation of Ezrin at the cleavage plane is the first sign for cell polarity and this aspect of the cell becomes the cell back. Together, the antagonistic interactions between the cell front and back lead to a robust polarization of the cell. Furthermore, we show that chemokine signaling can bias the establishment of the front-rear axis of the cell, thereby guiding the migrating cells toward sites of higher levels of the attractant. We compare these results to a theoretical model according to which a critical value of actin treadmilling flow can initiate a positive feedback loop that leads to the generation of the front-rear axis and to stable cell polarization. Together, our in vivo findings and the mathematical model, provide an explanation for the observed nonoriented migration of primordial germ cells in the absence of the guidance cue, as well as for the directed migration toward the region where the gonad develops.

scholarly journals Chemokine-biased robust self-organizing polarization of migrating cells in vivo

2019 ◽  
Author(s):  
Adan Olguin-Olguin ◽  
Anne Aalto ◽  
Benoît Maugis ◽  
Michal Reichman-Fried ◽  
Erez Raz
Keyword(s):  
Primordial Germ Cells ◽  
Critical Role ◽  
Cell Polarization ◽  
Cellular Functions ◽  
Motile Cells ◽  
Cell Front ◽  
Specific Proteins ◽  
Migrating Cells

The mechanisms facilitating the establishment of front-rear polarity in migrating cells are not fully understood, in particular in the context of bleb-driven directional migration. To gain further insight into this issue we utilized the migration of zebrafish primordial germ cells (PGCs) as an in vivo model. We followed the molecular and morphological cascade that converts apolar cells into polarized bleb-forming motile cells and analyzed the cross dependency among the different cellular functions we identified. Our results underline the critical role of antagonistic interactions between the front and the rear, in particular the role of biophysical processes including formation of barriers and transport of specific proteins to the back of the cell. These interactions direct the formation of blebs to a specific part of the cell that is specified as the cell front. In this way, spontaneous cell polarization facilitates non-directional cell motility and when biased by chemokine signals leads to migration towards specific locations.

scholarly journals E-cadherin focuses protrusion formation at the front of migrating cells by impeding actin flow

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Cecilia Grimaldi ◽  
Isabel Schumacher ◽  
Aleix Boquet-Pujadas ◽  
Katsiaryna Tarbashevich ◽  
Bart Eduard Vos ◽  
...  
Keyword(s):  
Primordial Germ Cells ◽  
Leading Edge ◽  
Cell Types ◽  
Restricted Area ◽  
Cell Front ◽  
Frictional Forces ◽  
Migrating Cells ◽  
E Cadherin

Abstract The migration of many cell types relies on the formation of actomyosin-dependent protrusions called blebs, but the mechanisms responsible for focusing this kind of protrusive activity to the cell front are largely unknown. Here, we employ zebrafish primordial germ cells (PGCs) as a model to study the role of cell-cell adhesion in bleb-driven single-cell migration in vivo. Utilizing a range of genetic, reverse genetic and mathematical tools, we define a previously unknown role for E-cadherin in confining bleb-type protrusions to the leading edge of the cell. We show that E-cadherin-mediated frictional forces impede the backwards flow of actomyosin-rich structures that define the domain where protrusions are preferentially generated. In this way, E-cadherin confines the bleb-forming region to a restricted area at the cell front and reinforces the front-rear axis of migrating cells. Accordingly, when E-cadherin activity is reduced, the bleb-forming area expands, thus compromising the directional persistence of the cells.

scholarly journals Dynamic filopodia are required for chemokine-dependent intracellular polarization during guided cell migration in vivo

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Dana Meyen ◽  
Katsiaryna Tarbashevich ◽  
Torsten U Banisch ◽  
Carolina Wittwer ◽  
Michal Reichman-Fried ◽  
...  
Keyword(s):  
Cell Migration ◽  
Single Cell ◽  
Primordial Germ Cells ◽  
Cell Polarization ◽  
In Vivo Model ◽  
Guidance Cue ◽  
Rac1 Activity ◽  
Cell Front ◽  
First Time

Cell migration and polarization is controlled by signals in the environment. Migrating cells typically form filopodia that extend from the cell surface, but the precise function of these structures in cell polarization and guided migration is poorly understood. Using the in vivo model of zebrafish primordial germ cells for studying chemokine-directed single cell migration, we show that filopodia distribution and their dynamics are dictated by the gradient of the chemokine Cxcl12a. By specifically interfering with filopodia formation, we demonstrate for the first time that these protrusions play an important role in cell polarization by Cxcl12a, as manifested by elevation of intracellular pH and Rac1 activity at the cell front. The establishment of this polarity is at the basis of effective cell migration towards the target. Together, we show that filopodia allow the interpretation of the chemotactic gradient in vivo by directing single-cell polarization in response to the guidance cue.

The active migration of Drosophila primordial germ cells

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3495-3503 ◽  
Author(s):  
M.K. Jaglarz ◽  
K.R. Howard
Keyword(s):  
Primary Culture ◽  
Germ Cells ◽  
Actin Polymerization ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Cell Polarization ◽  
Germ Cell Migration ◽  
Oriented Movement

We describe our analysis of primordial germ cell migration in Drosophila wild-type and mutant embryos using high resolution microscopy and primary culture in vitro. During migratory events the germ cells form transient interactions with each other and surrounding somatic cells. Both in vivo and in vitro they extend pseudopodia and the accompanying changes in the cytoskeleton suggest that actin polymerization drives these movements. These cellular events occur from the end of the blastoderm stage and are regulated by environmental cues. We show that the vital transepithelial migration allowing exit from the gut primordium and passage into the interior of the embryo is facilitated by changes in the structure of this epithelium. Migrating germ cells extend processes in different directions. This phenomenon also occurs in primary culture where the cells move in an unoriented fashion at substratum concentration-dependent rates. In vivo this migration is oriented leading germ cells to the gonadal mesoderm. We suggest that this guidance involves stabilization of states of an intrinsic cellular oscillator resulting in cell polarization and oriented movement.

scholarly journals In Vivo Transfer of Foreign DNA into Primordial Germ Cells (PGCs) of Chicken Embryos

1999 ◽  
Vol 12 (4) ◽  
pp. 520-524 ◽  
Author(s):  
K. Eguma ◽  
T. Soh ◽  
M. Hattori ◽  
N. Fujihara
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Chicken Embryos ◽  
Foreign Dna

Electron microscopic studies on the structure of motile primordial germ cells of Xenopus laevis in vitro

Development ◽  
1978 ◽  
Vol 46 (1) ◽  
pp. 119-133
Author(s):  
Janet Heasman ◽  
C. C. Wylie
Keyword(s):  
Xenopus Laevis ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Structural Features ◽  
Culture Conditions ◽  
Structural Basis ◽  
Electron Microscopic ◽  
Microscopic Studies

Primordial germ cells (PGCs) of Xenopus laevis have been isolated from early embryos and kept alive in vitro, in order to study the structural basis of their motility, using the transmission and scanning electron microscope. The culture conditions used mimicked as closely as possible the in vivo environment of migrating PGCs, in that isolated PGCs were seeded onto monolayers of amphibian mesentery cells. In these conditions we have demonstrated that: (a) No significant differences were found between the morphology of PGCs in vitro and in vivo. (b) Structural features involved in PGC movement in vitro include (i) the presence of a filamentous substructure, (ii) filopodial and blunt cell processes, (iii) cell surface specializations. These features are also characteristic of migratory PGCs studied in vivo. (c) PGCs in vitro have powers of invasion similar to those of migrating PGCs in vivo. They occasionally become completely surrounded by cells of the monolayer and, in this situation, bear striking resemblance to PGCs moving between mesentery cells to the site of the developing gonad in stage-44 tadpoles. We conclude that as far as it is possible to assess, the behaviour of isolated PGCs in these in vitro conditions mimics their activities in vivo. This allows us to study the ultrastructural basis of their migration.

140 LOCALIZATION OF PRIMORDIAL GERM CELLS IN DAY 21 BOVINE EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 188
Author(s):  
N. I. Alexopoulos ◽  
N. T. D'Cruz ◽  
P. Maddox-Hyttel
Keyword(s):  
Neural Tube ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Yolk Sac ◽  
Bovine Embryos ◽  
Surface Ectoderm ◽  
Oct4 Expression ◽  
Visceral Mesoderm ◽  
Stage Of Development

In most animal species, germ cell precursors, i.e., primordial germ cells (PGCs), arise from the epiblast and then migrate to the future gonadal ridge during development. At least in the mouse, PGCs may be cultured as embryonic germ cells that remain pluripotent. PGCs are the only cells in which OCT4 expression is maintained after gastrulation. The present study aimed at identifying the localization of PGCs in Day 21 in vivo-derived bovine embryos by immunohistochemical staining against OCT4. Six embryos were obtained after slaughter of superovulated heifers 21 days after insemination. The uterine tracts were flushed and embryos fixed, paraffin-embedded, and processed for immunohistochemistry. Embryos were sagitally sectioned, and selected serial sections were immunohistochemically stained for OCT4 to identify potential PGCs. Two embryos were at the neural groove stage. At this stage of development, the primitive gut had not yet been abstricted from the yolk sac and the allantois was not visible. A weak homogeneous OCT4 staining was localized to nuclei in a well-defined region of the epiblast, which was in the process of a gradual anterior to posterior differentiation into neural and surface ectoderm. Moreover, a strong OCT4 staining was localized to a few scattered cells found in the visceral mesoderm associated with the yolk sac in the region of the endoderm-hypoblast transition at some distance from the embryo proper. Four embryos were at the neural tube/somite stage. At this stage of development, the primitive gut had been defined and only the midgut was connected to the yolk sac. Furthermore, the allantois was visible as an anchor-shaped structure at the posterior end of the embryo. A strong OCT4 staining was found in nuclei of solitary cells in the endoderm and its associated visceral mesoderm of the ventral aspect of the mid and hindgut. The described OCT4 staining corresponds well with previous findings in the pig, in which presumptive PGCs are found in the endoderm epithelium during the neural groove stage. Later, during the early somite stages, they are localized in the endoderm and visceral mesoderm of the yolk sac and allantois, and in later somite stages, they are found in the developing genital ridge. This is, however, the first study to demonstrate the localization of these cells, at least by OCT4 staining, in bovine embryos at the neural groove and neural tube/somite stages.

scholarly journals Scribble, Lgl1, and myosin II form a complex in vivo to promote directed cell migration

2020 ◽  
Vol 31 (20) ◽  
pp. 2234-2248
Author(s):  
Maha Abedrabbo ◽  
Shoshana Ravid
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Myosin Ii ◽  
Leading Edge ◽  
Directed Cell Migration ◽  
Lethal Giant Larvae ◽  
And Migration ◽  
Migrating Cells

Here we show that Scribble (Scrib), Lethal giant larvae 1 (Lgl1), and myosin II form a complex in vivo and colocalize at the cell leading edge of migrating cells, and this colocalization is interdependent. Scrib and Lgl1 are required for proper cell adhesion, polarity, and migration.

scholarly journals Intracellular pH gradients in migrating cells

2011 ◽  
Vol 300 (3) ◽  
pp. C490-C495 ◽  
Author(s):  
Christine Martin ◽  
Stine F. Pedersen ◽  
Albrecht Schwab ◽  
Christian Stock
Keyword(s):  
Intracellular Ph ◽  
Cell Lines ◽  
Cell Polarization ◽  
Ph Gradients ◽  
Cell Protrusion ◽  
Spatial Asymmetry ◽  
Nhe1 Activity ◽  
Cell Front ◽  
Migrating Cells

Cell polarization along the axis of movement is required for migration. The localization of proteins and regulators of the migratory machinery to either the cell front or its rear results in a spatial asymmetry enabling cells to simultaneously coordinate cell protrusion and retraction. Protons might function as such unevenly distributed regulators as they modulate the interaction of focal adhesion proteins and components of the cytoskeleton in vitro. However, an intracellular pH (pHi) gradient reflecting a spatial asymmetry of protons has not been shown so far. One major regulator of pHi, the Na+/H+exchanger NHE1, is essential for cell migration and accumulates at the cell front. Here, we test the hypothesis that the uneven distribution of NHE1 activity creates a pHigradient in migrating cells. Using the pH-sensitive fluorescent dye BCECF, pHiwas measured in five cell lines (MV3, B16V, NIH3T3, MDCK-F1, EA.hy926) along the axis of movement. Differences in pHibetween the front and the rear end (ΔpHifront-rear) were present in all cell lines, and inhibition of NHE1 either with HOE642 or by absence of extracellular Na+caused the pHigradient to flatten or disappear. In conclusion, pHigradients established by NHE1 activity exist along the axis of movement.

Sign in / Sign up

Export Citation Format

Share Document