scholarly journals Embryo manipulation via assisted reproductive technology and epigenetic asymmetry in mammalian early development

2013 ◽  
Vol 368 (1609) ◽  
pp. 20120353 ◽  
Author(s):  
Takashi Kohda ◽  
Fumitoshi Ishino
Keyword(s):  
Assisted Reproductive Technology ◽  
Early Stage ◽  
Gene Activation ◽  
Reproductive Technology ◽  
Blastocyst Stage ◽  
Mammalian Development ◽  
Cell Stage ◽  
Genome Wide ◽  
Zygotic Gene ◽  
Developmental Risks

The early stage of mammalian development from fertilization to implantation is a period when global and differential changes in the epigenetic landscape occur in paternally and maternally derived genomes, respectively. The sperm and egg DNA methylation profiles are very different from each other, and just after fertilization, only the paternally derived genome is subjected to genome-wide hydroxylation of 5-methylcytosine, resulting in an epigenetic asymmetry in parentally derived genomes. Although most of these differences are not present by the blastocyst stage, presumably due to passive demethylation, the maintenance of genomic imprinting memory and X chromosome inactivation in this stage are of critical importance for post-implantation development. Zygotic gene activation from paternally or maternally derived genomes also starts around the two-cell stage, presumably in a different manner in each of them. It is during this period that embryo manipulation, including assisted reproductive technology, is normally performed; so it is critically important to determine whether embryo manipulation procedures increase developmental risks by disturbing subsequent gene expression during the embryonic and/or neonatal development stages. In this review, we discuss the effects of various embryo manipulation procedures applied at the fertilization stage in relation to the epigenetic asymmetry in pre-implantation development. In particular, we focus on the effects of intracytoplasmic sperm injection that can result in long-lasting transcriptome disturbances, at least in mice.

89 ZYGOTICALLY ACTIVATED GENES ARE SUPPRESSED IN MOUSE NUCLEAR-TRANSFERRED EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 162
Author(s):  
T. Suzuki ◽  
N. Minami ◽  
H. Imai
Keyword(s):  
Gene Expression ◽  
Somatic Cell ◽  
Early Stage ◽  
Mammalian Species ◽  
Expression Patterns ◽  
Gene Activation ◽  
Blastocyst Stage ◽  
Success Rates ◽  
Cell Nuclei ◽  
Cell Stage

Mammalian oocytes have the ability to confer totipotency to terminally differentiated somatic cell nuclei. Viable cloned animals have been produced by somatic cell nuclear transfer (NT) into oocytes in many mammalian species including mouse. However, the success rates of the production were quite low in all species. Many studies have measured differences in gene expression between NT and fertilized embryos in relatively advanced stages of development such as pre- and post-natal stages or the blastocyst stage. In the mouse, major zygotic gene activation (ZGA) occurs at the 2-cell stage after fertilization and leads to the transition of gene regulation from maternal control to embryonic control. Suppression of the ZGA by a transcription inhibitor was shown to decrease the viability of embryos, and causes developmental arrest at the 2-cell stage. An abnormal ZGA may therefore affect the viability of NT embryos and cause further abnormalities in later embryonic development. In the present study, we compared gene expression patterns using differential display RT-PCR (DDRT-PCR) between the NT and IVF embryos at the 2-cell stage to detect some abnormalities affecting later development of NT embryos. The developmental rate of NT embryos to blastocysts (32.9%) was significantly lower than that of IVF (92.7%) or PA (92.8%). In addition, the cell numbers of NT embryos at the blastocyst stage (39.5 � 2.6; n = 19) were less than those of IVF (66.8 � 2.1; n = 30) or PA embryos (48.2 � 2.1; n = 30). Using these embryos, we first identified 4 genes that were differentially expressed between NT and IVF embryos at the 2-cell stage. Among the identified genes, Inpp5b and Chst12 were up-regulated, and MuERV-L and Dnaja2 were down-regulated in the NT embryos compared with IVF embryos. Further analysis showed that the expression of zygotically activated genes such as Interferon-γ, Dub-1, Spz1, DD2106, and DD2111 were not properly activated in NT embryos, suggesting that the cellular process involved in the control of the zygotic genome activation is not appropriately regulated. These results indicate that abnormal gene expression has already occurred at the early stage of pre-implantation development as a failure of nuclear reprogramming.

scholarly journals Inositol transport in mouse oocytes and preimplantation embryos: effects of mouse strain, embryo stage, sodium and the hexose transport inhibitor, phloridzin

Reproduction ◽  
2003 ◽  
pp. 111-118 ◽  
Author(s):  
BD Higgins ◽  
MT Kane
Keyword(s):  
Gene Activation ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Sodium Dependent ◽  
Morula Stage ◽  
Zygotic Gene ◽  
Zygotic Gene Activation ◽  
The One ◽  
Inositol Uptake

The uptake of myo-inositol by mouse oocytes and preimplantation embryos of a crossbred (DBA x C57BL/6) and a purebred outbred strain (MF1) was measured using [2-(3)H]myo-inositol. Uptake in crossbred embryos increased about 15-fold between the one- and two-cell stages and increased again by about sixfold at the blastocyst stage compared with the morula stage. Uptake in purebred embryos increased about 42-fold between the one- and two-cell stages and increased more than threefold at the blastocyst stage compared with the morula stage. In all stages examined, except two-cell crossbred embryos, inositol uptake was, depending on the stage, either largely or partly sodium dependent and could be inhibited by the sodium-dependent hexose transport inhibitor, phloridzin. This is consistent with the hypothesis that transport occurs via a sodium myo-inositol transporter (SMIT) protein. In addition, there was strong evidence that a sodium-independent mechanism of uptake, possibly a channel, was switched on at the two-cell stage coincident with zygotic gene activation which resulted in 141-fold and 71-fold increases in sodium-independent uptake from the one-cell to two-cell stages in crossbred and purebred embryos, respectively. This mechanism was either abolished or drastically downregulated at the blastocyst stage, whereas sodium-dependent uptake was markedly upregulated. In two-cell crossbred embryos, there was a complete abolition of sodium-dependent uptake, again possibly regulated by zygotic gene activation. The hypothesis that the changes in mechanism of inositol uptake at about the two-cell stage are due to zygotic gene activation was supported by the finding that these changes did not occur in parthenogenetic two-cell embryos.

A Clinical Nomogram For Predicting Preterm Birth in Women Who Conceived Through Assisted Reproductive Technology

2021 ◽  
Author(s):  
Yaduan Lin ◽  
Fanchen He ◽  
Rui Gao ◽  
Ting Liu ◽  
Ke Zhao ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Assisted Reproductive Technology ◽  
Risk Model ◽  
Cox Regression ◽  
Early Stage ◽  
Statistical Significance ◽  
Reproductive Technology ◽  
Brier Score ◽  
Chronic Hypertension ◽  
Singleton Pregnancy

Abstract Background: We used prepregnant and gestational characteristics as predictors to develop and validated a nomogram predicting the risk of preterm birth (PTB) in assisted reproductive technology (ART) treated women. Methods: The National Vital Statistics System (NVSS) was queried for singleton ART-treated pregnant women from 2015 to 2019. Multivariable cox regression was used to develop the early (< 32 weeks) or late (< 37 weeks) PTB risk model using both statistical significance and clinical importance criteria for variable selection. The predictive accuracy was assessed, and bootstrapping was used for validation. A nomogram was constructed for the presentation of the final model. Results: ART-treated women who were over 45 years old, black, obese, had a history of cesarean section and PTB, restarting ART within 3 months, prepregnant diabetes, chronic hypertension, gestational diabetes, gestational hypertension, and eclampsia, had the highest risk for late and early-stage PTB. The nomogram with these variables accurately predicted PTB in ART women with a singleton pregnancy. (Brier score:0.121, calibration slope: 0.99, c-index: 0.684). Conclusion: We created a nomogram predicting the risk of early or late PTB in ART women with a singleton pregnancy, which could identify potentially at-risk women who seeking ART treatment and inform appropriate preterm care.

scholarly journals Minor zygotic gene activation is essential for mouse preimplantation development

2018 ◽  
Vol 115 (29) ◽  
pp. E6780-E6788 ◽  
Author(s):  
Ken-ichiro Abe ◽  
Satoshi Funaya ◽  
Dai Tsukioka ◽  
Machika Kawamura ◽  
Yutaka Suzuki ◽  
...  
Keyword(s):  
Dna Replication ◽  
Gene Activation ◽  
Marked Change ◽  
Cell Stage ◽  
Maternal Mrna ◽  
Maternal To Zygotic Transition ◽  
Before And After ◽  
H3k4me3 Mark ◽  
Zygotic Gene ◽  
Zygotic Gene Activation

In mice, transcription initiates at the mid-one-cell stage and transcriptional activity dramatically increases during the two-cell stage, a process called zygotic gene activation (ZGA). Associated with ZGA is a marked change in the pattern of gene expression that occurs after the second round of DNA replication. To distinguish ZGA before and after the second-round DNA replication, the former and latter are called minor and major ZGA, respectively. Although major ZGA are required for development beyond the two-cell stage, the function of minor ZGA is not well understood. Transiently inhibiting minor ZGA with 5, 6-dichloro-1-β-d-ribofuranosyl-benzimidazole (DRB) resulted in the majority of embryos arresting at the two-cell stage and retention of the H3K4me3 mark that normally decreases. After release from DRB, at which time major ZGA normally occurred, transcription initiated with characteristics of minor ZGA but not major ZGA, although degradation of maternal mRNA normally occurred. Thus, ZGA occurs sequentially starting with minor ZGA that is critical for the maternal-to-zygotic transition.

24 EFFECTS OF HISTONE METHYLATION RELATED GENES ON EPIGENETIC REPROGRAMMING AND ZYGOTIC GENE ACTIVATION IN OVINE SOMATIC CELL NUCLEAR TRANSFER (SCNT) EMBRYOS

2009 ◽  
Vol 21 (1) ◽  
pp. 112
Author(s):  
I. Choi ◽  
K. H. S. Campbell
Keyword(s):  
Cell Cycle ◽  
Somatic Cell ◽  
Embryo Development ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Gene Activation ◽  
Early Embryo ◽  
Cell Stage ◽  
Early Embryo Development ◽  
Zygotic Gene

After fertilization, early embryo development is dependent upon maternally inherited proteins and protein synthesised from maternal mRNA until zygotic gene activation (ZGA) occurs. The transition of transcriptional activity from maternal to embryonic control occurs with the activation of rRNA genes and the formation of the nucleolus at the 8- to 16-cell stage that coincides with a prolonged fourth cell cycle in bovine and ovine embryos. However, previous studies have reported a shift in the longest cell cycle (fifth cell cycle) in bovine somatic cell nuclear transfer (SCNT) embryos, suggesting that the major genome activation is delayed, possibly due to incomplete changes in chromatin structure such as hypermethylation and hypoacetylation of histone (Memili and First 2000 Zygote 8, 87–96; Holm et al. 2003 Cloning Stem Cells 5, 133–142). Although global gene expression profile studies have been carried out in somatic cell nuclear transfer embryos, little is known about the expression of genes which can alter chromatin structure in early embryo development and possibly effect ZGA. To determine whether epigenetic reprogramming of donor nuclei affected ZGA and expression profiles in SCNT embryos, ZBTB33 (zinc finger and BTB domain containing 33, also known as kaiso, a methy-CpG specific repressor), BRG1(brahma-related gene 1, SWI/SNF family of the ATP-dependent chromatin remodeling complexes), JMJD1A (jumonji domain containing 1A, H3K9me2/1-specific demethylase), JMJD1C (putative H3K9-specific demethylase), and JMJD2C (H3K9me3-specific demethylase) were examined by RT-PCR at different developmental stages [germinal vesicle (GV), metaphase II (MII), 8- to 16-cell, 16- to 32-cell, and blastocyst in both parthenogenetic and SCNT embryos]. All genes were detected in parthenogenetic and SCNT blastocyts, and ZBTB33 was also expressed in all embryos at all stages tested. However, the onset of expression of JMJD1C, containing POU5F1 binding site at 5′-promoter region and BRG1 required for ZGA are delayed in SCNT embryos as compared to parthenotes (16- v. 8-cell, and blastoocyst v. 16-cell stage). Furthermore, JMJD2C containing NANOG binding sites at the 3′-flanking region was expressed in GV and MII oocytes and parthenogenetic blastocysts, whereas in SCNT embryos, JMJD2C was only observed from the 16-cell stage onwards. Interestingly, JMJD1A, which is positively regulated by POU5F1, was not detected in GV and MII oocytes but was present in blastocyst stage embryos of both groups. Taken together, these results suggest that incomplete epigenetic modifications of genomic DNA and histones lead to a delayed onset of ZGA which may affect further development and establishment of totipotency. Subsequently, aberrant expression patterns reported previously in SCNT embryos may be attributed to improper expression of histone H3K9 and H3K4 demethylase genes during early embryo development.

scholarly journals 37DEVELOPMENTAL POTENTIAL OF CLONE CELLS IN MURINE CLONE-FERTILIZED AGGREGATION CHIMERAS

2004 ◽  
Vol 16 (2) ◽  
pp. 141
Author(s):  
S. Eckardt ◽  
N.A. Leu ◽  
K.J. McLaughlin
Keyword(s):  
Early Stage ◽  
Cumulus Cell ◽  
Blastocyst Stage ◽  
Wild Type ◽  
Cell Stage ◽  
Developmental Potential ◽  
Preimplantation Stage ◽  
Transgenic Embryos ◽  
Clone Cells

In both murine and porcine preimplantation stage clones, mosaicism in gene expression has been observed, indicating variation in transcription of some genes between cells of the individual clone (Boiani M et al., 2002 Genes Dev. 16, 1209–1219; Park KW et al., 2002 Biol. Reprod. 66, 1001–1005). This observation raises the question as to whether all blastomeres within one early-stage clone are equivalent, or whether there are differences in developmental potential. To address this, we aggregated preimplantation-stage clone embryos with fertilized embryos and assessed contribution of Oct4-GFP expressing cells of clone origin in blastocysts and in vitro outgrowths. In normal embryos, the Oct4-GFP transgene is expressed during preimplantation stages and reflects expression of Oct4 protein. Mouse cumulus cell clones were produced from cells transgenic for Oct4-GFP (Szabó PE et al., 2002 Mech. Dev. 115, 157–160) as described (Boiani M et al., 2002 Genes Dev. 16, 1209–1219). Four-cell-stage clones and synchronous fertilized non-transgenic embryos were aggregated in micro-wells after removal of the zona pellucida using acid Tyrode’s solution. Aggregates were cultured to the blastocyst stage in -MEM supplemented with bovine serum albumin (0.4% w/v). All control chimeras produced from four-cell-stage fertilized non-transgenic and Oct4-GFP transgenic embryos formed blastocysts, and 15 of 20 had GFP-expressing cells. The majority of clone-wild-type aggregates developed to the blastocyst stage (35/40); however, contribution of GFP-expressing cells was observed in fewer blastocysts compared to controls (12/35; P&lt;0.05). Contribution of GFP expressing clone cells to the ICM varied between 30% and 100% of cells as determined by subjective evaluation of GFP fluorescence overlaying bright-field images. During in vitro outgrowth formation of synchronous aggregation chimeras of clone and wild-type embryos, maintenance of clone contribution to the ICM mound was observed, but at a lower frequency (12% v. 34% at the blastocyst stage). The results suggest that aggregation with fertilized cells does not provide benefit to clone blastomeres during preimplantation stages. Possibly, clone blastomeres may not be competitive with wild-type blastomeres, or are developmentally asynchronous, which will be tested using asynchronous chimeras.

scholarly journals The XO and OY chromosome constitutions in the mouse

1968 ◽  
Vol 12 (2) ◽  
pp. 125-137 ◽  
Author(s):  
T. Morris
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Early Stage ◽  
Blastocyst Stage ◽  
Embryonic Mortality ◽  
Cell Stage ◽  
Large Group ◽  
Pregnant Females ◽  
The Mean

A study was made of reproductive performance and embryonic mortality in XO and XX females. In the stock used, the mean litter size of XO females (4·46) was greatly below that of XX ones (8·17). One series of pregnant females of both karyotypes was dissected after 15 days' gestation, and another series after 3½days' gestation. In the former, there was a significantly greater amount of embryonic mortality in XO females both before implantation and at the small and large mole stages. By far the greater amount occurred before implantation. The data from dissections after 3½ days' gestation concerned pre-implantation embryos, since normal embryos at this point are at the late morula or early blastocyst stage. The embryos from XO females contained a large group of obviously and characteristically abnormal ones; they comprised 60/280 of the embryos from XO females, compared with 4/189 of the XX ones. They appeared to have developed abnormally from a very early stage, probably the two-cell stage, and were considered to represent the missing OY class of zygotes. In addition, it was concluded that there was probably an abnormally low segregation of nullo-X gametes from XO females.

scholarly journals Congenital malformations and minor anomalies in newborns depending on the type of resolved infertility and health of the parents

2021 ◽  
pp. 22-28
Author(s):  
M. K. Soboleva ◽  
D. A. Кinsht
Keyword(s):  
Assisted Reproductive Technology ◽  
Congenital Malformations ◽  
Medical Center ◽  
Reproductive Technologies ◽  
Reproductive Technology ◽  
Blastocyst Stage ◽  
Fertility Treatment ◽  
Complete Continuity ◽  
History Of ◽  
Minor Anomalies

Introduction. The use of  sisted reproductive technologies has had sufficient experience to reduce the risks associated with the technologies themselves. But pediatricians remain concerned about the health of children born from induced pregnancies because of the influence of the parents’ initial health on perinatal outcomes. Congenital malformations remain socially significant, the risk of which may be higher for children from induced pregnancy.Objective: to evaluate the effect of initial parental health and the methods of assisted reproductive technology used on the formation of congenital malformations and minor anomalies in children from singleton induced pregnancies.Materials and Methods. A retrospective cohort study was conducted using data on live-born children from singleton induced pregnancy born at the Avicenna Medical Center (Novosibirsk) over the period from 2007 to 2017 (n = 409). The reproductive, somatic, and infectious history of the parents and the methods of assisted reproductive technology used were assessed. Parental fertility treatment up to childbirth was performed in the same center, which ensured complete continuity of follow-up. Differences between the groups of children from SIP with and without congenital anomalies were determined using Pearson’s chi-squared test.Results and discussion. We found that children with congenital malformations and minor anomalies were more often born as a result of subsequent pregnancies; thawed embryos transferred at the blastocyst stage were used in assisted reproductive technology programs (p < 0.05); exacerbations of herpes type 2 infection were diagnosed during the current pregnancy (p < 0.05). In the group of children with only CM, the parents had a longer history of infertility (8.3 ± 1.2) years; pregnancy was achieved by transferring fresh embryos at the blastocyst stage (in 68.2% of cases). In the group of children without congenital malformations and minor anomalies, the maternal infectious history was more severe: there were significantly more frequent cases of urogenital infections (p < 0.05) and exacerbations of herpes simplex virus type 1 during pregnancy (p < 0.05).Conclusion. A set of measures aimed at an earlier solution of the infertility problem is necessary for the primary prevention of congenital abnormalities associated with the age and duration of parental infertility.

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