DNA methylation pattern in mouse oocytes and their in vitro fertilized early embryos: effect of oocyte vitrification

Zygote ◽  
2012 ◽  
Vol 22 (2) ◽  
pp. 138-145 ◽  
Author(s):  
Ying Liang ◽  
Xiang-Wei Fu ◽  
Jun-Jie Li ◽  
Dian-Shuai Yuan ◽  
Shi-En Zhu
Keyword(s):  
Dna Methylation ◽  
Fluorescein Isothiocyanate ◽  
Methylation Pattern ◽  
Oocyte Vitrification ◽  
Developmental Potential ◽  
Mouse Oocytes ◽  
Early Embryos ◽  
Vitrification Solution ◽  
Early Mouse

SummaryThis study was conducted to investigate the pattern of DNA methylation in vitrified–thawed mouse oocytes and their in vitro fertilized early embryos. Firstly, mouse oocytes at metaphase II (MII) stage of meiosis were allocated randomly into three groups: (1) untreated (control); (2) exposed to vitrification solution without being plunged into liquid nitrogen (toxicity); or (3) vitrified by open-pulled straw (OPS) method (vitrification). Oocytes from all three groups were fertilized subsequently in vitro. The level of DNA methylation in the MII oocytes and their early embryos was then examined by immunofluorescence using an anti-5-methylcytosine (anti-5-MeC) monoclonal antibody and fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG. Developmental rates to 2-cell embryos (62.28%) and blastocysts (43.68%) of the vitrified–thawed oocytes were lower (P < 0.01) than those of fresh oocytes (81.47%, 61.99%) and vitrification solution treated (79.20%, 60.04%) oocytes. DNA methylation (as reflected by 5-MeC fluorescence intensity) in the vitrification group was less (P < 0.01) for MII oocyte and 2- to 8-cell stages compared with that in the control and toxicity groups. Accordingly, a reduction in global genomic methylation due to vitrification of MII oocytes may result in compromised in vitro developmental potential in early mouse embryos.

Defective zonae pellucidae in Zp2-null mice disrupt folliculogenesis, fertility and development

Development ◽  
2001 ◽  
Vol 128 (7) ◽  
pp. 1119-1126 ◽  
Author(s):  
T.L. Rankin ◽  
M. O'Brien ◽  
E. Lee ◽  
K. Wigglesworth ◽  
J. Eppig ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Embryonic Stem ◽  
Single Copy ◽  
Targeted Mutagenesis ◽  
Developmental Competence ◽  
Normal Male ◽  
Null Mouse ◽  
Developmental Potential ◽  
Early Embryos

All vertebrate eggs are surrounded by an extracellular matrix. This matrix is known as the zona pellucida in mammals and is critically important for the survival of growing oocytes, successful fertilization and the passage of early embryos through the oviduct. The mouse zona pellucida is composed of three glycoproteins (ZP1, ZP2 and ZP3), each encoded by a single copy gene. Using targeted mutagenesis in embryonic stem cells, Zp2-null mouse lines have been established. ZP1 and ZP3 proteins continue to be synthesized and form a thin zona matrix in early follicles that is not sustained in pre-ovulatory follicles. The abnormal zona matrix does not affect initial folliculogenesis, but there is a significant decrease in the number of antral stage follicles in ovaries isolated from mice lacking a zona pellucida. Few eggs are detected in the oviduct after stimulation with gonadotropins, and no two-cell embryos are recovered after mating Zp2-null females with normal male mice. The structural defect is more severe than that observed in Zp1-null mice, which have decreased fecundity, but not quite as severe as that observed in Zp3-null mice, which never form a visible zona pellucida and are sterile. Although zona-free oocytes matured and fertilized in vitro can progress to the blastocyst stage, the developmental potential of blastocysts derived from either Zp2- or Zp3-null eggs appears compromised and, after transfer to foster mothers, live births have not been observed. Thus, in addition to its role in fertilization and protection of early embryos, these data are consistent with the zona pellucida maintaining interactions between granulosa cells and oocytes during folliculogenesis that are critical to maximize developmental competence of oocytes.

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.

scholarly journals Methylation pattern polymorphism of cyp19a in Nile tilapia and hybrids

2018 ◽  
Vol 13 (1) ◽  
pp. 327-334 ◽  
Author(s):  
Xiaowu Chen ◽  
Yonghua Zhao ◽  
Yudong He ◽  
Jinliang Zhao
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Methylation Level ◽  
Molecular Mechanisms ◽  
Methylation Pattern ◽  
Male Ratio ◽  
Sex Development ◽  
Pattern Polymorphism ◽  
Fish Hybrids

AbstractSkewed sex development is prevalent in fish hybrids. However, the histological observation and molecular mechanisms remain elusive. In this study, we showed that the interspecific hybrids of the two fish species, Oreochromis niloticus and Oreochromis aureus, had a male ratio of 98.02%. Microscopic examination revealed that the gonads of both male and female hybrids were developmentally retarded. Compared with the ovaries, the testes of both O. niloticus and hybrids showed higher DNA methylation level in two selected regions in the promoter of cyp19a, the gonadal aromatase gene that converts androgens into estrogens, cyp19a showed higher level gene expression in the ovary than in the testis in both O. niloticus and hybrid tilapia. Methylation and gene expression level of cyp19a were negative correlation between the testis and ovary. Gene transcription was suppressed by the methylation of the cyp19a promoter in vitro. While there is no obvious difference of the methylation level in testis or ovary between O. niloticus and hybrids. Thus, the DNA methylation of the promoter of cyp19a may be an essential component of the sex maintenance, but not a determinant of high male ratio and developmental retardation of gonads in tilapia hybrids.

scholarly journals Dnmt1 binds and represses genomic retroelements via DNA methylation in mouse early embryos

2020 ◽  
Vol 48 (15) ◽  
pp. 8431-8444 ◽  
Author(s):  
Byungkuk Min ◽  
Jung Sun Park ◽  
Young Sun Jeong ◽  
Kyuheum Jeon ◽  
Yong-Kook Kang
Keyword(s):  
Dna Methylation ◽  
Cpg Islands ◽  
Endogenous Retrovirus ◽  
Dna Demethylation ◽  
Mouse Development ◽  
Genome Wide ◽  
Early Embryos ◽  
Dna Adenine Methylase ◽  
Early Mouse ◽  
Early Developmental

Abstract Genome-wide passive DNA demethylation in cleavage-stage mouse embryos is related to the cytoplasmic localization of the maintenance methyltransferase DNMT1. However, recent studies provided evidences of the nuclear localization of DNMT1 and its contribution to the maintenance of methylation levels of imprinted regions and other genomic loci in early embryos. Using the DNA adenine methylase identification method, we identified Dnmt1-binding regions in four- and eight-cell embryos. The unbiased distribution of Dnmt1 peaks in the genic regions (promoters and CpG islands) as well as the absence of a correlation between the Dnmt1 peaks and the expression levels of the peak-associated genes refutes the active participation of Dnmt1 in the transcriptional regulation of genes in the early developmental period. Instead, Dnmt1 was found to associate with genomic retroelements in a greatly biased fashion, particularly with the LINE1 (long interspersed nuclear elements) and ERVK (endogenous retrovirus type K) sequences. Transcriptomic analysis revealed that the transcripts of the Dnmt1-enriched retroelements were overrepresented in Dnmt1 knockdown embryos. Finally, methyl-CpG-binding domain sequencing proved that the Dnmt1-enriched retroelements, which were densely methylated in wild-type embryos, became demethylated in the Dnmt1-depleted embryos. Our results indicate that Dnmt1 is involved in the repression of retroelements through DNA methylation in early mouse development.

80 DNA METHYLATION OF INSULIN-LIKE GROWTH FACTOR 2 (IGF2) GENE IN DAY 14 IN VITRO-PRODUCED BOVINE EMBRYOS OF DIFFERENT SIZES

2015 ◽  
Vol 27 (1) ◽  
pp. 133
Author(s):  
J. O. Carvalho ◽  
M. M. Franco ◽  
G. M. Machado ◽  
M. A. N. Dode
Keyword(s):  
Dna Methylation ◽  
Growth Factor ◽  
Embryo Development ◽  
Methylation Pattern ◽  
Lower Percentage ◽  
Insulin Like Growth Factor ◽  
Bovine Embryos ◽  
Igf2 Gene ◽  
Exon 10

In mammals, a correct DNA methylation reprogramming and the maintenance of genomic imprinting after fertilization are essential for embryo development and pregnancy. One important imprinted gene, related to embryo development and placentation, is the insulin-like growth factor 2 (IGF2) gene. Therefore, embryos with different sizes could show differences in the methylation pattern of IGF2 gene. The aim of this study was to evaluate the methylation pattern of the differentially methylated region (DMR) located within exon 10 of the IGF2 gene, of in vitro-produced Nellore bovine embryos that were different in size on day D14 of development. The embryos were produced from oocytes obtained by follicular aspiration of slaughter house ovaries. On D7 after in vitro fertilization only grade I blastocysts were selected and, in groups of 10 embryos, were transferred non-surgically to the uteri of previously synchronized recipients with similar conditions. Seven days after being transferred, embryos were collected (Day 14 of development) and measured using Motic Images Plus 2.0 program (Motic, Richmond, BC, Canada). Embryos >45 mm were considered large (L) and those <25 mm were considered small (S). After being measured, a portion of each trophoblast layer was biopsied and used to determine the methylation status of the IGF2 gene by bisulfite sequencing. The methylation pattern was evaluated on individual embryos considered as separate replicates. At least 5 to 8 clones were evaluated per embryo and the sequences were analysed with the BiQAnalyser software (Max-Planck-Institut für Informatik, Saarbrücken, Germany), using the GenBank sequence NM_174087.3 as reference. The methylation pattern of the different groups was compared using Kruskal-Wallis test (P < 0.05). No differences in DNA methylation were found between S (26.7 ± 8.3%, n = 37 clones, 5 embryos) and L (34.8 ± 2.9%, n = 20 clones, 4 embryos) embryos. It is already known that the region studied is hypermethylated in sperm and hypomethylated in oocytes and, in some somatic cell types, it is expected to be around 50% methylated, being an imprinted region. Although we found a lower percentage of methylation than that expected for an imprinted region, this pattern may be the physiological pattern for trophoblast cells. This is the first report describing the methylation pattern of this region of the IGF2 gene in Day 14 bovine embryos of different sizes. It can be concluded that the methylation pattern of the intragenic DMR on exon 10 of IGF2 gene of in vitro-produced embryos on Day 14 of development is not affected by embryo size.This work was supported by CNPq, FAP-DF.

Effect of trichostatin A on fertilization and embryo development during extended culture of mouse oocyte

Zygote ◽  
2011 ◽  
Vol 20 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Byung Chul Jee ◽  
Jun Woo Jo ◽  
Jung Ryeol Lee ◽  
Chang Suk Suh ◽  
Seok Hyun Kim ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Embryo Development ◽  
Trichostatin A ◽  
Formation Rate ◽  
Control Group ◽  
Blastocyst Formation ◽  
Developmental Potential ◽  
Extended Culture ◽  
Mouse Oocytes

SummaryWe performed this study to investigate the effect of histone deacetylase inhibition during extended culture of in vitro matured mouse oocytes. In vitro matured mouse (BDF1) oocytes were cultured in vitro for 6, 12, and 24 h, respectively, and then inseminated. During in vitro culture for 6 and 12 h, two doses of trichostatin A (TSA), a histone deacetylase inhibitor, were added (100 nM and 500 nM) to the culture medium and the oocytes were then inseminated. During the 24-h in vitro culture, two doses of TSA were added (100 nM and 500 nM) to the medium and the oocytes were activated with 10 mM SrCl2. After the 6-h culture, the fertilization rate was similar to that of the control group, but the blastocyst formation rate was significantly decreased. After the 12-h culture, both the fertilization and blastocyst formation rates were significantly decreased. After the 24-h culture, total fertilization failure occurred. In the oocytes cultured for 6 and 12 h, the fertilization and blastocyst formation rates did not differ between the TSA-supplemented and control groups. Although extended culture of the mouse oocytes significantly affected their fertilization and embryo development, TSA supplementation did not overcome their decreased developmental potential.

scholarly journals Reprogramming DNA methylation in the mammalian life cycle: building and breaking epigenetic barriers

2013 ◽  
Vol 368 (1609) ◽  
pp. 20110330 ◽  
Author(s):  
Stefanie Seisenberger ◽  
Julian R. Peat ◽  
Timothy A. Hore ◽  
Fátima Santos ◽  
Wendy Dean ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Life Cycle ◽  
Cell Fate ◽  
Excision Repair ◽  
Primordial Germ Cells ◽  
Biological Significance ◽  
Epigenetic Reprogramming ◽  
Developmental Potential ◽  
Methylation Patterns

In mammalian development, epigenetic modifications, including DNA methylation patterns, play a crucial role in defining cell fate but also represent epigenetic barriers that restrict developmental potential. At two points in the life cycle, DNA methylation marks are reprogrammed on a global scale, concomitant with restoration of developmental potency. DNA methylation patterns are subsequently re-established with the commitment towards a distinct cell fate. This reprogramming of DNA methylation takes place firstly on fertilization in the zygote, and secondly in primordial germ cells (PGCs), which are the direct progenitors of sperm or oocyte. In each reprogramming window, a unique set of mechanisms regulates DNA methylation erasure and re-establishment. Recent advances have uncovered roles for the TET3 hydroxylase and passive demethylation, together with base excision repair (BER) and the elongator complex, in methylation erasure from the zygote. Deamination by AID, BER and passive demethylation have been implicated in reprogramming in PGCs, but the process in its entirety is still poorly understood. In this review, we discuss the dynamics of DNA methylation reprogramming in PGCs and the zygote, the mechanisms involved and the biological significance of these events. Advances in our understanding of such natural epigenetic reprogramming are beginning to aid enhancement of experimental reprogramming in which the role of potential mechanisms can be investigated in vitro . Conversely, insights into in vitro reprogramming techniques may aid our understanding of epigenetic reprogramming in the germline and supply important clues in reprogramming for therapies in regenerative medicine.

scholarly journals Deoxyribonucleic Acid Methylation Controls Cell Type-Specific Expression of Steroidogenic Factor 1

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5599-5609 ◽  
Author(s):  
Erling A. Hoivik ◽  
Linda Aumo ◽  
Reidun Aesoy ◽  
Haldis Lillefosse ◽  
Aurélia E. Lewis ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Rna Polymerase Ii ◽  
Methylation Status ◽  
Endocrine System ◽  
Methylation Pattern ◽  
Proximal Promoter ◽  
Specific Expression ◽  
Steroidogenic Factor 1 ◽  
In Cells

Steroidogenic factor 1 (SF1) is expressed in a time- and cell-specific manner in the endocrine system. In this study we present evidence to support that methylation of CpG sites located in the proximal promoter of the gene encoding SF1 contributes to the restricted expression pattern of this nuclear receptor. DNA methylation analyses revealed a nearly perfect correlation between the methylation status of the proximal promoter and protein expression, such that it was hypomethylated in cells that express SF1 but hypermethylated in nonexpressing cells. Moreover, in vitro methylation of this region completely repressed reporter gene activity in transfected steroidogenic cells. Bisulfite sequencing of DNA from embryonic tissue demonstrated that the proximal promoter was unmethylated in the developing testis and ovary, whereas it was hypermethylated in tissues that do not express SF1. Together these results indicate that the DNA methylation pattern is established early in the embryo and stably inherited thereafter throughout development to confine SF1 expression to the appropriate tissues. Chromatin immunoprecipitation analyses revealed that the transcriptional activator upstream stimulatory factor 2 and RNA polymerase II were specifically recruited to this DNA region in cells in which the proximal promoter is hypomethylated, providing functional support for the fact that lack of methylation corresponds to a transcriptionally active gene. In conclusion, we identified a region within the SF1/Sf1 gene that epigenetically directs cell-specific expression of SF1.

scholarly journals Full-term development of enucleated mouse oocytes fused with embryonic stem cells from different cell lines

Reproduction ◽  
2001 ◽  
pp. 729-733 ◽  
Author(s):  
T Amano ◽  
Y Kato ◽  
Y Tsunoda
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Cell Lines ◽  
Formation Rate ◽  
Embryonic Stem ◽  
Clear Correlation ◽  
Developmental Potential ◽  
Mouse Oocytes

The developmental potential of enucleated mouse oocytes receiving embryonic stem cells from ten lines with either the same or different genetic backgrounds using the cell fusion method was examined in vitro and in vivo. The development of nuclear-transferred oocytes into blastocysts was high (34-88%). However, there was no clear correlation between development into blastocysts after nuclear transfer and the chimaera formation rate of embryonic stem cells. The development into live young was low (1-3%) in all cell lines and 14 of 19 young died shortly after birth. Most of the live young had morphological abnormalities. Of the five remaining mice, two died at days 23 and 30 after birth, but the other three mice are still active at days 359 (mouse 1) and 338 (mice 4 and 5) after birth, with normal fertility. However, the reasons for the abnormalities and postnatal death of embryonic stem cell-derived mice are unknown.

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