scholarly journals Primordial germ cells do not migrate along nerve fibres in marmoset monkey and mouse embryos

Reproduction ◽  
2019 ◽  
pp. 101-109 ◽  
Author(s):  
E Wolff ◽  
M M Suplicki ◽  
R Behr
Keyword(s):  
Germ Cells ◽  
Peripheral Nerves ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Spatial Association ◽  
General Mechanism ◽  
Human Embryos ◽  
General Strategy ◽  
Marmoset Monkey ◽  
Specific Finding

Primordial germ cells (PGCs) are the embryonic precursors of spermatozoa and eggs. In mammals, PGCs arise early in embryonic development and migrate from their tissue of specification over a significant distance to reach their destinations, the genital ridges. However, the exact mechanism of translocation is still debated. A study on human embryos demonstrated a very close spatial association between migrating PGCs and developing peripheral nerves. Thus, it was proposed that peripheral nerves act as guiding structures for migrating PGCs. The goal of the present study is to test whether the association between nerves and PGCs may be a human-specific finding or whether this represents a general strategy to guide PGCs in mammals. Therefore, we investigated embryos of different developmental stages from the mouse and a non-human primate, the marmoset monkey (Callithrix jacchus), covering the phase from PGC emergence to their arrival in the gonadal ridge. Embryo sections were immunohistochemically co-stained for tubulin beta-3 chain (TUBB3) to visualise neurons and Octamer-binding protein 4 (OCT4 (POU5F1)) as marker for PGCs. The distance between PGCs and the nearest detectable neuron was measured. We discovered that in all embryos analysed of both species, the majority of PGCs (>94%) was found at a minimum distance of 50 µm to the closest neuron and, more importantly, that the PGCs had reached the gonads before any TUBB3 signal could be detected in the vicinity of the gonads. In conclusion, our data indicate that PGC migration along peripheral nerves is not a general mechanism in mammals.

scholarly journals Comparison of the Transcriptomic and Epigenetic Profiles of Gonadal Primordial Germ Cells of White Leghorn and Green-Legged Partridgelike Chicken Embryos

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1090
Author(s):  
Aleksandra Dunislawska ◽  
Maria Siwek ◽  
Katarzyna Stadnicka ◽  
Marek Bednarczyk
Keyword(s):  
Embryonic Development ◽  
Germ Cells ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Genetic Material ◽  
Reproductive Traits ◽  
Germline Stem Cells ◽  
White Leghorn ◽  
Methylation Analysis ◽  
Global Methylation

The Green-legged Partridgelike fowl is a native, dual-purpose Polish chicken. The White Leghorn has been intensively selected for several decades to mainly improve reproductive traits. Primordial germ cells (PGCs) represent the germline stem cells in chickens and are the only cells that can transfer the information stored in the genetic material from generation to generation. The aim of the study was to carry out a transcriptomic and an epigenetic comparison of the White Leghorn and Green-legged Partridgelike gonadal PGCs (gPGCs) at three developmental stages: days 4.5, 8, and 12 of the embryonic development. RNA and DNA were isolated from collected gPGCs. The RNA was further subjected to microarray analysis. An epigenetic analysis was performed based on the global methylation analysis and qMSP method for the particular silenced genes demonstrated in transcriptomic analysis. Statistically significant differences between the gPGCs from both breeds were detected on the day 8 of embryonic development. Global methylation analysis showed significant changes at the methylation level in the White Leghorn gPGCs on day 8 of embryonic development. The results suggest faster development of Green-legged Partridgelike embryos as compared to White Leghorn embryos. Changes in the levels of gene expression during embryonic development are determined by genetic and environmental factors, and this variability is influenced by breed and gender.

scholarly journals HIPSTR and thousands of lncRNAs are heterogeneously expressed in human embryos, primordial germ cells and stable cell lines

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Dinar Yunusov ◽  
Leticia Anderson ◽  
Lucas Ferreira DaSilva ◽  
Joanna Wysocka ◽  
Toshihiko Ezashi ◽  
...  
Keyword(s):  
Cell Lines ◽  
Germ Cells ◽  
Expression Patterns ◽  
Primordial Germ Cells ◽  
Population Level ◽  
Human Embryos ◽  
Cell Stage ◽  
Lncrna Gene ◽  
Stable Cell Lines ◽  
The Individual

Abstract Eukaryotic genomes are transcribed into numerous regulatory long non-coding RNAs (lncRNAs). Compared to mRNAs, lncRNAs display higher developmental stage-, tissue-, and cell-subtype-specificity of expression, and are generally less abundant in a population of cells. Despite the progress in single-cell-focused research, the origins of low population-level expression of lncRNAs in homogeneous populations of cells are poorly understood. Here, we identify HIPSTR (Heterogeneously expressed from the Intronic Plus Strand of the TFAP2A-locus RNA), a novel lncRNA gene in the developmentally regulated TFAP2A locus. HIPSTR has evolutionarily conserved expression patterns, its promoter is most active in undifferentiated cells, and depletion of HIPSTR in HEK293 and in pluripotent H1BP cells predominantly affects the genes involved in early organismal development and cell differentiation. Most importantly, we find that HIPSTR is specifically induced and heterogeneously expressed in the 8-cell-stage human embryos during the major wave of embryonic genome activation. We systematically explore the phenomenon of cell-to-cell variation of gene expression and link it to low population-level expression of lncRNAs, showing that, similar to HIPSTR, the expression of thousands of lncRNAs is more highly heterogeneous than the expression of mRNAs in the individual, otherwise indistinguishable cells of totipotent human embryos, primordial germ cells, and stable cell lines.

scholarly journals Bayesian inference of transcriptional branching identifies regulators of early germ cell development in humans

2017 ◽  
Author(s):  
Christopher A. Penfold ◽  
Anastasiya Sybirna ◽  
John Reid ◽  
Aracely Castillo Venzor ◽  
Elena Drousioti ◽  
...  
Keyword(s):  
Cell Fate ◽  
Germ Cells ◽  
Temporal Dynamics ◽  
Primordial Germ Cells ◽  
Series Data ◽  
Human Embryos ◽  
Marker Genes ◽  
Cell Fate Decisions ◽  
Stage Of Development

AbstractDuring embryonic development, cells undertake a series of fate decisions to form a complete organism comprised of various cell types, epitomising a branching process. A striking example of branching occurs in humans around the time of implantation, when primordial germ cells (PGCs), precursors of sperm and eggs, and somatic lineages are specified. Due to inaccessibility of human embryos at this stage of development, understanding the mechanisms of PGC specification remains difficult. The integrative modelling of single cell transcriptomics data from embryos and appropriate in vitro models should prove to be a useful resource for investigating this system, provided that the cells can be suitably ordered over a developmental axis. Unfortunately, most methods for inferring cell ordering were not designed with structured (time series) data in mind. Although some probabilistic approaches address these limitations by incorporating prior information about the developmental stage (capture time) of the cell, they do not allow the ordering of cells over processes with more than one terminal cell fate. To investigate the mechanisms of PGC specification, we develop a probabilistic pseudotime approach, branch-recombinant Gaussian process latent variable models (B-RGPLVMs), that use an explicit model of transcriptional branching in individual marker genes, allowing the ordering of cells over developmental trajectories with arbitrary numbers of branches. We use first demonstrate the advantage of our approach over existing pseudotime algorithms and subsequently use it to investigate early human development, as primordial germ cells (PGCs) and somatic cells diverge. We identify known master regulators of human PGCs, and predict roles for a variety of signalling pathways, transcription factors, and epigenetic modifiers. By concentrating on the earliest branched signalling events, we identified an antagonistic role for FGF receptor (FGFR) signalling pathway in the acquisition of competence for human PGC fate, and identify putative roles for PRC1 and PRC2 in PGC specification. We experimentally validate our predictions using pharmacological blocking of FGFR or its downstream effectors (MEK, PI3K and JAK), and demonstrate enhanced competency for PGC fate in vitro, whilst small molecule inhibition of the enzymatic component of PRC1/PRC2 reveals reduced capacity of cells to form PGCs in vitro. Thus, B-RGPLVMs represent a powerful and flexible data-driven approach for dissecting the temporal dynamics of cell fate decisions, providing unique insights into the mechanisms of early embryogenesis. Scripts relating to this analysis are available from: https://github.com/cap76/PGCPseudotime

scholarly journals When Regenerative Medicine Faces the Challenges of Reproductive Medicine: A Review Study on Recent Advances in the Strategies for Derivation of Gametes from Stem Cells

2020 ◽  
pp. 42-52
Author(s):  
María Gil Juliá ◽  
José V. Medrano
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Differentiation Strategy ◽  
Stem Cell Source ◽  
Potential Applications ◽  
Key Events

The murine model has allowed for the replication of all developmental stages of the mammalian germline in vitro, from embryonic stem cells to epiblast cells, primordial germ cells, and finally into functional haploid gametes. However, because of interspecies differences between mice and humans, these results are yet to be replicated in our species. Reports on the use of stem cells as a source of gametes, retrieved from public scientific databases, were analysed and classified according to the animal model used, the stem cell source and type, the differentiation strategy, and its potential application. This review offers a comprehensive compilation of recent publications of key events in the derivation of germ cells and gametogenesis in vitro, in both mice and human models. Additionally, studies intending to replicate the different stages in human cells in vitro, in order to obtain cells with a phenotype akin to functional human gametes, are also depicted. The authors present options for deriving gametes from stem cells in vitro and different reproductive options for specific groups of patients. Lastly, the potential applications of in vitro human gametogenesis are evaluated as well as the main limitations of the techniques employed. Even though it appears that we are far from being able to obtain gametes from pluripotent stem cells in vitro as a viable reproductive option, its current academic and clinical implications are extremely promising.

The Relation of the Interrenal Blastema to the Origin of the Somatic Tissues of the Gonad in Frog Tadpoles

Development ◽  
1954 ◽  
Vol 2 (4) ◽  
pp. 275-289
Author(s):  
Enrico Vannini ◽  
Armando Sabbadin
Keyword(s):  
Germ Cells ◽  
Developmental Stages ◽  
Primordial Germ Cells ◽  
Lateral Position ◽  
Medullary Tissue ◽  
Somatic Tissues ◽  
Frog Tadpoles ◽  
Dorsal Mesentery

As long ago as 1941 and 1942 one of us (Vannini) found in a series of developmental stages of frog tadpoles that the somatic components of the medullary tissue of the gonad have their origin in the interrenal blastema, and not, as was then generally supposed, in the mesonephric blastema. In the earliest stages examined at that time the gonad rudiment had the structure of ‘paired genital ridges’, lying at each side of the dorsal mesentery, and were furnished with primordial germ-cells, but were still without medullary tissue. The interrenal blastema occupied a median site in the tadpole's body, ventral to the aorta and dorsal to the two subcardinal veins. The mesonephric blastemata appeared distinctly separate from the interrenal rudiment, because they were situated in a more lateral position, contiguous with the Wolffian ducts. In later stages the medullary tissue (‘medulla’) penetrated within the genital ridges.

scholarly journals Erratum: Corrigendum: HIPSTR and thousands of lncRNAs are heterogeneously expressed in human embryos, primordial germ cells and stable cell lines

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Dinar Yunusov ◽  
Leticia Anderson ◽  
Lucas Ferreira DaSilva ◽  
Joanna Wysocka ◽  
Toshihiko Ezashi ◽  
...  
Keyword(s):  
Cell Lines ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Human Embryos ◽  
Stable Cell Lines

scholarly journals The reversible developmental unipotency of germ cells in chicken

Reproduction ◽  
2010 ◽  
Vol 139 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Jin Gyoung Jung ◽  
Young Mok Lee ◽  
Jin Nam Kim ◽  
Tae Min Kim ◽  
Ji Hye Shin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Developmental Stages ◽  
Production Systems ◽  
Primordial Germ Cells ◽  
Transmission Efficiency ◽  
Germline Transmission ◽  
Adult Testis

We recently developed bimodal germline chimera production approaches by transfer of primordial germ cells (PGCs) or embryonic germ cells (EGCs) into embryos and by transplantation of spermatogonial stem cells (SSCs) or germline stem cells (GSCs) into adult testes. This study was undertaken to investigate the reversible developmental unipotency of chicken germ cells using our established germline chimera production systems. First, we transferred freshly isolated SSCs from adult testis or in vitro cultured GSCs into stage X and stage 14–16 embryos, and we found that these transferred SSCs/GSCs could migrate to the recipient embryonic gonads. Of the 527 embryos that received SSCs or GSCs, 135 yielded hatchlings. Of 17 sexually mature males (35.3%), six were confirmed as germline chimeras through testcross analysis resulting in an average germline transmission efficiency of 1.3%. Second, PGCs/EGCs, germ cells isolated from embryonic gonads were transplanted into adult testes. The EGC transplantation induced germline transmission, whereas the PGC transplantation did not. The germline transmission efficiency was 12.5 fold higher (16.3 vs 1.3%) in EGC transplantation into testis (EGCs to adult testis) than that in SSC/GSC transfer into embryos (testicular germ cells to embryo stage). In conclusion, chicken germ cells from different developmental stages can (de)differentiate into gametes even after the germ cell developmental clock is set back or ahead. Use of germ cell reversible unipotency might improve the efficiency of germ cell-mediated germline transmission.

scholarly journals Dynamics of the transcriptome during chicken embryo development based on primordial germ cells

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Aleksandra Dunislawska ◽  
Agata Szczerba ◽  
Maria Siwek ◽  
Marek Bednarczyk
Keyword(s):  
Gene Expression ◽  
Embryo Development ◽  
Germ Cells ◽  
Developmental Stages ◽  
Single Cells ◽  
Primordial Germ Cells ◽  
Regulation Of Gene Expression ◽  
Cell Number ◽  
Early Developmental

Abstract Objective Regulation of gene expression during embryo development on the basis of migration of primordial germ cells (PGCs) in vivo has been rarely studied due to limited cell number and the necessity to isolate PGCs from a large number of embryos. Moreover, little is known about the comprehensive dynamics of the transcriptome in chicken PGCs during early developmental stages. The current study investigated transcriptome dynamics of chicken PGCs at key developmental stages: 4.5, 8 and 12 days of embryo incubation. PGCs were collected, and RNA was isolated using a commercial kit for single cells. The isolated RNA was subjected to microarray analysis (Agilent Technologies). Results Between 8 and 12 days of incubation, the highest number of genes was regulated. These data indicate that the most intense biological activity occurs between 8 and 12 days of embryo development. Heat map showed a significant decrease in gene expression on day 8, while it increased on day 12. The development of a precise method to isolate bird PGCs as well as the method to isolate RNA from single cells isolated from one embryo allows for early molecular analysis and detection of transcriptome changes during embryonic development.

A Quantitative Study of Primordial Germ Cells in the Male Rat

Development ◽  
1963 ◽  
Vol 11 (4) ◽  
pp. 715-740
Author(s):  
Heather M. Beaumont ◽  
Anita M. Mandl
Keyword(s):  
Quantitative Study ◽  
Germ Cells ◽  
Total Population ◽  
Developmental Stages ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Male Rat ◽  
Female Rat ◽  
Mitotic Proliferation ◽  
Prophase Of Meiosis

In mammals, as in other vertebrates, primordial germ cells arise extra-gonadally and migrate to the genital ridges (see Franchi, Mandl & Zuckerman, 1962). In the rat, the gonads undergo sex differentiation on the 14th day of gestation, i.e. some 2 days after the arrival of the primordial germ cells. In the female rat, the number of oögonia increases sharply, due to active mitotic proliferation, between the 14th and 18th day of gestation. Thereafter, the majority of germ cells enter the prophase of meiosis, and thus, by definition, become oöcytes. A large number of oöcytes undergo spontaneous degeneration, with the result that the total population decreases from a peak of about 75,000 (at 18·5 days) to about a third that number 2 days after birth. The decrease in the population is due to three distinct ‘waves’ of degeneration occurring at specific developmental stages (Beaumont & Mandl, 1962).

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