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Fu B, Ma H, Liu D. Essential roles of the nucleolus during early embryonic development: a regulatory hub for chromatin organization. Open Biol 2024; 14:230358. [PMID: 38689555 PMCID: PMC11065130 DOI: 10.1098/rsob.230358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/26/2023] [Accepted: 03/15/2024] [Indexed: 05/02/2024] Open
Abstract
The nucleolus is the most prominent liquid droplet-like membrane-less organelle in mammalian cells. Unlike the nucleolus in terminally differentiated somatic cells, those in totipotent cells, such as murine zygotes or two-cell embryos, have a unique nucleolar structure known as nucleolus precursor bodies (NPBs). Previously, it was widely accepted that NPBs in zygotes are simply passive repositories of materials that will be gradually used to construct a fully functional nucleolus after zygotic genome activation (ZGA). However, recent research studies have challenged this simplistic view and demonstrated that functions of the NPBs go beyond ribosome biogenesis. In this review, we provide a snapshot of the functions of NPBs in zygotes and early two-cell embryos in mice. We propose that these membrane-less organelles function as a regulatory hub for chromatin organization. On the one hand, NPBs provide the structural platform for centric and pericentric chromatin remodelling. On the other hand, the dynamic changes in nucleolar structure control the release of the pioneer factors (i.e. double homeobox (Dux)). It appears that during transition from totipotency to pluripotency, decline of totipotency and initiation of fully functional nucleolus formation are not independent events but are interconnected. Consequently, it is reasonable to hypothesize that dissecting more unknown functions of NPBs may shed more light on the enigmas of early embryonic development and may ultimately provide novel approaches to improve reprogramming efficiency.
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Affiliation(s)
- Bo Fu
- Institute of Animal Husbandry, HeiLongJiang Academy of
Agricultural Sciences, Harbin150086, People's Republic of China
- Key Laboratory of Combining Farming and Animal Husbandry,
Ministry of Agriculture and Rural Affairs, Harbin150086, People's Republic of China
| | - Hong Ma
- Institute of Animal Husbandry, HeiLongJiang Academy of
Agricultural Sciences, Harbin150086, People's Republic of China
- Key Laboratory of Combining Farming and Animal Husbandry,
Ministry of Agriculture and Rural Affairs, Harbin150086, People's Republic of China
| | - Di Liu
- Institute of Animal Husbandry, HeiLongJiang Academy of
Agricultural Sciences, Harbin150086, People's Republic of China
- Key Laboratory of Combining Farming and Animal Husbandry,
Ministry of Agriculture and Rural Affairs, Harbin150086, People's Republic of China
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2
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Bari MW, Morishita Y, Kishigami S. Heterogeneity of nucleolar morphology in four-cell mouse embryos after IVF: association with developmental potential. Anim Sci J 2023; 94:e13907. [PMID: 38102887 DOI: 10.1111/asj.13907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023]
Abstract
In mammals, around fertilization, the nucleolus of embryos transforms into the nucleolus precursor bodies (NPBs), which continue to mature until the blastocyst stage, leading to distinct morphological changes. In our study, we observed two types of nucleolar morphology in mouse in vitro fertilized embryos at the four-cell stage, which we refer to single nucleolus (SN) and multiple nucleoli (MN). To visualize nucleolar morphology, four-cell embryos were immunostained with anti-NOPP140 antibody. These embryos were categorized into five types based on the number of blastomeres carrying SN: SN4/MN0, SN3/MN1, SN2/MN2, SN1/MN3, and SN0/MN4, with percentages of 13, 27, 21, 23 and 9, respectively. Next, using a light microscope, we divided the four-cell in vitro fertilized embryos without fixation into two groups: those with at least two blastomeres displaying SN (SN embryos) and those without (MN embryos). Notably, significantly more SN embryos developed into blastocysts and offspring at 18.5 dpc compared with MN embryos. Furthermore, SN embryos displayed a higher NANOG-positive cell number at the blastocyst stage, significantly lower body and placental weights, resulting in a higher fetal/placental ratio. These findings suggest a close association between nucleolar state at the four-cell stage and subsequent developmental potential.
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Affiliation(s)
- Md Wasim Bari
- Department of Integrated Applied Life Science, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, Kofu, Japan
| | - Yoshiya Morishita
- Graduate School of Life and Environmental Sciences, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi Kofu, Japan
| | - Satoshi Kishigami
- Department of Integrated Applied Life Science, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, Kofu, Japan
- Graduate School of Life and Environmental Sciences, Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi Kofu, Japan
- Center for advanced Assisted Reproductive Technologies, University of Yamanashi, Kofu, Japan
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3
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Chebrout M, Koné MC, Jan HU, Cournut M, Letheule M, Fleurot R, Aguirre-Lavin T, Peynot N, Jouneau A, Beaujean N, Bonnet-Garnier A. Transcription of rRNA in early mouse embryos promotes chromatin reorganization and expression of major satellite repeats. J Cell Sci 2022; 135:274059. [DOI: 10.1242/jcs.258798] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 01/09/2022] [Indexed: 11/20/2022] Open
Abstract
During the first cell cycles of the early development, the chromatin of the embryo is highly reprogrammed alongside that embryonic genome starts its own transcription. The spatial organization of the genome is a major process that contributes to regulating gene transcription in time and space, however, it is poorly studied in the context of early embryos. To study the cause and effect link between transcription and spatial organization in embryos, we focused on the ribosomal genes, that are first silent and begin to transcribe during the 2-cell stage in the mouse. We demonstrated that ribosomal sequences and early unprocessed rRNAs are spatially organized in a very peculiar manner from the 2-cell to the 16-cell. Using drugs interfering with ribosomal DNA transcription, we show that this organization, totally different from somatic cells, depends on an active transcription of ribosomal genes and induces a unique chromatin environment that favors transcription of major satellite sequences after the 4-cell stage.
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Affiliation(s)
- Martine Chebrout
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Maïmouna Coura Koné
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Habib U. Jan
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Marie Cournut
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Martine Letheule
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Renaud Fleurot
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Tiphaine Aguirre-Lavin
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Nathalie Peynot
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Alice Jouneau
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Nathalie Beaujean
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
| | - Amélie Bonnet-Garnier
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350, Jouy-en-Josas, France
- Ecole Nationale Vétérinaire d'Alfort, BREED, 94700, Maisons-Alfort, France
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FULKA H, LOI P, PALAZZESE L, BENC M, FULKA, Jr. J. Nucleus reprogramming/remodeling through selective enucleation (SE) of immature oocytes and zygotes: a nucleolus point of view. J Reprod Dev 2022; 68:165-172. [PMID: 35431279 PMCID: PMC9184824 DOI: 10.1262/jrd.2022-004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It is now approximately 25 years since the sheep Dolly, the first cloned mammal where the somatic cell nucleus from an adult donor was used for transfer, was born. So far, somatic cell
nucleus transfer, where G1-phase nuclei are transferred into cytoplasts obtained by enucleation of mature metaphase II (MII) oocytes followed by the activation of the reconstructed cells, is
the most efficient approach to reprogram/remodel the differentiated nucleus. In general, in an enucleated oocyte (cytoplast), the nuclear envelope (NE, membrane) of an injected somatic cell
nucleus breaks down and chromosomes condense. This condensation phase is followed, after subsequent activation, by chromatin decondensation and formation of a pseudo-pronucleus (i) whose
morphology should resemble the natural postfertilization pronuclei (PNs). Thus, the volume of the transferred nuclei increases considerably by incorporating the content released from the
germinal vesicles (GVs). In parallel, the transferred nucleus genes must be reset and function similarly as the relevant genes in normal embryo reprogramming. This, among others, covers the
relevant epigenetic modifications and the appropriate organization of chromatin in pseudo-pronuclei. While reprogramming in SCNT is often discussed, the remodeling of transferred nuclei is
much less studied, particularly in the context of the developmental potential of SCNT embryos. It is now evident that correct reprogramming mirrors appropriate remodeling. At the same time,
it is widely accepted that the process of rebuilding the nucleus following SCNT is instrumental to the overall success of this procedure. Thus, in our contribution, we will mostly focus on
the remodeling of transferred nuclei. In particular, we discuss the oocyte organelles that are essential for the development of SCNT embryos.
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Affiliation(s)
- Helena FULKA
- Institute of Experimental Medicine, Prague, Czech Republic
| | - Pasqualino LOI
- Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy
| | - Luca PALAZZESE
- Institute of Genetics and Animal Biotechnology of the Polish Academy of Sciences, 05-552 Jastrzebiec, Poland
| | - Michal BENC
- Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Slovak Republic
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Su G, Wang L, Gao G, Wu S, Yang L, Wu M, Liu X, Yang M, Wei Z, Bai C, Li G. C23 gene regulates the nucleolin structure and biosynthesis of ribosomes in bovine intraspecific and interspecific somatic cell nuclear transfer embryos. FASEB J 2021; 35:e21993. [PMID: 34670005 DOI: 10.1096/fj.202100737rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/15/2021] [Accepted: 10/01/2021] [Indexed: 01/07/2023]
Abstract
Somatic cell nuclear transfer (SCNT) can reprogram differentiated somatic cells to produce individual animals, thus having advantages in animal breeding and chromatin reprogramming. Interspecies SCNT (iSCNT) provides extreme cases of reprogramming failure that can be used to understand the basic biological mechanism of genome reprogramming. It is important to understand the possible mechanisms for the failure of zygotic genome activation (ZGA) in iSCNT embryos in order to improve the efficiency of SCNT embryos. In the present study, we compared the development of bovine-bovine (B-B), ovine-ovine (O-O) SCNT, and ovine-bovine (O-B) iSCNT embryos and found that a developmental block existed in the 8-cell stage in O-B iSCNT embryos. RNA sequencing and q-PCR analysis revealed that the large ribosomal subunit genes (RPL) or the small ribosomal subunit genes (RPS) were expressed at lower levels in the O-B iSCNT embryos. The nucleolin (C23) gene that regulates the ribosomal subunit generation was transcribed at a lower level during embryonic development in O-B iSCNT embryos. In addition, the nucleolin exhibited a clear circular-ring structure in B-B 8-cell stage embryos, whereas this was shell-like or dot-like in the O-B embryos. Furthermore, overexpression of C23 could increase the blastocyst rate of both SCNT and iSCNT embryos and partly rectify the ring-like nucleolin structure and the expression of ribosomal subunit related genes were upregulation, while knockdown of C23 increased the shell-like nucleolin-structure in B-B cloned embryos and downregulated the expression of ribosomal subunit related genes. These results implied that abnormal C23 and ribosome subunit gene expression would lead to the developmental block of iSCNT embryos and ZGA failure. Overexpression of the C23 gene could partly improve the blastocyst development and facilitate the nucleolin structure in bovine preimplantation SCNT embryos.
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Affiliation(s)
- Guanghua Su
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Lina Wang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Guangqi Gao
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, Hohhot, China
| | - Shanshan Wu
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Lei Yang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Meiling Wu
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xuefei Liu
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Miaomiao Yang
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Zhuying Wei
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Chunling Bai
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Guangpeng Li
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, Hohhot, China
- College of Life Sciences, Inner Mongolia University, Hohhot, China
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Wang T, Na J. Fibrillarin-GFP Facilitates the Identification of Meiotic Competent Oocytes. Front Cell Dev Biol 2021; 9:648331. [PMID: 33937243 PMCID: PMC8082495 DOI: 10.3389/fcell.2021.648331] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/12/2021] [Indexed: 12/11/2022] Open
Abstract
The nucleolus undergoes significant functional changes and plays important roles during mammalian oocyte meiotic maturation. Fibrillarin (FBL) is the component of nucleolar small nuclear ribonucleoprotein (snRNP) particle and localizes to the dense fibrillar component (DFC) of the nucleolus. We found that FBL-GFP displays an uneven and cloudy localization in the nucleolus of non-surrounded nucleolus (NSN) oocytes, while it distributes evenly and to a few bright dots in the surrounded nucleolus (SN) oocytes. Accordingly, NSN oocytes showed active nascent RNA transcription, while the SN group was transcriptionally quiescent. NSN geminal vesicles also contained more DNA damage marker γH2AX foci. Based on different FBL-GFP patterns in live oocytes, the ones with superior meiotic maturation potential can be identified. Global transcriptome profiling revealed a significant difference in single SN and NSN oocytes. Thus, FBL-GFP can serve as a marker for nucleolus activity, which also correlates with transcription activity and the quality of oocytes.
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Affiliation(s)
- Ting Wang
- Center for Stem Cell Biology and Regenerative Medicine, School of Medicine, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Jie Na
- Center for Stem Cell Biology and Regenerative Medicine, School of Medicine, Tsinghua University, Beijing, China
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Migration speed of nucleolus precursor bodies in human male pronuclei: a novel parameter for predicting live birth. J Assist Reprod Genet 2021; 38:1725-1736. [PMID: 33811586 DOI: 10.1007/s10815-021-02172-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/22/2021] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To study the relationship between the migration speed of nucleolus precursor bodies (NPBs) in male and female pronuclei (mPN; fPN) and human embryo development during assisted reproduction. METHODS The migration speed of 263 NPBs from 47 zygotes was quantitated, and embryonic development was observed until the blastocyst stage. The central coordinates of mPN, fPN, and NPBs were noted at multiple timepoints. Then, the distance traveled by the NPBs between two sequential images was measured, and migration speed was calculated. Additionally, we investigated the relationship between NPB migration speed and ploidy status (N = 33) or live birth/ongoing pregnancy (LB/OP) (N = 60) after assisted reproduction. RESULTS The NPB migration speed in both mPN and fPN was significantly faster in the zygotes that developed into blastocysts (N = 25) than that in the zygotes that arrested (N = 22). The timing of blastulation was negatively correlated with NPB migration speed in the mPN. Faster NPB migration was significantly correlated with LB/OP. In multivariate logistic analysis, NPB migration speed in the mPN was the only morphokinetic parameter associated with LB/OP. In a receiver-operating characteristic curve analysis of LB/OP by the NPB migration speed in the mPN, the cut-off value was 4.56 μm/h. When this cut-off value was applied to blastocysts with preimplantation genetic testing for aneuploidy, 100% of the blastocysts faster than or equal to the cut-off value were euploid. CONCLUSION The NPBs migrated faster in zygotes having the potential to develop into a blastocyst, and eventually into a baby. This predictor could be an attractive marker for non-invasive embryo selection.
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Benc M, Strejcek F, Morovic M, Bartkova A, Murin M, Gad A, Bonnet-Garnier A, Percinic FP, Laurincik J. Improving the Quality of Oocytes with the Help of Nucleolotransfer Therapy. Pharmaceuticals (Basel) 2021; 14:ph14040328. [PMID: 33918523 PMCID: PMC8066131 DOI: 10.3390/ph14040328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/26/2021] [Accepted: 03/29/2021] [Indexed: 11/16/2022] Open
Abstract
The nucleolus is an important nucleus sub-organelle found in almost all eukaryotic cells. On the one hand, it is known as a differentiated active site of ribosome biogenesis in somatic cells, but on the other hand, in fully grown oocytes, zygotes, and early embryos (up to the major embryonic genome activation), it is in the form of a particular homogenous and compact structure called a fibrillar sphere. Nowadays, thanks to recent studies, we know many important functions of this, no doubt, interesting membraneless nucleus sub-organelle involved in oocyte maturation, embryonic genome activation, rRNA synthesis, etc. However, many questions are still unexplained and remain a mystery. Our aim is to create a comprehensive overview of the recent knowledge on the fibrillar sphere and envision how this knowledge could be utilized in further research in the field of biotechnology and nucleolotransfer therapy.
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Affiliation(s)
- Michal Benc
- Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Nabrezie mladeze 91, 94974 Nitra, Slovakia; (M.B.); (M.M.); (A.B.); (J.L.)
| | - Frantisek Strejcek
- Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Nabrezie mladeze 91, 94974 Nitra, Slovakia; (M.B.); (M.M.); (A.B.); (J.L.)
- Correspondence: ; Tel.: +421-037-6408-584
| | - Martin Morovic
- Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Nabrezie mladeze 91, 94974 Nitra, Slovakia; (M.B.); (M.M.); (A.B.); (J.L.)
| | - Alexandra Bartkova
- Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Nabrezie mladeze 91, 94974 Nitra, Slovakia; (M.B.); (M.M.); (A.B.); (J.L.)
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 27721 Libechov, Czech Republic; (M.M.); (A.G.)
| | - Matej Murin
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 27721 Libechov, Czech Republic; (M.M.); (A.G.)
| | - Ahmed Gad
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 27721 Libechov, Czech Republic; (M.M.); (A.G.)
| | - Amelie Bonnet-Garnier
- Université Paris-Saclay, UVSQ, INRAE, BREED, 78350 Jouy-en-Josas, France;
- Ecole Nationale Vétérinaire d’Alfort, BREED, 94700 Maisons-Alfort, France
| | - Florina Popovska Percinic
- Faculty of Veterinary Medicine, St. Cyril and Methodius University in Skopje, 1000 Skopje, North Macedonia;
| | - Jozef Laurincik
- Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Nabrezie mladeze 91, 94974 Nitra, Slovakia; (M.B.); (M.M.); (A.B.); (J.L.)
- Institute of Animal Physiology and Genetics, The Czech Academy of Sciences, 27721 Libechov, Czech Republic; (M.M.); (A.G.)
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9
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The nucleolus-like and precursor bodies of mammalian oocytes and embryos and their possible role in post-fertilization centromere remodelling. Biochem Soc Trans 2021; 48:581-593. [PMID: 32318710 DOI: 10.1042/bst20190847] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 12/14/2022]
Abstract
In nearly all somatic cells, the ribosome biosynthesis is a key activity. The same is true also for mammalian oocytes and early embryos. This activity is intimately linked to the most prominent nuclear organelles - the nucleoli. Interestingly, during a short period around fertilization, the nucleoli in oocytes and embryos transform into ribosome-biosynthesis-inactive structures termed nucleolus-like or nucleolus precursor bodies (NPBs). For decades, researchers considered these structures to be passive repositories of nucleolar proteins used by the developing embryo to rebuild fully functional, ribosome-synthesis competent nucleoli when required. Recent evidence, however, indicates that while these structures are unquestionably essential for development, the material is largely dispensable for the formation of active embryonic nucleoli. In this mini-review, we will describe some unique features of oocytes and embryos with respect to ribosome biogenesis and the changes in the structure of oocyte and embryonic nucleoli that reflect this. We will also describe some of the different approaches that can be used to study nucleoli and NPBs in embryos and discuss the different results that might be expected. Finally, we ask whether the main function of nucleolar precursor bodies might lie in the genome organization and remodelling and what the involved components might be.
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10
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Fulka H, Ogura A, Loi P, Fulka Jr J. Dissecting the role of the germinal vesicle nuclear envelope and soluble content in the process of somatic cell remodelling and reprogramming. J Reprod Dev 2019; 65:433-441. [PMID: 31423000 PMCID: PMC6815741 DOI: 10.1262/jrd.2019-017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Differentiated nuclei can be reprogrammed/remodelled to totipotency after their transfer to enucleated metaphase II (MII) oocytes. The process of reprogramming/remodelling is, however, only
partially characterized. It has been shown that the oocyte nucleus (germinal vesicle – GV) components are essential for a successful remodelling of the transferred nucleus by providing the
materials for pseudo-nucleus formation. However, the nucleus is a complex structure and exactly what nuclear components are required for a successful nucleus remodelling and reprogramming is
unknown. Till date, the only nuclear sub-structure experimentally demonstrated to be essential is the oocyte nucleolus (nucleolus-like body, NLB). In this study, we investigated what other
GV components might be necessary for the formation of normal-sized pseudo-pronuclei (PNs). Our results showed that the removal of the GV nuclear envelope with attached chromatin and
chromatin-bound factors does not substantially influence the size of the remodelled nuclei in reconstructed cells and that their nuclear envelopes seem to have normal parameters. Rather than
the insoluble nuclear lamina, the GV content, which is dissolved in the cytoplasm with the onset of oocyte maturation, influences the characteristics and size of transferred nuclei.
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Affiliation(s)
- Helena Fulka
- Institute of Molecular Genetics of the ASCR, 142 20 Prague, Czech Republic.,Institute of Experimental Medicine, 142 20 Prague, Czech Republic
| | - Atsuo Ogura
- RIKEN BioResource Center, Ibaraki 305-0074, Japan
| | - Pasqualino Loi
- Faculty of Veterinary Medicine, University of Teramo, Teramo 64100, Italy
| | - Josef Fulka Jr
- Institute of Animal Science, 140 00 Prague, Czech Republic
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11
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Kresoja-Rakic J, Santoro R. Nucleolus and rRNA Gene Chromatin in Early Embryo Development. Trends Genet 2019; 35:868-879. [PMID: 31327501 DOI: 10.1016/j.tig.2019.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/17/2019] [Accepted: 06/24/2019] [Indexed: 12/16/2022]
Abstract
The nucleolus is the largest substructure in the nucleus and forms around the nucleolar organizer regions (NORs), which comprise hundreds of rRNA genes. Recent evidence highlights further functions of the nucleolus that go beyond ribosome biogenesis. Data indicate that the nucleolus acts as a compartment for the location and regulation of repressive genomic domains and, together with the nuclear lamina, represents the hub for the organization of the inactive heterochromatin. In this review, we discuss recent findings that have revealed how nucleolar structure and rRNA gene chromatin states are regulated during early mammalian development and their contribution to the higher-order spatial organization of the genome.
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Affiliation(s)
- Jelena Kresoja-Rakic
- Department of Molecular Mechanisms of Disease, DMMD, University of Zurich, CH-8057 Zurich, Switzerland
| | - Raffaella Santoro
- Department of Molecular Mechanisms of Disease, DMMD, University of Zurich, CH-8057 Zurich, Switzerland.
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12
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Fulka H, Langerova A. Nucleoli in embryos: a central structural platform for embryonic chromatin remodeling? Chromosome Res 2018; 27:129-140. [PMID: 30406864 DOI: 10.1007/s10577-018-9590-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/17/2018] [Accepted: 10/24/2018] [Indexed: 10/27/2022]
Abstract
Nucleoli are the site of ribosomal RNA production and subunit assembly. In contrast to active nucleoli in somatic cells, where three basic sub-compartments can be observed, mammalian oocytes and early embryos contain atypical nucleoli termed "nucleolus-like bodies" or "nucleolus precursor bodies", respectively. Unlike their somatic counterparts, these structures are composed of dense homogenous fibrillar material and exhibit no polymerase activity. Irrespective of these unusual properties, they have been shown to be absolutely essential for embryonic development, as their microsurgical removal results in developmental arrest. Historically, nucleolus-like and nucleolus precursor bodies have been perceived as passive storage sites of nucleolar material, which is gradually utilized by embryos to construct fully functional nucleoli once they have activated their genome and have started to produce ribosomes. For decades, researchers have been trying to elucidate the composition of these organelles and provide the evidence for their repository role. However, only recently has it become clear that the function of these atypical nucleoli is altogether different, and rather than being involved in ribosome biogenesis, they participate in parental chromatin remodeling, and strikingly, the artificial introduction of a single NPB component is sufficient to rescue the developmental arrest elicited by the NPB removal. In this review, we will describe and summarize the experiments that led to the change in our understanding of these unique structures.
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Affiliation(s)
- Helena Fulka
- Institute of Animal Science, v.v.i., 104 00, Prague 10, Czech Republic. .,Institute of Molecular Genetics ASCR, v.v.i., 142 20, Prague 4, Czech Republic. .,Institute of Experimental Medicine ASCR, v.v.i., 142 20, Prague 4, Czech Republic.
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13
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The Oocyte’s Nucleolus Precursor Body: The Globe for Life. MACEDONIAN VETERINARY REVIEW 2018. [DOI: 10.2478/macvetrev-2018-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The nucleolus is the cell organelle responsible for ribosome synthesis and, hence, for protein synthesis. In the mammalian oocyte, the nucleolus compacts into a dense sphere with no ribosome synthesis well in advance of ovulation. It seems, that this body is of utmost importance for the development of the embryo. It is unknown, however, how it exerts this essential function. During the last two decades, great attention has been paid to the study of nucleogenesis in oocytes and early embryos, with transcription of ribosomal DNA being evaluated as one of the criteria of normal development. In this review, we summarize some aspects of nucleolus transformation during oocyte growth, as well as during early embryonic development with possible impact on the quality of the embryos used in biomedical research. This knowledge in connection with further observations will substantially contribute to the development of new criteria suitable for evaluation of oocytes and embryos used in biomedical application.
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14
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Kyogoku H, Wakayama T, Kitajima TS, Miyano T. Single nucleolus precursor body formation in the pronucleus of mouse zygotes and SCNT embryos. PLoS One 2018; 13:e0202663. [PMID: 30125305 PMCID: PMC6101414 DOI: 10.1371/journal.pone.0202663] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 08/07/2018] [Indexed: 11/18/2022] Open
Abstract
Mammalian oocytes and zygotes have nucleoli that are transcriptionally inactive and structurally distinct from nucleoli in somatic cells. These nucleoli have been termed nucleolus precursor bodies (NPBs). Recent research has shown that NPBs are important for embryonic development, but they are only required during pronuclear formation. After fertilization, multiple small NPBs are transiently formed in male and female pronuclei and then fuse into a single large NPB in zygotes. In cloned embryos produced by somatic cell nuclear transfer (SCNT), multiple NPBs are formed and maintained in the pseudo-pronucleus, and this is considered an abnormality of the cloned embryos. Despite this difference between SCNT and normal embryos, it is unclear how the size and number of NPBs in pronuclei is determined. Here, we show that in mouse embryos, the volume of NPB materials plays a major role in the NPB scaling through a limiting component mechanism and determines whether a single or multiple NPBs will form in the pronucleus. Extra NPB- and extra MII spindle-injection experiments demonstrated that the total volume of NPBs was maintained regardless of the pronucleus number and the ratio of pronucleus/NPB is important for fusion into a single NPB. Based on these results, we examined whether extra-NPB injection rescued multiple NPB maintenance in SCNT embryos. When extra-NPBs were injected into enucleated-MII oocytes before SCNT, the number of NPBs in pseudo-pronuclei of SCNT embryos was reduced. These results indicate that multiple NPB maintenance in SCNT embryos is caused by insufficient volume of NPB.
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Affiliation(s)
- Hirohisa Kyogoku
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Laboratory for Chromosome Segregation, Center for Developmental Biology, RIKEN, Kobe, Japan
- Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
- * E-mail:
| | - Teruhiko Wakayama
- Faculty of Life and Environmental Sciences, University of Yamanashi, Kofu, Japan
| | - Tomoya S. Kitajima
- Laboratory for Chromosome Segregation, Center for Developmental Biology, RIKEN, Kobe, Japan
- Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Takashi Miyano
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
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15
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Bonnet-Garnier A, Kiêu K, Aguirre-Lavin T, Tar K, Flores P, Liu Z, Peynot N, Chebrout M, Dinnyés A, Duranthon V, Beaujean N. Three-dimensional analysis of nuclear heterochromatin distribution during early development in the rabbit. Chromosoma 2018; 127:387-403. [PMID: 29666907 PMCID: PMC6096579 DOI: 10.1007/s00412-018-0671-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 03/06/2018] [Accepted: 04/03/2018] [Indexed: 01/29/2023]
Abstract
Changes to the spatial organization of specific chromatin domains such as constitutive heterochromatin have been studied extensively in somatic cells. During early embryonic development, drastic epigenetic reprogramming of both the maternal and paternal genomes, followed by chromatin remodeling at the time of embryonic genome activation (EGA), have been observed in the mouse. Very few studies have been performed in other mammalian species (human, bovine, or rabbit) and the data are far from complete. During this work, we studied the three-dimensional organization of pericentromeric regions during the preimplantation period in the rabbit using specific techniques (3D-FISH) and tools (semi-automated image analysis). We observed that the pericentromeric regions (identified with specific probes for Rsat I and Rsat II genomic sequences) changed their shapes (from pearl necklaces to clusters), their nuclear localizations (from central to peripheral), as from the 4-cell stage. This reorganization goes along with histone modification changes and reduced amount of interactions with nucleolar precursor body surface. Altogether, our results suggest that the 4-cell stage may be a crucial window for events necessary before major EGA, which occurs during the 8-cell stage in the rabbit.
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Affiliation(s)
| | - Kiên Kiêu
- UR341 MaIAGE, INRA, Université Paris Saclay, 78350 Jouy-en-Josas, France
| | | | - Krisztina Tar
- Present Address: Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- BioTalentum Ltd., Aulich Lajos str. 26, Gödöllő, 2100 Hungary
| | - Pierre Flores
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350 Jouy-en-Josas, France
| | - Zichuan Liu
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350 Jouy-en-Josas, France
- Present Address: Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Nathalie Peynot
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350 Jouy-en-Josas, France
| | - Martine Chebrout
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350 Jouy-en-Josas, France
| | - András Dinnyés
- BioTalentum Ltd., Aulich Lajos str. 26, Gödöllő, 2100 Hungary
| | | | - Nathalie Beaujean
- UMR BDR, INRA, ENVA, Université Paris Saclay, 78350 Jouy-en-Josas, France
- Present Address: Univ Lyon, Université Claude Bernard Lyon 1, Inserm, INRA, Stem Cell and Brain Research Institute U1208, USC1361, 69500 Bron, France
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16
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Benc M, Strejcek F, Murin M, Morovic M, Martinkova S, Jettmarova D, Pendovski L, Fulka J, Laurincik J. Nucleologenesis and Nucleolotransfer in Mammalian Oocytes: A Review. MACEDONIAN VETERINARY REVIEW 2017. [DOI: 10.1515/macvetrev-2017-0023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
An effort to improve development potential of early embryos is one of the main goals of biotechnology in the area of reproductive biology with application in veterinary or human medicine. Recent observations of the function of nucleolus or rather its forms before, during and after the fertilisation or parthenogenetic activation show the key role(s) of nucleolus in the processes of early genome activation. The nucleolus is a subnuclear structure (organelle) mainly involved in regulation of transcription and translation. This organelle has been characterized in detail by immunofluorescence, cell transfection and proteomics. This data was, however, mostly obtained in nucleoli of differentiated eukaryotic cells. Much less is known about the nucleolar structural changes and related functional processes in growing and fully grown mammalian oocytes, zygotes and early cleavage stage embryos, especially in the context of embryonic genome activation. It has been shown, that nucleoli in mammalian oocytes and early embryos have several forms and functions, which vary during the oocyte growth and embryonic development. Certain functions have not been fully described or explained, yet. The method of enucleolation, which allows to remove nucleoli from the oocytes or to exchange nucleoli between oocytes or zygotes, together with their proteomic and structural analyses brought new information about functions of nucleoli in oocytes and early cleavage-stage embryos and allowed to explain some new key roles of nucleoli during oocyte maturation and early embryonic development.
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Affiliation(s)
- Michal Benc
- Department of Zoology and Anthropology, Faculty of Natural Sciences , Constantine the Philosopher University in Nitra , Nabrezie mladeze 91, 949 74 Nitra , Slovak Republic
- Institute of Animal Science , Pratelstvi 815, 104 00 Prague - Uhrineves, Czech Republic
| | - Frantisek Strejcek
- Department of Botany and Genetics, Faculty of Natural Sciences , Constantine the Philosopher University in Nitra , Nabrezie mladeze 91, 949 74 Nitra , Slovak Republic
| | - Matej Murin
- Department of Botany and Genetics, Faculty of Natural Sciences , Constantine the Philosopher University in Nitra , Nabrezie mladeze 91, 949 74 Nitra , Slovak Republic
| | - Martin Morovic
- Department of Botany and Genetics, Faculty of Natural Sciences , Constantine the Philosopher University in Nitra , Nabrezie mladeze 91, 949 74 Nitra , Slovak Republic
| | - Stanislava Martinkova
- Institute of Animal Science , Pratelstvi 815, 104 00 Prague - Uhrineves, Czech Republic
| | - Dominika Jettmarova
- Institute of Animal Science , Pratelstvi 815, 104 00 Prague - Uhrineves, Czech Republic
| | - Lazo Pendovski
- Faculty of Veterinary Medicine-Skopje , Ss. Cyril and Methodius University in Skopje , st. Lazar Pop-Trajkov 5-7, 1000 Skopje , Macedonia (the former Yugoslav Republic of)
| | - Josef Fulka
- Institute of Animal Science , Pratelstvi 815, 104 00 Prague - Uhrineves, Czech Republic
| | - Jozef Laurincik
- Department of Zoology and Anthropology, Faculty of Natural Sciences , Constantine the Philosopher University in Nitra , Nabrezie mladeze 91, 949 74 Nitra , Slovak Republic
- Institute of Animal Physiology and Genetics AS CR , Rumburska 89, 277 21 Libechov , Czech Republic
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17
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Ogushi S, Yamagata K, Obuse C, Furuta K, Wakayama T, Matzuk MM, Saitou M. Reconstitution of the oocyte nucleolus in mice through a single nucleolar protein, NPM2. J Cell Sci 2017; 130:2416-2429. [PMID: 28600324 DOI: 10.1242/jcs.195875] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 05/31/2017] [Indexed: 12/28/2022] Open
Abstract
The mammalian oocyte nucleolus, the most prominent subcellular organelle in the oocyte, is vital in early development, yet its key functions and constituents remain unclear. We show here that the parthenotes/zygotes derived from enucleolated oocytes exhibited abnormal heterochromatin formation around parental pericentromeric DNAs, which led to a significant mitotic delay and frequent chromosome mis-segregation upon the first mitotic division. A proteomic analysis identified nucleoplasmin 2 (NPM2) as a dominant component of the oocyte nucleolus. Consistently, Npm2-deficient oocytes, which lack a normal nucleolar structure, showed chromosome segregation defects similar to those in enucleolated oocytes, suggesting that nucleolar loss, rather than micromanipulation-related damage to the genome, leads to a disorganization of higher-order chromatin structure in pronuclei and frequent chromosome mis-segregation during the first mitosis. Strikingly, expression of NPM2 alone sufficed to reconstitute the nucleolar structure in enucleolated embryos, and rescued their first mitotic division and full-term development. The nucleolus rescue through NPM2 required the pentamer formation and both the N- and C-terminal domains. Our findings demonstrate that the NPM2-based oocyte nucleolus is an essential platform for parental chromatin organization in early embryonic development.
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Affiliation(s)
- Sugako Ogushi
- The Hakubi Center for Advanced Research, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan .,Department of Anatomy and Cell Biology, Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Kazuo Yamagata
- Laboratory for Genomic Reprogramming, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Chikashi Obuse
- Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
| | - Keiko Furuta
- Division of Electron Microscopic Study, Center for Anatomical Studies, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Teruhiko Wakayama
- Laboratory for Genomic Reprogramming, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Martin M Matzuk
- Departments of Pathology & Immunology, Molecular and Cellular Biology, Molecular and Human Genetics, and Pharmacology, and Center for Drug Discovery, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Mitinori Saitou
- Department of Anatomy and Cell Biology, Graduate School of Medicine, Kyoto 606-8501, Japan.,Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Sakyo-ku, Kyoto 606-8501, Japan.,JST, CREST/ERATO, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.,Department of Reprogramming Science, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
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18
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Hamdane N, Tremblay MG, Dillinger S, Stefanovsky VY, Németh A, Moss T. Disruption of the UBF gene induces aberrant somatic nucleolar bodies and disrupts embryo nucleolar precursor bodies. Gene 2017; 612:5-11. [DOI: 10.1016/j.gene.2016.09.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/02/2016] [Accepted: 09/06/2016] [Indexed: 11/30/2022]
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Lavrentyeva E, Shishova K, Kagarlitsky G, Zatsepina O. Localisation of RNAs and proteins in nucleolar precursor bodies of early mouse embryos. Reprod Fertil Dev 2017; 29:509-520. [PMID: 26376167 DOI: 10.1071/rd15200] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 08/13/2015] [Indexed: 11/23/2022] Open
Abstract
Early embryos of all mammalian species contain morphologically distinct but transcriptionally silent nucleoli called the nucleolar precursor bodies (NPBs), which, unlike normal nucleoli, have been poorly studied at the biochemical level. To bridge this gap, here we examined the occurrence of RNA and proteins in early mouse embryos with two fluorochromes - an RNA-binding dye pyronin Y (PY) and the protein-binding dye fluorescein-5'-isothiocyanate (FITC). The staining patterns of zygotic NPBs were then compared with those of nucleolus-like bodies (NLBs) in fully grown surrounded nucleolus (SN)-type oocytes, which are morphologically similar to NPBs. We show that both entities contain proteins, but unlike NLBs, NPBs are significantly impoverished for RNA. Detectable amounts of RNA appear on the NPB surface only after resumption of rDNA transcription and includes pre-rRNAs and 28S rRNA as evidenced by fluorescence in situ hybridisation with specific oligonucleotide probes. Immunocytochemical assays demonstrate that zygotic NPBs contain rRNA processing factors fibrillarin, nucleophosmin and nucleolin, while UBF (the RNA polymerase I transcription factor) and ribosomal proteins RPL26 and RPS10 are not detectable. Based on the results obtained and data in the contemporary literature, we suggest a scheme of NPB assembly and maturation to normal nucleoli that assumes utilisation of maternally derived nucleolar proteins but of nascent rRNAs.
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Affiliation(s)
- Elena Lavrentyeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow, 117997, Russian Federation
| | - Kseniya Shishova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow, 117997, Russian Federation
| | - German Kagarlitsky
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow, 117997, Russian Federation
| | - Olga Zatsepina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow, 117997, Russian Federation
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20
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Borsos M, Torres-Padilla ME. Building up the nucleus: nuclear organization in the establishment of totipotency and pluripotency during mammalian development. Genes Dev 2016; 30:611-21. [PMID: 26980186 PMCID: PMC4803048 DOI: 10.1101/gad.273805.115] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In mammals, epigenetic reprogramming, the acquisition and loss of totipotency, and the first cell fate decision all occur within a 3-d window after fertilization from the one-cell zygote to the formation of the blastocyst. These processes are poorly understood in molecular detail, yet this is an essential prerequisite to uncover principles of stem cells, chromatin biology, and thus regenerative medicine. A unique feature of preimplantation development is the drastic genome-wide changes occurring to nuclear architecture. From studying somatic and in vitro cultured embryonic stem cells (ESCs) it is becoming increasingly established that the three-dimensional (3D) positions of genomic loci relative to each other and to specific compartments of the nucleus can act on the regulation of gene expression, potentially driving cell fate. However, the functionality, mechanisms, and molecular characteristics of the changes in nuclear organization during preimplantation development are only now beginning to be unraveled. Here, we discuss the peculiarities of nuclear compartments and chromatin organization during mammalian preimplantation development in the context of the transition from totipotency to pluripotency.
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Affiliation(s)
- Máté Borsos
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, U964, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale F-67404 Illkirch, France; Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München D-81377 München, Germany
| | - Maria-Elena Torres-Padilla
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, U964, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale F-67404 Illkirch, France; Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München D-81377 München, Germany
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21
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Pochukalina GN, Ilicheva NV, Podgornaya OI, Voronin AP. Nucleolus-like body of mouse oocytes contains lamin A and B and TRF2 but not actin and topo II. Mol Cytogenet 2016; 9:50. [PMID: 27347007 PMCID: PMC4921027 DOI: 10.1186/s13039-016-0259-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 06/18/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND During the final stages of oocyte development, all chromosomes join in a limited nuclear volume for the final formation of a single complex chromatin structure - the karyosphere. In the majority of mammalian species, the chromosomes surround a round protein/fibrillar body known as the central body, or nucleolus-like body (NLB). Nothing seems to unite the inner portion of the karyosphere with the nucleolus except position at its remnants. Nevertheless, in this study we will use term NLB as the conventional one for karyosphere with the central body. At the morphological level, NLBs consist of tightly-packed fibres of 6-10 nm. The biochemical structure of this dense, compact NLB fibre centre remains uncertain. RESULTS The aim of this study was to determine which proteins represent the NLB components at final stages of karyosphere formation in mouse oogenesis. To determine this, three antibodies (ABs) have been examined against different actin epitopes. Examination of both ABs against the actin N-end provided similar results: spots inside the nucleus. Double staining with AB against SC35 and actin revealed the colocalization of these proteins in IGCs (interchromatin granule clusters/nuclear speckles/SC35 domains). In contrast, examination of polyclonal AB against peptide at the C-end reveals a different result: actin is localized exclusively in connection with the chromatin. Surprisingly, no forms of actin or topoisomerase II are present as components of the NLB. It was discovered that: (1) lamin B is an NLB component from the beginning of NLB formation, and a major portion of it resides in the NLB at the end of oocyte development; (2) lamin A undergoes rapid movement into the NLB, and a majority of it remains in the NLB; (3) the telomere-binding protein TRF2 resides in the IGCs/nuclear speckles until the end of oocyte development, when significant part of it transfers to the NLB. CONCLUSIONS NLBs do not contain actin or topo II. Lamin B is involved from the beginning of NLB formation. Both Lamin A and TRF2 exhibit rapid movement to the NLB at the end of oogenesis. This dynamic distribution of proteins may reflect the NLB's role in future chromatin organization post-fertilisation.
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Affiliation(s)
| | - Nadya V. Ilicheva
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
| | - Olga I. Podgornaya
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
- />Saint Petersburg State University, St Petersburg, 199034 Russia
- />Far Eastern Federal University, Vladivostok, 690950 Russia
| | - Alexey P. Voronin
- />Institute of Cytology, Russian Academy of Sciences, St Petersburg, 194064 Russia
- />Saint Petersburg State University, St Petersburg, 199034 Russia
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22
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Koshel E, Galkina S, Saifitdinova A, Dyomin A, Deryusheva S, Gaginskaya E. Ribosomal RNA gene functioning in avian oogenesis. Cell Tissue Res 2016; 366:533-542. [PMID: 27339801 DOI: 10.1007/s00441-016-2444-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 05/18/2016] [Indexed: 12/18/2022]
Abstract
Despite long-term exploration into ribosomal RNA gene functioning during the oogenesis of various organisms, many intriguing problems remain unsolved. In this review, we describe nucleolus organizer region (NOR) activity in avian oocytes. Whereas oocytes from an adult avian ovary never reveal the formation of the nucleolus in the germinal vesicle (GV), an ovary from juvenile birds possesses both nucleolus-containing and non-nucleolus-containing oocytes. The evolutionary diversity of oocyte NOR functioning and the potential non-rRNA-related functions of the nucleolus in oocytes are also discussed.
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Affiliation(s)
- Elena Koshel
- Department of Cytology and Histology, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Svetlana Galkina
- Department of Cytology and Histology, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Alsu Saifitdinova
- Department of Cytology and Histology, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Alexandr Dyomin
- Department of Cytology and Histology, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia
| | - Svetlana Deryusheva
- Department of Cytology and Histology, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia.,Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Elena Gaginskaya
- Department of Cytology and Histology, Saint-Petersburg State University, Saint-Petersburg, 199034, Russia.
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23
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Jeon Y, Nam YH, Cheong SA, Kwak SS, Lee E, Hyun SH. Absence of nucleolus formation in raccoon dog-porcine interspecies somatic cell nuclear transfer embryos results in embryonic developmental failure. J Reprod Dev 2016; 62:345-50. [PMID: 27064112 PMCID: PMC5004789 DOI: 10.1262/jrd.2015-175] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Interspecies somatic cell nuclear transfer (iSCNT) can be a solution for preservation of endangered species that have limited oocytes. It has been reported that blastocyst production by iSCNT is successful even if the genetic distances between donors and recipients are large. In particular, domestic pig oocytes can support the development of canine to porcine iSCNT embryos. Therefore, we examined whether porcine oocytes may be suitable recipient oocytes for Korean raccoon dog iSCNT. We investigated the effects of trichostatin A (TSA) treatment on iSCNT embryo developmental patterns and nucleolus formation. Enucleated porcine oocytes were fused with raccoon dog fibroblasts by electrofusion and cleavage, and blastocyst development and nucleolus formation were evaluated. To our knowledge, this study is the first in which raccoon dog iSCNT was performed using porcine oocytes; we found that 68.5% of 158 iSCNT embryos had the ability to cleave. However, these iSCNT embryos did not develop past the 4-cell stage. Treatment with TSA did not affect iSCNT embryonic development; moreover, the nuclei failed to form nucleoli at 48 and 72 h post-activation (hpa). In contrast, pig SCNT embryos of the control group showed 18.8% and 87.9% nucleolus formation at 48 and 72 hpa, respectively. Our results demonstrated that porcine cytoplasts efficiently supported the development of raccoon dog iSCNT embryos to the 4-cell stage, the stage of porcine embryonic genome activation (EGA); however, these embryos failed to reach the blastocyst stage and showed defects in nucleolus formation.
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Affiliation(s)
- Yubyeol Jeon
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Chungbuk, Republic of Korea
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Koné MC, Fleurot R, Chebrout M, Debey P, Beaujean N, Bonnet-Garnier A. Three-Dimensional Distribution of UBF and Nopp140 in Relationship to Ribosomal DNA Transcription During Mouse Preimplantation Development. Biol Reprod 2016; 94:95. [PMID: 26984997 DOI: 10.1095/biolreprod.115.136366] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 03/08/2016] [Indexed: 12/31/2022] Open
Abstract
The nucleolus is a dynamic nuclear compartment that is mostly involved in ribosome subunit biogenesis; however, it may also play a role in many other biological processes, such as stress response and the cell cycle. Mainly using electron microscopy, several studies have tried to decipher how active nucleoli are set up during early development in mice. In this study, we analyzed nucleologenesis during mouse early embryonic development using 3D-immunofluorescent detection of UBF and Nopp140, two proteins associated with different nucleolar compartments. UBF is a transcription factor that helps maintain the euchromatic state of ribosomal genes; Nopp140 is a phosphoprotein that has been implicated in pre-rRNA processing. First, using detailed image analyses and the in situ proximity ligation assay technique, we demonstrate that UBF and Nopp140 dynamic redistribution between the two-cell and blastocyst stages (time of implantation) is correlated with morphological and structural modifications that occur in embryonic nucleolar compartments. Our results also support the hypothesis that nucleoli develop at the periphery of nucleolar precursor bodies. Finally, we show that the RNA polymerase I inhibitor CX-5461: 1) disrupts transcriptional activity, 2) alters preimplantation development, and 3) leads to a complete reorganization of UBF and Nopp140 distribution. Altogether, our results underscore that highly dynamic changes are occurring in the nucleoli of embryos and confirm a close link between ribosomal gene transcription and nucleologenesis during the early stages of development.
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Affiliation(s)
| | - Renaud Fleurot
- UMR BDR, INRA, ENVA, Université Paris Saclay, Jouy en Josas, France
| | - Martine Chebrout
- UMR BDR, INRA, ENVA, Université Paris Saclay, Jouy en Josas, France
| | - Pascale Debey
- Sorbonne-Universités, MNHN, CNRS, INSERM, Structure et instabilité des génomes, Paris, France
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Fulka H, Aoki F. Nucleolus Precursor Bodies and Ribosome Biogenesis in Early Mammalian Embryos: Old Theories and New Discoveries. Biol Reprod 2016; 94:143. [PMID: 26935600 DOI: 10.1095/biolreprod.115.136093] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/22/2016] [Indexed: 11/01/2022] Open
Abstract
In mammals, mature oocytes and early preimplantation embryos contain transcriptionally inactive structures termed nucleolus precursor bodies instead of the typical fibrillo-granular nucleoli. These nuclear organelles are essential and strictly of maternal origin. If they are removed from oocytes, the resulting embryos are unable to replace them and consequently fail to develop. Historically, nucleolus precursor bodies have been perceived as a passive repository site of nucleolar proteins that are required for embryos to form fully functional nucleoli. Recent results, however, contradict this long-standing dogma and show that these organelles are dispensable for nucleologenesis and ribosome biogenesis. In this article, we discuss the possible roles of nucleolus precursor bodies and propose how they might be involved in embryogenesis. Furthermore, we argue that these organelles are essential only shortly after fertilization and suggest that they might actively participate in centromeric chromatin establishment.
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Affiliation(s)
- Helena Fulka
- Institute of Animal Science, Prague, Czech Republic Institute of Molecular Genetics of the ASCR, Prague, Czech Republic
| | - Fugaku Aoki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
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Fulka H, Kyogoku H, Zatsepina O, Langerova A, Fulka J. Can Nucleoli Be Markers of Developmental Potential in Human Zygotes? Trends Mol Med 2015; 21:663-672. [DOI: 10.1016/j.molmed.2015.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/18/2015] [Accepted: 09/18/2015] [Indexed: 01/10/2023]
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Kyogoku H, Kitajima TS, Miyano T. Nucleolus precursor body (NPB): a distinct structure in mammalian oocytes and zygotes. Nucleus 2015; 5:493-8. [PMID: 25495074 DOI: 10.4161/19491034.2014.990858] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Nucleoli in mammalian oocytes and zygotes, sometimes referred to as nucleolus precursor bodies (NPBs), are compact and morphologically different from nucleoli in somatic cells. We applied a unique NPB analyzing method "enucleolation" technique to zygotes to remove the NPBs. It has been reported that oocyte NPBs are essential for embryonic development; in their absence, the oocytes complete maturation and can be fertilized, but no nucleoli are formed in the zygotes and embryos, leading to developmental failure. However, we found that when NPBs were removed from zygotes, the zygotes developed successfully to live-born pups. These results indicated that oocyte NPBs are essential for embryonic development, but zygote NPBs are not. In addition, the enucleolated zygotes formed somatic-type nucleoli during early embryonic development, demonstrating that somatic-type nucleoli do not originate from zygote NPBs. We summarize our recent investigation on NPBs, and provide additional comments and findings.
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Affiliation(s)
- Hirohisa Kyogoku
- a Laboratory for Chromosome Segregation ; Center for Developmental Biology ; RIKEN , Kobe , Japan
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28
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Dang-Nguyen TQ, Torres-Padilla ME. How cells build totipotency and pluripotency: nuclear, chromatin and transcriptional architecture. Curr Opin Cell Biol 2015; 34:9-15. [PMID: 25935759 DOI: 10.1016/j.ceb.2015.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 03/25/2015] [Accepted: 04/14/2015] [Indexed: 01/15/2023]
Abstract
Totipotent and pluripotent cells display different degrees of cellular plasticity. After fertilization, embryonic cells transit naturally from a totipotent to a pluripotent state. Major changes in nuclear architecture, chromatin mobility and gene expression occur during this transition. In particular, nuclear architecture has recently emerged as a potential regulator of heterochromatin formation in the early embryo. Future research should address whether a causal, functional link between nuclear organization and gene regulation is a general theme during reprogramming and the formation of pluripotent cells.
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Affiliation(s)
- Thanh Quang Dang-Nguyen
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM U964, Université de Strasbourg, F-67404 Illkirch, France
| | - Maria-Elena Torres-Padilla
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM U964, Université de Strasbourg, F-67404 Illkirch, France.
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29
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Shishova KV, Lavrentyeva EA, Dobrucki JW, Zatsepina OV. Nucleolus-like bodies of fully-grown mouse oocytes contain key nucleolar proteins but are impoverished for rRNA. Dev Biol 2014; 397:267-81. [PMID: 25481757 DOI: 10.1016/j.ydbio.2014.11.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 11/20/2014] [Accepted: 11/22/2014] [Indexed: 11/26/2022]
Abstract
It is well known that fully-grown mammalian oocytes, rather than typical nucleoli, contain prominent but structurally homogenous bodies called "nucleolus-like bodies" (NLBs). NLBs accumulate a vast amount of material, but their biochemical composition and functions remain uncertain. To clarify the composition of the NLB material in mouse GV oocytes, we devised an assay to detect internal oocyte proteins with fluorescein-5-isothiocyanate (FITC) and applied the fluorescent RNA-binding dye acridine orange to examine whether NLBs contain RNA. Our results unequivocally show that, similarly to typical nucleoli, proteins and RNA are major constituents of transcriptionally active (or non-surrounded) NLBs as well as of transcriptionally silent (or surrounded) NLBs. We also show, by exposing fixed oocytes to a mild proteinase K treatment, that the NLB mass in oocytes of both types contains nucleolar proteins that are involved in all major steps of ribosome biogenesis, including rDNA transcription (UBF), early rRNA processing (fibrillarin), and late rRNA processing (NPM1/nucleophosmin/B23, nucleolin/C23), but none of the nuclear proteins tested, including SC35, NOBOX, topoisomerase II beta, HP1α, and H3. The ribosomal RPL26 protein was detected within the NLBs of NSN-type oocytes but is virtually absent from NLBs of SN-type oocytes. Taking into account that the major class of nucleolar RNA is ribosomal RNA (rRNA), we applied fluorescence in situ hybridization with oligonucleotide probes targeting 18S and 28S rRNAs. The results show that, in contrast to active nucleoli, NLBs of fully-grown oocytes are impoverished for the rRNAs, which is consistent with the absence of transcribed ribosomal genes in the NLB mass. Overall, the results of this study suggest that NLBs of fully-grown mammalian oocytes serve for storing major nucleolar proteins but not rRNA.
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Affiliation(s)
- Kseniya V Shishova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russian Federation.
| | - Elena A Lavrentyeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russian Federation; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, GSP-1, Leninskiye Gory, MSU, 1-73, Office, Moscow 119991, Russian Federation.
| | - Jurek W Dobrucki
- Laboratory of Cell Biophysics, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa Street, 30-387 Krakow, Poland.
| | - Olga V Zatsepina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street, 16/10, Moscow 117997, Russian Federation.
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30
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Kyogoku H, Fulka J, Wakayama T, Miyano T. De novo formation of nucleoli in developing mouse embryos originating from enucleolated zygotes. J Cell Sci 2014. [DOI: 10.1242/jcs.157040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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