scholarly journals Transient pluripotent cell populations during primitive ectoderm formation: correlation of in vivo and in vitro pluripotent cell development.

2002 ◽  
Vol 115 (2) ◽  
pp. 329-339 ◽  
Author(s):  
T. A. Pelton ◽  
S. Sharma ◽  
T. C. Schulz ◽  
J. Rathjen ◽  
P. D. Rathjen

Formation and differentiation of a pluripotent cell population is central to mammalian development, and the isolation, identification and manipulation of human pluripotent cells is predicted to be of therapeutic use. Within the early mammalian embryo, two distinct populations of pluripotent cells have been described: the inner cell mass (ICM), which differentiates to form a second pluripotent cell populations, the primitive ectoderm. Indirect evidence suggests the existence of temporally distinct intermediate pluripotent cell populations as primitive ectoderm is formed. We coupled an in vitro model of primitive ectoderm formation (the transition of embryonic stem cells to early primitive ectoderm-like (EPL) cells) with ddPCR-based techniques to identify three novel genes, Psc1, CRTR-1 and PRCE, that were expressed differently during pluripotent cell progression. Detailed mapping of these genes with Oct4, Rex1 and Fgf5 on pregastrulation embryos provided the first molecular evidence for the existence of successive, temporally distinct pluripotent cell populations in the embryo between the ICM and primitive ectoderm. No evidence was found for spatial heterogeneity within the Oct4+ pool. The transition between populations correlated with morphological or developmental alterations in pluripotent cells in vivo. Genes that are temporally expressed during pluripotent cell progression may provide an opportunity for molecular discrimination of pluripotent cells at different stages of maturation in vivo and an understanding of the cellular origins and properties of pluripotent cell lines isolated from diverse sources. Furthermore, the strong correlation of gene expression demonstrated between EPL cell formation in vitro and primitive ectoderm formation in vivo validates EPL cells as a model for primitive ectoderm, thereby providing a model system for the investigation of pluripotent differentiation and an opportunity for directed differentiation of pluripotent cells to therapeutically useful cell populations.

1998 ◽  
Vol 10 (8) ◽  
pp. 535 ◽  
Author(s):  
T. A. Pelton ◽  
M. D. Bettess ◽  
J. Lake ◽  
J. Rathjen ◽  
P. D. Rathjen

Early mammalian embryogenesis is characterised by the coordinated proliferation, differentiation, migration and apoptosis of a pluripotent cell pool that is able to give rise to extraembryonic lineages and all the cell types of the embryo proper. These cells retain pluripotent differentiation capability, defined in this paper as the ability to form all cell types of the embryo and adult, until differentiation into the three embryonic germ layers at gastrulation. Our understanding of pluripotent cell biology and molecular regulation has been hampered by the difficulties associated with experimental manipulation of these cells in vivo. However, a more detailed understanding of pluripotent cell behaviour is emerging from the application of molecular technologies to early mouse embryogenesis. The construction of mouse mutants by gene targeting, mapping of gene expression in vivo, and modelling of cell decisions in vitro are providing insight into the cellular origin, identity and action of key developmental regulators, and the nature of pluripotent cells themselves. In this review we discuss the properties of early embryonic pluripotent cells in vitro and in vivo, focusing on progression from inner cell mass (ICM) cells in the blastocyst to the onset of gastrulation.


2009 ◽  
Vol 21 (9) ◽  
pp. 63
Author(s):  
L. Ganeshan ◽  
C. O'Neill

The developmental viability of the early embryo requires the formation of the inner cell mass (ICM) at the blastocyst stage. The ICM contributes to all cell lineages within the developing embryo in vivo and the embryonic stem cell (ESC) lineage in vitro. Commitment of cells to the ICM lineage and its pluripotency requires the expression of core transcription factors, including Nanog and Pou5f1 (Oct4). Embryos subjected to culture in vitro commonly display a reduced developmental potential. Much of this loss of viability is due to the up-regulation of TRP53 in affected embryos. This study investigated whether increased TRP53 disrupts the expression of the pluripotency proteins and the normal formation of the ICM lineage. Mouse C57BL6 morulae and blastocysts cultured from zygotes (modHTF media) possessed fewer (p < 0.001) NANOG-positive cells than equivalent stage embryos collected fresh from the uterus. Blocking TRP53 actions by either genetic deletion (Trp53–/–) or pharmacological inhibition (Pifithrin-α) reversed this loss of NANOG expression during culture. Zygote culture also resulted in a TRP53-dependent loss of POU5F1-positive cells from resulting blastocysts. Drug-induced expression of TRP53 (by Nutlin-3) also caused a reduction in formation of pluripotent ICM. The loss of NANOG- and POU5F1-positive cells caused a marked reduction in the capacity of blastocysts to form proliferating ICM after outgrowth, and a consequent reduced ability to form ESC lines. These poor outcomes were ameliorated by the absence of TRP53, resulting in transmission distortion in favour of Trp53–/– zygotes (p < 0.001). This study shows that stresses induced by culture caused TRP53-dependent loss of pluripotent cells from the early embryo. This is a cause of the relative loss of viability and developmental potential of cultured embryos. The preferential survival of Trp53–/– embryos after culture due to their improved formation of pluripotent cells creates a genetic danger associated with these technologies.


2012 ◽  
Vol 24 (1) ◽  
pp. 220
Author(s):  
J. K. Park ◽  
H. S. Kim ◽  
K. J. Uh ◽  
K. H. Choi ◽  
H. M. Kim ◽  
...  

Since pluripotent cells were first derived from the inner cell mass (ICM) of mouse blastocysts, tremendous efforts have been made to establish embryonic stem cell (ESC) lines in several domestic species including the pig; however, authentic porcine ESCs have not yet been established. It has proven difficult to derive pluripotent cells of naïve state that represents full pluripotency, due to the frequent occurrence of spontaneous differentiation into an EpiSC-like state during culture in pigs. We have been able to derive EpiSC-like porcine embryonic stem cell (pESC) lines of a differentiated non-ES cell state from blastocyst stage porcine embryos of various origins, including in vitro fertilized (IVF), in vivo derived, IVF aggregated and parthenogenetic embryos. In addition, we have generated induced pluripotent stem cells (piPSCs) via plasmid transfection of reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) into porcine fibroblast cells. In this study, we analysed characteristics such as marker expression, pluripotency and the X chromosome inactivation (XCI) status of our EpiSC-like pESC lines along with our piPSC line. Our results show that these cell lines demonstrate the expression of genes associated with the Activin/Nodal and FGF2 pathways along with the expression of pluripotent markers Oct4, Sox2, Nanog, SSEA4, TRA 1-60 and TRA 1-81. Furthermore all of these cell lines showed in vitro differentiation potential; female XCI activity and a normal karyotype. Here we provide preliminary results that suggest that, as a nonpermissive species, the porcine species undergoes reprogramming into a primed state during the establishment of pluripotent stem cell lines. This work was supported by the BioGreen 21 Program (#20070401034031, PJ0081382011), Rural Development Administration, Republic of Korea.


2000 ◽  
Vol 113 (3) ◽  
pp. 555-566 ◽  
Author(s):  
J. Lake ◽  
J. Rathjen ◽  
J. Remiszewski ◽  
P.D. Rathjen

We have undertaken an in vitro differentiation analysis of two related, interconvertible, pluripotent cell populations, ES and early primitive ectoderm-like (EPL) cells, which are most similar in morphology, gene expression, cytokine responsiveness and differentiation potential in vivo to ICM and early primitive ectoderm, respectively. Pluripotent cells were differentiated in vitro as aggregates (embryoid bodies) and the appearance and abundance of cell lineages were assessed by morphology and gene expression. Differentiation in EPL cell embryoid bodies recapitulated normal developmental progression in vivo, but was advanced in comparison to ES cell embryoid bodies, with the rapid establishment of late primitive ectoderm specific gene expression, and subsequent loss of pluripotent cell markers. Nascent mesoderm was formed earlier and more extensively in EPL cell embryoid bodies, and resulted in the appearance of terminally differentiated mesodermal cell types prior to and at higher levels than in ES cell embryoid bodies. Nascent mesoderm in EPL cell embryoid bodies was not specified but could be programmed to alternative fates by the addition of exogenous factors. EPL cells remained competent to form primitive endoderm even though this is not the normal fate of primitive ectoderm in vivo. The establishment of primitive ectoderm-like gene expression and inability to participate in embryogenesis following blastocyst injection is therefore not directly associated with restriction in the ability to form extra-embryonic lineages. However, the EPL cell embryoid body environment did not support differentiation of primitive endoderm to visceral endoderm, indicating the lack of an inductive signal for visceral endoderm formation deduced to originate from the pluripotent cells. Similarly, the inability of EPL cells to form neurons when differentiated as embryoid bodies was attributable to perturbation of the differentiation environment and loss of inductive signals rather than a restricted differentiation potential. Reversion of EPL cells to ES cells was accompanied by restoration of ES cell-like differentiation potential. These results demonstrate the ability of pluripotent cells to adopt developmentally distinct, stable cell states with altered differentiation potentials.


2021 ◽  
Author(s):  
Giuliano Crispatzu ◽  
Rizwan Rehimi ◽  
Tomas Pachano ◽  
Tore Bleckwehl ◽  
Sara de la Cruz Molina ◽  
...  

AbstractPoised enhancers (PEs) represent a limited and genetically distinct set of distal regulatory elements that control the induction of developmental genes in a hierarchical and non-redundant manner. Before becoming activated in differentiating cells, PEs are already bookmarked in pluripotent cells with unique chromatin and topological features that could contribute to their privileged regulatory properties. However, since PEs were originally identified and subsequently characterized using embryonic stem cells (ESC) as an in vitro differentiation system, it is currently unknown whether PEs are functionally conserved in vivo. Here, we generate and mine various types of genomic data to show that the chromatin and 3D structural features of PEs are conserved among mouse pluripotent cells both in vitro and in vivo. We also uncovered that, in mouse pluripotent cells, the interactions between PEs and their bivalent target genes are globally controlled by the combined action of Polycomb, Trithorax and architectural proteins. Moreover, distal regulatory sequences located close to developmental genes and displaying the typical genetic (i.e. proximity to CpG islands) and chromatin (i.e. high accessibility and H3K27me3 levels) features of PEs are commonly found across vertebrates. These putative PEs show high sequence conservation, preferentially within specific vertebrate clades, with only a small subset being evolutionary conserved across all vertebrates. Lastly, by genetically disrupting evolutionary conserved PEs in mouse and chicken embryos, we demonstrate that these regulatory elements play essential and non-redundant roles during the induction of major developmental genes in vivo.


2005 ◽  
Vol 17 (2) ◽  
pp. 237 ◽  
Author(s):  
G. Lazzari ◽  
I. Lagutina ◽  
G. Crotti ◽  
P. Turini ◽  
S. Colleoni ◽  
...  

Attempts to derive true embryonic stem cells in large farm animals rely on the supply of good quality embryos. In these species, including the pig, pre-implantation-stage embryos can be produced by in vitro techniques from slaughterhouse ovaries. The objective of this study was to evaluate the ability of the inner cell masses (ICMs) of pig embryos, produced in vitro by different methods, to provide viable initial outgrowths of ICM cells that could be subsequently subcultured and expanded. Porcine oocytes were recovered from slaughtered donors and matured in vitro for 40–44 h in DMEM-F12 supplemented with 10% FCS, 0.05 IU LH and FSH (Menogon, Ferring, Milan, Italy), 0.3 mM cystine, 0.5 mM cysteamine, 50 ng/mL long-EGF, 100 ng/mL long-IGF1, 5 ng/mL bFGF (Sigma-Aldrich, Milan, Italy) in 5% CO2 at 38.5°C. Boar frozen-thawed semen was separated on a percoll gradient and diluted in TALP medium with PHE (penicillamine, hypotaurine, epinefrine) to a concentration ranging from 0.05 to 0.1 million sperm per mL. Oocytes were partially decumulated, co-incubated with sperm for 24 h, and finally denuded and cultured in microdrops of mSOFaa or NCSU. After cleavage, approximately half of the cleaved embryos were surgically transferred into the sheep oviduct for 4 days of in vivo culture and the remaining embryos were left in vitro in the two media. On Day +6 in vivo-cultured embryos were recovered from the sheep oviduct. Blastocyst formation and quality were comparatively evaluated in the three culture groups. Quality specifically referred to the morphology/size of the ICM according to the following criteria: ICM A (large/prominent), ICM B (flat), and ICM C (non-visible). All embryos with a visible inner cell mass were subjected to microdissection with needles to recover the ICMs that were then plated on feeder-layers of mitomycin-treated STO fibroblasts. Attachment and outgrowth was evaluated 48–72 h post-plating. Results are presented in Table 1. Our data indicate that in vivo culture of pig embryos in the sheep oviduct greatly enhance both blastocyst development and ICM quality. As a consequence the efficiency of outgrowth formation, following plating for ES cell derivation, was significantly higher with ICMs derived from IVM-IVF pig embryos cultured in vivo as compared to their in vitro-cultured counterparts. Within the two culture media tested for in vitro culture, SOF and NCSU, the rate of blastocyst formation was similar but the quality of SOF-cultured embryos is higher. In conclusion, embryo/ICM quality represents a fundamental requirement for the derivation of ES cell lines, and in vivo culture in the sheep oviduct provides the most efficient source of high quality IVM-IVF pig embryos. Table 1. Blastocyst development and ICM quality of in vitro-produced pig embryos This work was supported by the Istituto Superiore di Sanità, Programma Nazionale Cellule Staminali, Rome, Italy, grant No. CS 11.


2010 ◽  
Vol 88 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Guoliang Meng ◽  
Shiying Liu ◽  
Xiangyun Li ◽  
Roman Krawetz ◽  
Derrick E. Rancourt

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the blastocyst. Because of their ability to differentiate into a variety of cell types, human embryonic stem cells (hESCs) provide an unlimited source of cells for clinical medicine and have begun to be used in clinical trials. Presently, although several hundred hESC lines are available in the word, only few have been widely used in basic and applied research. More and more hESC lines with differing genetic backgrounds are required for establishing a bank of hESCs. Here, we report the first Canadian hESC lines to be generated from cryopreserved embryos and we discuss how we navigated through the Canadian regulatory process. The cryopreserved human zygotes used in this study were cultured to the blastocyst stage, and used to isolate ICM via microsurgery. Unlike previous microsurgery methods, which use specialized glass or steel needles, our method conveniently uses syringe needles for the isolation of ICM and subsequent hESC lines. ICM were cultured on MEF feeders in medium containing FBS or serum replacer (SR). Resulting outgrowths were isolated, cut into several cell clumps, and transferred onto fresh feeders. After more than 30 passages, the two hESC lines established using this method exhibited normal morphology, karyotype, and growth rate. Moreover, they stained positively for a variety of pluripotency markers and could be differentiated both in vitro and in vivo. Both cell lines could be maintained under a variety of culture conditions, including xeno-free conditions we have previously described. We suggest that this microsurgical approach may be conducive to deriving xeno-free hESC lines when outgrown on xeno-free human foreskin fibroblast feeders.


2011 ◽  
Vol 17 (4) ◽  
pp. 474-497 ◽  
Author(s):  
Monika Nowak-Imialek ◽  
Wilfried Kues ◽  
Joseph W. Carnwath ◽  
Heiner Niemann

AbstractPluripotent cells are unique because of their ability to differentiate into the cell lineages forming the entire organism. True pluripotent stem cells with germ line contribution have been reported for mice and rats. Human pluripotent cells share numerous features of pluripotentiality, but confirmation of their in vivo capacity for germ line contribution is impossible due to ethical and legal restrictions. Progress toward derivation of embryonic stem cells from domestic species has been made, but the derived cells were not able to produce germ line chimeras and thus are termed embryonic stem-like cells. However, domestic animals, in particular the domestic pig (Sus scrofa), are excellent large animals models, in which the clinical potential of stem cell therapies can be studied. Reprogramming technologies for somatic cells, including somatic cell nuclear transfer, cell fusion, in vitro culture in the presence of cell extracts, in vitro conversion of adult unipotent spermatogonial stem cells into germ line derived pluripotent stem cells, and transduction with reprogramming factors have been developed with the goal of obtaining pluripotent, germ line competent stem cells from domestic animals. This review summarizes the present state of the art in the derivation and maintenance of pluripotent stem cells in domestic animals.


Reproduction ◽  
2020 ◽  
Vol 159 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Wei Cui ◽  
Agnes Cheong ◽  
Yongsheng Wang ◽  
Yuran Tsuchida ◽  
Yong Liu ◽  
...  

Microspherule protein 1 (MCRS1, also known as MSP58) is an evolutionarily conserved protein that has been implicated in various biological processes. Although a variety of functions have been attributed to MCRS1 in vitro, mammalian MCRS1 has not been studied in vivo. Here we report that MCRS1 is essential during early murine development. Mcrs1 mutant embryos exhibit normal morphology at the blastocyst stage but cannot be recovered at gastrulation, suggesting an implantation failure. Outgrowth (OG) assays reveal that mutant blastocysts do not form a typical inner cell mass (ICM) colony, the source of embryonic stem cells (ESCs). Surprisingly, cell death and histone H4 acetylation analysis reveal that apoptosis and global H4 acetylation are normal in mutant blastocysts. However, analysis of lineage specification reveals that while the trophoblast and primitive endoderm are properly specified, the epiblast lineage is compromised and exhibits a severe reduction in cell number. In summary, our study demonstrates the indispensable role of MCRS1 in epiblast development during early mammalian embryogenesis.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Giuliano Crispatzu ◽  
Rizwan Rehimi ◽  
Tomas Pachano ◽  
Tore Bleckwehl ◽  
Sara Cruz-Molina ◽  
...  

AbstractPoised enhancers (PEs) represent a genetically distinct set of distal regulatory elements that control the expression of major developmental genes. Before becoming activated in differentiating cells, PEs are already bookmarked in pluripotent cells with unique chromatin and topological features that could contribute to their privileged regulatory properties. However, since PEs were originally characterized in embryonic stem cells (ESC), it is currently unknown whether PEs are functionally conserved in vivo. Here, we show that the chromatin and 3D structural features of PEs are conserved among mouse pluripotent cells both in vitro and in vivo. We also uncovered that the interactions between PEs and their target genes are globally controlled by the combined action of Polycomb, Trithorax and architectural proteins. Moreover, distal regulatory sequences located close to developmental genes and displaying the typical genetic (i.e. CpG islands) and chromatin (i.e. high accessibility and H3K27me3 levels) features of PEs are commonly found across vertebrates. These putative PEs show high sequence conservation within specific vertebrate clades, with only a few being evolutionary conserved across all vertebrates. Lastly, by genetically disrupting PEs in mouse and chicken embryos, we demonstrate that these regulatory elements play essential roles during the induction of major developmental genes in vivo.


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