Embryonic stem cells are derived from inner cell mass of the preimplanted blastocyst or from primordial germ cells of the early embryos, with the capacity of unlimited growth and differentiation potential. Embryonic stem cells(ES cells) can differentiate into all kinds of cells and organs under proper condition. Due to this characteristics ES cells have the attractive prospect in basic research, transplantation and gene therapy.
Blastocyst ; cytology ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; Germ Cells ; cytology ; Humans ; Research ; trends

Embryonic stem cells (ESCs) is one of the best cell types for regenerative medicine. It is derived from inner cell mass of the blastocyst stage and characterized by self-renewal and pluripotency, which are regulated by kinds of signal molecules, such as the Wnt/β-catenin signaling pathway. β-catenin is a multifunctional protein and plays a key role in Wnt/β-catenin signaling pathway. β-catenin involves self-renewal of ESCs and promotes the differentiation of ESCs into three primary germ layers in space and time. Elucidating the mechanisms of β-catenin in regulating the self-renewal and pluripotency of ESCs will pave the way to use it in research and application.
Blastocyst ; cytology ; Cell Differentiation ; Embryonic Stem Cells ; cytology ; Humans ; Wnt Signaling Pathway ; beta Catenin ; physiology

To discuss the effect of co-culture on the quality of mouse blastocysts and their epigenetic modification. We divided mouse zygotes into three co-culture experiment groups : with granular cells (group I ), oviduct epithelium cells (group II) and oviduct tissue (group III). Meanwhile, we set up control A (cultured in vitro, only KSOM (KCl+ simplex optimized medium)) and control B (cultured in vivo). Then we compared cleavage rate and blastocyst rate among different groups. After that we evaluated the quality of blastocysts by using ICM/TE (Inner cell mass/Trophectoderm cells) ratio via staining with propidium iodide and Hoechest333258, and analyzed the level of genome methylation and histone acetylation by immunofluorescence. Compared with the control group A, the co-culture groups had increased cleavage rate and blastocyst rate (P < 0.05), blastocyst cells and the ICM/TE ratio of co-culture groups were higher (P < 0.05), the level of genome methylation and histone acetylation had no significant difference between groups in vitro (P > 0.05), but the level of genome methylation in vivo was significantly higher than that of in vitro (P < 0.05). The co-culture methods can successfully promote the development rate of embryos in vitro, and improve the quality of the blastocyst. However, the methods have drawbacks in changing the abnormal genome methylation with in vitro culture.
Animals ; Blastocyst ; cytology ; Coculture Techniques ; DNA Methylation ; Epigenesis, Genetic ; genetics ; Epithelial Cells ; cytology ; Fallopian Tubes ; cytology ; Female ; Male ; Mice

OBJECTIVEUsing nested polymerase chain reaction (PCR) to perform preimplantation gender diagnosis.

METHODSOne (or two) lymphocyte and blastomere (n=50/group) were collected and prepared under the following conditions: (1) water only (H(2)O); (2) freeze-thaw liquid nitrogen, then boiling; (3) potassium hydroxide/dithiotheriol, heated to 65 degree centigrade, followed by acid neutralization (KOH). Cells were analyzed by PCR using nested primers amplification with amelogenin gene.

RESULTSThe amplification rate and allele dropout (ADO) rate for male lymphocytes by the three methods were 83%, 94%, 95% and 24%, 12%, 4%, respectively. Using two cells per reaction did not increase the amplification rate for the KOH method.

CONCLUSIONThe KOH method for DNA preparation is superior to the other methods evaluated. Dual blastomere biopsy and independent blastomere analysis may improve preimplantation diagnostic reliability.

Amelogenin ; Blastocyst ; cytology ; metabolism ; Blastomeres ; cytology ; metabolism ; DNA ; genetics ; Dental Enamel Proteins ; genetics ; Female ; Genotype ; Humans ; Lymphocytes ; cytology ; metabolism ; Male ; Polymerase Chain Reaction ; methods ; Sex Determination Analysis ; methods

The present study was conducted to develop an effective method for establishment of porcine parthenogenetic embryonic stem cells (ppESCs) from parthenogenetically activated oocyte-derived blastocysts. The addition of 10% fetal bovine serum (FBS) to the medium on the 3rd day of oocyte culturing improved the development of blastocysts, attachment of inner cell masses (ICMs) onto feeder cells, and formation of primitive ppESC colonies. ICM attachment was further enhanced by basic fibroblast growth factor, stem cell factor, and leukemia inhibitory factor. From these attached ICMs, seven ppESC lines were established. ppESC pluripotency was verified by strong enzymatic alkaline phosphatase activity and the expression of pluripotent markers OCT3/4, Nanog, and SSEA4. Moreover, the ppESCs were induced to form an embryoid body and teratoma. Differentiation into three germ layers (ectoderm, mesoderm, and endoderm) was confirmed by the expression of specific markers for the layers and histological analysis. In conclusion, data from the present study suggested that our modified culture conditions using FBS and cytokines are highly useful for improving the generation of pluripotent ppESCs.
Animals ; Blastocyst/*cytology ; Cell Culture Techniques/*veterinary ; *Cell Differentiation ; Cytokines/metabolism ; Embryonic Stem Cells/*cytology ; Parthenogenesis ; Pluripotent Stem Cells/*cytology ; Swine/*physiology

The influence of inner cell mass (ICM) and trophectoderm (TE) score on pregnancy outcomes in frozen-thawed blastocyst transfer cycles was analyzed. A retrospective analysis of 741 cycles of frozen-thawed blastosysts transfer was performed. All cycles were divided into four groups based on the number and morphological score of blastocysts: S-ICM B/TE B group (n=91), the single blastocyst transfer of ICM B and TE B; D-ICM B/TE B group (n=579), double blastocysts transfer of ICM B/TE B; D-ICM B/TE C group (n=35), double blastocysts transfer of ICM B/TE C; and D-ICM C/TE B group (n=36), double blastocysts transfer of TE B/ICM C. The pregnancy outcomes were compared among the four groups. As compared with D-ICM B/TE C group, the clinical pregnancy rate, implantation rate and multiple pregnancy rate were increased in D-ICM B/TE B group (74.96% vs. 57.14%, 57.43% vs. 37.14%, and 48.62% vs. 25%, respectively, P<0.05 for all). Clinical pregnancy rate and implantation rate in D-ICM B/TE B group were also higher than in D-ICM C/TE B group (74.96% vs. 50%, and 57.43% vs. 33.33%, both P<0.05). Multivariable Logistic regression analysis indicated that ICM score was a better predictive parameter for clinical pregnancy (OR=3.05, CI 1.70-5.46, P<0.001), while the trophectoderm score was a better one for early abortion (OR=0.074, CI 0.03-0.19, P<0.001). Clinical pregnancy rate and multiple pregnancy rate in S-ICM B/TE B group were significantly lower than those in D-ICM B/TE B group (46.15% vs. 74.96%, and 2.38% vs. 48.62%, both P<0.05), but there was no significant difference in the implantation rate between the two groups. It was suggested that the higher score of ICM and TE may be indicative of the better pregnancy outcomes. The ICM score is a better predictor of clinical pregnancy than TE, while TE score is a better one in predicting early abortion. Single ICM B/TE B blastocyst transfer in frozen-thawed cycles can also get satisfactory pregnancy outcomes.
Adult ; Analysis of Variance ; Blastocyst ; cytology ; Blastocyst Inner Cell Mass ; cytology ; Cryopreservation ; methods ; Embryo Implantation ; Embryo Transfer ; methods ; statistics & numerical data ; Female ; Fertilization in Vitro ; methods ; statistics & numerical data ; Humans ; Pregnancy ; Pregnancy Outcome ; Pregnancy Rate ; Retrospective Studies

With the advancements of stem cells and regenerative medicine, interspecies chimera has become a hot topic and will pave a new way of providing donor sources in organ transplantation. However, the interspecies chimera is confronted with a number of scientific questions and technical obstacles, including selections of appropriate embryonic stage and appropriate culture medium; those factors will deeply influence the developmental balance between donor cells and receptor embryos. Due to its relatively rapid reproductive cycle and similar organ size to human's, porcine is a very potential donor candidate to study these questions. To compare the development and chimeric efficiency of interspecies embryos, we tested and evaluated three different culture systems, PZM-3 (Porcine zygotic medium), culture medium for iPSCs (N2B27) and 3.5 h of N2B27 before PZM-3 (N2B27(3.5 h)), and two different embryonic stages, 8-cell and blastocyst in mouse-porcine chimeric embryos using parthenogenetically activated porcine embryos and mouse induced pluripotent stem cells (miPS). The results showed that, PZM-3 was beneficial for both development of chimeric embryos and miPSCs proliferation in porcine embryos in the 8-cell injection group. After early blastocyst injection, the chimeric efficiency did not appear significantly different among the three culture systems but was lower than 8-cell injection. In summary, the results suggest that 8-cell injection and PZM-3 culture medium are more beneficial to the in vitro development and chimeric efficiency of mouse-porcine chimeric embryos.
Animals ; Blastocyst ; Chimera ; Culture Media ; Embryo Culture Techniques ; veterinary ; Embryo, Mammalian ; Embryonic Development ; Induced Pluripotent Stem Cells ; cytology ; Mice ; Swine

To study the effects of mouse cytomegalovirus (MCMV) on the in vitro maturation, fertilization, cleavage and blastula formation of mouse oocytes, the immature oocytes were infected in vitro by MCMVs of different dosages (100 TCID(50), 10 TCID(50) and 1 TCID(50)). The oocytes were then observed for in vitro maturation, fertilization, cleavage and blastula formation and the ultrastructural changes after the culture with the viruses. Our results showed that no significant differences were found in IVM, IVF, cleavage and blastula formation among the groups treated with of virus of various dosages. And ultrastructural abnormality was observed in the oocytes treated by 100 TCID(50) of viruses. It is concluded that MCMV did not have any conspicuous effects on IVM, IVF, cleavage and blastula formation of murine immature oocytes.
Blastocyst ; Cells, Cultured ; Cleavage Stage, Ovum ; Cytomegalovirus Infections ; Fertilization ; Muromegalovirus/*pathogenicity ; Oocytes/cytology ; Oocytes/growth & development ; Oocytes/*virology

BackgroundDespite recent advances that have improved the pregnancy success rates that can be achieved via in vitro fertilization (IVF) therapy, it is not yet clear which blastocyst morphological parameters best predict the outcomes of single blastocyst transfer. In addition, most of the previous studies did not exclude the effect of embryo aneuploidy on blastocysts transfer. Thus, the present study investigated the predictive value of various parameters on the pregnancy outcomes achieved via the transfer of frozen euploid blastocysts.

MethodsThe study retrospectively analyzed 914 single euploid blastocyst transfer cycles that were performed at the Peking University Third Hospital Reproductive Medical Center between June 2011 and May 2016. The expansion, trophectoderm (TE), and inner cell mass (ICM) quality of the blastocysts were assessed based on blastocyst parameters, and used to differentiate between "excellent", "good", "average", and "poor"-quality embryos. The relationship between these embryo grades and the achieved pregnancy outcomes was then analyzed via the Chi-square and logistic regression tests.

ResultsFor embryo grades of excellent, good, average and poor, the clinical pregnancy rates were 65.0%, 59.3%, 50.3% and 33.3%, respectively; and the live-birth rates were 50.0%, 49.7%, 42.3% and 25.0%, respectively. Both the clinical pregnancy rate (χ = 21.28, P = 0.001) and live-birth rate (χ = 13.50, P < 0.001) increased with the overall blastocyst grade. Both rates were significantly higher after the transfer of a blastocyst that exhibited either an A-grade or B-grade TE, and similarly, an A-grade ICM, than after the transfer of a blastocyst that exhibited a C-grade TE and/or ICM. The degree of blastocyst expansion had no apparent effect on the clinical pregnancy or live-birth rate. All odds ratio were adjusted for patient age, body mass index, length (years) of infertility history, and infertility type.

ConclusionsA higher overall euploid blastocyst quality is shown to correlate most strongly with optimal pregnancy outcomes. The study thus supports the use of the described TE and ICM morphological grades to augment current embryo selection criteria.

Blastocyst ; cytology ; physiology ; Chi-Square Distribution ; Embryo Transfer ; Female ; Humans ; Logistic Models ; Odds Ratio ; Pregnancy ; Pregnancy Outcome ; Retrospective Studies

The mouse eggs in the various stages, of the development prior to implantation were collected and measurements were made on both the largest and smallest diameters of the vitellus, inner and outer surface of the zona pellucida. The various stages of development used were ovarian oocytes (germinal vesiA®e stage), ovulated but unfertilized egg, ovulated and fertilized egg, the 2-cell embryo on the second day of pregnancy, 4-8-cell embryo on the third day of pregnancy and morulablastocyst on the fourth day of pregnancy, A further comparative study on unfertilized and fertilized tubal eggs was made, The time of l2 hours after H.C.G. injection was chosen as the starting point from which to follow the collection of eggs every 3 hours for 24 hours. Since the volume gives a better comparison of size than diameter, the volume of the total eggs, intrazonal cavity, perivitelline space and the various were calculated for the various preimplantation stages of mouse egg. The volume of zona pellucida was also calsulated by subtraction of the volume of the inner zonal cavity from the volume of total egg and compared with the zona pellucida thickness. All calculations were made by computor(CEIR Time-sharing Computor). The diameter and volume of the vitellus in the ovarian oocyte is the largest one of any stage during the preimplantation stages of development, while the total volume of the entire egg as determined from the diameter of outer surface of the zona pellucida of the ovarian cocyte is the smallest one of any stage during development. The diameter and total volume of the entire egg increases from the ovarian oocytes to the first day of pregnancy and then gradually decreases until the third day of pregnancy. An increase in these parameters again takes place on the fourth day of pregnancy. The zona pellucida of the tubal ova is thicker than that of the oocyte, with the zona pellucida of the fertilized egg being definitely thinner when compared with unfertilized eggs. This phenomenon of decreased thickness in fertilized egg may be associated with zona reaction. The perivitelline space between the vitellus and zona pellucida thus formed following ovulation occupied approximately 40 percent of the total volume enclosed by the inner surface of the zona pellucida (intrazonal cavity) in the 1-cell tubal ova. Neither the cause of the rapid accumulation of fluid after ovulation which resulted in the production of the perivitelline space nor the actual time of the formation of the perivitelline space are known. Some possible reasons for the formation or origin of the perivitelline space are discussed. The size and shape of the vitellus undergo compartive reduction during preimplantation stages of development. The possible reason for the reduction of vitelline volume are discussed.
Animal ; Blastocyst ; Embryo/cytology* ; Embryo Implantation ; Embryo and Fetal Development ; Female ; Fertilization ; Mice ; Ovulation ; Ovum/cytology ; Ovum/growth & development ; Temperature ; Time Factors