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Shikata D, Yamamoto T, Honda S, Ikeda S, Minami N. H4K20 monomethylation inhibition causes loss of genomic integrity in mouse preimplantation embryos. J Reprod Dev 2020; 66:411-419. [PMID: 32378528 PMCID: PMC7593633 DOI: 10.1262/jrd.2020-036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Maintaining genomic integrity in mammalian early embryos, which are deficient in DNA damage repair, is critical for normal preimplantation and subsequent
development. Abnormalities in DNA damage repair in preimplantation embryos can cause not only developmental arrest, but also diseases such as congenital
disorders and cancers. Histone H4 lysine 20 monomethylation (H4K20me1) is involved in DNA damage repair and regulation of gene expression. However, little is
known about the role of H4K20me1 during mouse preimplantation development. In this study, we revealed that H4K20me1 mediated by SETD8 is involved in maintaining
genomic integrity. H4K20me1 was present throughout preimplantation development. In addition, reduction in the level of H4K20me1 by inhibition of SETD8 activity
or a dominant-negative mutant of histone H4 resulted in developmental arrest at the S/G2 phase and excessive accumulation of DNA double-strand breaks. Together,
our results suggest that H4K20me1, a type of epigenetic modification, is associated with the maintenance of genomic integrity and is essential for
preimplantation development. A better understanding of the mechanisms involved in maintaining genome integrity during preimplantation development could
contribute to advances in reproductive medicine and technology.
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Affiliation(s)
- Daiki Shikata
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Takuto Yamamoto
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Shinnosuke Honda
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Shuntaro Ikeda
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Naojiro Minami
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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2
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Lin CJ, Koh FM, Wong P, Conti M, Ramalho-Santos M. Hira-mediated H3.3 incorporation is required for DNA replication and ribosomal RNA transcription in the mouse zygote. Dev Cell 2014; 30:268-79. [PMID: 25087892 DOI: 10.1016/j.devcel.2014.06.022] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 05/09/2014] [Accepted: 06/25/2014] [Indexed: 10/25/2022]
Abstract
Extensive chromatin reprogramming occurs at fertilization and is thought to be under the control of maternal factors, but the underlying mechanisms remain poorly understood. We report that maternal Hira, a chaperone for the histone variant H3.3, is required for mouse development past the zygote stage. Male pronucleus formation is inhibited upon deletion of Hira due to a lack of nucleosome assembly in the sperm genome. Hira mutant oocytes are incapable of developing parthenogenetically, indicative of a role for Hira in the female genome. Both parental genomes show highly reduced levels of DNA replication and transcription in the mutants. It has long been thought that transcription is not required for zygote development. Surprisingly, we found that Hira/H3.3-dependent transcription of ribosomal RNA is required for first cleavage. Our results demonstrate that Hira-mediated H3.3 incorporation is essential for parental genome reprogramming and reveal an unexpected role for rRNA transcription in the mouse zygote.
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Affiliation(s)
- Chih-Jen Lin
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, 35 Medical Center Way, San Francisco, CA 94143, USA
| | - Fong Ming Koh
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, 35 Medical Center Way, San Francisco, CA 94143, USA
| | - Priscilla Wong
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, 35 Medical Center Way, San Francisco, CA 94143, USA
| | - Marco Conti
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, 35 Medical Center Way, San Francisco, CA 94143, USA
| | - Miguel Ramalho-Santos
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Center for Reproductive Sciences, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, 35 Medical Center Way, San Francisco, CA 94143, USA.
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3
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Hajkova P, Jeffries SJ, Lee C, Miller N, Jackson SP, Surani MA. Genome-wide reprogramming in the mouse germ line entails the base excision repair pathway. Science 2010; 329:78-82. [PMID: 20595612 DOI: 10.1126/science.1187945] [Citation(s) in RCA: 345] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Genome-wide active DNA demethylation in primordial germ cells (PGCs), which reprograms the epigenome for totipotency, is linked to changes in nuclear architecture, loss of histone modifications, and widespread histone replacement. Here, we show that DNA demethylation in the mouse PGCs is mechanistically linked to the appearance of single-stranded DNA (ssDNA) breaks and the activation of the base excision repair (BER) pathway, as is the case in the zygote where the paternal pronucleus undergoes active DNA demethylation shortly after fertilization. Whereas BER might be triggered by deamination of a methylcytosine (5mC), cumulative evidence indicates other mechanisms in germ cells. We demonstrate that DNA repair through BER represents a core component of genome-wide DNA demethylation in vivo and provides a mechanistic link to the extensive chromatin remodeling in developing PGCs.
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Affiliation(s)
- Petra Hajkova
- Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.,MRC Clinical Sciences Centre, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Sean J Jeffries
- Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Caroline Lee
- Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Nigel Miller
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Stephen P Jackson
- Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - M Azim Surani
- Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
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4
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Jung T, Streffer C. Effects of Caffeine on Protein Phosphorylation and Cell Cycle Progression in X-irradiated Two-cell Mouse Embryos. Int J Radiat Biol 2009; 62:161-8. [PMID: 1355509 DOI: 10.1080/09553009214551971] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The G2 phase/mitosis transition in cleavage-stage mouse embryos is correlated with an increased phosphorylation of a defined set of proteins at 46, 35, 30, and 29 kDa. Cell cleavage and the associated changes in protein phosphorylation are delayed after X-irradiation. To understand the mechanism of the caffeine-induced uncoupling of mitosis and the cellular reactions to DNA-damaging agents, we have studied the effects of caffeine treatment on cell cycle progression and protein phosphorylation in two-cell mouse embryos after X-irradiation. Caffeine alone had no effect on timing of and changes in phosphorylation associated with the embryonic cell cycle. In combination with X-rays, however, caffeine was able to override the radiation induced G2 block and restored the normal timing of these phosphorylation changes after X-irradiation. However, new additional changes in protein phosphorylation appeared after the combined treatment. Isobutylmethylxanthine (IBMX), a substance chemically related to caffeine but a more specific inhibitor of the phosphodiesterase that breaks down cyclic AMP, reduced the radiation induced G2 block from 4 to 5 h to about 1 h and restored the cell cycle associated changes in protein phosphorylation. However, the same new changes which appeared after the combined treatment of caffeine and X-rays were observed after the combination of IBMX and X-irradiation. IBMX specific changes in protein phosphorylation were detected in both the single and the combined treatment. These results indicate a similar action of caffeine and IBMX in overriding the radiation induced G2 block in two-cell mouse embryos.
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Affiliation(s)
- T Jung
- Department of Molecular Embryology, AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK
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Philipps DL, Wigglesworth K, Hartford SA, Sun F, Pattabiraman S, Schimenti K, Handel M, Eppig JJ, Schimenti JC. The dual bromodomain and WD repeat-containing mouse protein BRWD1 is required for normal spermiogenesis and the oocyte-embryo transition. Dev Biol 2008; 317:72-82. [PMID: 18353305 DOI: 10.1016/j.ydbio.2008.02.018] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 02/05/2008] [Accepted: 02/05/2008] [Indexed: 11/24/2022]
Abstract
A novel mutation, repro5, was isolated in a forward genetic screen for infertility mutations induced by ENU mutagenesis. Homozygous mutant mice were phenotypically normal but were infertile. Oocytes from mutant females appeared normal, but were severely maturation-defective in that they had reduced ability to progress to metaphase II (MII), and those reaching MII were unable to progress beyond the two pronuclei stage following in vitro fertilization (IVF). Mutant males exhibited defective spermiogenesis, resulting in oligoasthenoteratospermia. Genetic mapping, positional cloning, and complementation studies with a disruption allele led to the identification of a mutation in Brwd1 (Bromodomain and WD repeat domain containing 1) as the causative lesion. Bromodomain-containing proteins typically interact with regions of chromatin containing histones hyperacetylated at lysine residues, a characteristic of chromatin in early spermiogenesis before eventual replacement of histones by the protamines. Previous data indicated that Brwd1 is broadly expressed, encoding a putative transcriptional regulator that is believed to act on chromatin through interactions with the Brg1-dependent SWI/SNF chromatin-remodeling pathway. Brwd1 represents one of a small number of genes whose elimination disrupts gametogenesis in both sexes after the major events of meiotic prophase I have been completed.
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Affiliation(s)
- Dana L Philipps
- Cornell University, College of Veterinary Medicine, Ithaca, NY 14850, USA
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6
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Minami N, Suzuki T, Tsukamoto S. Zygotic gene activation and maternal factors in mammals. J Reprod Dev 2007; 53:707-15. [PMID: 17827882 DOI: 10.1262/jrd.19029] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Zygotic gene activation (ZGA) is the first event of gene expression after fertilization. Following fertilization, ZGA occurs within a short time interval depending on the animal species. Until ZGA, maternal proteins and transcripts stored in oocytes control embryonic development, indicating the importance of maternal factors for development. Somatic cell cloning also proves the potential of oocyte to reprogram the differentiated cell nuclei to embryonic nuclei. Recent studies show that the epigenetic modifications of nuclei play important roles in controlling gene expression during ZGA. However, the mechanisms that control ZGA remain largely unknown. This review will cover the current understanding of ZGA. Specifically, it will focus on the maternal factors that control gene expression during early embryogenesis.
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Affiliation(s)
- Naojiro Minami
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
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7
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Stojanov T, O'Neill C. In vitro fertilization causes epigenetic modifications to the onset of gene expression from the zygotic genome in mice. Biol Reprod 2001; 64:696-705. [PMID: 11159375 DOI: 10.1095/biolreprod64.2.696] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The effect of in vitro fertilization (IVF) and culture of mouse preimplantation embryos in vitro on the onset of expression of insulin-like growth factor 1 (IGF-1) ligand and receptor, insulin ligand and receptor, alpha-transforming growth factor (alpha-TGF) ligand, PAF:acetylhydrolase 1b (Pafah1b; alpha(1), alpha(2), and beta subunits of the enzyme), and the transcription requiring complex proteins (TRC) was examined. The IGF-1 ligand was detected in preimplantation embryos by immunofluorescence at all developmental stages tested. However, IVF and culture significantly reduced the amount of protein detected in the 8-cell embryo and blastocyst (P: < 0.001), and this was due to a delayed onset of expression of the mRNA for IGF-1 ligand from the zygotic genome. The expression of the alpha(1) subunit of Pafah1b was first detected at the 2-cell stage in fresh embryos, but expression was significantly retarded (P: < 0.001) when IVF and ISF (in situ-fertilized) zygotes were cultured in vitro. In vitro fertilization or ISF did not delay the onset of expression of TRC nor mRNA for the IGF-1 receptor, insulin receptor, alpha(2) or beta subunit of Pafah1b, nor did they effect alpha-TGF protein synthesis. Thus, IVF causes epigenetic modification in the normal pattern of expression of some but not all genes involved in normal embryo growth and survival.
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Affiliation(s)
- T Stojanov
- Human Reproduction Unit, Department of Physiology, University of Sydney, Royal North Shore Hospital of Sydney, St. Leonards, NSW 2065, Australia
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8
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Mechanisms of regulation of early embryogenesis. Russ J Dev Biol 2000. [DOI: 10.1007/bf02758818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Abstract
We have used two different experimental approaches to demonstrate topological separation of parental genomes in preimplantation mouse embryos: mouse eggs fertilized with 5-bromodeoxyuridine (BrdU)-labeled sperm followed by detection of BrdU in early diploid embryos, and differential heterochromatin staining in mouse interspecific hybrid embryos. Separation of chromatin according to parental origin was preserved up to the four-cell embryo stage and then gradually disappeared. In F1 hybrid animals, genome separation was also observed in a proportion of somatic cells. Separate nuclear compartments during preimplantation development, when extreme chromatin remodelling occurs, and possibly in some differentiated cell types, may be associated with epigenetic reprogramming.
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Affiliation(s)
- Wolfgang Mayer
- Max-Planck-Institut für Molekulare Genetik, 14195 Berlin, Germany
| | - Avril Smith
- Max-Planck-Institut für Molekulare Genetik, 14195 Berlin, Germany
| | - Reinald Fundele
- Max-Planck-Institut für Molekulare Genetik, 14195 Berlin, Germany
| | - Thomas Haaf
- Max-Planck-Institut für Molekulare Genetik, 14195 Berlin, Germany
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10
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Mayer W, Niveleau A, Walter J, Fundele R, Haaf T. Demethylation of the zygotic paternal genome. Nature 2000; 403:501-2. [PMID: 10676950 DOI: 10.1038/35000656] [Citation(s) in RCA: 902] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- W Mayer
- Max Planck Institute of Molecular Genetics, Berlin, Germany
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11
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Abstract
Eggs and early embryos appear to be programmed to undertake particular developmental decisions at characteristic times, although precisely how these decisions are timed is unknown. We discuss the possible roles and interactions during early vertebrate development of two broad categories of timers: 1) those that involve cyclic or sequential mechanisms, referred to as clocks; and 2) those that require an increase or decrease in some factor to a threshold level for progression of time, referred to as hourglass timers. It is concluded that both clock-like timers linked to various features of the cell cycle and hourglass timers are involved in early developmental timing. The possible involvement of elements of circadian clock timers is also considered. BioEssays 22:57-63, 2000.
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Affiliation(s)
- M H Johnson
- Department of Anatomy, University of Cambridge, Downing Street, Cambridge, UK
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12
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Latham KE. Mechanisms and control of embryonic genome activation in mammalian embryos. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 193:71-124. [PMID: 10494621 DOI: 10.1016/s0074-7696(08)61779-9] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Activation of transcription within the embryonic genome (EGA) after fertilization is a complex process requiring a carefully coordinated series of nuclear and cytoplasmic events, which collectively ensure that the two parental genomes can be faithfully reprogrammed and restructured before transcription occurs. Available data indicate that inappropriate transcription of some genes during the period of nuclear reprogramming can have long-term detrimental effects on the embryo. Therefore, precise control over the time of EGA is essential for normal embryogenesis. In most mammals, genome activation occurs in a stepwise manner. In the mouse, for example, some transcription occurs during the second half of the one-cell stage, and then a much greater phase of genome activation occurs in two waves during the two-cell stage, with the second wave producing the largest onset of de novo gene expression. Changes in nuclear structure, chromatin structure, and cytoplasmic macromolecular content appear to regulate these periods of transcriptional activation. A model is presented in which a combination of cell cycle-dependent events and both translational and posttranslational regulatory mechanisms within the cytoplasm play key roles in mediating and regulating EGA.
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Affiliation(s)
- K E Latham
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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13
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Abstract
The delivery of the paternal genome to the egg is a primary goal of fertilization. In preparation for this step, the nucleus of the developing spermatozoon undergoes extensive morphological and biochemical transformations during spermatogenesis to yield a tightly compacted sperm nucleus. These modifications are essentially reversed during fertilization. As a result, the incorporated sperm nucleus undergoes many steps in the egg cytoplasm as it develops into a male pronucleus. The sperm nucleus (1) loses its nuclear envelope, (2) undergoes nucleoprotein remodeling, (3) decondenses and increases in size, (4) becomes more spherical, (5) acquires a new nuclear envelope, and (6) becomes functionally competent to synthesize DNA and RNA. These changes are coordinate with meiotic processing of the maternal chromatin, and often result in behaviors asynchronous with the maternal chromatin. For example, in eggs fertilized during meiosis, the sperm nucleus decondenses while the maternal chromatin remains condensed. A model is presented that suggests some reasons why this puzzling behavior exists. Defects in any of the processes attending male pronuclear development often result in infertility. New assisted reproductive technologies have been developed that ensure delivery of the sperm nucleus to the egg cytoplasm so that a healthy embryo is produced. An emerging challenge is to further characterize the molecular mechanisms that control sperm nuclear transformations and link these to causes of human infertility. Further understanding of this basic process promises to revolutionize our understanding of the mystery of the beginning of new life.
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Affiliation(s)
- S J Wright
- Department of Biology, University of Dayton, Ohio 45469, USA
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14
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Bouniol-Baly C, Nguyen E, Besombes D, Debey P. Dynamic organization of DNA replication in one-cell mouse embryos: relationship to transcriptional activation. Exp Cell Res 1997; 236:201-11. [PMID: 9344600 DOI: 10.1006/excr.1997.3708] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have analyzed the spatial and temporal relationship between transcription and replication sites during the first cell cycle in mouse embryos. Embryos were microinjected with both 5-bromouridine-5'-triphosphate and digoxygenin-11-deoxyuridine-5'-triphosphate to visualize transcription and replication sites respectively. We detected six different phases of replication during S phase and dated the onset of zygotic transcription at the end of the S phase. Using confocal microscopy, we showed that there is essentially no colocalization of replication and transcription sites at this stage of development. Moreover, studies on aphidicolin-treated embryos demonstrated that inhibition of DNA replication does not hinder transcriptional activation at the 1-cell stage.
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Affiliation(s)
- C Bouniol-Baly
- Laboratoire Associé Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Recherche Agronomique (INRA), Paris, France. bouniol@.ibpc.fr
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15
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Samaké S, Smith LC. Synchronization of cell division in eight-cell bovine embryos produced in vitro: Effects of aphidicolin. Theriogenology 1997; 48:969-76. [PMID: 16728186 DOI: 10.1016/s0093-691x(97)00323-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/1996] [Accepted: 06/10/1997] [Indexed: 11/16/2022]
Abstract
To date, methods for synchronizing the cell division of ungulate embryos without reducing their developmental potential have not been reliable or simple. The overall objective of this study was to determine the reliability of aphidicolin, a powerful inhibitor of eukaryotic DNA synthesis, to arrest and synchronize blastomere division in cleavage-stage bovine embryos and to assess its reversibility and toxicity in vitro. Eight-cell stage embryos obtained at 58 h post insemination were treated with several concentrations of aphidicolin for 12 h. Treated embryos were assessed for cleavage arrest, chromatin morphology and DNA synthesis; scored for blastocyst formation and hatching rate; and fixed for determination of the number of nuclei. Complete arrest of cell division was observed at aphidicolin concentrations of 1.4 microM and above. At these concentrations, no morphological alteration to interphase chromatin was observed in treated embryos compared with the controls. Removal of aphidicolin led to at least a 4-h delay before resumption of DNA synthesis and cleavage. The ability of treated embryos to reach the blastocyst stage in vitro, the hatching rate and the number of cells per blastocyst were significantly reduced compared with the control group. Since the ability of treated embryos to develop to the blastocyst stage was significantly reduced even at the minimal effective dosage, it is concluded that aphidicolin is unlikely to provide suitable cell cycle synchronization without damage to the embryos.
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Affiliation(s)
- S Samaké
- Centre de recherche en reproduction animale Département de biomédecine vétérinaire Faculté de médecine vétérinaire Université de Montréal, Saint-Hyacinthe, PQ, Canada
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16
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Abstract
The first round of DNA replication has been proposed to provide a window of opportunity for maternally-derived transcription factors to gain access to their cognate cis-binding DNA sequences and thereby reprogram the pattern of gene expression that occurs during the 2-cell stage. Using high-resolution, two-dimensional electrophoresis of metabolically radio-labeled polypeptides, we report the expression of a group of several polypeptides whose synthesis in the 2-cell embryo is due to transcription (i.e., alpha-amanitin-sensitive) and depends on the first round of DNA replication (i.e., aphidicolin-sensitive). We also describe the synthesis of another subset of alpha-amanitin-sensitive polypeptides whose expression does not require the first round of DNA replication (i.e., aphidicolin-insensitive). These results are consistent with the proposed role of the first round of DNA replication in reprogramming the pattern of gene expression.
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Affiliation(s)
- W Davis
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018, USA
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17
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Chastant S, Christians E, Campion E, Renard JP. Quantitative control of gene expression by nucleocytoplasmic interactions in early mouse embryos: consequence for reprogrammation by nuclear transfer. Mol Reprod Dev 1996; 44:423-32. [PMID: 8844684 DOI: 10.1002/(sici)1098-2795(199608)44:4<423::aid-mrd1>3.0.co;2-n] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
HSP 70.1 is one of the first genes to be expressed in the mouse embryo at the time of zygotic genome activation. We studied the regulation of this gene, using a transgene associating HSP 70.1 promoter and the firefly luciferase reporter gene, which allows the precise quantification of HSP 70.1 level of expression on individual embryos. In the present work, we show first that the level of HSP 70.1 expression at the two-cell stage is significantly higher (around two-fold) in embryos whose maternal cytoplasm is from C3H strain than with BALB/c strain. We verified that this difference is not an artefact of the use of transgenic embryos, of the time of first cleavage, or of in vitro culture. This regulation of HSP 70.1 level of expression is controlled by strain-specific maternal modifiers and is independent of replication, syngamy, and mitosis. Following nuclear transfer, reactivation of HSP 70.1 is also subjected to the same epigenetic influence. Only the strain-of-origin of the recipient cytoplast modulates the level of HSP 70.1 reprogrammation; the origin of donor nucleus is not significant, demonstrating the reversibility of this strain effect. These results point out the importance of the quality of recipient cytoplast in the intensity of gene reprogrammation, which may be of importance for nuclear transfer efficiency.
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Affiliation(s)
- S Chastant
- Unité de Biologie du Développement, INRA, Jouy-en-Josas, France
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18
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19
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Nothias JY, Majumder S, Kaneko KJ, DePamphilis ML. Regulation of gene expression at the beginning of mammalian development. J Biol Chem 1995; 270:22077-80. [PMID: 7673179 DOI: 10.1074/jbc.270.38.22077] [Citation(s) in RCA: 227] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The maternal to zygotic transition can be viewed as a cascade of events that begins when fertilization triggers the zygotic clock that delays early ZGA until formation of a 2-cell embryo. Early ZGA, in turn, appears to be required for expression of late ZGA, and late ZGA is required to form a 4-cell embryo. ZGA in mammals is a time-dependent mechanism rather than a cell cycle-dependent mechanism that delays both transcription and translation of nascent transcripts. Thus, zygotic gene transcripts appear to be handled differently than maternal mRNA, a phenomenon also observed in Xenopus (55). The length of this delay is species-dependent, occurring at the 2-cell stage in mice, the 4-8-cell stage in cows and humans, and the 8-16-cell stage in sheep and rabbits (4). However, concurrent with formation of a 2-cell embryo in the mouse and rabbit (47,56), perhaps in all mammals, a general chromatin-mediated repression of promoter activity appears. Repression factors are inherited by the maternal pronucleus from the oocyte but are absent in the paternal pronucleus and not available until sometime during the transition from a late 1-cell to a 2-cell embryo. This means that paternally inherited genes are exposed to a different environment in fertilized eggs than are maternally inherited genes, a situation that could contribute to genomic imprinting. Chromatin-mediated repression of promoter activity prior to ZGA is similar to what is observed during Xenopus embryogenesis (31,32) and ensures that genes are not expressed until the appropriate time in development when positive acting factors, such as enhancers, can relieve this repression. The ability to use enhancers appears to depend on the acquisition of specific co-activators at the 2-cell stage in mice and perhaps later in other mammals (47,56), concurrent with ZGA. Even then, the mechanism by which enhancers communicate with promoters changes during development (Fig. 2), providing an opportunity for enhancer-mediated stimulating of TATA-less promoters (e.g. housekeeping genes) early during development while eliminating this mechanism later during development.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J Y Nothias
- Roche Institute of Molecular Biology, Roche Research Center, Nutley, New Jersey 07110-1199, USA
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20
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Ciemerych MA. Chromatin condensation activity and cortical activity during the first three cell cycles of a mouse embryo. Mol Reprod Dev 1995; 41:416-24. [PMID: 7576609 DOI: 10.1002/mrd.1080410404] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One-cell parthenogenetic haploid embryos and blastomeres of the 2- and 4-cell diploid mouse embryos were observed in vitro for the occurrence of two cytoplasmic activities: the cortical activity and the chromatin condensation activity. For this purpose anucleated halves (AHs) and nucleated halves (NHs) were produced by bisection of one-cell embryos and of blastomeres. The cortical activity (manifested by surface deformations) was observed only during the first cleavage cycle. In AHs the surface activity began at the same time as in NHs and disappeared before the time of the cleavage division of nucleated halves. Anucleate fragments of blastomeres from 2- and 4-cell embryos did not exhibit any cortical activity. In the absence of the native nucleus the chromatin condensation activity (assayed by premature chromatin condensation of interphase thymocyte nuclei introduced into cytoplasts by cell fusion) could also have been detected only in the first cleavage cycle. In AHs this activity appeared at the time when NHs started to cleave and disappeared after the NHs finished the first cleavage division. AHs obtained from 2-cell and 4-cell stage blastomeres did not reveal condensation activity.
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Affiliation(s)
- M A Ciemerych
- Department of Embryology, University of Warsaw, Poland
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21
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Clayton L, McConnell JM, Johnson MH. Control of the surface expression of uvomorulin after activation of mouse oocytes. ZYGOTE 1995; 3:177-89. [PMID: 7582920 DOI: 10.1017/s0967199400002550] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Uvomorulin (E-cadherin) is the major cell adhesion molecule responsible for intercellular adhesion in early mouse embryos. In contrast to other cell adhesion molecules, it is not detectable on the cell surface until around 6 h after fertilisation or parthenogenetic activation, at the time when pronuclear formation occurs (Clayton, L., Stinchcombe, S.V. and Johnson, M.H., Zygote 1, 333-44, 1993). In order to investigate this developmental control of surface expression of uvomorulin, we examined the effects of inhibitors of various cellular processes on the appearance of uvomorulin at the oocyte surface, as assessed immunocytochemically. Inhibitors of cytoskeletal assembly (cytochalasin D and nocodazole), protein synthesis (puromycin and anisomycin), and DNA synthesis (aphidicolin) had no effect on surface expression. Brefeldin A, which inhibits intracellular transport and secretion, did prevent surface expression, but monensin did not. The effects of brefeldin were reversible; following 8 h of treatment, recovery of surface expression after removal of brefeldin began within 2 h. The time-course of surface expression post-activation suggested a link with pronuclear formation. However, when pronuclear formation was advanced experimentally using 6-dimethylaminopurine (DMAP), concomitant advancement of surface uvomorulin was not observed. Similarly, surface expression of uvomorulin did not accompany puromycin-induced pronuclear formation in maturing meiotic metaphase 1 (MI) oocytes in vitro. Thus, surface uvomorulin expression does not appear to be linked simply to pronuclear formation. Proteolytic processing of both newly synthesised and total uvomorulin to generate mature molecule from precursor increased within 30 min to 1 h after activation, and also occurred in the continued presence of brefeldin, suggesting that uvomorulin processing appears to be controlled independently of its surface expression.
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Affiliation(s)
- L Clayton
- Department of Anatomy, University of Cambridge, UK
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22
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Vautier D, Besombes D, Chassoux D, Aubry F, Debey P. Redistribution of nuclear antigens linked to cell proliferation and RNA processing in mouse oocytes and early embryos. Mol Reprod Dev 1994; 38:119-30. [PMID: 7521649 DOI: 10.1002/mrd.1080380202] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have systematically analyzed by indirect immunofluorescence the subcellular distribution of nuclear antigens in relation to developmental stages of maturing mouse oocytes and developing embryos. Antigens were of two types: (1) a protein whose nuclear localization in interphase somatic cells depends on their proliferative state protein recognized by a monoclonal antibody 43B1N, and (2) snRNP polypeptides recognized by autoimmune sera of anti-Sm and anti-RNP type. The protein recognized by 43B1N was present in the germinal vesicle of oocytes from antral follicles, but absent from the nuclei during the first hours of embryonic life up to the middle to late 2-cell stage. Starting from this stage, it was always found in nuclei of interphase blastomeres, where its "speckles" co-localized with the speckles containing high concentrations of snRNP polypeptides. SnRNP polypeptides recognized by anti-Sm and anti-RNP sera were in turn found in nuclei of all developmental stages. When embryos were treated with aphidicolin or cytochalasin D to arrest cell division, the 43B1N reacting protein was again localized in the pronuclei at 42 hr post-hCG, i.e., slightly later than the onset of transcriptional activity. These results suggest a progressive building up of nuclei during embryonic development, which could influence gene expression.
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Affiliation(s)
- D Vautier
- Laboratoire Associé INSERM, Institut de Biologie Physico-Chimique, Paris, France
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23
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Abstract
Expression of the embryonic genome has been examined during preimplantation rat development. Proteins synthesized at different stages of embryogenesis were labelled with [35S]methionine and then separated by one-dimensional gel electrophoresis. A major transformation in the pattern of protein synthesis has been observed between the two- and the four-cell stages of embryonic development. Also the culture of embryos with an inhibitor of transcription (alpha-amanitin) has shown that the first alpha-amanitin-sensitive events take place during the late two-cell stage. However, inhibition of transcription does not arrest the embryo development up to the four-cell stage. Taken together, the results indicate that in rats the initiation of embryonic gene activation occurs at the late two-cell stage. However, the first two cleavage divisions can occur in the absence of transcription.
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24
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Abstract
Zygotic gene activation (ZGA) is the critical event that governs the transition from maternal to embryonic control of development. In the mouse, ZGA occurs during the 2-cell stage and appears to be regulated by the time following fertilization, i.e. a zygotic clock, rather than by progression through the first cell cycle. The onset of ZGA must depend on maternally inherited proteins, and post-translational modification of these maternally derived proteins is likely to play a role in ZGA. Consistent with this prediction is that protein phosphorylation catalyzed by the cAMP-dependent protein kinase is involved in ZGA and that protein synthesis is not required for ZGA. Recent results suggest that ZGA may occur earlier than previously thought, i.e. not during the 2-cell stage, but rather in G2 of the 1-cell embryo. Thus ZGA may comprise a period of minor gene activation in the 1-cell embryo that is followed by a period of major gene activation in the 2-cell embryo. Following ZGA, the expression of constitutively activated genes may require an enhancer.
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Affiliation(s)
- R M Schultz
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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25
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Winston NJ, Johnson MH, Braude PR. Assessment of the cellular DNA content of whole mounted mouse and human oocytes and of blastomeres containing single or multiple nuclei. ZYGOTE 1993; 1:17-25. [PMID: 8081798 DOI: 10.1017/s0967199400001258] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The nuclear DNA content of intact, live or fixed, human and mouse oocytes and blastomeres has been measured rapidly and reliably. Chromosomal DNA has been stained with DAPI, the fluorescent emission from which has been measured photocytometrically. In vitro fertilised mouse oocytes and embryos at various stages of development were assessed for their DNA content. The mean values of 1C, 2C and 4C DNA content were clearly different, and it was possible to assign correctly individual values for DNA content to each class with 92%, 61% and 81% confidence respectively. Maintaining the cells as whole mounts allowed other morphological and structural features to be examined. When formation of multiple micronuclei was induced in mouse oocytes by their insemination in the presence of nocodazole, the additive signal from all the micronuclei in one zygote was equivalent to the expected DNA content. Application to early human blastomeres of this photocytometric technique for measurement of the total cellular DNA content revealed that multinucleated blastomeres contained 2C to 4C DNA levels, consistent with a diploid DNA content.
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Affiliation(s)
- N J Winston
- Department of Anatomy, University of Cambridge, UK
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26
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Miranda M, Majumder S, Wiekowski M, DePamphilis ML. Application of firefly luciferase to preimplantation development. Methods Enzymol 1993; 225:412-33. [PMID: 8231867 DOI: 10.1016/0076-6879(93)25029-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M Miranda
- Department of Cell and Developmental Biology, Roche Research Center, Nutley, New Jersey 07110
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27
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Vernet M, Bonnerot C, Briand P, Nicolas JF. Application of LacZ gene fusions to preimplantation development. Methods Enzymol 1993; 225:434-51. [PMID: 8231868 DOI: 10.1016/0076-6879(93)25030-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M Vernet
- Laboratoire de Génétique et Pathologie Expérimentales, INSERM, Institut Cochin de Génétique Moléculaire, Paris, France
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28
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Schwartz DA, Schultz RM. Zygotic gene activation in the mouse embryo: involvement of cyclic adenosine monophosphate-dependent protein kinase and appearance of an AP-1-like activity. Mol Reprod Dev 1992; 32:209-16. [PMID: 1323305 DOI: 10.1002/mrd.1080320305] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Protein phosphorylation catalyzed by the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) is implicated in regulating zygotic gene activation in the two-cell mouse embryo (Poueymirou and Schultz; Dev Biol 133:588-599, 1989). We now provide evidence that H8, which is a PKA inhibitor, inhibits expression of an hsp70-driven beta-galactosidase reporter gene and that the concentration-dependence of this inhibition is similar to that for inhibiting expression of a stage-specific gene(s) that is a product of zygotic gene activation. We also demonstrate that neither cAMP nor serum can stimulate the expression, as detected by a histochemical assay, of a cAMP response element (CRE)- or serum response element (SRE)-driven beta-galactosidase reporter gene, respectively, in either germinal vesicle-intact oocytes or aphidicolin-arrested one-cell embryos that are chronologically at the tw-cell stage. In contrast, although 12-O-tetradecanoyl phorbol-13-acetate (TPA) does not stimulate expression of a TPA response element (TRE)-driven beta-galactosidase reporter gene in germinal vesicle-intact oocytes, it stimulates such expression in aphidicolin-arrested one-cell embryos. Moreover, TPA can stimulate the expression of either a CRE- or an SRE-driven beta-galactosidase reporter gene in such embryos. Results of these studies further implicate protein phosphorylation in regulating zygotic gene activation, along with its role in modulating enhancer function in the early mouse embryo.
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Affiliation(s)
- D A Schwartz
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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29
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Vernet M, Bonnerot C, Briand P, Nicolas JF. Changes in permissiveness for the expression of microinjected DNA during the first cleavages of mouse embryos. Mech Dev 1992; 36:129-39. [PMID: 1373952 DOI: 10.1016/0925-4773(92)90064-q] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
LacZ DNA and LacZ RNA were microinjected during the first cleavages of embryos. LacZ DNA was not expressed before 18-19 h post insemination (hpi) but LacZ RNA was translated. Before 22 hpi LacZ DNA was expressed in the pronuclei of the one-cell embryos and the polypeptides of the minor, but not the major activation period of the genome were synthesized. This suggests a negative control of transcription before 18-19 hpi and demonstrates that its resumption is independent of the first cleavage and of the major activation of the genome. At the time of the minor activation the eggs contain the trans-acting elements to express a variety of genes that they do not express. It may indicate that, the minor and the major activation of the genome are differently controlled.
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Affiliation(s)
- M Vernet
- Laboratoire de Génétique et Pathologie Expérimentales, INSERM Institut Cochin de Génétique Moléculaire, Paris, France
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30
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Latham KE, Solter D, Schultz RM. Acquisition of a transcriptionally permissive state during the 1-cell stage of mouse embryogenesis. Dev Biol 1992; 149:457-62. [PMID: 1309712 DOI: 10.1016/0012-1606(92)90300-6] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Zygotic gene transcription initiates during the 2-cell stage of mouse embryogenesis. To learn more of the nature and timing of events leading up to transcriptional activation, we evaluated the ability of enucleated 1-cell-stage embryos to support transcription of the 2-cell-stage-specific gene(s) encoding the 70,000-Da transcription-requiring complex (TRC). Nuclei were transplanted from transcriptionally inhibited alpha-amanitin or N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide (H8)-treated 2-cell-stage embryos to either late or early enucleated 1-cell-stage recipients. Expression of the TRC gene(s) was much greater following transfer to late 1-cell than early 1-cell-stage recipients. In addition, treatment of early 1-cell-stage recipients with N6-monobutyryl cyclic AMP following transplantation of a nucleus from an H8-treated donor increased the rate of TRC synthesis to a value similar to that observed for late 1-cell-stage recipients. These results indicate that during the first cell cycle and prior to initiation of zygotic gene expression, the embryonic cytoplasm undergoes a transition from a transcriptionally nonpermissive to permissive state.
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Affiliation(s)
- K E Latham
- Wistar Institute of Anatomy and Biology, University of Pennsylvania, Philadelphia 19104
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31
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Wiekowski M, Miranda M, DePamphilis ML. Regulation of gene expression in preimplantation mouse embryos: effects of the zygotic clock and the first mitosis on promoter and enhancer activities. Dev Biol 1991; 147:403-14. [PMID: 1916016 DOI: 10.1016/0012-1606(91)90298-h] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Previous studies have reported that promoters requiring enhancers for full activity in mammalian somatic cells also require enhancers when injected into mouse two-cell embryos, whereas the same promoters can be expressed just as efficiently in the absence of an enhancer when injected into arrested one-cell embryos. Experiments were designed to determine whether this phenomenon reflected normal developmental changes at the beginning of mammalian development, or simply differences in the physiological states of these cells under the experimental conditions employed. The activity of three different promoters that function in a wide variety of mammalian cells was measured both in embryos whose morphological development was arrested and in embryos that continued development in vitro. Expression of the injected gene was related to the onset of zygotic gene expression ("zygotic clock"), the phase of the cell proliferation cycle, the use of aphidicolin to arrest cell proliferation, and formation of two-cell embryos in vitro and in vivo. The results demonstrated that promoter activity was tightly linked to zygotic gene expression, while the need for enhancers to stimulate promoter activity depended only on formation of a two-cell embryo. These results further support the hypothesis that the first mitosis induces a general repression of promoters prior to initiation of zygotic gene expression that is relieved specifically by enhancers.
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Affiliation(s)
- M Wiekowski
- Department of Cell and Developmental Biology, Roche Institute of Molecular Biology, Nutley, New Jersey 07110
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32
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Jung T, Streffer C. Association of protein phosphorylation and cell cycle progression after X-irradiation of two-cell mouse embryos. Int J Radiat Biol 1991; 60:511-23. [PMID: 1679090 DOI: 10.1080/09553009114552351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Studies of protein phosphorylation in the second cell cycle of mouse embryos were assessed by [32P]-incorporation and one- and two-dimensional electrophoresis. Unirradiated and X-irradiated embryos were compared. X-irradiation in the G2 phase led to a block in this cell cycle phase. The phosphorylation of proteins with molecular weights of 30 and 46 kDa specifically correlated with the G2 phase-mitosis transition in normally dividing and in irradiated embryos. The time lag in the phosphorylation of these proteins between the unirradiated and X-irradiated embryos was identical to the duration of the radiation-induced G2 block. X-irradiation immediately decreased the phosphorylation of a 29 kDa protein to below detectable levels. Re-phosphorylation of this protein preceded the following mitosis. It is suggested that the 29 kDa protein may be involved in the regulation of events that led to the radiation induced G2 block and the initiation of mitosis after release.
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Affiliation(s)
- T Jung
- Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, Germany
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33
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Manejwala FM, Logan CY, Schultz RM. Regulation of hsp70 mRNA levels during oocyte maturation and zygotic gene activation in the mouse. Dev Biol 1991; 144:301-8. [PMID: 2010034 DOI: 10.1016/0012-1606(91)90423-z] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Protein phosphorylation catalyzed by the cAMP-dependent protein kinase is implicated in transcriptional activation of the embryonic genome in the two-cell mouse embryo, while heat shock protein (hsp70) has been identified as one of the first products of zygotic gene activation. Using reverse transcription-polymerase chain reaction we have analyzed relative changes in the amount of hsp70 mRNA during oocyte maturation and early embryogenesis. We report that the amount of hsp70 mRNA decreases after germinal vesicle breakdown, while inhibiting germinal vesicle breakdown inhibits this maturation-associated decrease. The amount of hsp70 mRNA increases between the one- and two-cell stages. This increase is inhibited by either alpha-amanitin or the cAMP-dependent protein kinase inhibitor H-8; the same concentration of H-7, which is a more potent inhibitor of protein kinase C, has little inhibitory effect on this increase in the relative amount of hsp70 mRNA. Last, addition of cycloheximide to one-cell embryos late in G2 inhibits neither cleavage to the two-cell stage nor the increase in the relative amount of hsp70 mRNA. These results strengthen the previous proposal that protein phosphorylation is involved in zygotic gene activation in the two-cell mouse embryo.
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Affiliation(s)
- F M Manejwala
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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34
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Conover JC, Temeles GL, Zimmermann JW, Burke B, Schultz RM. Stage-specific expression of a family of proteins that are major products of zygotic gene activation in the mouse embryo. Dev Biol 1991; 144:392-404. [PMID: 2010038 DOI: 10.1016/0012-1606(91)90431-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Transcriptional activation of the embryonic genome occurs during the two-cell stage in the mouse embryo and is marked by the synthesis of a set of alpha-amanitin-sensitive proteins of Mr 73,000, 70,000, and 68,000. We have characterized these three proteins by two-dimensional gel electrophoresis of [35S]methionine radiolabeled two-cell embryos. Their isoelectric points range from 6.2 to 6.8 and their synthesis, which can constitute 5-10% of total protein synthesis, is restricted to the two-cell stage. These proteins are not heat shock proteins that have previously been reported as major products of transcriptional activation. Peptide mapping by limited proteolysis indicates that these three proteins are highly related to one another and the results of pulse-chase experiments indicate that they are likely to be degraded by the eight-cell stage. These proteins are nuclear-associated and insoluble in 2% Triton X-100/0.3 M KCl. Although these proteins share some features with somatic lamins--they exhibit solubility properties similar to somatic lamins--they do not cross-react with polyclonal antibodies to either lamins A/C or B, nor do they comigrate with somatic lamins on two-dimensional gels. Additional evidence that these proteins are not lamins is that although treatment of two-cell embryos with okadaic acid, which is an inhibitor of protein phosphatases 1 and 2A, results in precocious nuclear envelope breakdown, the proteins remain insoluble in 2% Triton X-100/0.3 M KCl.
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Affiliation(s)
- J C Conover
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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35
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Richoux V, Renard JP, Babinet C. Synthesis and developmental regulation of an egg specific mouse protein translated from maternal mRNA. Mol Reprod Dev 1991; 28:218-29. [PMID: 2015080 DOI: 10.1002/mrd.1080280303] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Proteins synthesized by DDK mice embryos were analyzed by 2D electrophoresis and a new egg-specific polypeptide, D14, was identified. The protein is characterized by its high rate of synthesis and electrophoretic properties (MW 36,500, pl greater than 8). The synthesis of D14 is strictly developmentally regulated: starting in the maturing oocyte in the few hours following germinal vesicle breakdown (GVBD), it remains high over the first cell cycle and decreases abruptly during the two-cell stage. The arrest of D14 synthesis is triggered by egg activation and does not directly depend on transcription by the zygotic genome. Nevertheless, drugs that perturb the onset of zygotic transcription concomitantly inhibit D14 arrest of synthesis. D14 is present in both cytoplasmic and nuclear compartments at the two-cell stage; it is very stable and remains detectable at least until the eight-cell stage in the preimplantation embryo. Embryos of wild strains of mice synthesized either D14 or a D14 related polypeptide at a rate comparable to that of DDK embryos, which was at least ten times greater than that found in other laboratory strains. Both the developmental regulation and the genetic variability in its rate of synthesis make D14 an interesting polypeptide for the study of regulation of maternal information in the very early stages of mouse embryo development.
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Affiliation(s)
- V Richoux
- Unité de Génétique des Mammifères, Institut Pasteur, Paris, France
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36
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Affiliation(s)
- E K Boon-Niermeijer
- Department of Molecular Cell Biology, University of Utrecht, The Netherlands
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37
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Besterman B, Schultz RM. Regulation of mouse preimplantation development: inhibitory effect of genistein, an inhibitor of tyrosine protein phosphorylation, on cleavage of one-cell embryos. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1990; 256:44-53. [PMID: 2401883 DOI: 10.1002/jez.1402560107] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We investigated the effects of genistein, an inhibitor of tyrosine protein phosphorylation, on mouse 1-cell embryos, since in response to mitogenic stimuli tyrosine protein phosphorylation in somatic cells is implicated in initiation of DNA synthesis. Genistein inhibits cleavage of 1-cell embryos in a concentration-dependent and reversible manner; biochanin A, which is a less potent inhibitor of tyrosine protein phosphorylation, is a less potent inhibitor of cell cleavage. Genistein does not inhibit [35S]methionine incorporation, but does inhibit [3H]thymidine incorporation. Consistent with genistein's ability to inhibit cleavage by inhibiting DNA synthesis is that the loss of genistein's ability to inhibit cleavage corresponds with exit of the 1-cell embryos from S phase. Genistein is likely to inhibit tyrosine protein phosphorylation in situ, since it reduces by 80% the relative amount of [32P]phosphotyrosine present in 1-cell embryos; genistein does not inhibit either [32P]orthophosphate uptake or incorporation. As anticipated, genistein has little effect on inhibiting changes in the pattern of phosphoprotein synthesis during the first cell cycle, since tyrosine protein phosphorylation constitutes a small percentage of total protein phosphorylation. Alkalai treatment of [32P]radiolabeled phosphoproteins transferred to Immobilon reveals a base-resistant set of phosphoproteins of Mr = 32,000 that displays cell-cycle changes in phosphorylation. Although these properties suggest that these phosphoproteins may be related to the p34cdc2 protein kinase, phosphoamino acid analysis of [32P]radiolabeled phosphoproteins reveals that they are not enriched for phosphotyrosine; the inactive for p34cdc2 protein kinase contains a high level of phosphotyrosine. Results of these experiments suggest that tyrosine protein phosphorylation in response to the fertilizing sperm may be involved in initiating DNA synthesis in the 1-cell embryo, as well as converting a meiotic cell cycle to a mitotic one.
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Affiliation(s)
- B Besterman
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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38
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Poueymirou WT, Schultz RM. Regulation of mouse preimplantation development: inhibitory effect of the calmodulin antagonist W-7 on the first cleavage. Mol Reprod Dev 1990; 26:211-6. [PMID: 2115792 DOI: 10.1002/mrd.1080260303] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The calmodulin antagonist W-7 inhibits cleavage of 1-cell mouse embryos in a concentration-dependent manner. This inhibition is likely to be specific for a calmodulin-mediated process, since the less active congener W-5 does not inhibit cleavage when used at concentrations of W-7 that do. Concentrations of W-7 that inhibit cleavage and do not inhibit either the uptake or incorporation of [35S]methionine do inhibit [3H]thymidine incorporation; similar concentrations of W-5 do not inhibit [3H]thymidine incorporation. Consistent with W-7's ability to inhibit cleavage by inhibiting DNA synthesis is that addition of W-7 at later times that correspond with exit from S phase results in cleavage to the 2-cell stage. Although W-7 does inhibit cleavage of 1-cell embryos, it does not inhibit transcriptional activation, which occurs in the 2-cell embryo and is characterized by the synthesis of a group of proteins of Mr = 70,000. Results of these experiments suggest a role for calmodulin in the first cell cycle of the mouse embryo and provide another example in which zygotic gene activation is not dependent on progression through the first cell cycle.
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Affiliation(s)
- W T Poueymirou
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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39
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Dean WL, Schultz GA. Relocalization of small ribonucleoprotein particles (snRNPs) during the first cell cycle of mouse embryo development is independent of RNA synthesis, DNA synthesis and cytokinesis. CELL DIFFERENTIATION AND DEVELOPMENT : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF DEVELOPMENTAL BIOLOGISTS 1990; 31:43-51. [PMID: 2146003 DOI: 10.1016/0922-3371(90)90089-f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The process of localization of small nuclear ribonucleoprotein particles (snRNPs) during the first cell cycle of mouse embryo development was investigated following treatment of fertilized eggs with cytochalasin D, aphidicolin and alpha-amanitin. The pattern of accumulation of snRNPs in nuclei of treated embryos as assessed by indirect immunofluorescence was unaffected by the inhibitors. The results demonstrate that the localization of snRNPs during the first cell cycle does not require ongoing cytokinesis, DNA replication or transcription of RNA polymerase II genes. These findings suggest that maternally derived snRNPs become localized to the nucleus of the fertilized ovum prior to the reinitiation of transcription from the zygote genome and are required for processing of messenger RNA precursors when genetic activity of the embryonic genome is activated at the early 2-cell stage.
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Affiliation(s)
- W L Dean
- Department of Medical Biochemistry, University of Calgary, Alberta, Canada
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40
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Jones J, Schultz RM. Pertussis toxin-catalyzed ADP-ribosylation of a G protein in mouse oocytes, eggs, and preimplantation embryos: developmental changes and possible functional roles. Dev Biol 1990; 139:250-62. [PMID: 2110913 DOI: 10.1016/0012-1606(90)90294-s] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
G proteins, which in many somatic cells serve as mediators of signal transduction, were identified in preimplantation mouse embryos by their capacity to undergo pertussis toxin-catalyzed ADP-ribosylation. Two pertussis toxin (PT) substrates with Mr = 38,000 and 39,000 (alpha 38 and alpha 39) are present in approximately equal amounts. Relative to the amount in freshly isolated germinal vesicle (GV)-intact oocytes, the amount of PT-catalyzed ADP-ribosylation of alpha 38-39 falls during oocyte maturation, rises between the one- and two-cell stages, falls by the eight-cell and morula stages, and increases again by the blastocyst stage. The decrease in PT-catalyzed ADP-ribosylation of alpha 38-39 that occurs during oocyte maturation, however, does not require germinal vesicle breakdown (GVBD), since inhibiting GVBD with 3-isobutyl-1-methyl xanthine (IBMX) does not prevent the decrease in the extent of PT-catalyzed ADP-ribosylation. A biologically active phorbol diester (12-O-tetradecanoyl phorbol 13-acetate, TPA), but not an inactive one (4 alpha-phorbol 12,13-didecanoate, 4 alpha-PDD), totally inhibits the increase in PT-catalyzed ADP-ribosylation of alpha 38-39 that occurs between the one- and two-cell stage; TPA inhibits cleavage, but not transcriptional activation, which occurs in the two-cell embryo (Poueymirou and Schultz, 1987. Dev. Biol. 121, 489-498). In contrast, cytochalasin D, genistein, or aphidicolin, each of which inhibits cleavage of one-cell embryos, or alpha-amanitin or H8, each of which inhibits transcriptional activation but not cleavage of one-cell embryos, have little or much smaller inhibitory effects on the increase in PT-catalyzed ADP-ribosylation of alpha 38-39. Results of immunoblotting experiments using an antibody that is highly specific for alpha il-3 reveal the presence of a cross-reactive species of Mr = 38,000 (alpha 38) in the GV-intact oocyte, metaphase II-arrested egg, and one-, two-cell embryos. Relative to these stages, a reduced amount of this species is present in the eight-cell, morula, and blastocyst stages. Treatment of oocytes with PT results in a small but significant acceleration in the rate of GVBD, but has no effect on the extent of polar body emission. Treatment of one-cell embryos with PT has no effect on the extent of cleavage, onset of transcriptional activation at the two-cell stage, or development of two-cell embryos to the hatching blastocyst stage.
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Affiliation(s)
- J Jones
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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Poueymirou WT, Schultz RM. Regulation of mouse preimplantation development: inhibition of synthesis of proteins in the two-cell embryo that require transcription by inhibitors of cAMP-dependent protein kinase. Dev Biol 1989; 133:588-99. [PMID: 2543602 DOI: 10.1016/0012-1606(89)90061-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Perturbing the changes in protein phosphorylation accompanying the first cleavage can inhibit the appearance of a set of proteins whose synthesis is inhibited by alpha-amanitin (transcription-requiring proteins, TRPs) (W. T. Poueymirou and R. M. Schultz, 1987, Dev. Biol. 121, 489-498); synthesis of the TRPs is likely to represent activation of transcription of the embryonic genome that occurs at the 2-cell stage during mouse development. In the present study, we report the effects of three different inhibitors of the cAMP-dependent protein kinase, N-[2-(methylamino)ethyl]-5-isoquinoline-sulfonamide (H8), (Rp)-cAMPs, and protein kinase inhibitor (PKI), each of which inhibits the kinase by a different mechanism, on cleavage of 2-cell embryos and synthesis of the TRPs. Two-cell embryos possess PK-A activity, which is inhibited by each of these inhibitors. Both H8 and (Rp)-cAMPs inhibit cleavage of 2-cell embryos in a concentration-dependent manner; similar concentrations of H7, which is a less potent inhibitor of PK-A, do not inhibit cleavage. H8 and (Rp)-cAMPS inhibit in a concentration-dependent manner TRP synthesis, whereas higher concentrations of H7 are required to inhibit TRP synthesis. Microinjected PKI also inhibits synthesis of the TRPs. In addition, H8 inhibits the accumulation of translatable messenger RNAs that are likely to encode for the TRPs. Last, H8, but not H7, inhibits the phosphorylation of a phosphoprotein in 2-cell embryos. Results of these studies suggest a role for protein phosphorylation catalyzed by cAMP-dependent protein kinase in regulating transcription in the early mouse embryo.
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Affiliation(s)
- W T Poueymirou
- Department of Biology, University of Pennsylvania, Philadelphia 19104-6018
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Pratt HP. Marking time and making space: chronology and topography in the early mouse embryo. INTERNATIONAL REVIEW OF CYTOLOGY 1989; 117:99-130. [PMID: 2684893 DOI: 10.1016/s0074-7696(08)61335-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- H P Pratt
- Department of Anatomy, University of Cambridge, England
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Zagris N, Matthopoulos D. Stage-specific gene expression in early chick embryo. DEVELOPMENTAL GENETICS 1989; 10:333-8. [PMID: 2507206 DOI: 10.1002/dvg.1020100409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Inhibition of DNA replication by aphidicolin in the chick morula interferes with its progression to a normal blastula and prevents induction of the first morphogenetic cell movements of primitive streak formation. Embryos in aphidicolin synthesize some polypeptides typical of blastula but do not display all the characteristic features of morula to blastula transition. Inhibition of DNA replication interferes with the sequential synthesis of maternally coded polypeptides and with the activation of the embryonic genome in the chick embryo.
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Affiliation(s)
- N Zagris
- Department of Biology, University of Patras, Greece
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Grinfeld S, Gilles J, Jacquet P, Baugnet-Mahieu L. Late division kinetics in relation to modification of protein synthesis in mouse eggs blocked in the G2 phase after X-irradiation. INTERNATIONAL JOURNAL OF RADIATION BIOLOGY AND RELATED STUDIES IN PHYSICS, CHEMISTRY, AND MEDICINE 1987; 52:77-90. [PMID: 3496312 DOI: 10.1080/09553008714551501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mouse zygotes (BALB/c) blocked in the G2 phase of the first cell cycle after X-irradiation were allowed to develop in culture medium. Delayed cleavage occurred at the same time in embryos exposed to 1 or 2 Gy and late division coincided with the second division in controls. Two-dimensional electrophoresis showed that blocked irradiated embryos underwent the same modifications in protein synthesis as control embryos of the same age, except during first mitosis, for three polypeptide sets of 30, 35 and 45 kilodaltons molecular weight. The most remarkable difference between them was the appearance in cleaving controls of three spots at 35 kilodaltons that were absent in blocked irradiated embryos. It is assumed that blocked embryos 'missed' some signal necessary for cell division, but remained ready to cleave when a second signal occurred. Eggs from the BALB/c strain were particularly susceptible to this effect of X-irradiation but it was also found in eggs from other strains, irradiated with much higher doses.
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Affiliation(s)
- V N Bolton
- Department of Obstetrics and Gynaecology, University of Cambridge Clinical School, Rosie Maternity Hospital, England
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