Studies on the locomotion of primordial germ cells from Xenopus laevis in vitro

Development ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 149-161
Author(s):  
Janet Heasman ◽  
Tim Mohun ◽  
C. C. Wylie
Keyword(s):  
Xenopus Laevis ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Cell Movement ◽  
Embryonic Cell ◽  
Artificial Substrates ◽  
Embryonic Cells ◽  
Adult Kidney

The mechanism of embryonic cell movement is poorly understood. Primordial germ cells (PGCs) of the anuran amphibian Xenopus laevis migrate individually from their site of determination in the embryonic endoderm to their site of differentiation, in the developing gonad. PGCs have been isolated during their migratory phase from tadpoles, and their movement studied in vitro on a variety of natural and artificial substrates. On all artificial substrates used, including acid-washed glass, tissue-culture plastics, poly-L-Iysine-coated glass, and collagen, the PGCs move by amoeboid extrusion of hemispherical lobopodia. Several considerations make it unlikely that this is the mechanism employed in vivo. On living cellular substrates, e.g. monolayers of Xenopus laevis embryonic cells, adult kidney cells, and adult mesentery cells, PGCs become firmly attached and undergo phases of elongation and contraction. They move by elongation, coupled with the extrusion of filopodia, followed by waves of contraction, and ultimately by retraction of the trailing end of the cell. Evidence is presented that this is the mode of locomotion normally employed by PGCs in vivo.

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.

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.

Selective decrease of chick embryonic primordial germ cells in vivo and in vitro by soft X-ray irradiation

2006 ◽  
Vol 95 (1-2) ◽  
pp. 67-74 ◽  
Author(s):  
Jeong M. Lim ◽  
Huck M. Kwon ◽  
Duk K. Kim ◽  
Jin N. Kim ◽  
Tae S. Park ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
X Ray

scholarly journals Visualization of X chromosome reactivation in mouse primordial germ cells in vivo

Biology Open ◽  
2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Yoshikazu Haramoto ◽  
Mino Sakata ◽  
Shin Kobayashi
Keyword(s):  
X Chromosome ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Cell ◽  
Epigenetic Memory ◽  
Genital Ridge ◽  
X Chromosomes ◽  
Hprt Locus ◽  
Mouse System

ABSTRACT X chromosome inactivation (XCI), determined during development, remains stable after embryonic cell divisions. However, primordial germ cells (PGCs) are exceptions in that XCI is reprogrammed and inactivated X chromosomes are reactivated. Although interactions between PGCs and somatic cells are thought to be important for PGC development, little is known about them. Here, we performed imaging of X chromosome reactivation (XCR) using the ‘Momiji’ mouse system, which can monitor the X chromosome's inactive and active states using two color fluorescence reporter genes, and investigated whether interactions would affect XCR in PGCs. Based on their expression levels, we found that XCR of the Pgk1 locus began at embryonic day (E)10.5 and was almost complete by E13.5. During this period, PGCs became distributed uniformly in the genital ridge, proliferated, and formed clusters; XCR progressed accordingly. In addition, XCR of the Pgk1 locus preceded that of the Hprt locus, indicating that the timing of epigenetic memory erasure varied according to the locus of each of these X-linked genes. Our results indicate that XCR proceeds along with the proliferation of PGCs clustered within the genital ridge. This article has an associated First Person interview with the first author of the paper.

The formation of the gonadal ridge in Xenopus laevis

Development ◽  
1976 ◽  
Vol 35 (1) ◽  
pp. 149-157
Author(s):  
C. C. Wylie ◽  
T. B. Roos
Keyword(s):  
Xenopus Laevis ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Time Lapse ◽  
Active Movement ◽  
Surface Phenomena ◽  
Cytoplasmic Processes

Previous studies have described the morphology, including the ultrastructure, of primordial germ cells (PGCs), and the cells with which they associate to form the gonadal ridge, in Xenopus laevis. In order to test their capacity for active movement we have studied single, isolated PGCs in vitro. Time-lapse studies of these cells reveal that they are motile, using broad cytoplasmic processes. The fact that these cells are very large and easy to manipulate in vitro makes them an attractive subject of study, particularly with respect to the mechanism of their movement and the surface phenomena which guide them to the site of the gonadal ridge.

scholarly journals Intense Expression of GFP Gene in Gonads of Chicken Embryos by Transfecting Circulating Primordial Germ Cells in vitro and in vivo

2007 ◽  
Vol 44 (4) ◽  
pp. 416-425 ◽  
Author(s):  
Mitsuru Naito ◽  
Takeo Minematsu ◽  
Takashi Harumi ◽  
Takashi Kuwana
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Chicken Embryos ◽  
Gfp Gene

scholarly journals Migratory and adhesive properties of Xenopus laevis primordial germ cells in vitro

Biology Open ◽  
2013 ◽  
Vol 2 (12) ◽  
pp. 1279-1287 ◽  
Author(s):  
A. Dzementsei ◽  
D. Schneider ◽  
A. Janshoff ◽  
T. Pieler
Keyword(s):  
Xenopus Laevis ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Adhesive Properties

scholarly journals In vivo and in vitro differentiation of male germ cells in the mouse

Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Orly Lacham-Kaplan
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Cellular Interactions ◽  
Germ Cell Differentiation

Primordial germ cells appear in the embryo at about day 7 after coitum. They proliferate and migrate towards the genital ridge. Once there, they undergo differentiation into germ stem cells, known as ‘A spermatogonia’. These cells are the foundation of spermatogenesis. A spermatogonia commit to spermatogenesis, stay undifferentiated or degenerate. The differentiation of primordial germ cells to migratory, postmigratory and germ stem cells is dependent on gene expression and cellular interactions. Some of the genes that play a crucial role in germ cell differentiation are Steel, c-Kit, VASA, DAZL, fragilis, miwi, mili, mil1 and mil2. Their expression is stage specific, therefore allowing solid identification of germ cells at different developmental phases. In addition to the expression of these genes, other markers associated with germ cell development are nonspecific alkaline phosphatase activity, the stage specific embryonic antigen, the transcription factor Oct3/4 and β1- and α6-integrins. Commitment of cells to primordial germ cells and to A spermatogonia is also dependent on induction by the bone morphogenetic protein (BMP)-4. With this knowledge, researchers were able to isolate germ stem cells from embryonic stem cell-derived embryoid bodies, and drive these into gametes either in vivo or in vitro. Although no viable embryos were obtained from these gametes, the prospects are that this goal is not too far from being accomplished.

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