Tracing the origin of the placental trophoblast cells in mouse embryo development†

2019 ◽  
Vol 102 (3) ◽  
pp. 598-606
Author(s):  
Shanshan Guo ◽  
Xiuhong Cui ◽  
Xiangxiang Jiang ◽  
Shuguang Duo ◽  
Shiwen Li ◽  
...  

Abstract The placenta, which originates from the trophectoderm (TE), is the first organ to form during mammalian embryogenesis. Recent studies based on bioinformatics analysis have revealed that heterogeneous gene expression initiates cell-fate decisions and directs two distinct cell fates by modulating the balance of pluripotency and differentiation as early as the four-cell stage. However, direct developmental evidence to support this is still lacking. To address at which stage the cell fate of the TE and inner cell mass (ICM) is determined, in this study, we administered a microinjection of Cre mRNA into a single blastomere of the mTmG mouse at different cleavage stages before implantation to examine the distributions of the descendants of the single-labeled cell in the mouse fetus and the placenta at E12.5. We found that the descendants of the labeled cells at the two-cell stage contributed to both the placenta and the fetus. Notably, the derivatives of the labeled cells at the four-cell stage fell into three categories: (1) distributed in both embryonic and extraembryonic lineages, (2) distributed only in mouse placental trophoblast layers, or (3) distributed only in the lineage derived from the ICM. In addition, these results fell in line with single-cell studies focusing on gene expression patterns that characterize particular lineages within the blastocyst. In conclusion, this study shows that the four-cell blastomeres differ in their individual developmental properties insofar as they contribute to either or both the ICM and trophoblast fate.

Reproduction ◽  
2006 ◽  
Vol 132 (1) ◽  
pp. 45-57 ◽  
Author(s):  
N T Rogers ◽  
G Halet ◽  
Y Piao ◽  
J Carroll ◽  
M S H Ko ◽  
...  

A series of Ca2+ oscillations during mammalian fertilization is necessary and sufficient to stimulate meiotic resumption and pronuclear formation. It is not known how effectively development continues in the absence of the initial Ca2+ signal. We have triggered parthenogenetic egg activation with cycloheximide that causes no Ca2+ increase, with ethanol that causes a single large Ca2+ increase, or with Sr2+ that causes Ca2+ oscillations. Eggs were co-treated with cytochalasin D to make them diploid and they formed pronuclei and two-cell embryos at high rates with each activation treatment. However, far fewer of the embryos that were activated by cycloheximide reached the blastocyst stagecompared tothose activated by Sr2+ orethanol. Any cycloheximide-activated embryos that reached the blastocyst stage had a smaller inner cell mass number and a greater rate of apoptosis than Sr2+-activated embryos. The poor development of cycloheximide-activated embryos was due to the lack of Ca2+ increase because they developed to blastocyst stages at high rates when co-treated with Sr2+ or ethanol. Embryos activated by either Sr2+ or cycloheximide showed similar signs of initial embryonic genome activation (EGA) when measured using a reporter gene. However, microarray analysis of gene expression at the eight-cell stage showed that activation by Sr2+ leads to a distinct pattern of gene expression from that seen with embryos activated by cycloheximide. These data suggest that activation of mouse eggs in the absence of a Ca2+ signal does not affect initial parthenogenetic events, but can influence later gene expression and development.


2006 ◽  
Vol 18 (2) ◽  
pp. 231 ◽  
Author(s):  
F. Gandolfi ◽  
F. Cillo ◽  
S. Antonini ◽  
S. Colleoni ◽  
I. Lagutina ◽  
...  

Homeobox genes have been demonstrated to be important in patterning and lineage specification during early embryogenesis. Nanog belongs to the family of DNA-binding transcription factors and has been shown to maintain pluripotency of embryonic stem cells, both in murine and human. Par3 plays an essential role in determining cell fate of the early mouse embryo, leading to the generation of the inner cell mass and the trophectoderm. No information is available on these genes in the bovine; therefore, the aim of the present study was to identify and characterize Nanog and Par3 expression in bovine embryos. Oocytes recovered from slaughterhouse ovaries were matured for 22 h, fertilized in vitro and then cultured in mSOFaa medium. RNA was extracted from pools of five oocytes and embryos at different stages of development (2-, 4-, 8-, 16-cell, morula and blastocyst). It was then reverse transcribed, and PCR runs were carried out with primers specifically designed for Nanog and Par3, based on the sequence data bank available. The amplified products were separated on a 2% TAE agarose gel, purified, sequenced and aligned using Clustal W. Comparison of the bovine Nanog cDNA sequence (EMBL AM039957) with databases revealed a 84% degree of homology with the human, 97% with the mouse, and 82% with the goat genes. IVF bovine embryos express Nanog only upon genome activation, becoming detectable from the 8-cell stage onward indicating that Nanog is zygotically expressed in the bovine similar to what happens in mouse, pig and goat. Bovine Par3 cDNA sequence (EMBL AM039956) shows a high degree of homology with human (83%), mouse (81%), and rat (79%). Also Par3 is expressed only upon the maternal to embryonic transition (MET) at the 8-cell stage. As opposed to the expression patterns of other early embryo genes, like Oct-4 and Zar-1, Nanog and Par3 expression patterns in bovine embryos closely resemble those described in the mouse. Since both are absent in the ooplasm and before MET, they represent useful markers for genome activation. This work was supported by FIRB RBNE01HPMX, FIRST 2004 and ESF-EuroStells.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tim Liebisch ◽  
Armin Drusko ◽  
Biena Mathew ◽  
Ernst H. K. Stelzer ◽  
Sabine C. Fischer ◽  
...  

AbstractDuring the mammalian preimplantation phase, cells undergo two subsequent cell fate decisions. During the first decision, the trophectoderm and the inner cell mass are formed. Subsequently, the inner cell mass segregates into the epiblast and the primitive endoderm. Inner cell mass organoids represent an experimental model system, mimicking the second cell fate decision. It has been shown that cells of the same fate tend to cluster stronger than expected for random cell fate decisions. Three major processes are hypothesised to contribute to the cell fate arrangements: (1) chemical signalling; (2) cell sorting; and (3) cell proliferation. In order to quantify the influence of cell proliferation on the observed cell lineage type clustering, we developed an agent-based model accounting for mechanical cell–cell interaction, i.e. adhesion and repulsion, cell division, stochastic cell fate decision and cell fate heredity. The model supports the hypothesis that initial cell fate acquisition is a stochastically driven process, taking place in the early development of inner cell mass organoids. Further, we show that the observed neighbourhood structures can emerge solely due to cell fate heredity during cell division.


Development ◽  
2000 ◽  
Vol 127 (17) ◽  
pp. 3865-3876
Author(s):  
M.S. Rones ◽  
K.A. McLaughlin ◽  
M. Raffin ◽  
M. Mercola

Notch signaling mediates numerous developmental cell fate decisions in organisms ranging from flies to humans, resulting in the generation of multiple cell types from equipotential precursors. In this paper, we present evidence that activation of Notch by its ligand Serrate apportions myogenic and non-myogenic cell fates within the early Xenopus heart field. The crescent-shaped field of heart mesoderm is specified initially as cardiomyogenic. While the ventral region of the field forms the myocardial tube, the dorsolateral portions lose myogenic potency and form the dorsal mesocardium and pericardial roof (Raffin, M., Leong, L. M., Rones, M. S., Sparrow, D., Mohun, T. and Mercola, M. (2000) Dev. Biol., 218, 326–340). The local interactions that establish or maintain the distinct myocardial and non-myocardial domains have never been described. Here we show that Xenopus Notch1 (Xotch) and Serrate1 are expressed in overlapping patterns in the early heart field. Conditional activation or inhibition of the Notch pathway with inducible dominant negative or active forms of the RBP-J/Suppressor of Hairless [Su(H)] transcription factor indicated that activation of Notch feeds back on Serrate1 gene expression to localize transcripts more dorsolaterally than those of Notch1, with overlap in the region of the developing mesocardium. Moreover, Notch pathway activation decreased myocardial gene expression and increased expression of a marker of the mesocardium and pericardial roof, whereas inhibition of Notch signaling had the opposite effect. Activation or inhibition of Notch also regulated contribution of individual cells to the myocardium. Importantly, expression of Nkx2. 5 and Gata4 remained largely unaffected, indicating that Notch signaling functions downstream of heart field specification. We conclude that Notch signaling through Su(H) suppresses cardiomyogenesis and that this activity is essential for the correct specification of myocardial and non-myocardial cell fates.


2008 ◽  
Vol 28 (21) ◽  
pp. 6668-6680 ◽  
Author(s):  
Albertus T. J. Wierenga ◽  
Edo Vellenga ◽  
Jan Jacob Schuringa

ABSTRACT The level of transcription factor activity critically regulates cell fate decisions, such as hematopoietic stem cell (HSC) self-renewal and differentiation. We introduced STAT5A transcriptional activity into human HSCs/progenitor cells in a dose-dependent manner by overexpression of a tamoxifen-inducible STAT5A(1*6)-estrogen receptor fusion protein. Induction of STAT5A activity in CD34+ cells resulted in impaired myelopoiesis and induction of erythropoiesis, which was most pronounced at the highest STAT5A transactivation levels. In contrast, intermediate STAT5A activity levels resulted in the most pronounced proliferative advantage of CD34+ cells. This coincided with increased cobblestone area-forming cell and long-term-culture-initiating cell frequencies, which were predominantly elevated at intermediate STAT5A activity levels but not at high STAT5A levels. Self-renewal of progenitors was addressed by serial replating of CFU, and only progenitors containing intermediate STAT5A activity levels contained self-renewal capacity. By extensive gene expression profiling we could identify gene expression patterns of STAT5 target genes that predominantly associated with a self-renewal and long-term expansion phenotype versus those that identified a predominant differentiation phenotype.


2009 ◽  
Vol 21 (9) ◽  
pp. 21
Author(s):  
J. M. Campbell ◽  
I. Vassiliev ◽  
M. B. Nottle ◽  
M. Lane

Human ESCs are produced from embryos donated at the mid-stage of pre-implantation development. This cryostorage reduced viability. However, it has been shown that this can be improved by the addition of growth factors to culture medium. The aim of the present study was to examine whether the addition of insulin to embryo culture medium from the 8-cell stage of development increases the number of ES cell progenitor cells in the epiblast in a mouse model. In vivo produced mouse zygotes (C57Bl6 strain) were cultured in G1 medium for 48h to the 8-cell stage, followed by culture in G2 supplemented with insulin (0, 0.17, 1.7 and 1700pM) for 68h, at 37 o C , in 5% O2, 6%CO2, 89% N2 . The number of cells in the inner cell mass (ICM) and epiblast was determined by immunohistochemical staining for Oct4 and Nanog. ICM cells express Oct4, epiblast cells express both Oct4 and Nanog. The addition of insulin at the concentrations examined did not increase the ICM. However, at 1.7pM insulin increased the number of epiblast cells (6.6±0.5 cells vs 4.1±0.5, P=0.001) in the ICM, which increased the proportion of the ICM that was epiblast (38.9±3.7% compared to 25.8±3.4% in the control P=0.01). This indicates that the increase in the epiblast is brought about by a shift in cell fate as opposed to an increase in cell division. The effect of insulin on the proportion of cells in the epiblast was investigated using inhibitors of phosphoinositide3-kinase (PI3K) (LY294002, 50µM); one of insulin's main second messengers, and p53 (pifithrin-α, 30µg/ml); a pro-apoptotic protein inactivated by PI3K. Inhibition of PI3K eliminated the increase caused by insulin (4.5±0.3 cells versus 2.2±0.3 cells, P<0.001), while inhibition of p53 increased the epiblast cell number compared to the control (7.1±0.8 and 4.1±0.7 respectively P=0.001). This study shows that insulin increases epiblast cell number through the activation of PI3K and the inhibition of p53, and may be a strategy for improving ESC isolation from human embryos.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Jan J Zylicz ◽  
Maud Borensztein ◽  
Frederick CK Wong ◽  
Yun Huang ◽  
Caroline Lee ◽  
...  

Early mouse development is regulated and accompanied by dynamic changes in chromatin modifications, including G9a-mediated histone H3 lysine 9 dimethylation (H3K9me2). Previously, we provided insights into its role in post-implantation development (Zylicz et al., 2015). Here we explore the impact of depleting the maternally inherited G9a in oocytes on development shortly after fertilisation. We show that G9a accumulates typically at 4 to 8 cell stage to promote timely repression of a subset of 4 cell stage-specific genes. Loss of maternal inheritance of G9a disrupts the gene regulatory network resulting in developmental delay and destabilisation of inner cell mass lineages by the late blastocyst stage. Our results indicate a vital role of this maternally inherited epigenetic regulator in creating conducive conditions for developmental progression and on cell fate choices.


2012 ◽  
Vol 24 (1) ◽  
pp. 183 ◽  
Author(s):  
J. Teson ◽  
K. Lee ◽  
L. Spate ◽  
R. S. Prather

One of the key regulators of gene expression in mammals is DNA methylation. The Tet family (Tet1–3) is suggested to be involved in regulating the level of methylation by hydroxylating a methyl group from 5-methylcytosine to form 5-hydroxymethylcystosine. This hydroxylation alters the 3-dimensional structure of the DNA and results in altered gene expression. Previous studies conducted in the mouse have shown that Tet1 is important for inner cell mass specification by regulating the apparent level of methylation on a specific promoter region in blastocysts and Tet3 is related to the apparent paternal DNA demethylation after fertilization by hydroxylating the paternal genome. The objective of this study was to investigate the expression profile of the Tet family in porcine oocytes and pre-implantation-stage embryos derived from IVF and somatic cell nuclear transfer (SCNT). The RNA was isolated from donor cells, germinal vesicle (GV), MII and 2-cell and blastocyst stage embryos (20 oocytes or embryos per group). Levels of mRNA for each Tet gene were measured by quantitative real-time RT-PCR. The levels of each mRNA transcript were compared to YWHAG, a housekeeping gene that shows a constant level of expression throughout pre-implantation embryo development and normalized to the GV stage. The analysis was repeated with 3 biological replications and 2 experimental replications. Differences in gene expression were compared by ANOVA and P < 0.05 was considered significant. No difference was found in the levels of the Tet family members between GV and MII stage oocytes. Compared with GV stage oocytes, up-regulation of Tet3 at the 2-cell stage was detected in both IVF and SCNT embryos, 4.7 and 6.2 fold, respectively. A dramatic increase in Tet1 was also observed at the blastocyst stage in IVF and SCNT embryos when compared with the GV stage, 65.7 and 79.7 fold increases, respectively. Interestingly, the level of Tet3 was down-regulated in blastocyst embryos at a 25 or more fold decrease compared with GV. The level of Tet2 remained constant throughout embryo development. Embryos (2-cell and blastocyst) compared from IVF and SCNT showed no difference in Tet expression levels. Donor cells had significantly lower levels of Tet2 and Tet3 when compared with GV. Our results indicate that the Tet family shows a dynamic expression profile during porcine pre-implantation embryo development. High expression of Tet3 in 2-cell stage embryos suggests its importance during the post-activation demethylation process. The increase of Tet1 transcript in blastocysts suggests that Tet1 is involved in regulating the type of methylation at the blastocyst stage. These results are consistent with results from previous mouse studies. There was no misregulated expression of the Tet family in SCNT embryos compared with IVF embryos, thus indicating successful reprogramming of the Tet family after SCNT. Lower levels of Tet2 and Tet3 would indicate that Tet1 is important for maintaining type of methylation in donor cells. This is the first report on the profile of the Tet family during porcine pre-implantation embryo development and further studies are needed to clarify their role during this stage.


1997 ◽  
Vol 8 (2) ◽  
pp. 303-312 ◽  
Author(s):  
S A Louis ◽  
G B Spiegelman ◽  
G Weeks

It has been previously demonstrated that the expression of an activated rasD gene in wild-type Dictyostelium cells results in formation of aggregates with multitips, instead of the normal single tips, and a block in further development. In an attempt to better understand the role of activated RasD development, we examined cell-type-specific gene expression in a strain stably expressing high levels of RasD[G12T]. We found that the expression of prestalk cell-specific genes ecmA and tagB was markedly enhanced, whereas the expression of the prespore cell-specific gene cotC was reduced to very low levels. When the fate of cells in the multitipped aggregate was monitored with an ecmA/lacZ fusion, it appeared that most of the cells eventually adopted prestalk gene expression characteristics. When mixtures of the [G12T]rasD cells and Ax3 cells were induced to differentiate, chimeric pseudoplasmodia were not formed. Thus, although the [G12T]rasD transformant had a marked propensity to form prestalk cells, it could not supply the prestalk cell population when mixed with wild-type cells. Both stalk and spore cell formation occurred in low cell density monolayers of the [G12T]rasD strain, suggesting that at least part of the inhibition of stalk and spore formation during multicellular development involved inhibitory cell interactions within the cell mass. Models for the possible role of rasD in development are discussed.


2020 ◽  
Author(s):  
Anna Pretschner ◽  
Sophie Pabel ◽  
Markus Haas ◽  
Monika Heiner ◽  
Wolfgang Marwan

AbstractDynamics of cell fate decisions are commonly investigated by inferring temporal sequences of gene expression states by assembling snapshots of individual cells where each cell is measured once. Ordering cells according to minimal differences in expression patterns and assuming that differentiation occurs by a sequence of irreversible steps, yields unidirectional, eventually branching Markov chains with a single source node. In an alternative approach, we used multinucleate cells to follow gene expression taking true time series. Assembling state machines, each made from single-cell trajectories, gives a network of highly structured Markov chains of states with different source and sink nodes including cycles, revealing essential information on the dynamics of regulatory events. We argue that the obtained networks depict aspects of the Waddington landscape of cell differentiation and characterize them as reachability graphs that provide the basis for the reconstruction of the underlying gene regulatory network.


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