5-Hydroxymethylcytosine in the mammalian zygote is linked with epigenetic reprogramming

Wossidlo, Mark; Nakamura, Toshinobu; Lepikhov, Konstantin; Marques, C. Joana; Zakhartchenko, Valeri; Boiani, Michele; Arand, Julia; Nakano, Toru; Reik, Wolf; Walter, Jörn

doi:10.1038/ncomms1240

Cited by 710 publications

(701 citation statements)

References 32 publications

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“…38 It likely acts through protection against hydroxylation of 5-methylcytosine by the Tet3 protein. 39 5-hydroxymethylcytosine is not recognized by Dnmt1 and thus, without this protection, maternal imprints can be subject to replication-dependent passive demethylation. Zfp57 is an oocytederived maternal factor involved in preimplantation maintenance of both paternal and maternal imprints at multiple loci such as the paternally methylated intergenic ICR (IG-DMR) within the Dlk1-Meg3 locus (Meg3 is also known as Gtl2) and the maternally methylated Mest, Peg3 and Snrpn ICRs (Figure 1).…”

Section: Imprint Maintenance In Early Embryosmentioning

confidence: 99%

Genomic imprinting and its relevance to congenital disease, infertility, molar pregnancy and induced pluripotent stem cell

Tomizawa

Sasaki

2012

J Hum Genet

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Genomic imprinting is an epigenetic gene-marking phenomenon that occurs in the germline, whereby genes are expressed from only one of the two parental copies in embryos and adults. Imprinting is essential for normal mammalian development and its disruption can cause various developmental defects and diseases. The process of imprinting in the germline involves DNA methylation of the imprint control regions (ICRs), and resulting parental-specific methylation imprints are maintained in the zygote and act as the marks controlling imprinted gene expression. Recent studies in mice have revealed new factors involved in imprint establishment during gametogenesis and maintenance during early development. Clinical studies have identified cases of imprinting disorders where involvement of factors shared by multiple ICRs for establishment or maintenance is suspected. These include Beckwith-Wiedemann syndrome, transient neonatal diabetes, Silver-Russell syndrome and others. More severe disruptions can lead to recurrent molar pregnancy, miscarriage or infertility. Imprinting defects may also occur during assisted reproductive technology or cell reprogramming. In this review, we summarize our current knowledge on the mechanisms of imprint establishment and maintenance, and discuss the relationship with various human disorders.

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Section: Imprint Maintenance In Early Embryosmentioning

confidence: 99%

Genomic imprinting and its relevance to congenital disease, infertility, molar pregnancy and induced pluripotent stem cell

Tomizawa

Sasaki

2012

J Hum Genet

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“…Two examples of enzymes that are thought to play a part in active DNA demethylation are growth arrest and DNA damage-inducible 45α (GADD45α) 42 and activation-induced deaminase (AID) 45 . More recently, in mouse eggs and early embryos, the TET enzymes have been shown to help active DNA demethylation by hydroxylating of methylated cytosine [46][47][48] . This active process leads to replication-independent changes in the levels of methylated cytosine in DNA.…”

Section: Histone and Dna Modificationsmentioning

confidence: 99%

Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process?

Jullien

Pasque²,

Halley-Stott³

et al. 2011

Nat Rev Mol Cell Biol

105

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Differentiated cells can be experimentally reprogrammed back to pluripotency by nuclear transfer, cell fusion or induced pluripotent stem cell technology. Nuclear transfer and cell fusion can lead to efficient reprogramming of gene expression. The egg and oocyte reprogramming process includes the exchange of somatic proteins for oocyte proteins, the post-translational modification of histones and the demethylation of DNA. These events occur in an ordered manner and on a defined timescale, indicating that reprogramming by nuclear transfer and by cell fusion rely on deterministic processes.The remarkable stability of cell differentiation under normal conditions can be reversed experimentally by nuclear transfer, cell fusion and induced pluripotent stem (iPS) cell technology [1][2][3][4][5] . This provides an opportunity to generate pluripotent embryonic cells from adult cells of the same individual and hence opens the possibilit y of cell replacement without the need for immunosuppression.iPS cell technology makes use of the overexpression of transcription factors (FIG. 1a) and has been extensively reviewed, so it is not discussed in detail [6][7][8][9] . To generate entirely unrelated cell types by iPS cell technology, treated cells must be grown for multiple cell divisions over a long period of time (up to 3 weeks). By contrast, nuclear transfer and cell fusion do not involve the overexpression of new genes, and instead make use of natura components present in eggs and some early embryos to initiate new transcription.There are two kinds of nuclear transfer experiments: egg-NT involves the transfer of a single somatic nucleus to an unfertilize d enucleated egg (in both mammals and amphibians) 1 (FIG. 1b); and ooc-NT involves the transplantation of multiple somatic cell nuclei into the germinal vesicle (the nucleus) of a growing meiotic prophase amphibian oocyte (an immature egg) 10 (FIG. 1c). Note that the terms egg and oocyte refer to different developmental stages in amphibians and mammals: amphibian eggs are in metaphase II of meiosis, which is equivalent to mouse metaphase II stage oocytes, whereas their immediate precursors, oocytes, are blocked in meiotic prophase I, which is equivalent to mouse germinal vesicle stage oocytes.© 2011 Macmillan Publishers Limited. All rights reserved Correspondence to J.B.G.j.gurdon@gurdon.cam.ac.uk. Competing interests statementThe authors declare no competing financial interests. There are important differences between the two types of nuclear transfer experimen t. Extensive cell division takes place in egg-NT experiments, and functional new cell types appear as the nuclear transplant embryo develops. By contrast, in ooc-NT experiments, no new cell types are formed, and neither the oocyte nor the introduced nuclei divide, but there is a direct transition from nuclei of differentiated cells to reprogrammed nuclei that transcribe pluripotency genes. Analysis of the mechanism of reprogramming (which involves transcription of pluripotency and other genes) in egg-NT expe...

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“…Furthermore, a study of the DNA methylation pattern in human 3PN zygotes established that active demethylation of the paternal PN occurs post-fertilization in both c-IVF and ICSI [32]. In addition, recent studies have shown that the demethylation of paternal PN is induced by conversion from 5mC to 5hmC by ten-eleven translocation methylcytosine dioxygenases (TETs) [9][10][11]. Among TET proteins, TET3 is intensely expressed in oocytes and zygotes.…”

Section: Discussionmentioning

confidence: 99%

“…Recently, it was found that 5-methylcytosine (5mC) in the paternal genome is specifically converted to 5-hydroxymethylcytosine (5hmC) during the pronuclear stage [9][10][11]. Although these three studies were conducted in animals, we applied a similar approach in this study, using epigenetic divergence to determine the origin of mPN and fPN in abnormal human zygotes with 1PN and 3PN.…”

Section: Introductionmentioning

confidence: 99%

Diagnosis of abnormal human fertilization status based on pronuclear origin and/or centrosome number

Kai¹,

Iwata²,

Iba³

et al. 2015

J Assist Reprod Genet

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Purpose Normally fertilized zygotes generally show two pronuclei (2PN) and the extrusion of the second polar body. Conventional in vitro fertilization (c-IVF) and intracytoplasmic sperm injection (ICSI) often result in abnormal monopronuclear (1PN), tripronuclear (3PN), or other polypronuclear zygotes. In this study, we performed combined analyses of the methylation status of pronuclei (PN) and the number of centrosomes, to reveal the abnormal fertilization status in human zygotes. Method We used differences in DNA methylation status (5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC)) to discriminate between male and female PN in human zygotes. These results were also used to analyze the centrosome number to indicate how many sperm entered into the oocyte. Result Immunofluorescent analysis shows that all of the normal 2PN zygotes had one 5mC/5hmC double-positive PN and one 5mC-positive PN, whereas a parthenogenetically activated oocyte had only 5mC staining of the PN. All of the zygotes derived from ICSI (1PN, 3PN) had two centrosomes as did all of the 2PN zygotes derived from c-IVF. Of the 1PN zygotes derived from c-IVF, more than 50 % had staining for both 5mC and 5hmC in a single PN, and one or two centrosomes, indicating fertilization by a single sperm. Meanwhile, most of 3PN zygotes derived from c-IVF had a 5mC-positive PN and two 5mC/5hmC double-positive PNs, and had four or five centrosomes, suggesting polyspermy. Conclusions We have established a reliable method to identify the PN origin based on the epigenetic status of the genome and have complemented these results by counting the centrosomes of zygotes.

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5-Hydroxymethylcytosine in the mammalian zygote is linked with epigenetic reprogramming

Cited by 710 publications

References 32 publications

Genomic imprinting and its relevance to congenital disease, infertility, molar pregnancy and induced pluripotent stem cell

Genomic imprinting and its relevance to congenital disease, infertility, molar pregnancy and induced pluripotent stem cell

Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process?

Diagnosis of abnormal human fertilization status based on pronuclear origin and/or centrosome number

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