Metabolic and developmental responses of preimplantation embryos to platelet activating factor (PAF)

1992 ◽  
Vol 4 (4) ◽  
pp. 387 ◽  
Author(s):  
JP Ryan ◽  
C O'Neill ◽  
AJ Ammit ◽  
CG Roberts
Keyword(s):  
Culture Media ◽  
Platelet Activating Factor ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Mouse Bioassay ◽  
Limiting Factor ◽  
Cell Stage ◽  
Culture In Vitro ◽  
Developmental Potential

Platelet activating factor (PAF) is an ether phospholipid produced by preimplantation embryos of a number of species. Production of PAF by embryos has been measured by detecting thrombocytopenia in a splenectomized mouse bioassay, platelet aggregation bioassays in vitro and a specific radioimmunoassay. Production is highly variable and is adversely affected by culture in vitro. It has, however, been correlated with morphology, development rates in vitro and the pregnancy potential of embryos following transfer. Investigations using PAF-antagonists have established an essential role for PAF in early pregnancy. Together with studies that have shown PAF to have direct effects on embryonic metabolism during culture in vitro, these observations suggest that PAF acts as an embryonic autocoid. Hence, a major site of action for embryo-derived PAF in vivo is the embryo itself. Supplementation of embryo culture media with PAF had no effect on the rate of development in vitro of 2-cell mouse embryos through to the blastocyst stage. However, PAF increased cell numbers of blastocysts cultured from the 2-cell stage and the mitotic index of embryos at both the 8-cell and blastocyst stages. Supplementation of culture media with PAF has also been shown to increase the implantation potential of both mouse and human embryos cultured in vitro. In the mouse, the effect of PAF in enhancing implantation rates was most evident when the developmental potential of untreated embryos was suboptimal. These observations suggest that the production of embryo-derived PAF is one limiting factor in maintaining the viability of embryos cultured in vitro.

Intracellular localisation of platelet-activating factor during mammalian embryo development in vitro: a comparison of cattle, mouse and human

2019 ◽  
Vol 31 (4) ◽  
pp. 658
Author(s):  
L. T. M. Vandenberghe ◽  
B. Heindryckx ◽  
K. Smits ◽  
M. Popovic ◽  
K. Szymanska ◽  
...  
Keyword(s):  
Platelet Activating Factor ◽  
Preimplantation Embryos ◽  
Mammalian Embryo ◽  
Developmental Potential ◽  
Nuclear Envelope Breakdown ◽  
Cytosolic Phospholipase ◽  
Carrier Molecule ◽  
Development In Vitro ◽  
Intracellular Localisation

Platelet-activating factor (PAF) is a well-known marker for embryo quality and viability. For the first time, we describe an intracellular localisation of PAF in oocytes and embryos of cattle, mice and humans. We showed that PAF is represented in the nucleus, a signal that was lost upon nuclear envelope breakdown. This process was confirmed by treating the embryos with nocodazole, a spindle-disrupting agent that, as such, arrests the embryo in mitosis, and by microinjecting a PAF-specific antibody in bovine MII oocytes. The latter resulted in the absence of nuclear PAF in the pronuclei of the zygote and reduced further developmental potential. Previous research indicates that PAF is released and taken up from the culture medium by preimplantation embryos invitro, in which bovine serum albumin (BSA) serves as a crucial carrier molecule. In the present study we demonstrated that nuclear PAF does not originate from an extracellular source because embryos cultured in polyvinylpyrrolidone or BSA showed similar levels of PAF in their nuclei. Instead, our experiments indicate that cytosolic phospholipase A2 (cPLA2) is likely to be involved in the intracellular production of PAF, because treatment with arachidonyl trifluoromethyl ketone (AACOCF3), a specific cPLA2 inhibitor, clearly lowered PAF levels in the nuclei of bovine embryos.

Expression of mRNA encoding leukaemia inhibitory factor (LIF) and its receptor (LIFRβ) in buffalo preimplantation embryos produced in vitro: markers of successful embryo implantation

Zygote ◽  
2012 ◽  
Vol 21 (2) ◽  
pp. 203-213 ◽  
Author(s):  
S. Eswari ◽  
G. Sai Kumar ◽  
G. Taru Sharma
Keyword(s):  
Culture Media ◽  
Total Cell ◽  
Inhibitory Factor ◽  
Preimplantation Embryos ◽  
Leukaemia Inhibitory Factor ◽  
Hatching Rate ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Significant Difference

SummaryThe objective of this study was to evaluate the effect of supplementation of recombinant leukaemia inhibitory factor (LIF) in culture media on blastocyst development, total cell number and blastocyst hatching rates and the reverse transcription-polymerase chain reaction analysis of preimplantation buffalo embryos to determine whether they contain the LIF-encoding mRNA and its beta receptor (LIFRβ) genes in different stages of preimplantation buffalo embryos. Cumulus–oocyte complexes retrieved from slaughterhouse buffalo ovaries were matured in vitro and fertilized using frozen buffalo semen. After 18 h of co-incubation with sperm, the presumptive zygotes were cultured in modified synthetic oviductal fluid without (control) or with rhLIF (100 ng/ml). There was no significant difference in the overall cleavage rate up to morula stage however the development of blastocysts, hatching rate and total cell numbers were significantly higher in the LIF-treated group than control. Transcripts for LIFRβ were detected from immature, in vitro-matured oocytes and in the embryos up to blastocyst stage, while transcripts for the LIF were detected from 8–16-cell stage up to blastocyst, which indicated that embryo-derived LIF can act in an autocrine manner on differentiation process and blastocyst formation. This study indicated that the addition of LIF to the embryo culture medium improved development of blastocysts, functional (hatching) and morphological (number of cells) quality of the blastocysts produced in vitro. The stage-specific expression pattern of LIF and LIFRβ mRNA transcripts in buffalo embryos indicated that LIF might play an important role in the preimplantation development and subsequent implantation of buffalo embryos.

scholarly journals Transcription of paternal Y-linked genes in the human zygote as early as the pronucleate stage

Zygote ◽  
1994 ◽  
Vol 2 (4) ◽  
pp. 281-287 ◽  
Author(s):  
Asangla Ao ◽  
Robert P. Erickson ◽  
Robert M.L. Winston ◽  
Alan H Handysude
Keyword(s):  
Mammalian Species ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Cell Stage ◽  
Gonad Differentiation ◽  
Embryonic Genome ◽  
Human Preimplantation Embryos

SummaryGlobal activation of the embryonic genome occurs at the 4– to 8–cell stage in human embryos and is marked by continuation of early cleavage divisions in the presence of transcriptional inhibitors. Here we demonstrate, using recerse transcripase–polymerase chin reaction (Rt–PCR), the presence of transcripts for wo paternal Y chromosomal genes, ZFY and SRY in human preimplantation embryos. ZFY transcripts were detected as early as the pronucleate stage, 20–24 h post-insemination In vitro and at intermediate stages up to the blastocyst stage. SRY Transcripts were also detected at 2–cell to blastocyos observed in many mammalian species focuses attention on the role of events in six determination prior to gonad differentiation.

2-Cell Stage Arrest in Human Embryos: Incidence and Developmental Potential in Different Culture Media

2000 ◽  
Vol 74 (3) ◽  
pp. S222 ◽  
Author(s):  
L. Chi ◽  
E. DeJesus ◽  
A. Adler ◽  
J.A. Grifo ◽  
A.S. Berkeley ◽  
...  
Keyword(s):  
Culture Media ◽  
Human Embryos ◽  
Cell Stage ◽  
Developmental Potential

Actions of platelet activating factor (PAF) on gametes and embryos: clinical aspects

1992 ◽  
Vol 4 (4) ◽  
pp. 399 ◽  
Author(s):  
IL Pike ◽  
AJ Ammit ◽  
C O'Neill
Keyword(s):  
Platelet Activating Factor ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Clinical Aspects ◽  
Embryo Viability ◽  
Human Follicular Fluid ◽  
Body Tissues ◽  
Paf Antagonists ◽  
Human Ivf

Platelet activating factor (PAF) is a phospholipid widespread in body tissues. Previous reviews have discussed its production by preimplantation embryos and the evidence implicating it as an autocrine mediator in aspects of gamete and embryo physiology. Human spermatozoa contain variable amounts of PAF, the amount contained depending on the source and method of preparation of the sperm. Incubation of human sperm with PAF tends to increase their forward velocity, especially in samples with slow motility. PAF treatment causes an increase in the proportion of acrosome-reacted sperm and in their ability to penetrate both zona-free hamster ova and cervical mucus. PAF has been found in human follicular fluid at ovulation. A role for PAF in ovulation has been suggested, because PAF antagonists reduce the rate of ovulation in rats. In some studies, modest improvements to mouse in vitro fertilization (IVF) rates have been achieved with PAF supplementation of media under specific conditions. Furthermore, in the rabbit and mouse, PAF antagonists have been reported to inhibit fertilization in vivo and in vitro respectively. However, addition of PAF to human IVF medium, but only at the time of insemination and fertilization, had no effect on either fertilization or pregnancy rates. Sensitive bio- and immuno-assays have shown that PAF is secreted by human embryos into their fluid milieu. PAF secretion by these zygotes during culture, although markedly variable, has been correlated with the achievement of pregnancy and pregnancy outcome. Although the secretion of PAF by the mouse embryo decreases during culture in vitro, exogenous PAF enhances embryo viability during culture. Similarly, culture of human zygotes in PAF-supplemented medium prior to embryo transfer significantly increases the chance of achieving pregnancy. Both the implantation and live-birth rates are increased in human IVF by addition of PAF to the medium.

scholarly journals Dynamics and clinical relevance of maternal mRNA clearance during the oocyte-to-embryo transition in humans

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qian-Qian Sha ◽  
Wei Zheng ◽  
Yun-Wen Wu ◽  
Sen Li ◽  
Lei Guo ◽  
...  
Keyword(s):  
Mrna Decay ◽  
Meiotic Spindle ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Developmental Potential ◽  
Maternal Mrna ◽  
Before And After ◽  
Maternal Transcripts ◽  
Human Preimplantation Embryos

Abstract Maternal mRNA clearance is an essential process that occurs during maternal-to-zygotic transition (MZT). However, the dynamics, functional importance, and pathological relevance of maternal mRNA decay in human preimplantation embryos have not yet been analyzed. Here we report the zygotic genome activation (ZGA)-dependent and -independent maternal mRNA clearance processes during human MZT and demonstrate that subgroups of human maternal transcripts are sequentially removed by maternal (M)- and zygotic (Z)-decay pathways before and after ZGA. Key factors regulating M-decay and Z-decay pathways in mouse have similar expression pattern during human MZT, suggesting that YAP1-TEAD4 transcription activators, TUT4/7-mediated mRNA 3ʹ-oligouridylation, and BTG4/CCR4-NOT-induced mRNA deadenylation may also be involved in the regulation of human maternal mRNA stability. Decreased expression of these factors and abnormal accumulation of maternal transcripts are observed in the development-arrested embryos of patients who seek assisted reproduction. Defects of M-decay and Z-decay are detected with high incidence in embryos that are arrested at the zygote and 8-cell stages, respectively. In addition, M-decay is not found to be affected by maternal TUBB8 mutations, although these mutations cause meiotic cell division defects and zygotic arrest, which indicates that mRNA decay is regulated independent of meiotic spindle assembly. Considering the correlations between maternal mRNA decay defects and early developmental arrest of in vitro fertilized human embryos, M-decay and Z-decay pathway activities may contribute to the developmental potential of human preimplantation embryos.

170 EXPRESSION PATTERN OF THE Sox2 GENE IN BOVINE OOCYTES AND IN VITRO-DERIVED EMBRYOS

2008 ◽  
Vol 20 (1) ◽  
pp. 165 ◽  
Author(s):  
T. A. L. Brevini ◽  
S. Antonini ◽  
F. Cillo ◽  
G. Pennarossa ◽  
S. Colleoni ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Inner Cell Mass ◽  
False Negative ◽  
Cell Mass ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Developmental Potential ◽  
Sox2 Expression ◽  
Bovine Oocytes

Sox2 is a member of the Sox (SRY-related HMGbox) family. It acts to maintain developmental potential and marks the pluripotent lineage of the early mouse embryo; in particular, as in the case of Oct-4 and Nanog, Sox2 is expressed specifically in the inner cell mass (ICM) and in the epiblast of this species. Moreover, it plays an important role in the transcription network that maintains stem cell pluripotency, interacting with other factors such as Oct-4 and Nanog. Little information is available on this gene in bovine; therefore aims of the present study were: a) to identify and characterize the Sox2 expression profile in bovine oocytes and preimplantation embryos; and b) to investigate its expression pattern in ICM and trophectoderm (TE). Bovine oocytes and embryos were obtained by in vitro maturation and fertilization; blastocysts at Day 7 post-insemination underwent microsurgery to separate TE from ICM. mRNA was isolated from 3 pools, each consisting of 5 MII oocytes, 2-, 4-, 8-, and 16-cell embryos, morulae, blastocysts, ICMs, and TEs. Semi-quantitative analysis of Sox2 expression was performed in the exponential phase of PCR amplification using rabbit globin as exogenous control. Data were analyzed with one-way ANOVA, followed by multiple pairwise comparisons with Tukey test (SigmaStat 2.03, SPSS, Inc., Chicago, IL, USA). Values are presented as mean � SEM and differences of P ≤ 0.05 are considered significant. In order to rule out false negative results, PCR amplifications of isolated ICMs and TEs were extended to the plateau phase. Fragment identity was confirmed by sequencing. Comparison of bovine Sox2 cDNA sequence (EMBL AM774325) with databases revealed a 98%, 93%, and 87% homology with sheep, human, and mouse, respectively. Sox2 mRNA was detectable in oocytes as well as in embryos at the different developmental stages analyzed. Semi-quantitative expression studies revealed that Sox2 was present as both maternal and embryonic transcript; in particular, a statistically significant increase from the 8-cell stage, concomitant with embryo genome activation, was observed. Differently from the mouse, Sox2 was expressed in both bovine ICM and TE, resembling the profile previously shown for Oct-4 (van Eijk et al. 1999 Biol. Reprod. 60, 1093–1103), and suggesting that Sox2 expression might be regulated by Oct-4 also in bovine, as described in mouse and human. These findings also suggest that its expression may become restricted to the ICM only at the expanded hatched stage, as previously described for Oct-4 in pig embryos (Vejlsted et al. 2006 Mol. Reprod. Dev. 73, 709–718). This work was supported by PRIN 2006, FIRST 2005, TECLA-MIUR, and EUROSTELLS-ESF.

scholarly journals TRPM7 and CaV3.2 channels mediate Ca2+ influx required for egg activation at fertilization

2018 ◽  
Vol 115 (44) ◽  
pp. E10370-E10378 ◽  
Author(s):  
Miranda L. Bernhardt ◽  
Paula Stein ◽  
Ingrid Carvacho ◽  
Christopher Krapp ◽  
Goli Ardestani ◽  
...  
Keyword(s):  
Rational Design ◽  
Culture Media ◽  
Mammalian Development ◽  
Developmental Potential ◽  
Store Depletion ◽  
Offspring Growth ◽  
Mechanistic Basis ◽  
Genetic Mouse Models

The success of mammalian development following fertilization depends on a series of transient increases in egg cytoplasmic Ca2+, referred to as Ca2+ oscillations. Maintenance of these oscillations requires Ca2+ influx across the plasma membrane, which is mediated in part by T-type, CaV3.2 channels. Here we show using genetic mouse models that TRPM7 channels are required to support this Ca2+ influx. Eggs lacking both TRPM7 and CaV3.2 stop oscillating prematurely, indicating that together they are responsible for the majority of Ca2+ influx immediately following fertilization. Fertilized eggs lacking both channels also frequently display delayed resumption of Ca2+ oscillations, which appears to require sperm–egg fusion. TRPM7 and CaV3.2 channels almost completely account for Ca2+ influx observed following store depletion, a process previously attributed to canonical store-operated Ca2+ entry mediated by STIM/ORAI interactions. TRPM7 serves as a membrane sensor of extracellular Mg2+ and Ca2+ concentrations and mediates the effects of these ions on Ca2+ oscillation frequency. When bred to wild-type males, female mice carrying eggs lacking TRPM7 and CaV3.2 are subfertile, and their offspring have increased variance in postnatal weight. These in vivo findings confirm previous observations linking in vitro experimental alterations in Ca2+ oscillatory patterns with developmental potential and offspring growth. The identification of TRPM7 and CaV3.2 as key mediators of Ca2+ influx following fertilization provides a mechanistic basis for the rational design of culture media that optimize developmental potential in research animals, domestic animals, and humans.

scholarly journals Comparative Analyses of Single-Cell Transcriptomic Profiles between In Vitro Totipotent Blastomere-like Cells and In Vivo Early Mouse Embryonic Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3111
Author(s):  
Po-Yu Lin ◽  
Denny Yang ◽  
Chi-Hsuan Chuang ◽  
Hsuan Lin ◽  
Wei-Ju Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Single Cell ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Developmental Potential ◽  
Functional Features ◽  
Early Mouse ◽  
Extraembryonic Tissues

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are ‘true’ totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely ‘cluster 3’, as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.

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