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

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.

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 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.

scholarly journals Human Reproduction is Regulated by Retrotransposons derived from Ancient Hominin-Specific Viral Infections

2020 ◽  
Author(s):  
Yu Tao ◽  
Xiinyu Xiang ◽  
Fei-Man Hsu ◽  
Julien Pontis ◽  
Didier Trono ◽  
...  
Keyword(s):  
Germ Cells ◽  
Viral Infections ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Chromatin Accessibility ◽  
Dna Demethylation ◽  
Human Reproduction ◽  
Epigenetic Landscape

Abstract Germ cells are essential to pass DNA from one generation to the next. In human reproduction, germ cell development begins with the specification of primordial germ cells (PGCs) and a failure to specify PGCs leads to human infertility. Recent studies have revealed that the transcription factor network required for PGC specification has diverged in mammals, and this has a significant impact on our understanding of human reproduction. Here, we evaluated the emerging epigenetic landscape during hPGC specification using a combination of in vivo and in vitro analysis of hPGCs/hPGC-like cells (hPGCLCs) and human embryonic stem cells (hESCs). Our data reveals that hominid restricted Transposable Elements (TEs) partly derived from ancient viruses are pre-bound by the transcription factors TFAP2C and NANOG in undifferentiated hESCs, become transcriptionally induced during PGC specification and undergo dynamic epigenetic reprogramming leading to increased chromatin accessibility, localized DNA demethylation and establishment of broad peaks of H3K27ac. Using KRAB mediated CRISPRi we show that blocking this remodeling has a significant impact on hPGC specification. In summary, our data reveals that human reproduction requires the establishment of an epigenetic landscape during hPGC specification driven by the acquisition of hominid-specific TEs that were derived from ancient viral infections that entered the hominid germline less than 5 million years ago.

scholarly journals Invasive behaviour of mouse primordial germ cells in vitro

1986 ◽  
Vol 86 (1) ◽  
pp. 133-144
Author(s):  
D. Stott ◽  
C.C. Wylie
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Time Lapse ◽  
Cell Types ◽  
Fluorescent Labelling ◽  
Mouse Embryo Fibroblast ◽  
Substrate Interaction ◽  
Close Contacts

We have isolated migrating primordial germ cells (PGCs) from 10.5-day mouse embryos and studied their behaviour when cultured on a mouse embryo fibroblast (STO) cell line. Living and fixed PGCs were identified by fluorescent labelling with a monoclonal antibody specific for PGCs in the culture system used. The behaviour of the cells was studied using interference reflexion microscopy (IRM) and time-lapse video cinematography. The IRM pattern displayed by PGCs is typical of highly motile cell types, the cells lack focal contacts and possess large areas of close contacts indicative of weak membrane to substrate interaction. The PGCs exhibit relatively high rates of translocation and lack contact inhibition. They were observed to underlap STO cells in subconfluent monolayers and to penetrate between the cells of confluent monolayers, becoming located between the monolayer and its substrate. These observations support the hypothesis that migrating mouse PGCs are inherently motile and are able transiently to disrupt the adhesion of surrounding cells. These results suggest that PGCs actively migrate to the developing gonad in vivo.

scholarly journals Normal Embryonic and Germ Cell Development in Mice Lacking α1,3-Fucosyltransferase IX (Fut9) Which Show Disappearance of Stage-Specific Embryonic Antigen 1

2004 ◽  
Vol 24 (10) ◽  
pp. 4221-4228 ◽  
Author(s):  
Takashi Kudo ◽  
Mika Kaneko ◽  
Hiroko Iwasaki ◽  
Akira Togayachi ◽  
Shoko Nishihara ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Mouse Embryos ◽  
Lewis X ◽  
Strong Activity ◽  
Embryonic Antigen ◽  
Stage Specific Embryonic Antigen

ABSTRACT Stage-specific embryonic antigen 1 (SSEA-1), an antigenic epitope defined as a Lewis x carbohydrate structure, is expressed during the 8-cell to blastocyst stages in mouse embryos and in primordial germ cells, undifferentiated embryonic stem cells, and embryonic carcinoma cells. For many years, SSEA-1 has been implicated in the development of mouse embryos as a functional carbohydrate epitope in cell-to-cell interaction during morula compaction. In a previous study, α1,3-fucosyltransferase IX (Fut9) exhibited very strong activity for the synthesis of Lewis x compared to other α1,3-fucosyltransferases in an in vitro substrate specificity assay. Fut4 and Fut9 transcripts were expressed in mouse embryos. The Fut9 transcript was detected in embryonic-day-13.5 gonads containing primordial germ cells, but the Fut4 transcript was not. In order to identify the role of SSEA-1 and determine the key enzyme for SSEA-1 synthesis in vivo, we have generated Fut9-deficient (Fut9−/−) mice. Fut9−/− mice develop normally, with no gross phenotypic abnormalities, and are fertile. Immunohistochemical analysis revealed an absence of SSEA-1 expression in early embryos and primordial germ cells of Fut9−/− mice. Therefore, we conclude that expression of the SSEA-1 epitope in the developing mouse embryo is not essential for embryogenesis in vivo.

scholarly journals Nuclear Reprogramming in Mouse Primordial Germ Cells: Epigenetic Contribution

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Massimo De Felici
Keyword(s):  
Germ Cells ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Germ Cell Tumors ◽  
Cell Lineage ◽  
Epigenetic Modifications ◽  
Epigenetic Reprogramming ◽  
Nuclear Reprogramming

The unique capability of germ cells to give rise to a new organism, allowing the transmission of primary genetic information from generation to generation, depends on their epigenetic reprogramming ability and underlying genomic totipotency. Recent studies have shown that genome-wide epigenetic modifications, referred to as “epigenetic reprogramming”, occur during the development of the gamete precursors termed primordial germ cells (PGCs) in the embryo. This reprogramming is likely to be critical for the germ line development itself and necessary to erase the parental imprinting and setting the base for totipotency intrinsic to this cell lineage. The status of genome acquired during reprogramming and the associated expression of key pluripotency genes render PGCs susceptible to transform into pluripotent stem cells. This may occurin vivounder still undefined condition, and it is likely at the origin of the formation of germ cell tumors. The phenomenon appears to be reproduced under partly definedin vitroculture conditions, when PGCs are transformed into embryonic germ (EG) cells. In the present paper, I will try to summarize the contribution that epigenetic modifications give to nuclear reprogramming in mouse PGCs.

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