Protamine–histone replacement and DNA replication in the male mouse pronucleus

Nonchev, Stefan; Tsanev, Roumen

doi:10.1002/mrd.1080250113

Cited by 105 publications

(59 citation statements)

References 22 publications

(20 reference statements)

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“…The male pronucleus is stripped of the protamines while DNA is actively demethylated and repackaged with newly synthesized histones in the zygote. 61,62 The female complement of chromosomes becomes demethylated via a passive mechanism and stable in their patterns within a mouse throughout its life, implying that the level of methylation is set early in development and stable for life. The distribution of variable expressivity has been shifted at these metastable epialleles following maternal exposure to nutritional and environmental factors.…”

mentioning

confidence: 99%

Timing is everything

2011

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mentioning

confidence: 99%

Timing is everything

2011

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“…these two phases are concomitant with the replacement of the sperm protamines by histones, synthesised during oocyte growth and stocked in the cytoplasm. the result of this nucleoprotein exchange is that the paternal chromatin now drastically expands as the thick smooth bundles of the sperm nucleus are transformed in thin nucleosome bearing fibbers, able to sustain DNA replication (20,26). indeed, the highly relaxed chromatin of both male and female pronuclei is entering the S phase of the first zygotic cell cycle.…”

Section: The Pronuclei -20 Years Latermentioning

confidence: 99%

“…Rumen tsanev developed experimental approaches to address zygote genome activation and pronuclear morphology. Using cell microsurgery combined to electron microscopy, he studied the dynamics of protamine to histone replacement and pronuclear chromatin transformations in freshly fertilised mouse eggs and generated pioneering data about the sequence of events in the first zygotic cell cycle (26), (Fig.1). in this review we want to outline the tremendous advances in this field of research generated by the novels tools and cutting edge technology approaches in imaging and bioinformatics.…”

Section: Introductionmentioning

confidence: 99%

The Pronuclei - 20 Years Later

Nonchev

Cassoly²

2009

Biotechnology & Biotechnological Equipment

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“…A variety of techniques, including autoradiographic detection of tritiated chromatin-associated proteins and immunostaining using antibodies against sperm basic proteins, have established that protamines are removed from sperm chromatin by the end of oocyte anaphase II (Ecklund and Levine, 1975;Kopecny and Pavlok, 1975;Rodman et al, 1981). In a similar way, histones become immunologically detectable before the first round of embryonic DNA replication begins (Nonchev and Tsanev, 1990;Adenot et al, 1997). Nonetheless, the precise timing of histone assembly on to the paternal chromatin at fertilization has not been established.…”

Section: Morphological and Molecular Remodelling Of The Sperm Chromatmentioning

confidence: 99%

Remodelling the paternal chromatin at fertilization in mammals

McLay¹

2003

Reproduction

105

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At fertilization, the highly condensed and transcriptionally inert chromatin of the spermatozoa becomes remodelled into the decondensed and transcriptionally competent chromatin of the male pronucleus. The chromatin initially becomes dispersed and then transiently recondenses into a small mass upon entry into the ooplasm. This morphological change is coincident with and likely dependent on the replacement of the sperm-specific protamines by oocyte-supplied histones and the organization of the chromatin into nucleosomes. The chromatin then extensively decondenses within the male pronucleus and acquires many of the proteins that are associated with the maternal chromatin. Nonetheless, the paternal chromatin manifests distinct characteristics, including transient hyperacetylation of histone H4, increased transcription of endogenous and microinjected genes, and replication-independent demethylation of DNA. Sperm chromatin remodelling is controlled by an oocyte activity that appears during meiotic maturation and disappears approximately 3 h after activation (release from metaphase II arrest), and which requires factors associated with the germinal vesicle of the oocyte. The molecular components of this activity remain largely unknown. In frogs, nucleoplasmin is required to assemble histones H2A and H2B onto the paternal chromatin. Evidence is presented that related proteins may perform similar functions in mammals. Identifying the mechanisms that underlie sperm chromatin remodelling at fertilization may be relevant for understanding reprogramming of somatic cell nuclei after transfer into oocytes.Fertilization achieves two objectives: it re-initiates the cell cycle of the dormant egg, and it produces an embryo that contains one functional copy each of the maternal and paternal genomes. The second objective is ensured through a variety of mechanisms, including the block to polyspermy, the completion of the second meiotic division in the oocyte, and the biochemical remodelling of the sperm chromatin to form the male pronucleus. Remodelling of the paternal chromatin at fertilization is necessary because although the paternal genome is required for embryonic development, the DNA of the mature spermatozoa is compacted and transcriptionally inactive. The process through which this remodelling occurs is reviewed here.Biparental androgenetic and gynogenetic mammalian embryos produced by pronuclear transplantation arrest development at mid-gestation (McGrath and Solter, 1984;Surani et al., 1984). These well-known experiments of McGrath and Solter (1984) and Surani et al.

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Protamine–histone replacement and DNA replication in the male mouse pronucleus

Cited by 105 publications

References 22 publications

Timing is everything

Timing is everything

The Pronuclei - 20 Years Later

Remodelling the paternal chromatin at fertilization in mammals

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