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Cai P, Casas CJ, Plancarte GQ, Hua LL, Mikawa T. Ipsilateral restriction of chromosome movement along a centrosome, and apical-basal axis during the cell cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.27.534352. [PMID: 37034601 PMCID: PMC10081237 DOI: 10.1101/2023.03.27.534352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Little is known about how distance between homologous chromosomes are controlled during the cell cycle. Here, we show that the distribution of centromere components display two discrete clusters placed to either side of the centrosome and apical/basal axis from prophase to G 1 interphase. 4-Dimensional live cell imaging analysis of centromere and centrosome tracking reveals that centromeres oscillate largely within one cluster, but do not cross over to the other cluster. We propose a model of an axis-dependent ipsilateral restriction of chromosome oscillations throughout mitosis.
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Cavazza T, Takeda Y, Politi AZ, Aushev M, Aldag P, Baker C, Choudhary M, Bucevičius J, Lukinavičius G, Elder K, Blayney M, Lucas-Hahn A, Niemann H, Herbert M, Schuh M. Parental genome unification is highly error-prone in mammalian embryos. Cell 2021; 184:2860-2877.e22. [PMID: 33964210 PMCID: PMC8162515 DOI: 10.1016/j.cell.2021.04.013] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 02/05/2021] [Accepted: 04/08/2021] [Indexed: 12/19/2022]
Abstract
Most human embryos are aneuploid. Aneuploidy frequently arises during the early mitotic divisions of the embryo, but its origin remains elusive. Human zygotes that cluster their nucleoli at the pronuclear interface are thought to be more likely to develop into healthy euploid embryos. Here, we show that the parental genomes cluster with nucleoli in each pronucleus within human and bovine zygotes, and clustering is required for the reliable unification of the parental genomes after fertilization. During migration of intact pronuclei, the parental genomes polarize toward each other in a process driven by centrosomes, dynein, microtubules, and nuclear pore complexes. The maternal and paternal chromosomes eventually cluster at the pronuclear interface, in direct proximity to each other, yet separated. Parental genome clustering ensures the rapid unification of the parental genomes on nuclear envelope breakdown. However, clustering often fails, leading to chromosome segregation errors and micronuclei, incompatible with healthy embryo development.
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Affiliation(s)
- Tommaso Cavazza
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Yuko Takeda
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, NE1 4EP Newcastle upon Tyne, UK
| | - Antonio Z Politi
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Magomet Aushev
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, NE1 4EP Newcastle upon Tyne, UK
| | - Patrick Aldag
- Institute of Farm Animal Genetics, Biotechnology, Friedrich-Loeffler-Institute, Mariensee, 31535 Neustadt, Germany
| | | | - Meenakshi Choudhary
- Newcastle Fertility Centre at Life, Newcastle upon Tyne Hospitals NHS Foundation Trust, NE1 4EP Newcastle upon Tyne, UK
| | - Jonas Bucevičius
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | | - Kay Elder
- Bourn Hall Clinic, CB23 2TN Cambridge, UK
| | | | - Andrea Lucas-Hahn
- Institute of Farm Animal Genetics, Biotechnology, Friedrich-Loeffler-Institute, Mariensee, 31535 Neustadt, Germany
| | - Heiner Niemann
- Institute of Farm Animal Genetics, Biotechnology, Friedrich-Loeffler-Institute, Mariensee, 31535 Neustadt, Germany
| | - Mary Herbert
- Wellcome Centre for Mitochondrial Research, Biosciences Institute, Newcastle University, NE1 4EP Newcastle upon Tyne, UK; Newcastle Fertility Centre at Life, Newcastle upon Tyne Hospitals NHS Foundation Trust, NE1 4EP Newcastle upon Tyne, UK
| | - Melina Schuh
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
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Nyhus C, Pihl M, Hyttel P, Hall VJ. Evidence for nucleolar dysfunction in Alzheimer's disease. Rev Neurosci 2019; 30:685-700. [PMID: 30849050 DOI: 10.1515/revneuro-2018-0104] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/08/2019] [Indexed: 11/15/2022]
Abstract
The nucleolus is a dynamically changing organelle that is central to a number of important cellular functions. Not only is it important for ribosome biogenesis, but it also reacts to stress by instigating a nucleolar stress response and is further involved in regulating the cell cycle. Several studies report nucleolar dysfunction in Alzheimer's disease (AD). Studies have reported a decrease in both total nucleolar volume and transcriptional activity of the nucleolar organizing regions. Ribosomes appear to be targeted by oxidation and reduced protein translation has been reported. In addition, several nucleolar proteins are dysregulated and some of these appear to be implicated in classical AD pathology. Some studies also suggest that the nucleolar stress response may be activated in AD, albeit this latter research is rather limited and requires further investigation. The purpose of this review is to draw the connections of all these studies together and signify that there are clear changes in the nucleolus and the ribosomes in AD. The nucleolus is therefore an organelle that requires more attention than previously given in relation to understanding the biological mechanisms underlying the disease.
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Affiliation(s)
- Caitlin Nyhus
- Department of Veterinary and Animal Sciences, Faculty of Health Sciences, University of Copenhagen, Grønnegårdsvej 7, Frederiksberg C DK-1870, Denmark
| | - Maria Pihl
- Department of Veterinary and Animal Sciences, Faculty of Health Sciences, University of Copenhagen, Grønnegårdsvej 7, Frederiksberg C DK-1870, Denmark
| | - Poul Hyttel
- Department of Veterinary and Animal Sciences, Faculty of Health Sciences, University of Copenhagen, Grønnegårdsvej 7, Frederiksberg C DK-1870, Denmark
| | - Vanessa Jane Hall
- Department of Veterinary and Animal Sciences, Faculty of Health Sciences, University of Copenhagen, Grønnegårdsvej 7, Frederiksberg C DK-1870, Denmark
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Mudrak OS, Nazarov IB, Jones EL, Zalensky AO. Positioning of chromosomes in human spermatozoa is determined by ordered centromere arrangement. PLoS One 2012; 7:e52944. [PMID: 23300830 PMCID: PMC3531364 DOI: 10.1371/journal.pone.0052944] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 11/26/2012] [Indexed: 12/20/2022] Open
Abstract
The intranuclear positioning of chromosomes (CHRs) is a well-documented fact; however, mechanisms directing such ordering remain unclear. Unlike somatic cells, human spermatozoa contain distinct spatial markers and have asymmetric nuclei which make them a unique model for localizing CHR territories and matching peri-centromere domains. In this study, we established statistically preferential longitudinal and lateral positioning for eight CHRs. Both parameters demonstrated a correlation with the CHR gene densities but not with their sizes. Intranuclear non-random positioning of the CHRs was found to be driven by a specific linear order of centromeres physically interconnected in continuous arrays. In diploid spermatozoa, linear order of peri-centromeres was identical in two genome sets and essentially matched the arrangement established for haploid cells. We propose that the non-random longitudinal order of CHRs in human spermatozoa is generated during meiotic stages of spermatogenesis. The specific arrangement of sperm CHRs may serve as an epigenetic basis for differential transcription/replication and direct spatial CHR organization during early embryogenesis.
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Affiliation(s)
- Olga S Mudrak
- Institute of Cytology, Russian Academy of Sciences, St Petersburg, Russia.
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Gavrilova EV, Kuznetsova IS, Enukashvily NI, Noniashvili EM, Dyban AP, Podgornaya OI. Localization of satellite DNA and associated proteins in respect to nucleolar precursor bodies in one- and two-cell mouse embryos. ACTA ACUST UNITED AC 2009. [DOI: 10.1134/s1990519x0903002x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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van der Heijden GW, van den Berg IM, Baart EB, Derijck AAHA, Martini E, de Boer P. Parental origin of chromatin in human monopronuclear zygotes revealed by asymmetric histone methylation patterns, differs between IVF and ICSI. Mol Reprod Dev 2009; 76:101-8. [PMID: 18481364 DOI: 10.1002/mrd.20933] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In mouse zygotes, many post-translational histone modifications are asymmetrically present in male and female pronuclei. We investigated whether this principle could be used to determine the genetic composition of monopronuclear human zygotes in conventional IVF and ICSI. First we determined whether male female asymmetry is conserved from mouse to human by staining polypronuclear zygotes with antibodies against a subset of histone N-tail post-translational modifications. To analyze human monopronuclear zygotes, a modification, H3K9me3, was selected that is present in the maternal chromatin. After IVF a total of 45 monopronuclear zygotes were obtained. In 39 (87%) of zygotes a nonuniform staining pattern was observed, proof of a bi-parental origin and assumed to result into a diploid conception. Two zygotes showed no staining for the modification, indicating that the single pronucleus was of paternal origin. Four zygotes contained only maternally derived chromatin. ICSI-derived monopronuclear zygotes (n = 33) could also be divided into three groups based on the staining pattern of their chromatin: (1) of maternal origin (n = 15), (2) of paternal origin (n = 8) or (3) consisting of two chromatin domains as dominating in IVF (n = 10). Our data show that monopronuclear zygotes originating from IVF generally arise through fusion of parental chromatin after sperm penetration. Monopronuclear zygotes derived from ICSI in most cases contain uni-parental chromatin. The fact that chromatin was of paternal origin in 24% of ICSI and in 4% of the IVF zygotes confirms earlier results obtained by FISH on cleavage stages. Our findings are of clinical importance in IVF and ICSI practice.
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Affiliation(s)
- G W van der Heijden
- Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Kuznetsova IS, Enukashvily NI, Noniashvili EM, Shatrova AN, Aksenov ND, Zenin VV, Dyban AP, Podgornaya OI. Evidence for the existence of satellite DNA-containing connection between metaphase chromosomes. J Cell Biochem 2007; 101:1046-61. [PMID: 17340617 DOI: 10.1002/jcb.21237] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Physical connections between mitotic chromosomes have been reported previously. It was assumed that the interchromosome connection was based on the DNA-protein thread. However, the data about DNA sequences and protein component in the thread is fragmentary. We demonstrated on the mouse cultured cell line and prematurely condensed chromosomes that: (a) all four mouse satellite DNA fragments (major and minor satellite, mouse satellite 3 (MS3) and mouse satellite 4 (MS4)) were involved in the thread formation; (b) MS4 was involved in the thread to the least extent among all the other fragments; (c) telomere was never a member of the thread; (d) the thread was synthesized at a late G(2) phase; (e) RNA helicase p68 and CENP-B were among the protein components of the interchromosome connection. It was shown by FACS analysis that in mouse and human cell lines: (1) the flow karyotype spectrums were never free from chromosome aggregates; (2) chromosome association did not depend on the chromosome length and each chromosome was free to associate with the other.
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Affiliation(s)
- I S Kuznetsova
- Institute of Cytology RAS, Tikhoretsky Avenue 4, St Petersburg, Russia
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Probst AV, Santos F, Reik W, Almouzni G, Dean W. Structural differences in centromeric heterochromatin are spatially reconciled on fertilisation in the mouse zygote. Chromosoma 2007; 116:403-15. [PMID: 17447080 DOI: 10.1007/s00412-007-0106-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 03/07/2007] [Accepted: 03/13/2007] [Indexed: 11/27/2022]
Abstract
In mammals, paternal and maternal pronuclei undergo profound chromatin reorganisation upon fertilisation. How these events are orchestrated within centromeric regions to ensure proper chromosome segregation in the following cellular divisions is unknown. In this study, we followed the dynamic unfolding of the centromeric regions, i.e. the centric and pericentric satellite repeats, by DNA fluorescent in situ hybridization (FISH) during the first cell cycle up to the two-cell stage. The distinct chromatin from female and male gametes both undergo rapid remodelling and reach a zygotic organisation in which the satellites occupy restricted spatial domains surrounding the nucleolar precursor body. A transition from this zygotic to a somatic cell-like organisation takes place during the two-cell stage. Using 3D immuno-FISH, we find that, whereas maternal pericentric regions are marked with H3K9me3, H4K20me3 and HP1beta, paternal ones only showed HP1beta marking. Thus, despite different chromatin features, male and female pronuclei organise their centromeric regions in the same way within the nuclei to align chromosomes on the metaphase plate and segregate them appropriately. Our findings highlight the importance of ensuring a proper centromere function while preserving the distinction of parental genome origin during the return to totipotency in the zygote.
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Affiliation(s)
- Aline V Probst
- Laboratory of Nuclear Dynamics and Nuclear Plasticity, UMR218 CNRS/Institut Curie, 75248, Paris Cedex 05, France
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Yamazaki T, Yamagata K, Baba T. Time-lapse and retrospective analysis of DNA methylation in mouse preimplantation embryos by live cell imaging. Dev Biol 2007; 304:409-19. [PMID: 17274975 DOI: 10.1016/j.ydbio.2006.12.046] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 12/18/2006] [Accepted: 12/19/2006] [Indexed: 12/13/2022]
Abstract
Genome-wide change of DNA methylation in preimplantation embryos is known to be important for the nuclear reprogramming process. A synthetic RNA encoding enhanced green fluorescence protein fused to the methyl-CpG-binding domain and nuclear localization signal of human MBD1 was microinjected into metaphase II-arrested or fertilized oocytes, and the localization of methylated DNA was monitored by live cell imaging. Both the central part of decondensing sperm nucleus and the rim region of the nucleolus in the male pronucleus were highly DNA-methylated during pronuclear formation. The methylated paternal genome undergoing active DNA demethylation in the enlarging pronucleus was dispersed, assembled, and then migrated to the nucleolar rim. The female pronucleus contained methylated DNA predominantly in the nucleoplasm. When the localization of methylated DNA in preimplantation embryos was examined, a configurational change of methylated chromatin dramatically occurred during the transition of 2-cell to 4-cell embryos. Moreover, retrospective analysis demonstrated that a noticeable number of the oocytes reconstructed by round spermatid injection (ROSI) possess small, bright dots of methylated chromatin in the nucleoplasm of male pronucleus. These ROSI oocytes showed a significantly low rate of 2-cell formation, thus suggesting that the poor embryonic development of the ROSI oocytes may result from the abnormal localization of methylated chromatin.
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Affiliation(s)
- Taiga Yamazaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki 305-8572, Japan
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10
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Martin C, Brochard V, Migné C, Zink D, Debey P, Beaujean N. Architectural reorganization of the nuclei upon transfer into oocytes accompanies genome reprogramming. Mol Reprod Dev 2006; 73:1102-11. [PMID: 16736527 DOI: 10.1002/mrd.20506] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The ability of cloned embryos to sustain full-term development depends on the ability of the recipient ooplasm to reprogram the donor cell genome. As the nuclear architecture has recently emerged as a key-factor in the regulation of gene expression, we questioned whether early embryos obtained from transfer of ES metaphasic chromosomes into mouse ooplasm would adopt the somatic or embryonic type of nuclear organization. We have particularly focused on the arrangement of chromosomal territories with respect to the nucleolar compartment, and the pericentric heterochromatin domains called chromocenters. We found that nuclear transfer triggers profound chromatin rearrangements including the dispersion of the donor cell chromocenters components. These rearrangements lead to a typical 1-cell pronuclear organization, namely a radial arrangement of the chromosome territories with centromeres attached to the nucleoli, which adopt the compact fibrillar structure of nucleolar precursor bodies (NPBs). Subsequently, during the second cycle, the cloned embryos undergo further reorganization with the establishment of new chromocenters, clustered in one part of the nucleus, as during normal embryogenesis. We could also establish that the adequate distribution of chromosomal territories at the pronuclear stage seems important for the development until blastocyst.
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Affiliation(s)
- Catherine Martin
- UMR 13-1198 Biologie du Développement, Institut National de Recherche Agronomique, Domaine de Vilvert, Jouy-en-Josas, France
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11
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Enukashvily N, Donev R, Sheer D, Podgornaya O. Satellite DNA binding and cellular localisation of RNA helicase P68. J Cell Sci 2005; 118:611-22. [PMID: 15657085 DOI: 10.1242/jcs.01605] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We purified a 68-kDa protein from the mouse nuclear matrix using ion exchange and affinity chromatography. Column fractions were tested for specific binding to mouse minor satellite DNA using a gel mobility shift assay. The protein was identified by mass spectrometry as RNA helicase P68. In fixed cells, P68 was found to shuttle in and out of SC35 domains, forming fibres and granules in a cell-cycle dependent manner. Analysis of the P68 sequence revealed a short potential coiled-coil domain that might be involved in the formation of P68 fibres. Contacts between centromeres and P68 granules were observed during all phases of the cycle but they were most prominent in mitosis. At this stage, P68 was found in both the centromeric regions and the connections between chromosomes. Direct interaction of P68/DEAD box RNA helicase with satellite DNAs in vitro has not been demonstrated for any other members of the RNA helicase family.
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Affiliation(s)
- Natella Enukashvily
- Cell Cultures Department, Institute of Cytology, Tikhoretsky, 4, St Petersburg, 194064, Russia.
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12
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Abstract
In human spermatozoa, the arrangement of chromosomes is non-random. Characteristic features are association of centromeres in the interior chromocenter and peripheral location of telomeres. In this paper, we have investigated the highest level of order in DNA packing in sperm--absolute and relative intranuclear chromosome positioning. Asymmetrical nuclear shape, existence of a defined spatial marker, and the haploid complement of chromosomes facilitated an experimental approach using in situ hybridization. Our results showed the tendency for non-random intranuclear location of individual chromosome territories. Moreover, centromeres demonstrated specific intranuclear position, and were located within a limited area of nuclear volume. Additionally, the relative positions of centromeres were non-random; some were found in close proximity, while other pairs showed significantly greater intercentromere distances. Therefore, a unique and specific adherence may exist between chromosomes in sperm. The observed chromosome order is discussed in relation to sperm nuclei decondensation, and reactivation during fertilization.
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Affiliation(s)
- Irina A Zalenskaya
- The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, VA 23507-1627, USA
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Longo F, Garagna S, Merico V, Orlandini G, Gatti R, Scandroglio R, Redi CA, Zuccotti M. Nuclear localization of NORs and centromeres in mouse oocytes during folliculogenesis. Mol Reprod Dev 2004; 66:279-90. [PMID: 14502607 DOI: 10.1002/mrd.10354] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Mouse oocytes at the germinal vesicle stage are characterized by one of two nuclear morphologies: surrounded nucleolus (SN), in which the nucleolus is surrounded by a rim of Hoechst positive chromatin and not surrounded nucleolus (NSN), in which this rim is essentially absent. This morphological difference has a biological relevance as NSN oocytes are transcriptionally active, yet incapable of development beyond the two-cell stage. Whereas SN oocytes, which are transcriptionally inactive, are capable of development to the blastocyst stage. To further our understanding of the nuclear organization of the mouse oocyte during folliculogenesis, we have conducted a series of investigations employing silver methods that stain nucleolus organizer region (NOR), centromeres, and heterochromatin, as well as, specific antibodies for centromeres. Results obtained by a variety of microscopic methods (light, electron, immunochemical, and confocal) demonstrate: (1) a changing pattern of NOR staining during folliculogenesis that is specific to follicular type, and (2) significant differences in the organization of NORs and centromeres of isolated, antral NSN, and SN oocytes. These observations suggest possible means by which, chromosomes of mature, germinal vesicle oocytes are organized with respect to the nucleolus.
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Affiliation(s)
- Frank Longo
- Laboratorio di Biologia dello Sviluppo e Centro di Eccellenza in Biologia Applicata, Universita' degli Studi di Pavia, Piazza Botta 9, Pavia, Italy
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Chen CK, Shen GY, Horng SG, Wang CW, Huang HY, Wang HS, Soong YK. The relationship of pronuclear stage morphology and chromosome status at cleavage stage. J Assist Reprod Genet 2003; 20:413-20. [PMID: 14649381 PMCID: PMC3455171 DOI: 10.1023/a:1026232625659] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Infertile couples undergoing in vitro fertilization-embryo transfer (IVF-ET) program were included to study the relationship of pronuclear stage morphology and chromosome status at cleavage stage. METHODS Eighteen to twenty-one hours after fertilization, zygotes were checked for pronuclear morphology with modified Scott Z-score system. After embryo transfer on day 3, arrested or non-transferred 2 PN embryos were spread for fluorescence in situ hybridization (FISH) staining of probes to chromosomes 18, X and Y. RESULTS Ninety-eight embryos were successfully fixed and stained. The chromosome status were recorded in each 2 PN score group: 7 (54%) of 13 embryos in Z2 group, 14 (35%) of 40 in Z3 group and 10 (36%) of 28 in Z4 group being normal diploid. Z1 group has 12 (71%) of 17 embryos being normal diploid, which is significantly more than Z3 (p = 0.020) and Z4 group (p = 0.033). CONCLUSION Our results demonstrated a high probability to get normal diploid embryos if good morphology at pronuclear stage was used as selection criteria, especially for Z1 score embryos.
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Affiliation(s)
- Chun-Kai Chen
- Department of Obstetrics and Gynecology, Lin-Kou Medical Center, Chang Gung Memorial Hospital and Medical College, 5, Fu-Hsing Street, Kwei-Shan, Tao-Yuan 333, Taiwan.
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Podgornaya OI, Voronin AP, Enukashvily NI, Matveev IV, Lobov IB. Structure-specific DNA-binding proteins as the foundation for three-dimensional chromatin organization. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 224:227-96. [PMID: 12722952 DOI: 10.1016/s0074-7696(05)24006-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Any functions of tandem repetitive sequences need proteins that specifically bind to them. Telomere-binding TRF2/MTBP attaches telomeres to the nuclear envelope in interphase due to its rod-domain-like motif. Interphase nuclei organized as a number of sponge-like ruffly round chromosome territories that could be rotated from outside. SAF-A/hnRNP-U and p68-helicase are proteins suitable to do that. Their location in the interchromosome territory space, ATPase domains, and the ability to be bound by satellite DNAs (satDNA) make them part of the wires used to help chromosome territory rotates. In case of active transcription p68-helicase can be involved in the formation of local "gene expression matrices" and due to its satDNA-binding specificity cause the rearrangement of the local chromosome territory. The marks of chromatin rearrangement, which have to be heritable, could be provided by SAF-A/hnRNP-U. During telophase unfolding the proper chromatin arrangement is restored according to these marks. The structural specificity of both proteins to the satDNAs provides a regulative but relatively stable mode of binding. The structural specificity of protein binding could help to find the "magic" centromeric sequence. With future investigations of proteins with the structural specificity of binding during early embryogenesis, when heterochromatin formation goes on, the molecular mechanisms of the "gene gating" hypothesis (Blobel, 1985) will be confirmed.
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Affiliation(s)
- O I Podgornaya
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg 194064, Russia
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16
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Nagy ZP, Dozortsev D, Diamond M, Rienzi L, Ubaldi F, Abdelmassih R, Greco E. Pronuclear morphology evaluation with subsequent evaluation of embryo morphology significantly increases implantation rates. Fertil Steril 2003; 80:67-74. [PMID: 12849803 DOI: 10.1016/s0015-0282(03)00569-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To elucidate the relative predictive value of implantation markers at different stages of preimplantation development. DESIGN Correlation of pronuclear morphology with embryo morphology and implantation rates in retrospective and prospective analysis of in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI) treatment cycles. SETTING Private infertility center. PATIENT(S) A total of 441 couples undergoing infertility treatment. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Size of pronuclei and distance between them, the number and polarization of nucleolus precursor bodies (NPB) at the one-cell stage, embryo cleavage and fragmentation rates on days 2 and 3, and pregnancy and implantation rates. RESULT(S) Polarization of the NPB in both pronuclei had a statistically significant correlation with normal membrane breakage during ICSI (40%, compared with 33% easy, and 31% difficult membrane breakage) and also with faster cleavage and lower fragmentation rates of embryos. Sixty-one percent of implanting embryos had polarization of the NPB in both pronuclei compared with 37% for all embryos. Larger distance between pronuclei and their unequal size had a statistically significant correlation with slower cleavage and inferior embryo quality. Embryo selection based on only pronuclear morphology or on only day-3 embryo morphology yielded implantation rates of 15.1% and 12.1%, respectively. Embryo selection based on sequential evaluation of both pronuclear morphology and embryo morphology on day 3 resulted in a 21.1% implantation rate. CONCLUSION(S) Polarization of NPB in both pronuclei is as reliable marker of implantation as embryo morphology on day 3. However, pronuclear morphology assessment improves embryo selection only when it is combined with embryo morphology evaluation on day 3.
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Affiliation(s)
- Zsolt P Nagy
- Clinica e Centro de Pesquisa em Reproducao Humana Dr. Roger Abdelmassih, São Paulo, Brazil.
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17
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Coskun S, Hellani A, Jaroudi K, Al-Mayman H, Al-Kabra M, Qeba M. Nucleolar precursor body distribution in pronuclei is correlated to chromosomal abnormalities in embryos. Reprod Biomed Online 2003; 7:86-90. [PMID: 12930583 DOI: 10.1016/s1472-6483(10)61734-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In-vitro generated human embryos have low implantation rates and high chromosomal abnormalities. Embryos are mostly selected on the basis of microscopic morphological examination. The relationship between pronuclear morphology and chromosomal abnormalities was investigated in this study. Zygotes were scored according to pronuclear morphology on day 1. Excess embryos that were not transferred or cryopreserved on day 3 were fixed. Chromosomes 13, 18, 21, X and Y were analysed by fluorescence in-situ hybridization (FISH). A total of 125 embryos were analysed; 58 (46%) were abnormal, 32 (26%) were mosaic and 35 (28%) were normal. Results were analysed according to different pronuclear morphology. Zygotes with polarized pattern had a significantly lower incidence of chromosome abnormality than those with a non-polarized pattern. The presence of cytoplasmic halo, the size of each pronucleus and the number of nucleolar precursor body had no significant effect on chromosomal abnormalities. In conclusion, embryos generated from zygotes with polarized pattern have fewer chromosomal abnormalities compared with other patterns. A simple microscopic examination during fertilization confirmation would be useful to select embryos with fewer chromosomal abnormalities, preferably in combination with other observations shown to correlate with chromosomal abnormalities.
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Affiliation(s)
- Serdar Coskun
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, PO Box 3354, MBC 10, Riyadh, 11211, Saudi Arabia.
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Weier HU. DNA fiber mapping techniques for the assembly of high-resolution physical maps. J Histochem Cytochem 2001; 49:939-48. [PMID: 11457922 DOI: 10.1177/002215540104900802] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
High-resolution physical maps are indispensable for directed sequencing projects or the finishing stages of shotgun sequencing projects. These maps are also critical for the positional cloning of disease genes and genetic elements that regulate gene expression. Typically, physical maps are based on ordered sets of large insert DNA clones from cosmid, P1/PAC/BAC, or yeast artificial chromosome (YAC) libraries. Recent technical developments provide detailed information about overlaps or gaps between clones and precisely locate the position of sequence tagged sites or expressed sequences, and thus support efforts to determine the complete sequence of the human genome and model organisms. Assembly of physical maps is greatly facilitated by hybridization of non-isotopically labeled DNA probes onto DNA molecules that were released from interphase cell nuclei or recombinant DNA clones, stretched to some extent and then immobilized on a solid support. The bound DNA, collectively called "DNA fibers," may consist of single DNA molecules in some experiments or bundles of chromatin fibers in others. Once released from the interphase nuclei, the DNA fibers become more accessible to probes and detection reagents. Hybridization efficiency is therefore increased, allowing the detection of DNA targets as small as a few hundred base pairs. This review summarizes different approaches to DNA fiber mapping and discusses the detection sensitivity and mapping accuracy as well as recent achievements in mapping expressed sequence tags and DNA replication sites.
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Affiliation(s)
- H U Weier
- Department of Subcellular Structure, Life Sciences Division, University of California, Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California, USA.
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