scholarly journals Chromosome hydroxymethylation patterns in human zygotes and cleavage-stage embryos

Reproduction ◽  
2015 ◽  
Vol 149 (3) ◽  
pp. 223-233 ◽  
Author(s):  
Olga A Efimova ◽  
Anna A Pendina ◽  
Andrei V Tikhonov ◽  
Irina D Fedorova ◽  
Mikhail I Krapivin ◽  
...  
Keyword(s):  
Preimplantation Embryos ◽  
Parental Origin ◽  
Cleavage Stage ◽  
Metaphase Chromosomes ◽  
Parental Chromosome ◽  
Sister Chromatids ◽  
Methylation Patterns ◽  
Chromosome Bands ◽  
Human Zygotes ◽  
Zygotic Genome

We report the sequential changes in 5-hydroxymethylcytosine (5hmC) patterns in the genome of human preimplantation embryos during DNA methylation reprogramming. We have studied chromosome hydroxymethylation and methylation patterns in triploid zygotes and blastomeres of cleavage-stage embryos. Using indirect immunofluorescence, we have analyzed the localization of 5hmC and its co-distribution with 5-methylcytosine (5mC) on the QFH-banded metaphase chromosomes. In zygotes, 5hmC accumulates in both parental chromosome sets, but hydroxymethylation is more intensive in the poorly methylated paternal set. In the maternal set, chromosomes are highly methylated, but contain little 5hmC. Hydroxymethylation is highly region specific in both parental chromosome sets: hydroxymethylated loci correspond to R-bands, but not G-bands, and have well-defined borders, which coincide with the R/G-band boundaries. The centromeric regions and heterochromatin at 1q12, 9q12, 16q11.2, and Yq12 contain little 5mC and no 5hmC. We hypothesize that 5hmC may mark structural/functional genome ‘units’ corresponding to chromosome bands in the newly formed zygotic genome. In addition, we suggest that the hydroxymethylation of R-bands in zygotes can be treated as a new characteristic distinguishing them from G-bands. At cleavages, chromosomes with asymmetrical hydroxymethylation of sister chromatids appear. They decrease in number during cleavages, whereas totally non-hydroxymethylated chromosomes become numerous. Taken together, our findings suggest that, in the zygotic genome, 5hmC is distributed selectively and its pattern is determined by both parental origin of chromosomes and type of chromosome bands – R, G, or C. At cleavages, chromosome hydroxymethylation pattern is dynamically changed due to passive and non-selective overall loss of 5hmC, which coincides with that of 5mC.

DNA Methylation Patterns of Metaphase Chromosomes in Human Preimplantation Embryos

2011 ◽  
Vol 132 (1-2) ◽  
pp. 1-7 ◽  
Author(s):  
A.A. Pendina ◽  
O.A. Efimova ◽  
I.D. Fedorova ◽  
O.A. Leont’eva ◽  
E.M. Shilnikova ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Preimplantation Embryos ◽  
Metaphase Chromosomes ◽  
Methylation Patterns ◽  
Human Preimplantation Embryos

Asymmetric DNA methylation between sister chromatids of metaphase chromosomes in mouse embryos upon bisphenol A action

2017 ◽  
Vol 74 ◽  
pp. 1-9 ◽  
Author(s):  
E.L. Patkin ◽  
N.A. Grudinina ◽  
L.K. Sasina ◽  
E.M. Noniashvili ◽  
L.I. Pavlinova ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Bisphenol A ◽  
Mouse Embryos ◽  
Metaphase Chromosomes ◽  
Sister Chromatids

scholarly journals Inhibition of DRP1 Impedes Zygotic Genome Activation and Preimplantation Development in Mice

2021 ◽  
Vol 9 ◽  
Author(s):  
Yuanyuan Li ◽  
Ning-Hua Mei ◽  
Gui-Ping Cheng ◽  
Jing Yang ◽  
Li-Quan Zhou
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryos ◽  
Dependent Manner ◽  
Zygotic Genome Activation ◽  
Preimplantation Embryo Development ◽  
Cell Embryo ◽  
Embryo Stage ◽  
Genome Activation ◽  
Zygotic Genome

Mitochondrion plays an indispensable role during preimplantation embryo development. Dynamic-related protein 1 (DRP1) is critical for mitochondrial fission and controls oocyte maturation. However, its role in preimplantation embryo development is still lacking. In this study, we demonstrate that inhibition of DRP1 activity by mitochondrial division inhibitor-1, a small molecule reported to specifically inhibit DRP1 activity, can cause severe developmental arrest of preimplantation embryos in a dose-dependent manner in mice. Meanwhile, DRP1 inhibition resulted in mitochondrial dysfunction including decreased mitochondrial activity, loss of mitochondrial membrane potential, reduced mitochondrial copy number and inadequate ATP by disrupting both expression and activity of DRP1 and mitochondrial complex assembly, leading to excessive ROS production, severe DNA damage and cell cycle arrest at 2-cell embryo stage. Furthermore, reduced transcriptional and translational activity and altered histone modifications in DRP1-inhibited embryos contributed to impeded zygotic genome activation, which prevented early embryos from efficient development beyond 2-cell embryo stage. These results show that DRP1 inhibition has potential cytotoxic effects on mammalian reproduction, and DRP1 inhibitor should be used with caution when it is applied to treat diseases. Additionally, this study improves our understanding of the crosstalk between mitochondrial metabolism and zygotic genome activation.

scholarly journals Electron microscopy of gold-labeled human and equine chromosomes.

1989 ◽  
Vol 37 (9) ◽  
pp. 1443-1447 ◽  
Author(s):  
P E Messier ◽  
R Drouin ◽  
C L Richer
Keyword(s):  
Electron Microscopy ◽  
Chromosome Banding ◽  
Protein A ◽  
Gold Complex ◽  
Chromosome Identification ◽  
Chromosomal Dna ◽  
Metaphase Chromosomes ◽  
Sister Chromatids ◽  
Antigen Localization ◽  
Chromatin Reorganization

We present an immunochemical technique for the detection of 5-bromo-2'-deoxyuridine (BrdU) incorporated discontinuously into the chromosomal DNA. A monoclonal anti-BrdU antibody and a protein A-gold complex were used to produce chromosome banding of human and equine chromosomes, specific for electron microscopy (EM). Well-defined bands, symmetry of sister chromatids, concordance between homologues, and band patterns similar to those observed by light microscopy facilitate chromosome identification and karyotyping. From prophase to late metaphase, chromosomes condense and bands appear to fuse. The fusion appears to be owing to chromatin reorganization. Our results underline the value of using immunogold reagents, which are ideal probes for antigen localization on chromosomes.

Parental origin of chromatin in human monopronuclear zygotes revealed by asymmetric histone methylation patterns, differs between IVF and ICSI

2009 ◽  
Vol 76 (1) ◽  
pp. 101-108 ◽  
Author(s):  
G.W. van der Heijden ◽  
I.M. van den Berg ◽  
E.B. Baart ◽  
A.A.H.A. Derijck ◽  
E. Martini ◽  
...  
Keyword(s):  
Histone Methylation ◽  
Parental Origin ◽  
Methylation Patterns

scholarly journals Mouse satellite DNA, centromere structure, and sister chromatid pairing.

1986 ◽  
Vol 103 (4) ◽  
pp. 1145-1151 ◽  
Author(s):  
L M Lica ◽  
S Narayanswami ◽  
B A Hamkalo
Keyword(s):  
Electron Microscopy ◽  
Sister Chromatid ◽  
Satellite Dna ◽  
Marker Chromosome ◽  
Restriction Enzymes ◽  
Centromeric Heterochromatin ◽  
Mitotic Chromosomes ◽  
Metaphase Chromosomes ◽  
Sister Chromatids ◽  
Mouse Satellite Dna

The experiments described were directed toward understanding relationships between mouse satellite DNA, sister chromatid pairing, and centromere function. Electron microscopy of a large mouse L929 marker chromosome shows that each of its multiple constrictions is coincident with a site of sister chromatid contact and the presence of mouse satellite DNA. However, only one of these sites, the central one, possesses kinetochores. This observation suggests either that satellite DNA alone is not sufficient for kinetochore formation or that when one kinetochore forms, other potential sites are suppressed. In the second set of experiments, we show that highly extended chromosomes from Hoechst 33258-treated cells (Hilwig, I., and A. Gropp, 1973, Exp. Cell Res., 81:474-477) lack kinetochores. Kinetochores are not seen in Miller spreads of these chromosomes, and at least one kinetochore antigen is not associated with these chromosomes when they were subjected to immunofluorescent analysis using anti-kinetochore scleroderma serum. These data suggest that kinetochore formation at centromeric heterochromatin may require a higher order chromatin structure which is altered by Hoechst binding. Finally, when metaphase chromosomes are subjected to digestion by restriction enzymes that degrade the bulk of mouse satellite DNA, contact between sister chromatids appears to be disrupted. Electron microscopy of digested chromosomes shows that there is a significant loss of heterochromatin between the sister chromatids at paired sites. In addition, fluorescence microscopy using anti-kinetochore serum reveals a greater inter-kinetochore distance than in controls or chromosomes digested with enzymes that spare satellite. We conclude that the presence of mouse satellite DNA in these regions is necessary for maintenance of contact between the sister chromatids of mouse mitotic chromosomes.

scholarly journals What makes the maternal X chromosome resistant to undergoing imprinted X inactivation?

2017 ◽  
Vol 372 (1733) ◽  
pp. 20160365 ◽  
Author(s):  
Takashi Sado
Keyword(s):  
X Chromosome ◽  
Chromatin Structure ◽  
Noncoding Rna ◽  
X Inactivation ◽  
Preimplantation Embryos ◽  
Parental Origin ◽  
Random Fashion ◽  
In Cis ◽  
Mary Lyon ◽  
Extraembryonic Tissues

In the mouse, while either X chromosome is chosen for inactivation in a random fashion in the embryonic tissue, the paternally derived X chromosome is preferentially inactivated in the extraembryonic tissues. It has been shown that the maternal X chromosome is imprinted so as not to undergo inactivation in the extraembryonic tissues. X-linked noncoding Xist RNA becomes upregulated on the X chromosome that is to be inactivated. An antisense noncoding RNA, Tsix , which occurs at the Xist locus and has been shown to negatively regulate Xist expression in cis, is imprinted to be expressed from the maternal X in the extraembryonic tissues. Although Tsix appears to be responsible for the imprint laid on the maternal X, those who disagree with this idea would point out the fact that Tsix has not yet been expressed from the maternal X when Xist becomes upregulated on the paternal but not the maternal X at the onset of imprinted X-inactivation in preimplantation embryos. Recent studies have demonstrated, however, that there is a prominent difference in the chromatin structure at the Xist locus depending on the parental origin, which I suggest might account for the repression of maternal Xist in the absence of maternal Tsix at the preimplantation stages. This article is part of the themed issue ‘X-chromosome inactivation: a tribute to Mary Lyon’.

scholarly journals Maternally expressed NLRP2 links the subcortical maternal complex (SCMC) to fertility, embryogenesis and epigenetic reprogramming

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Sangeetha Mahadevan ◽  
Varsha Sathappan ◽  
Budi Utama ◽  
Isabel Lorenzo ◽  
Khalied Kaskar ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Embryonic Development ◽  
Subcellular Localization ◽  
Crucial Role ◽  
Preimplantation Embryos ◽  
Maternal Genome ◽  
Embryonic Loss ◽  
Cytoplasmic Complex ◽  
Zygotic Genome

Abstract Mammalian parental genomes contribute differently to early embryonic development. Before activation of the zygotic genome, the maternal genome provides all transcripts and proteins required for the transition from a highly specialized oocyte to a pluripotent embryo. Depletion of these maternally-encoded transcripts frequently results in failure of preimplantation embryonic development, but their functions in this process are incompletely understood. We found that female mice lacking NLRP2 are subfertile because of early embryonic loss and the production of fewer offspring that have a wide array of developmental phenotypes and abnormal DNA methylation at imprinted loci. By demonstrating that NLRP2 is a member of the subcortical maternal complex (SCMC), an essential cytoplasmic complex in oocytes and preimplantation embryos with poorly understood function, we identified imprinted postzygotic DNA methylation maintenance, likely by directing subcellular localization of proteins involved in this process, such as DNMT1, as a new crucial role of the SCMC for mammalian reproduction.

scholarly journals Mitochondrial DNA Copy Number in Cleavage Stage Human Embryos—Impact on Infertility Outcome

2022 ◽  
Vol 44 (1) ◽  
pp. 273-287
Author(s):  
Amira Podolak ◽  
Joanna Liss ◽  
Jolanta Kiewisz ◽  
Sebastian Pukszta ◽  
Celina Cybulska ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Copy Number ◽  
Human Reproduction ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Embryo Morphology ◽  
Cleavage Stage ◽  
Mtdna Copy Number ◽  
Developmental Potential ◽  
Mitochondrial Dna Copy Number

A retrospective case control study was undertaken at the molecular biology department of a private center for reproductive medicine in order to determine whether any correlation exists between mitochondrial DNA (mtDNA) content of cleavage-stage preimplantation embryos and their developmental potential. A total of 69 couples underwent IVF treatment (averaged women age: 36.5, SD 4.9) and produced a total of 314 embryos. A single blastomere was biopsied from each embryo at the cleavage stage (day-3 post-fertilization) subjected to low-pass next generation sequencing (NGS), for the purpose of detecting aneuploidy. For each sample, the number of mtDNA reads obtained after analysis using NGS was divided by the number of reads attributable to the nuclear genome. The mtDNA copy number amount was found to be higher in aneuploid embryos than in those that were euploid (mean mtDNA ratio ± SD: 6.3 ± 7.5 versus 7.1 ± 5.8, p < 0.004; U Mann–Whitney test), whereas no statistically significant differences in mtDNA content were seen in relation to embryo morphology (6.6 ± 4.8 vs. 8.5 ± 13.6, p 0.09), sex (6.6 ± 4.1 vs. 6.2 ± 6.8, p 0.16), maternal age (6.9 ± 7.8 vs. 6.7 ± 4.5, p 0.14) or its ability to implant (7.4 ± 6.6 vs. 5.1 ± 4.6, p 0.18). The mtDNA content cannot serve as a useful biomarker at this point in development. However, further studies investigating both quantitative and qualitative aspects of mtDNA are still required to fully evaluate the relationship between mitochondrial DNA and human reproduction.

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