STUDY QUESTION: Is the spindle assembly checkpoint (SAC) active during human preimplantation development?. SUMMARY ANSWER: Mitotic spindle disruption during mitosis activates the SAC from at least Day 3 of human preimplantation development, but this does not lead to apoptosis until Day 5.. WHAT IS KNOWN ALREADY: Human preimplantation embryos frequently acquire chromosomal abnormalities, but the mechanisms behind this are poorly understood. It has been speculated that a dysfunctional SAC could be responsible. Although research has shown that the SAC components are present during early human development, functional studies are lacking.. STUDY DESIGN, SIZE, DURATION: In vitro study using human preimplantation embryos in a university research laboratory. We studied a total of 38 Day-3, 38 Day-4, 29 Day-5 and 21 Day-6 human preimplantation embryos, donated for research, during 16 h of incubation.. PARTICIPANT/MATERIALS, SETTING, METHODS: We cultured human preimplantation embryos overnight in a ...
TY - JOUR. T1 - Brain and sperm cell surface antigen (NS-4) on preimplantation mouse embryos. AU - Solter, Davor. AU - Camartin, Melitta. PY - 1976/1/1. Y1 - 1976/1/1. N2 - Antiserum prepared in rabbit against 4-day-old mouse cerebellum (anti-NS-4 serum) reacts in the complement-mediated cytotoxicity test with unfertilized and fertilized mouse eggs, cleavage stage embryos, and cells of the trophoblast and inner cell mass of the mouse blastocyst. This activity is specifically removed by absorption of antiserum with adult mouse brain and epididymal sperm but not with adult liver, spleen, kidney, and thymocytes. The antiserum reacts most strongly with cells of the trophoblast and inner cell mass and, in order of decreasing reactivity, with four- to eight-cell stage embryos, zygotes, unfertilized eggs, and two-cell stage embryos.. AB - Antiserum prepared in rabbit against 4-day-old mouse cerebellum (anti-NS-4 serum) reacts in the complement-mediated cytotoxicity test with unfertilized and fertilized ...
Introduction: Cryopreservation is possible for all stages of pre-implantation embryos. It has been reported that survival rate of blastocyst is comparably lower than other stages. There is a high volume of fluid in blastocoel cavity that can be a good ground for ice crystals formation, resulting in damage to the cell structure. In this study, the effects of artificial collapseand reduction of the fluid volume in blastocyst cavity before vitrification process on the survival rate and quality of blastocysts were assessed by estimating the expression levels of Oct4, Nanog, Sox2, and Klf4.. Materials & Methods: Mouse blastocysts divided into 5 groups including: A) Vitrified- thawed blastocysts, B) Vitrified- thawed blastocysts after artificial collapse, C) Collapsed blastocysts, D) Immersed blastocysts in vitrification/warming solutions and E) Fresh blastocysts as control group. The survival and hatching rate of embryos were evaluated and the expression of pluripotency-specific genes was assessed by ...
Calcitonin secretion in the pregnant uterus is tightly regulated by the ovarian hormones, estrogen and progesterone, which limit its expression to a brief period preceding blastocyst implantation. The binding of calcitonin to a G protein-coupled receptor activates adenylate cyclase and elevates cytosolic Ca2+ levels. The acceleration of preimplantation embryonic development that is known to occur upon elevation of intracellular Ca2+ prompted an investigation into calcitonin regulation of blastocyst differentiation. Using reverse transcription and the polymerase chain reaction to estimate the relative abundance of calcitonin receptor mRNA, a 25-fold accumulation of the splice variant, CR-1a, was observed in embryos between the 1-cell and 8-cell stages. Cytosolic free Ca2+ levels were rapidly elevated in embryos at the 4-cell to blastocyst stages after exposure to 10 nM calcitonin. Blastocysts treated for 30 minutes with 10 nM calcitonin differentiated in vitro at an accelerated rate, as assessed ...
Totipotent non-committed inner cell mass (ICM) cells from human blastocysts, if demonstrated to be capable of proliferating in vitro without differentiation, will have several beneficial uses, not only in the treatment of neurodegenerative and genetic disorders, but also as a model in studying the events involved in embryogenesis and genomic manipulation. Nine patients admitted to an in-vitro fertilization programme donated 21 spare embryos for this study. All 21 embryos were grown from the 2-pronuclear until blastocyst stages on a human tubal epithelial monolayer in commercial Earles medium (Medicult, Denmark) supplemented with 10% human serum. The medium was changed after blastocyst formation to Changs medium supplemented with 1000 units/ml of human leukaemia inhibitory factor (HLIF) and the embryos left undisturbed for 72 h to allow the hatched ICM and trophoblast to attach to the feeder monolayer. Nineteen of the 21 embryos from nine patients produced healthy ICM lumps which could be ...
Selective labelling of polar trophectoderm cells in early mouse blastocysts has allowed the fate of polar cells to be followed during in vitro and in vivo blastocyst development. Results show that there is cell movement from polar to mural regions as blastocysts grow. This indicates that trophectode …
Immunosurgery is a useful technique for the isolation of inner cell masses from murine blastocysts. Conventionally, rabbit antisera made ad hoc against murine splenic or fetal cells or fibroblasts have been used as antibody sources. We investigated the feasibility of using commercially available rabbit antiserum to murine erythrocytes (anti-RBC) and compared it with rabbit antiserum generated ad hoc to murine L-cells (anti-L-cell). Our results indicate that anti-RBC is at least as effective as anti-L-cell serum for the immunosurgical isolation of inner cell masses, which became either miniblastocysts (later forming outgrowths) or embryoid bodies (undergoing ectoderm-endodermlike differentiation within 48 h). Because anti-RBC is commercially available, the technical modification described herein increases the accessibility of the immunosurgical protocol for the isolation of murine inner cell masses.
The accumulation of substrate carbon by mouse embryos was measured following incubation in U-14C-glucose. Following a 30-min incubation period 273 × 10-14 and 301×10-14g atoms of substrate carbon per embryo were found in 2- and 8-cell embryos respectively. By comparison, the figures for unfertilized and fertilized ova were 14 × 10 -14 and 45 × 10-14 g atoms of substrate carbon.. The intracellular concentration of substrate carbon was timedependent in both 2- and 8-cell embryos. After an 80-min incubation, substrate carbon in the 8-cell embryo was almost double that in the 2-cell embryo. Accumulation did not occur during incubations at 5° C and there was competition between glucose and galactose for uptake. The results are discussed in relation to the energy requirements of the developing zygote. ...
Fibronectin 1 (FN1), a glycoprotein component of the extracellular matrix, exerts different functions during reproductive processes such as fertilisation, gastrulation and implantation. FN1 expression has been described to increase significantly from the morula towards the early blastocyst stage, suggesting that FN1 may also be involved in early blastocyst formation. By alternative splicing at 3 defined regions, different FN1 isoforms are generated, each with a unique biological function. The analysis of the alternative FN1 splicing on the one hand and the search for candidate FN1 receptors on the other hand during early bovine embryo development may reveal more about its function during bovine preimplantation embryo development. RT-qPCR quantification of the FN1 splice isoforms in oocytes, embryos, cumulus cells and adult tissue samples revealed a large variation in overall FN1 expression and in splice variant expression. Moreover, two new FN1 transcript variants were identified, the first one
Generation Functional Lungs Conditional Blastocyst Complementation Using Pluripotent PubMed Journal Articles published on BioPortfolio | BioPortfolio
Early development and implantation of the embryo.. A. The zygote stage begins upon fertilization of the secondary oocyte by the sperm. The zygote contains both pro-nuclei and is contained within the zona pellucida, until the blastocyst stage. B. The morula stage. Following compaction and symmetrical cleavage divisions of the blastomeres (the cells of the early embryo), the embryo contains 8 (early morula) to 32 cells (morula). The inner cells will give rise to the inner cell mass, whereas the outer cells will give rise to the trophoblast, which forms a cavity called the blastocoele cavity. C. The blastocyst stage. The developing embryo is defined as a blastocyst from the appearance of the blastocoele cavity, and now contains two cell populations- the surrounding outer trophoblast cells, and the inner cell mass cells, located at one side of the inner cavity. The portion of the trophoblast nearest to the inner cell mass is called the polar trophoblast (embryonic pole) and the portion of the ...
Embryos cryopreserved after reaching blastocyst stage on day 7 were compared to those cryopreserved on days 5 and 6. Day 7 blastocysts have lower but clinically important pregnancy rates.
Oct4 is required for lineage priming in the developing inner cell mass of the mouse blastocyst[4] "The transcription factor Oct4 is required in vitro for establishment and maintenance of embryonic stem cells and for reprogramming somatic cells to pluripotency. In vivo, it prevents the ectopic differentiation of early embryos into trophoblast. Here, we further explore the role of Oct4 in blastocyst formation and specification of epiblast versus primitive endoderm lineages using conditional genetic deletion. Experiments involving mouse embryos deficient for both maternal and zygotic Oct4 suggest that it is dispensable for zygote formation, early cleavage and activation of Nanog expression. Nanog protein is significantly elevated in the presumptive inner cell mass of Oct4 null embryos, suggesting an unexpected role for Oct4 in attenuating the level of Nanog, which might be significant for priming differentiation during epiblast maturation. Induced deletion of Oct4 during the morula to blastocyst ...
Hewitson, L.C., Leese, H.J. (1993) Energy metabolism of the trophectoderm and inner cell mass of the mouse blastocyst. J Exp Zool. 267:337-343. Hewitson, L.C., Martin, K.L., Leese, H.J. (1996) Effects of metabolic inhibitors on mouse preimplantation embryo development and the energy metabolism of isolated inner cell masses. Mol Reprod Dev. 43:323-330. Hewitson, L., Simerly, C., Tengowski, M.W, Sutovsky, P., Navara, C,S., Haavisto, A.J. and Schatten, G. (1996) Microtubule and chromatin configurations during rhesus intracytoplasmic sperm injection: Successes and Failures. Biol. Reprod. 55:271-280. Hewitson, L., Haavisto A, Simerly C, Jones J and Schatten G (1997) Microtubule organization and chromatin configurations in hamster oocytes during fertilization, parthenogenetic activation and after insemination with human sperm. Biol.Reprod. 57: 967-975. Hewitson L, Takahashi D, Dominko T, Simerly C, and Schatten G. (1998) Fertilization and embryo development to blastocysts after intracytoplasmic sperm ...
A sequential study was made of non-delayed and of experimentally delayed rat blastocysts. Alterations in shape, axis lengths and area of non-delayed blastocysts first appeared on the afternoon of Day 5 of pregnancy. Similar changes were observed in delayed blastocysts beginning 12 hr after the simultaneous administration of oestrone and progesterone. In both cases implantation occurred within the subsequent 24 hr. In contrast, delayed blastocysts maintained only with progesterone were markedly larger than normal but failed to demonstrate typical pre-implantation changes or to implant. Therefore it was concluded that changes necessary for and indicative of impending implantation are induced by the synergistic action of oestrone and progesterone on the blastocyst.. Blastocysts from non-delayed and delayed, oestrone-treated animals were consistently free of their zonae pellucidae at least 18 hr prior to implantation-6 hr after pre-implantation changes were initially noted. Progesterone, although it ...
Measuring gene expression in individual cells is crucial for understanding the gene regulatory network controlling human embryonic development. Here we apply single-cell RNA sequencing (RNA-Seq) analysis to 124 individual cells from human preimplantation embryos and human embryonic stem cells (hESCs …
The cell lineage of the mouse was studied from the 2-cell stage to the blastocyst. Lineage to the 8-cell stage was followed under the microscope. Each cell from the 2-cell stage divided to form two daughter cells which remained attached. Subsequently, these two daughters each produced two descendants; one of these descendants regularly lay deep in the structure of the embryo while the other was peripheral. Lineage to the blastocyst was followed by injecting oil drops into cells at the 8-cell stage, and then following the segregation of these drops into the inner cell mass and trophectoderm. Between the 8-cell stage and the blastocyst, the deep cells contributed more frequently to the inner cell mass than did the peripheral cells.. ...
Treatment of in vitro matured bovine oocytes with colcemid results in a membrane protrusion that contains maternal chromosomes, which can be easily removed by aspiration. Four experiments were designed to evaluate the overall and temporal effects of conditioned medium (CM) by bovine cumulus cells on development of nuclear transfer (NT) bovine embryos and to examine the chromosomal composition and allocation of inner cell mass (ICM) and trophectoderm (TE) of the subsequent blastocysts. The nuclear transfer embryos were cultured in various CR1aa media conditioned by preculture with bovine cumulus cells. Development to the blastocyst stage in BSA-containing CM (BCM) and serum-containing CM (SCM) were similar to co-culture group (24-30%). The 24 hr-conditioned BCM yielded higher blastocyst development than 48 and 72 hr-conditioned BCM. Temporary exposure of embryos to BCM and SCM followed by CR1aa was also studied. Morula and blastocyst development were not different among the groups cultured in BCM for 72,
Bangalore Infertility Treatments center,The couple undergoing for IVF/ICSI have more embryos.Blastocyst Culture,Technique in IVF to select the best embryo.
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In humans, reproduction is considered a relatively inefficient process, when compared with other mammalian species and the chance of achieving a spontaneous pregnancy after timed intercourse is at the most 20-30%. Chromosome segregation errors are a well-known inherent feature of cell division in human preimplantation embryos produced by in vitro ... read more fertilization (IVF). The occurrence of such errors, which results in embryos containing chromosomally abnormal (aneuploid) cells, is believed to be the main cause for the reported inefficiency of human reproduction, as it may lead to pre-clinical pregnancy losses. In this thesis we start by evaluating the impact of ovarian stimulation administrated to patients undergoing IVF on the development of IVF-derived human embryos. We conclude that although the use of ovarian stimulation is considered relatively safe, further studies are needed to increase the knowledge on this subject and reduce potential effects on embryo development and ...
Computational analysis of single-cell transcriptomics data elucidates the stabilization of Oct4 expression in the E3.25 mouse preimplantation embryo [6] "Our computational analysis focuses on the 32- to 64-cell mouse embryo transition, Embryonic day (3.25), whose study in literature is concentrated mainly on the search for an early onset of the second cell-fate decision, the specification of the inner cell mass (ICM) to primitive endoderm (PE) and epiblast (EPI). We analysed single-cell (sc) microarray transcriptomics data from E3.25 using Hierarchical Optimal k-Means (HOkM) clustering, and identified two groups of ICM cells: a group of cells from embryos with less than 34 cells (E3.25-LNCs), and another group of cells from embryos with more than 33 cells (E3.25-HNCs), corresponding to two developmental stages. Although we found massive underlying heterogeneity in the ICM cells at E3.25-HNC with over 3,800 genes with transcriptomics bifurcation, many of which are PE and EPI markers, we showed ...
The expression of microRNAs (miRNAs) is essential for the proper development of the mammalian embryo. A maternal exposure to endocrine disrupting chemicals during preimplantation bears the potential for transgenerational inheritance of disease through the epigenetic perturbation of the developing embryo. A comprehensive assembly of embryo-specific miRNAs and respective isoforms (isomiR) is lacking to date. We aimed at revealing the sex-specific miRNA expression profile of single porcine blastocysts developing in gilts orally exposed to exogenous estradiol-17 β (E2). Therefore we analyzed the miRNA profile specifically focusing on isomiRs and potentially embryo-specific miRNAs. Deep sequencing of small RNA (small RNA-seq) result in the detection of miRNA sequences mapping to known and predicted porcine miRNAs as well as novel miRNAs highly conserved in human and cattle. A set of highly abundant miRNAs and a large number of rarely expressed miRNAs were identified by using a small RNA analysis pipeline,
The molecular regulation of mammalian peri-implantation development is complex and difficult to study in vivo. We successfully cultured hamster blastocysts through hatching and peri-attachment stages, using a chemically defined medium, HECM-2h. Using this system, we showed that a species-specific, embryonic cysteine-like protease is involved in blastocyst hatching and that the process is modulated by growth factors. In particular, heparin binding-epidermal growth factor (HB-EGF) or leukemia inhibitory factor (LIF) enhance blastocyst hatching, and the former also improves attachment and trophoblast outgrowth. We observed interesting changing patterns of expression of mRNA and/or immunoreactive protein for EGF, HB-EGF, LIF and transforming growth factor-beta (TGF-beta) in the embryo and/or endometrial tissue, during peri-implantation development. Together, it appears that hamster blastocyst hatching, attachment and trophoblast outgrowth are regulated by autocrine and/or paracrine growth factors, ...
Blastocyst Transfer and treatment at Santati Fertility Center in Mumbai and Thane, the Indias largest independent infertility Blastocyst Transfer treatment provider
We examined the in vitro developmental competence of parthenogenetic activation (PA) oocytes activated by an electric pulse (EP) and treated with various concentrations of AZD5438 for 4 h. Treatment with 10 µM AZD5438 for 4 h significantly improved the blastocyst formation rate of PA oocytes in comparison with 0, 20, or 50 µM AZD5438 treatment (46.4% vs. 34.5%, 32.3%, and 24.0%, respectively; P , 0.05). The blastocyst formation rate was higher in the group treated with AZD5438 for 4 h than in the groups treated with AZD5438 for 2 or 6 h (42.8% vs. 38.6% and 37.2%, respectively; P , 0.05). Furthermore, 66.67% of blastocysts derived from these AZD5438-treated PA oocytes had a diploid karyotype. The blastocyst formation rate of PA and somatic cell nuclear transfer (SCNT) embryos was similar between oocytes activated by an EP and treated with 2 mM 6-dimethylaminopurine for 4 h and those activated by an EP and treated with 10 µM AZD5438 for 4 h (11.11% vs. 13.40%, P , 0.05). In addition, the level ...
We examined the in vitro developmental competence of parthenogenetic activation (PA) oocytes activated by an electric pulse (EP) and treated with various concentrations of AZD5438 for 4 h. Treatment with 10 µM AZD5438 for 4 h significantly improved the blastocyst formation rate of PA oocytes in comparison with 0, 20, or 50 µM AZD5438 treatment (46.4% vs. 34.5%, 32.3%, and 24.0%, respectively; P < 0.05). The blastocyst formation rate was higher in the group treated with AZD5438 for 4 h than in the groups treated with AZD5438 for 2 or 6 h (42.8% vs. 38.6% and 37.2%, respectively; P > 0.05). Furthermore, 66.67% of blastocysts derived from these AZD5438-treated PA oocytes had a diploid karyotype. The blastocyst formation rate of PA and somatic cell nuclear transfer (SCNT) embryos was similar between oocytes activated by an EP and treated with 2 mM 6-dimethylaminopurine for 4 h and those activated by an EP and treated with 10 µM AZD5438 for 4 h (11.11% vs. 13.40%, P > 0.05). In addition, the level ...
The aim in developing this approach to the study of implantation has been to establish a method which will permit the investigation of the process extracorporeally, thus providing conditions that are more readily controllable than those obtainable in an experimental animal. Shaffers method of organ culture has been adapted to the needs of the present investigation and it has been found that somewhat more than half of the rabbit blastocysts, explanted on strips of endometrium and incubated on them as combined explants, became implanted within 48 to 72 h. ...
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The preference of fertilized (IVF) and somatic cell nuclear transfer (SCNT) presumptive zygotes for different media when cultured in vitro to the blastocyst stage was evaluated in this study. The experiment comprised two zygote production methods (IVF and SCNT) × two culture media (mSOF and G1.5/G2.5) factorial design in which culture droplets that contained approximate 30 presumptive zygotes formed the experimental plots for the assessment of cleavage and blastocyst development. There were 15 to 20 replicates (culture droplets) per treatment combination. Sub-samples 30 to 41 of the blastocysts produced were assessed for cell number and cell apoptosis. A further 10 blastocysts per treatment combination were used for quantitative real-time polymerase chain reaction (RT-PCR) to evaluate the relative abundance of Hsp70 and Bax mRNA. Presumptive zygotes produced by IVF were developmentally more competent than SCNT zygotes in terms of cleavage rate (66.9 vs. 57.0%; P , 0.05) and blastocyst ...
Nilsson, B. O., Jin, M., Larsson, A. and Sundström, P. (1996), Human Autoantibodies Recognizing Human and Mouse Preimplantation Stages. American Journal of Reproductive Immunology, 36: 135-140. doi: 10.1111/j.1600-0897.1996.tb00154.x ...
The preimplantation period of development represents the highest interval of embryonic loss throughout pregnancy. It is therefore imperative that we elucidate the mechanisms involved in regulating preimplantation embryonic responses to stress and that govern development. The MAPK pathways are involved in both responding to environmental stress and regulation of development throughout embryogenesis, and are therefore good candidates to study the mechanisms involved in preimplantation embryonic adaptation to stress and development. The preimplantation embryo culminates in the development of a fluid filled structure called the blastocyst. It is at this stage the first differentiation events occur and the trophectoderm (TE), which will go on to form the embryonic portion of the placenta, develops. The p38 MAPK is required for embryo development to proceed beyond the 8-16 cell stage as well to play an adaptive role in regulating embryonic response to culture stress. My hypothesis is that the MAPK
In a mouse model, in vitro fertilization or extended embryo culture leads to the increased expression of TRP53 in susceptible embryos. Ablation of the TRP53 gene improved embryo viability indicating that increased expression of TRP53 is a cause of the reduction of embryo viability resulting from in vitro fertilization or embryo culture. This study investigates the status of TRP53 expression in human embryos produced by intracytoplasmic sperm injection. Following fertilization, embryos were cultured for 96 h and then cryopreserved. Immediately upon thawing they were fixed in formaldehyde and subjected to immunostaining for TRP53. Staining was visualized by confocal microscopy. Negative controls were incubated with isotype control immunoglobulin and showed negligible staining. All embryos showed TRP53 staining above negative controls. TRP53 staining was heterogenous within and between embryos. An embryo that showed retarded development showed high levels of TRP53 expression. A blastocyst that had ...
A preparation and a method of making composite blastocysts (CBs) from aggregates of dissociated cells of non-viable pre-embryos are disclosed. The CB is characterized morphologically by having two distinct tissue types, the inner cell mass (ICM) and the trophectoderm (TE), and a blastocoelic cavity (BC). The ICM is differentially stainable with bisbenzimide and the TE is differentially stainable with propidium iodide. The ICM is pluripotent in that it contains embryonic stem (ES) cells. The TE cells are pluripotent in that they can give rise to all cell types normally derived from TE cells. The primate TE is characterized by the production of chorionic gonadotrophin. The method of making CBs is an aggregation process (AP) comprising inter alia the following steps: 1) dissociation of discarded pre-embryos; 2) isolation of single nucleated cells from dissociated discarded pre-embryos; 3) microsurgical encapsulation of several cells within a host zona pellucida or artificial aggregation with or without a
Bilaminar blastocyst or Bilaminar disc refers to the epiblast and the hypoblast, evolved from the embryoblast. These two layers are sandwiched between two balloons: the primitive yolk sac and the amniotic cavity. The inner cell mass, the embryoblast, begins to transform into two distinct epithelial layers just before implantation occurs. The epiblast is the outer layer that consists of columnar cells.The inner layer is called the hypoblast, or primitive endoderm, which is composed of cuboidal cells. As the two layers become evident, a basement membrane presents itself between the layers. The final two layers of the embryoblast are known collectively as the bilaminar embryonic disc as well as the bilaminar blastocyst or bilaminar blastoderm. This bilaminar blastocyst also defines the primitive dorsal ventral axis. Blastocyst implantation will occur during the second week of fetal development in the endometrium of the uterus; the epiblast is dorsal and the hypoblast is ventral. The zygote ...
The effect of glucose and insulin on the in vitro development of the rat preimplantation embryo was studied by incubating rat blastocysts recovered on days 5 or 6 of pregnancy in the absence or presence of increasing levels of glucose and/or insulin for 24 or 48 h. A differential cell-staining method allowed the separate counting of inner cell mass (ICM) and trophectoderm (TE) cells at the end of the incubation period. In a high-glucose medium (17 mM), ICM and, to a lesser extent, TE developments were significantly and irreversibly inhibited. Low insulin concentrations (3 pM) stimulated ICM and TE development in the presence of 1.1 or 6 mM glucose. Higher insulin levels (30-600 pM) in a 6-mM glucose medium, resulted in a dose-dependent inhibition of ICM and, to a lesser extent, TE development after both 24 and 48 h. This insulin-induced inhibition was reversible if insulin was removed from the medium after 24 h. In the absence of glucose in the medium, insulin was neither stimulatory nor ...
ICR albino mouse embryos (n=4lS0) were used to determine production of progesterone and estradiol. In Experiment I, cultures containing 20 (n=lO), 40 (n=lO) or 60 (n=6) early blastocysts were incubated in 13 X 100 rom tubes with .25 ml BMOC-2 for 20 h under 5% CO2 and air at 37C. Also, 20 (n=4) , 40 (n=7) and 60 (n=6) control embryos were frozen at -90C after flushing. Viability was determined by culturing 20 (n=5) , 40 (n=7) and 60 (n=6) for 24 h at which time percent normal development was microscopically evaluated.. In Experiment II, 40 embryos at either morula, early blastocyst or late blastocyst (n=lO) stage were cultured similarly. Viability and control steroid levels were determined on n=5, n=7 and n=7 cultures. Incubated and control cultures were extracted with diethyl ether and progesterone and estradiol isolated on Sephadex LH-20 columns prior to quantification by radioimmunoassay.. Viability for all cultures was 95.6 + .05% (~+SD). In Experiment I, incubated progesterone and estradiol ...
In the present study, we report that suppression of Nek2 expression by RNAi resulted in developmental defects at the second mitosis of the mouse early embryos. Many blastomeres in the Nek2-suppressed embryos were arrested at M phase with abnormal spindle structures. These results confirm that Nek2 is essential for embryonic mitosis, especially for proper segregation of chromosomes.. Phenotypes of Nek2-suppressed mouse embryos are comparable to those of the Xenopus embryos in which the Nek2 activity was reduced by microinjection of the mRNA for kinase-inactive form of Nek2B or of the Nek2 antibody (Uto and Sagata, 2000). Depletion of Nek2 resulted in fragmentation or dispersal of the centrosomes and eventually in interference of embryonic development of both species. In addition, our results are consistent with a previous report in which removal of the Nek2 proteins from Xenopus egg extracts did not disturb entry into mitosis and accompanying condensation of chromosomes (Fry et al., 2000). ...
Principal Investigator:SAIJO YASUO, Project Period (FY):2015-04-01 - 2017-03-31, Research Category:Grant-in-Aid for Challenging Exploratory Research, Research Field:Respiratory organ internal medicine
STUDY QUESTION: To what extent do patient- and treatment-related factors explain the variation in morphokinetic parameters proposed as embryo viability markers?. SUMMARY ANSWER: Up to 31% of the observed variation in timing of embryo development can be explained by embryo origin, but no single factor elicits a systematic influence.. WHAT IS KNOWN ALREADY: Several studies report that culture conditions, patient characteristics and treatment influence timing of embryo development, which have promoted the perception that each clinic must develop individual models. Most of the studies have, however, treated embryos from one patient as independent observations, and only very few studies that evaluate the influence from patient- and treatment-related factors on timing of development or time-lapse parameters as predictors of viability have controlled for confounding, which implies a high risk of overestimating the statistical significance of potential correlations.. STUDY DESIGN, SIZE, DURATION: ...
A.P. Wong et al, "Directed differentiation of human pluripotent stem cells into mature airway epithelia expressing functional CFTR protein," Nat. Biotechnol., vol. 30, no. 9, pp. 876-882, Sept. 2012.. Y. Yamanaka et al, "FGF signal-dependent segregation of primitive endoderm and epiblast in the mouse blastocyst," Development, vol. 137, no. 5, pp. 715-724, March 2010.. C. Chazaud et al, "Early lineage segregation between epiblast and primitive endoderm in mouse blastocysts through the Grb2-Mapk pathway," Dev. Cell, vol. 10, no. 5, pp. 615-624, May 2006.. H. Niwa et al, "Interaction between Oct3/4 and Cdx2 Determines trophectoderm differentiation," Cell, vol. 123, no. 5, pp. 917-929, Dec. 2005.. A. Nagy et al, "Derivation of completely cell culture-derived mice from early-passage embryonic stem cells," Proc. Natl. Acad. Sci. U.S.A., vol. 90, no. 18, pp. 8424-8428, Sept. 1993. ...
article{1048354, abstract = {Recent studies have shown that short-term exposure of oocytes to a stressor such as hydrostatic pressure or osmotic stress might induce stress tolerance in embryos. The aim of the present study was to investigate the consequences of short-term hydrogen peroxide (H2O2) exposure to bovine in vitro matured cumulus-oocyte complexes (COCs) on subsequent preimplantation embryo development and apoptosis. in the first experiment, mature COCs were incubated in H2O2 at concentrations ranging between 0.01 and 100 mu mol/l, and subsequently fertilized and cultured. Oocyte incubation with 50-100 mu mol/l of H2O2 resulted in a significantly higher blastocyst yield (47.3\%) in comparison with control medium (31.8\%), while apoptotic cell ratio was inversely related with H2O2 concentration. In the second experiment, we showed that the stress tolerance after H2O2 exposure was not mediated by increased glutathione content in treated oocytes nor by enhanced fertilization or ...
Even before implantation, three cell lineages are apparent in the blastocyst of mouse and human. Outermost is the trophectoderm that will contribute trophoblast to the placenta. The inner cell mass has already differentiated into the epiblast and the primitive endoderm or hypoblast. For mouse, this much has been clear since the pioneering studies of Emil Selenka (here). ...
A blastocyst is a cellular mass that forms early in the embryo development process in mammals. Humans develop a blastocyst about...
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The total cell count of the H33342-stained blastocyst. An H33342-stained blastocyst from the control group revealed a total of 77 visible nuclei observed from d
Weve just had a negative result from our first IVF ICSI antagonist cycle. Had 6 eggs; 4 fertilised; vacuoles developed by day 3; no good blastocyst at day 5 to transfer; transferred a early blastocyst on day 6 that was slow and collapsed - page 2
Blastocyst Definition - A blastocyst is a fertilized egg that has developed for 5-6 days and contains 3 distinct features including a fluid-filled...
Recent reports show that more fertility clinics in the country implement the procedure of blastocyst transfers to decrease the risk of multiple births from…
The inner cell mass (ICM) is the part of the blastocyst that is fated to become the embryo, amnion, and yolk sac. In contrast, the trophectoderm cells of the blastocyst will contribute to extra-embryonic tissues, such as the placenta and umbilical cord. Cells of the ICM are pluripotent, meaning they can give rise to all the cell lineages (ectoderm, endoderm, and mesoderm) found in the body. The ICM is, thus, a source of embryonic stem cells.. ...