1
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Junyent S, Meglicki M, Vetter R, Mandelbaum R, King C, Patel EM, Iwamoto-Stohl L, Reynell C, Chen DY, Rubino P, Arrach N, Paulson RJ, Iber D, Zernicka-Goetz M. The first two blastomeres contribute unequally to the human embryo. Cell 2024; 187:2838-2854.e17. [PMID: 38744282 DOI: 10.1016/j.cell.2024.04.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 12/06/2023] [Accepted: 04/22/2024] [Indexed: 05/16/2024]
Abstract
Retrospective lineage reconstruction of humans predicts that dramatic clonal imbalances in the body can be traced to the 2-cell stage embryo. However, whether and how such clonal asymmetries arise in the embryo is unclear. Here, we performed prospective lineage tracing of human embryos using live imaging, non-invasive cell labeling, and computational predictions to determine the contribution of each 2-cell stage blastomere to the epiblast (body), hypoblast (yolk sac), and trophectoderm (placenta). We show that the majority of epiblast cells originate from only one blastomere of the 2-cell stage embryo. We observe that only one to three cells become internalized at the 8-to-16-cell stage transition. Moreover, these internalized cells are more frequently derived from the first cell to divide at the 2-cell stage. We propose that cell division dynamics and a cell internalization bottleneck in the early embryo establish asymmetry in the clonal composition of the future human body.
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Affiliation(s)
- Sergi Junyent
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Maciej Meglicki
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Roman Vetter
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zürich, Basel 4058, Switzerland; Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058 Basel, Switzerland
| | - Rachel Mandelbaum
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA 90033, USA
| | - Catherine King
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Ekta M Patel
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Lisa Iwamoto-Stohl
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Clare Reynell
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Dong-Yuan Chen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Patrizia Rubino
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA 90033, USA
| | | | - Richard J Paulson
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA 90033, USA
| | - Dagmar Iber
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zürich, Basel 4058, Switzerland; Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058 Basel, Switzerland
| | - Magdalena Zernicka-Goetz
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK.
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2
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Jin H, Han Y, Wang H, Li JXH, Shen W, Zhang L, Chen L, Jia S, Yuan P, Chen H, Meng A. The second polar body contributes to the fate asymmetry in the mouse embryo. Natl Sci Rev 2022; 9:nwac003. [PMID: 35919785 PMCID: PMC9337984 DOI: 10.1093/nsr/nwac003] [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] [Received: 11/17/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 12/02/2022] Open
Abstract
The polar bodies (PBs) are extruded microcells during oocyte meiosis and generally regarded as inessentials for embryonic development. Therefore, PBs have been widely used as important materials for pre-implantation genetic diagnosis in human. Here we report that the second PB (PB2) in the mouse zygote may play roles in cell-fate specification and post-implantation development. A subset of mRNAs encoding pluripotency-related factors are enriched in PB2. Nascent proteins may be synthesized in PB2 after fertilization and transport from PB2 to the zygote before the two-cell stage. The PB2-attached blastomere (pbB) at the two-cell stage, compared to the other blastomere (npbB), likely contributes more descendants to the inner cell mass (ICM) lineage in the blastocyst. Removal of PB2 from the zygote or transient blockage of material exchange between PB2 and the zygote by nocodazole treatment appears to cause a loss of the ICM fate bias of pbB. PB2 removal or nocodazole treatment also results in abnormal post-implantation development. Injection of PB2 lysate into pbB of PB2-removed two-cell-stage embryos may reset the cell-fate preference and rescue post-implantation development. Our data collectively suggest that PB2 would demarcate the earliest cell-fate asymmetry of the mouse zygote and be required for post-implantation development.
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Affiliation(s)
- Hongbin Jin
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Yang Han
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Huasong Wang
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - J Xiao He Li
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Weimin Shen
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Lin Zhang
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Luxi Chen
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Shunji Jia
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Ping Yuan
- Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou510120, China
| | - Hui Chen
- Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou510120, China
| | - Anming Meng
- Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
- Center for Reproductive Genetics and Reproductive Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou510120, China
- Guangzhou Laboratory, Guangzhou510320, China
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3
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Filimonow K, de la Fuente R. Specification and role of extraembryonic endoderm lineages in the periimplantation mouse embryo. Theriogenology 2021; 180:189-206. [PMID: 34998083 DOI: 10.1016/j.theriogenology.2021.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 12/12/2022]
Abstract
During mammalian embryo development, the correct formation of the first extraembryonic endoderm lineages is fundamental for successful development. In the periimplantation blastocyst, the primitive endoderm (PrE) is formed, which gives rise to the parietal endoderm (PE) and visceral endoderm (VE) during further developmental stages. These PrE-derived lineages show significant differences in both their formation and roles. Whereas differentiation of the PE as a migratory lineage has been suggested to represent the first epithelial-to-mesenchymal transition (EMT) in development, organisation of the epithelial VE is of utmost importance for the correct axis definition and patterning of the embryo. Despite sharing a common origin, the striking differences between the VE and PE are indicative of their distinct roles in early development. However, there is a significant disparity in the current knowledge of each lineage, which reflects the need for a deeper understanding of their respective specification processes. In this review, we will discuss the origin and maturation of the PrE, PE, and VE during the periimplantation period using the mouse model as an example. Additionally, we consider the latest findings regarding the role of the PrE-derived lineages and early embryo morphogenesis, as obtained from the most recent in vitro models.
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Affiliation(s)
- Katarzyna Filimonow
- Department of Experimental Embryology, Institute of Genetics and Animal Biotechnology of the Polish Academy of Sciences, Jastrzębiec, Poland.
| | - Roberto de la Fuente
- Department of Experimental Embryology, Institute of Genetics and Animal Biotechnology of the Polish Academy of Sciences, Jastrzębiec, Poland.
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Abe T, Kutsuna N, Kiyonari H, Furuta Y, Fujimori T. ROSA26 reporter mouse lines and image analyses reveal distinct region-specific cell behaviors in the visceral endoderm. Development 2018; 145:dev.165852. [PMID: 30327323 DOI: 10.1242/dev.165852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 10/08/2018] [Indexed: 11/20/2022]
Abstract
The early post-implantation mouse embryo changes dramatically in both size and shape. These morphological changes are based on characteristic cellular behaviors, including cell growth and allocation. To perform clonal analysis, we established a Cre/loxP-based reporter mouse line, R26R-ManGeKyou, that enables clonal labeling with multiple colors. We also developed a novel ImageJ plugin, LP-Clonal, for quantitative measurement of the tilt angle of clonal cluster shape, enabling identification of the direction of cluster expansion. We carried out long-term and short-term lineage tracking. We also performed time-lapse imaging to characterize cellular behaviors using R26-PHA7-EGFP and R26R-EGFP These images were subjected to quantitative image analyses. We found that the proximal visceral endoderm overlying the extra-embryonic ectoderm shows coherent cell growth in a proximal-anterior to distal-posterior direction. We also observed that directional cell migration is coupled with cell elongation in the anterior region. Our observations suggest that the behaviors of visceral endoderm cells vary between regions during peri-implantation stages.
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Affiliation(s)
- Takaya Abe
- Animal Resource Development, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan .,Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Animal Resource Development Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan
| | - Natsumaro Kutsuna
- Department of Integrated Biosciences, Graduate School of Frontier Science, The University of Tokyo, Kashiwa 277-8562, Japan.,Research & Development Department, LPixel Inc., TechLab 6F, Otemachi Building, 1-6-1, Otemachi, Chiyoda-ku, Tokyo, 100-0004, Japan
| | - Hiroshi Kiyonari
- Animal Resource Development, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Animal Resource Development Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan
| | - Yasuhide Furuta
- Animal Resource Development, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Animal Resource Development Unit, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan
| | - Toshihiko Fujimori
- Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Genetic Engineering Team, RIKEN Center for Life Science Technologies, 2-2-3 Minatojima Minami-machi, Chuou-ku, Kobe 650-0047, Japan.,Division of Embryology, National Institute for Basic Biology (NIBB), Okazaki 444-8787, Japan.,Department of Basic Biology, School of Life Science, Sokendai 444-8787, Japan
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5
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Abstract
We present an overview of symmetry breaking in early mammalian development as a continuous process from compaction to specification of the body axes. While earlier studies have focused on individual symmetry-breaking events, recent advances enable us to explore progressive symmetry breaking during early mammalian development. Although we primarily discuss embryonic development of the mouse, as it is the best-studied mammalian model system to date, we also highlight the shared and distinct aspects between different mammalian species. Finally, we discuss how insights gained from studying mammalian development can be generalized in light of self-organization principles. With this review, we hope to highlight new perspectives in studying symmetry breaking and self-organization in multicellular systems.
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Affiliation(s)
- Hui Ting Zhang
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany;
| | - Takashi Hiiragi
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany;
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6
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Morris SA. Human embryos cultured in vitro to 14 days. Open Biol 2017; 7:rsob.170003. [PMID: 28123056 PMCID: PMC5303284 DOI: 10.1098/rsob.170003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 01/06/2017] [Indexed: 11/12/2022] Open
Abstract
We know a great deal about the development of the mammalian embryo until the time that the blastocyst implants into the uterus. With model organisms such as the mouse, we have also developed a considerable understanding of development immediately around gastrulation as embryos can be recovered at this stage for short-term in vitro culture. However, the intervening period of development remained a ‘black box’ because it takes place as the blastocyst is implanting into the uterus. Over the past 6 years, techniques pioneered and developed in Magdalena Zernicka-Goetz's laboratory for the in vitro culture of embryos through these implantation stages have opened up this box, affording the first glimpse of embryonic development through these previously hidden stages. Remarkably, the techniques developed with mouse embryos are equally applicable to human embryos, ushering the very first opportunities for studying our own development throughout this time. Here, I outline how the culture methods were developed, paving the way to culture of the human embryo to the point of gastrulation, an accomplishment recognized as the People's Choice for the Scientific Breakthrough of 2016 in Science magazine. I also discuss the new ethical challenges raised by the possibility of extending the time limits for human embryo culture.
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Affiliation(s)
- Samantha A Morris
- Department of Developmental Biology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, Campus Box 8103, St. Louis, MO 63110, USA .,Department of Genetics, Center of Regenerative Medicine, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, Campus Box 8103, St. Louis, MO 63110, USA
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7
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Cofre J, Abdelhay E. Cancer Is to Embryology as Mutation Is to Genetics: Hypothesis of the Cancer as Embryological Phenomenon. ScientificWorldJournal 2017; 2017:3578090. [PMID: 28553657 PMCID: PMC5434308 DOI: 10.1155/2017/3578090] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/20/2017] [Indexed: 01/20/2023] Open
Abstract
Despite numerous advances in cell biology, genetics, and developmental biology, cancer origin has been attributed to genetic mechanisms primarily involving mutations. Embryologists have expressed timidly cancer embryological origin with little success in leveraging the discussion that cancer could involve a set of conventional cellular processes used to build the embryo during morphogenesis. Thus, this "cancer process" allows the harmonious and coherent construction of the embryo structural base, and its implementation as the embryonic process involves joint regulation of differentiation, proliferation, cell invasion, and migration, enabling the human being recreation of every generation. On the other hand, "cancer disease" is the representation of an abnormal state of the cell that might happen in the stem cells of an adult person, in which the mechanism for joint gene regulating of differentiation, proliferation, cell invasion, and migration could be reactivated in an entirely inappropriate context.
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Affiliation(s)
- Jaime Cofre
- Laboratório de Embriologia Molecular e Câncer, Universidade Federal de Santa Catarina, Sala 313b, 88040-900 Florianópolis, SC, Brazil
| | - Eliana Abdelhay
- Divisão de Laboratórios do CEMO, Instituto Nacional do Câncer, Rio de Janeiro, RJ, Brazil
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8
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Houston DW. Vertebrate Axial Patterning: From Egg to Asymmetry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:209-306. [PMID: 27975274 PMCID: PMC6550305 DOI: 10.1007/978-3-319-46095-6_6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The emergence of the bilateral embryonic body axis from a symmetrical egg has been a long-standing question in developmental biology. Historical and modern experiments point to an initial symmetry-breaking event leading to localized Wnt and Nodal growth factor signaling and subsequent induction and formation of a self-regulating dorsal "organizer." This organizer forms at the site of notochord cell internalization and expresses primarily Bone Morphogenetic Protein (BMP) growth factor antagonists that establish a spatiotemporal gradient of BMP signaling across the embryo, directing initial cell differentiation and morphogenesis. Although the basics of this model have been known for some time, many of the molecular and cellular details have only recently been elucidated and the extent that these events remain conserved throughout vertebrate evolution remains unclear. This chapter summarizes historical perspectives as well as recent molecular and genetic advances regarding: (1) the mechanisms that regulate symmetry-breaking in the vertebrate egg and early embryo, (2) the pathways that are activated by these events, in particular the Wnt pathway, and the role of these pathways in the formation and function of the organizer, and (3) how these pathways also mediate anteroposterior patterning and axial morphogenesis. Emphasis is placed on comparative aspects of the egg-to-embryo transition across vertebrates and their evolution. The future prospects for work regarding self-organization and gene regulatory networks in the context of early axis formation are also discussed.
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Affiliation(s)
- Douglas W Houston
- Department of Biology, The University of Iowa, 257 BB, Iowa City, IA, 52242, USA.
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9
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Hosseini SM, Moulavi F, Tanhaie-Vash N, Asgari V, Ghanaei HR, Abedi-Dorche M, Jafarzadeh N, Gourabi H, Shahverdi AH, Dizaj AV, Shirazi A, Nasr-Esfahani MH. The Principal Forces of Oocyte Polarity Are Evolutionary Conserved but May Not Affect the Contribution of the First Two Blastomeres to the Blastocyst Development in Mammals. PLoS One 2016; 11:e0148382. [PMID: 27030988 PMCID: PMC4816511 DOI: 10.1371/journal.pone.0148382] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/18/2016] [Indexed: 11/26/2022] Open
Abstract
Oocyte polarity and embryonic patterning are well-established features of development in lower species. Whether a similar form of pre-patterning exists in mammals is currently under hot debate in mice. This study investigated this issue for the first time in ovine as a large mammal model. Microsurgical trisection of unfertilized MII-oocytes revealed that cortical cytoplasm around spindle (S) contained significant amounts of total maternal mRNAs and proteins compared to matched cytoplast hemispheres that were located either near (NS) or far (FS) -to-spindle. RT-qPCR provided striking examples of maternal mRNA localized to subcellular substructures S (NPM2, GMNN, H19, PCAF, DNMT3A, DNMT1, and STELLA), NS (SOX2, NANOG, POU5F1, and TET1), and FS (GCN) of MII oocyte. Immunoblotting revealed that specific maternal proteins DNMT3A and NANOG were asymmetrically enriched in MII-spindle-half of the oocytes. Topological analysis of sperm entry point (SEP) revealed that sperm preferentially entered via the MII-spindle-half of the oocytes. Even though, the topological position of first cleavage plane with regard to SEP was quite stochastic. Spatial comparison of lipid content revealed symmetrical distribution of lipids between 2-cell blastomeres. Lineage tracing using Dil, a fluorescent dye, revealed that while the progeny of leading blastomere of 2-cell embryos contributed to more cells in the developed blastocysts compared to lagging counterpart, the contributions of leading and lagging blastomeres to the embryonic-abembryonic parts of the developed blastocysts were almost unbiased. And finally, separated sister blastomeres of 2-cell embryos had an overall similar probability to arrest at any stage before the blastocyst (2-cell, 4-cell, 8-cell, and morula) or to achieve the blastocyst stage. It was concluded that the localization of maternal mRNAs and proteins at the spindle are evolutionarily conserved between mammals unfertilized ovine oocyte could be considered polar with respect to the spatial regionalization of maternal transcripts and proteins. Even though, the principal forces of this definitive oocyte polarity may not persist during embryonic cleavages.
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Affiliation(s)
- Sayyed-Morteza Hosseini
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Fariba Moulavi
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Nima Tanhaie-Vash
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Vajihe Asgari
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hamid-Reza Ghanaei
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Maryam Abedi-Dorche
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Naser Jafarzadeh
- Department of Medical Physics, Tarbiat Modares University, Tehran, Iran
| | - Hossein Gourabi
- Department of Genetics at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, P.O. Box: 19395–4644, Tehran, Iran
| | - Abdol-Hossein Shahverdi
- Department of Embryology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Medicine, ACECR, Tehran, Iran
| | - Ahmad Vosough Dizaj
- Department of Reproductive Imaging at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Abolfazl Shirazi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
- Research Institute of Animal Embryo Technology, Shahrekord University, Shahrekord, Iran
- * E-mail: (AS); (MHNE)
| | - Mohammad-Hossein Nasr-Esfahani
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
- * E-mail: (AS); (MHNE)
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10
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Jedrusik A. Making the first decision: lessons from the mouse. Reprod Med Biol 2015; 14:135-150. [PMID: 29259411 PMCID: PMC5715835 DOI: 10.1007/s12522-015-0206-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 03/31/2015] [Indexed: 01/06/2023] Open
Abstract
Pre-implantation development encompasses a period of 3-4 days over which the mammalian embryo has to make its first decision: to separate the pluripotent inner cell mass (ICM) from the extra-embryonic epithelial tissue, the trophectoderm (TE). The ICM gives rise to tissues mainly building the body of the future organism, while the TE contributes to the extra-embryonic tissues that support embryo development after implantation. This review provides an overview of the cellular and molecular mechanisms that control the critical aspects of this first decision, and highlights the role of critical events, namely zytotic genome activation, compaction, polarization, asymmetric cell divisions, formation of the blastocyst cavity and expression of key transcription factors.
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Affiliation(s)
- Agnieszka Jedrusik
- Wellcome Trust/CR UK Gurdon InstituteTennis Court RoadCB2 1QNCambridgeUK
- Department of Physiology, Development and NeuroscienceUniversity of CambridgeDowning StreetCB2 3DYCambridgeUK
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11
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Uterine Rbpj is required for embryonic-uterine orientation and decidual remodeling via Notch pathway-independent and -dependent mechanisms. Cell Res 2014; 24:925-42. [PMID: 24971735 PMCID: PMC4123295 DOI: 10.1038/cr.2014.82] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 04/14/2014] [Accepted: 05/13/2014] [Indexed: 12/29/2022] Open
Abstract
Coordinated uterine-embryonic axis formation and decidual remodeling are hallmarks of mammalian post-implantation embryo development. Embryonic-uterine orientation is determined at initial implantation and synchronized with decidual development. However, the molecular mechanisms controlling these events remain elusive despite its discovery a long time ago. In the present study, we found that uterine-specific deletion of Rbpj, the nuclear transducer of Notch signaling, resulted in abnormal embryonic-uterine orientation and decidual patterning at post-implantation stages, leading to substantial embryo loss. We further revealed that prior to embryo attachment, Rbpj confers on-time uterine lumen shape transformation via physically interacting with uterine estrogen receptor (ERα) in a Notch pathway-independent manner, which is essential for the initial establishment of embryo orientation in alignment with uterine axis. While at post-implantation stages, Rbpj directly regulates the expression of uterine matrix metalloproteinase in a Notch pathway-dependent manner, which is required for normal post-implantation decidual remodeling. These results demonstrate that uterine Rbpj is essential for normal embryo development via instructing the initial embryonic-uterine orientation and ensuring normal decidual patterning in a stage-specific manner. Our data also substantiate the concept that normal mammalian embryonic-uterine orientation requires proper guidance from developmentally controlled uterine signaling.
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12
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Morris SA, Graham SJL, Jedrusik A, Zernicka-Goetz M. The differential response to Fgf signalling in cells internalized at different times influences lineage segregation in preimplantation mouse embryos. Open Biol 2013; 3:130104. [PMID: 24258274 PMCID: PMC3843820 DOI: 10.1098/rsob.130104] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lineage specification in the preimplantation mouse embryo is a regulative process. Thus, it has been difficult to ascertain whether segregation of the inner-cell-mass (ICM) into precursors of the pluripotent epiblast (EPI) and the differentiating primitive endoderm (PE) is random or influenced by developmental history. Here, our results lead to a unifying model for cell fate specification in which the time of internalization and the relative contribution of ICM cells generated by two waves of asymmetric divisions influence cell fate. We show that cells generated in the second wave express higher levels of Fgfr2 than those generated in the first, leading to ICM cells with varying Fgfr2 expression. To test whether such heterogeneity is enough to bias cell fate, we upregulate Fgfr2 and show it directs cells towards PE. Our results suggest that the strength of this bias is influenced by the number of cells generated in the first wave and, mostly likely, by the level of Fgf signalling in the ICM. Differences in the developmental potential of eight-cell- and 16-cell-stage outside blastomeres placed in the inside of chimaeric embryos further support this conclusion. These results unite previous findings demonstrating the importance of developmental history and Fgf signalling in determining cell fate.
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Affiliation(s)
- Samantha A Morris
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
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13
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Chen Q, Zhang Y, Elad D, Jaffa AJ, Cao Y, Ye X, Duan E. Navigating the site for embryo implantation: Biomechanical and molecular regulation of intrauterine embryo distribution. Mol Aspects Med 2013; 34:1024-42. [DOI: 10.1016/j.mam.2012.07.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 07/31/2012] [Indexed: 01/03/2023]
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14
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Ectogenesis: what could be learned from novel in-vitro culture systems? Reprod Biomed Online 2013; 26:555-61. [PMID: 23528284 DOI: 10.1016/j.rbmo.2013.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/06/2013] [Accepted: 02/12/2013] [Indexed: 11/20/2022]
Abstract
Early mammalian development consists of two distinct phases separated by the event of implantation. Whereas much has been discovered about developmental mechanisms prior to implantation, the inability to culture and follow in real time cell behaviour over the period of implantation means that the second phase has not been explored in as much detail. Recently, a novel in-vitro culture system was described that permits continuous culture and time-lapse observations through the peri- and early post-implantation stages. This system has already delivered detailed information on the cellular processes accompanying early morphogenesis and allowed direct connections to be established between events occurring at the two developmental phases. This review discusses the potential of this novel technology and its possible applications that could have not only impact on basic science but also practical implications for human medicine.
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15
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Morris SA, Guo Y, Zernicka-Goetz M. Developmental plasticity is bound by pluripotency and the Fgf and Wnt signaling pathways. Cell Rep 2012; 2:756-65. [PMID: 23041313 PMCID: PMC3607220 DOI: 10.1016/j.celrep.2012.08.029] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 08/15/2012] [Accepted: 08/27/2012] [Indexed: 01/05/2023] Open
Abstract
Plasticity is a well-known feature of mammalian development, and yet very little is known about its underlying mechanism. Here, we establish a model system to examine the extent and limitations of developmental plasticity in living mouse embryos. We show that halved embryos follow the same strict clock of developmental transitions as intact embryos, but their potential is not equal. We have determined that unless a minimum of four pluripotent cells is established before implantation, development will arrest. This failure can be rescued by modulating Fgf and Wnt signaling to enhance pluripotent cell number, allowing the generation of monozygotic twins, which is an otherwise rare phenomenon. Knowledge of the minimum pluripotent-cell number required for development to birth, as well as the different potentials of blastomeres, allowed us to establish a protocol for splitting an embryo into one part that develops to adulthood and another that provides embryonic stem cells for that individual.
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Affiliation(s)
- Samantha A Morris
- Wellcome Trust/Cancer Research Gurdon Institute, Cambridge CB2 1QN, UK
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16
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Morris SA, Grewal S, Barrios F, Patankar SN, Strauss B, Buttery L, Alexander M, Shakesheff KM, Zernicka-Goetz M. Dynamics of anterior-posterior axis formation in the developing mouse embryo. Nat Commun 2012; 3:673. [PMID: 22334076 PMCID: PMC3293425 DOI: 10.1038/ncomms1671] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 01/09/2012] [Indexed: 12/12/2022] Open
Abstract
The development of an anterior-posterior (AP) polarity is a crucial process that in the mouse has been very difficult to analyse, because it takes place as the embryo implants within the mother. To overcome this obstacle, we have established an in-vitro culture system that allows us to follow the step-wise development of anterior visceral endoderm (AVE), critical for establishing AP polarity. Here we use this system to show that the AVE originates in the implanting blastocyst, but that additional cells subsequently acquire AVE characteristics. These 'older' and 'younger' AVE domains coalesce as the egg cylinder emerges from the blastocyst structure. Importantly, we show that AVE migration is led by cells expressing the highest levels of AVE marker, highlighting that asymmetry within the AVE domain dictates the direction of its migration. Ablation of such leading cells prevents AVE migration, suggesting that these cells are important for correct establishment of the AP axis.
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Affiliation(s)
- Samantha A. Morris
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK
- These authors contributed equally to this work.
- Present address: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School; Department of Medicine, Division of Hematology/Oncology, Children's Hospital Boston, Massachusetts, USA
| | - Seema Grewal
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK
- These authors contributed equally to this work.
| | - Florencia Barrios
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK
- These authors contributed equally to this work.
| | - Sameer N. Patankar
- Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Bernhard Strauss
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, UK
| | - Lee Buttery
- Drug Delivery and Tissue Engineering, Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Morgan Alexander
- Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Kevin M. Shakesheff
- Drug Delivery and Tissue Engineering, Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK
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17
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Abstract
Early development of the mouse comprises a sequence of cell fate decisions in which cells are guided along a pathway of restricted potential and increasing specialisation. The first choice faced by cells of the embryo is whether to become trophectoderm (TE) or inner cell mass (ICM); TE is an extra-embryonic tissue which will form the embryonic portion of the placenta, whilst ICM gives rise to cells responsible for generating the foetus. In the second cell fate decision, the ICM is further refined into pluripotent cells forming the future body of the embryo, epiblast (EPI) and extra-embryonic primitive endoderm (PE), a tissue essential for patterning the embryo and establishing the developmental circulation. Understanding this early lineage segregation is critical for informing attempts to capture pluripotency and direct cell fate in vitro. Unlike the predictability of nonmammalian cell fate, development of the mouse embryo retains the flexibility to adapt to changing circumstances during development. Here we describe these first cell fate decisions, how they can be biased whilst maintaining flexibility and, finally, some of the molecular circuitry underlying early fate choice.
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Affiliation(s)
- Samantha A Morris
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
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18
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Takaoka K, Yamamoto M, Hamada H. Origin and role of distal visceral endoderm, a group of cells that determines anterior-posterior polarity of the mouse embryo. Nat Cell Biol 2011; 13:743-52. [PMID: 21623358 DOI: 10.1038/ncb2251] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 04/05/2011] [Indexed: 12/15/2022]
Abstract
Anterior-posterior polarity of the mouse embryo has been thought to be established when distal visceral endoderm (DVE) at embryonic day (E) 5.5 migrates toward the future anterior side to form anterior visceral endoderm (AVE). Lefty1, a marker of DVE and AVE, is asymmetrically expressed in implanting mouse embryos. We now show that Lefty1 is expressed first in a subset of epiblast progenitor cells and then in a subset of primitive endoderm progenitors. Genetic fate mapping indicated that the latter cells are destined to become DVE. In contrast to the accepted notion, however, AVE is not derived from DVE but is newly formed after E5.5 from Lefty1(-) visceral endoderm cells that move to the distal tip. Concomitant with DVE migration, all visceral endoderm cells in the embryonic region undergo global movement. In embryos subjected to genetic ablation of Lefty1-expressing DVE cells, AVE was formed de novo but the visceral endoderm including the newly formed AVE failed to migrate, indicating that DVE guides the migration of AVE by initiating the global movement of visceral endoderm cells. Future anterior-posterior polarity is thus already determined by Lefty1(+) blastomeres in the implanting blastocyst.
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Affiliation(s)
- Katsuyoshi Takaoka
- Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University, and CREST, Japan Science and Technology Corporation, 1-3Yamada-oka, Suita, Osaka 565-0871, Japan.
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19
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Rojas A, Schachterle W, Xu SM, Martín F, Black BL. Direct transcriptional regulation of Gata4 during early endoderm specification is controlled by FoxA2 binding to an intronic enhancer. Dev Biol 2010; 346:346-55. [PMID: 20692247 DOI: 10.1016/j.ydbio.2010.07.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 07/22/2010] [Accepted: 07/27/2010] [Indexed: 10/19/2022]
Abstract
The embryonic endoderm is a multipotent progenitor cell population that gives rise to the epithelia of the digestive and respiratory tracts, the liver and the pancreas. Among the transcription factors that have been shown to be important for endoderm development and gut morphogenesis is GATA4. Despite the important role of GATA4 in endoderm development, its transcriptional regulation is not well understood. In this study, we identified an intronic enhancer from the mouse Gata4 gene that directs expression to the definitive endoderm in the early embryo. The activity of this enhancer is initially broad in all endodermal progenitors, as demonstrated by fate mapping analysis using the Cre/loxP system, but becomes restricted to the dorsal foregut and midgut, and associated organs such as dorsal pancreas and stomach. The function of the intronic Gata4 enhancer is dependent upon a conserved Forkhead transcription factor-binding site, which is bound by recombinant FoxA2 in vitro. These studies identify Gata4 as a direct transcriptional target of FoxA2 in the hierarchy of the transcriptional regulatory network that controls the development of the definitive endoderm.
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Affiliation(s)
- Anabel Rojas
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CIBERDEM, Sevilla, Spain.
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20
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Origin and formation of the first two distinct cell types of the inner cell mass in the mouse embryo. Proc Natl Acad Sci U S A 2010; 107:6364-9. [PMID: 20308546 DOI: 10.1073/pnas.0915063107] [Citation(s) in RCA: 232] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A crucial question in mammalian development is how cells of the early embryo differentiate into distinct cell types. The first decision is taken when cells undertake waves of asymmetric division that generate one daughter on the inside and one on the outside of the embryo. After this division, some cells on the inside remain pluripotent and give rise to the epiblast, and hence the future body, whereas others develop into the primitive endoderm, an extraembryonic tissue. How the fate of these inside cells is decided is unknown: Is the process random, or is it related to their developmental origins? To address this question, we traced all cells by live-cell imaging in intact, unmanipulated embryos until the epiblast and primitive endoderm became distinct. This analysis revealed that inner cell mass (ICM) cells have unrestricted developmental potential. However, cells internalized by the first wave of asymmetric divisions are biased toward forming pluripotent epiblast, whereas cells internalized in the next two waves of divisions are strongly biased toward forming primitive endoderm. Moreover, we show that cells internalized by the second wave up-regulate expression of Gata6 and Sox17, and changing the expression of these genes determines whether the cells become primitive endoderm. Finally, with our ability to determine the origin of cells, we find that inside cells that are mispositioned when they are born can sort into the correct layer. In conclusion, we propose a model in which the timing of cell internalization, cell position, and cell sorting combine to determine distinct lineages of the preimplantation mouse embryo.
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21
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Abstract
A mature animal body contains a variety of different cell types, and these cells are distributed in a well-organized fashion along the body axes. One of the major questions in developmental biology is how cells acquire different characteristics. In addition, it is important to understand how the embryo forms the body axes and how cells are allocated along these axes during development. Among mammalian species, the molecular mechanisms that regulate embryonic development have been well analyzed and characterized in mice. Here, mouse preimplantation embryonic development is briefly summarized and our current understanding of this complex process based on recent observations is reviewed.
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Affiliation(s)
- Toshihiko Fujimori
- Division of Embryology, National Institute for Basic Biology, Okazaki, Aichi, Japan.
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22
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Abstract
This review describes the three classical models (mosaic, positional, and polarization) proposed to explain blastocyst formation and summarizes the evidence concerning them. It concludes that the polarization model incorporates elements of the other two models and best explains most known information. I discuss key requirements of a molecular basis for the generation and stabilization of polarity and identify ezrin/E-cadherin, PAR proteins, and Cdx2 as plausible key molecular players. I also discuss the idea of a network process operating to build cell allocations progressively into committed differences. Finally, this review critically considers the possibility of developmental information being encoded within the oocyte and zygote. No final decision can be reached on a mechanism of action underlying any encoded information, but a cell interaction process model is preferred over one that relies solely on differential inheritance.
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Affiliation(s)
- Martin H Johnson
- Department of Physiology, Development, and Neuroscience and Center for Trophoblast Research, The Anatomy School, Cambridge CB2 3DY, United Kingdom.
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23
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Zernicka-Goetz M, Morris SA, Bruce AW. Making a firm decision: multifaceted regulation of cell fate in the early mouse embryo. Nat Rev Genet 2009; 10:467-77. [PMID: 19536196 DOI: 10.1038/nrg2564] [Citation(s) in RCA: 220] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The preimplantation mammalian embryo offers a striking opportunity to address the question of how and why apparently identical cells take on separate fates. Two cell fate decisions are taken before the embryo implants; these decisions set apart a group of pluripotent cells, progenitors for the future body, from the distinct extraembryonic lineages of trophectoderm and primitive endoderm. New molecular, cellular and developmental insights reveal the interplay of transcriptional regulation, epigenetic modifications, cell position and cell polarity in these two fate decisions in the mouse. We discuss how mechanisms proposed in previously distinct models might work in concert to progressively reinforce cell fate decisions through feedback loops.
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Affiliation(s)
- Magdalena Zernicka-Goetz
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK. m.zernicka-goetz@
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24
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Meilhac SM, Adams RJ, Morris SA, Danckaert A, Le Garrec JF, Zernicka-Goetz M. Active cell movements coupled to positional induction are involved in lineage segregation in the mouse blastocyst. Dev Biol 2009; 331:210-21. [PMID: 19422818 DOI: 10.1016/j.ydbio.2009.04.036] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 04/29/2009] [Accepted: 04/29/2009] [Indexed: 11/19/2022]
Abstract
In the mouse blastocyst, some cells of the inner cell mass (ICM) develop into primitive endoderm (PE) at the surface, while deeper cells form the epiblast. It remained unclear whether the position of cells determines their fate, such that gene expression is adjusted to cell position, or if cells are pre-specified at random positions and then sort. We have tracked and characterised dynamics of all ICM cells from the early to late blastocyst stage. Time-lapse microscopy in H2B-EGFP embryos shows that a large proportion of ICM cells change position between the surface and deeper compartments. Most of this cell movement depends on actin and is associated with cell protrusions. We also find that while most cells are precursors for only one lineage, some give rise to both, indicating that lineage segregation is not complete in the early ICM. Finally, changing the expression levels of the PE marker Gata6 reveals that it is required in surface cells but not sufficient for the re-positioning of deeper cells. We provide evidence that Wnt9A, known to be expressed in the surface ICM, facilitates re-positioning of Gata6-expressing cells. Combining these experimental results with computer modelling suggests that PE formation involves both cell sorting movements and position-dependent induction.
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25
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Abstract
The definitive axes of the mouse embryo can be unequivocally identified in embryos dissected at 5.5 days of gestation. However, how and when are these axes established remains an open question. At pre-implantation stages, different approaches have been aimed at determining if events occurring in the zygote influence the geometrical arrangement of the blastocyst. An intense debate has focused on whether the mouse embryo is a pre-patterned or a regulative structure. At post-implantation stages, the efforts have been concentrated in understanding how extra-embryonic tissues affect the formation of the primitive streak, the caudal marker of the anteroposterior axis. Here I summarize the last 10 years of research in this field.
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Affiliation(s)
- Jaime A Rivera-Perez
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
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26
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Torres-Padilla ME, Richardson L, Kolasinska P, Meilhac SM, Luetke-Eversloh MV, Zernicka-Goetz M. The anterior visceral endoderm of the mouse embryo is established from both preimplantation precursor cells and by de novo gene expression after implantation. Dev Biol 2007; 309:97-112. [PMID: 17662710 PMCID: PMC3353121 DOI: 10.1016/j.ydbio.2007.06.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 06/26/2007] [Accepted: 06/28/2007] [Indexed: 10/23/2022]
Abstract
Initiation of the development of the anterior-posterior axis in the mouse embryo has been thought to take place only when the anterior visceral endoderm (AVE) emerges and starts its asymmetric migration. However, expression of Lefty1, a marker of the AVE, was recently found to initiate before embryo implantation. This finding has raised two important questions: are the cells that show such early, preimplantation expression of this AVE marker the real precursors of the AVE and, if so, how does this contribute to the establishment of the AVE? Here, we address both of these questions. First, we show that the expression of another AVE marker, Cer1, also commences before implantation and its expression becomes consolidated in the subset of ICM cells that comprise the primitive endoderm. Second, to determine whether the cells showing this early Cer1 expression are true precursors of the AVE, we set up conditions to trace these cells in time-lapse studies from early periimplantation stages until the AVE emerges and becomes asymmetrically displaced. We found that Cer1-expressing cells are asymmetrically located after implantation and, as the embryo grows, they become dispersed into two or three clusters. The expression of Cer1 in the proximal domain is progressively diminished, whilst it is reinforced in the distal-lateral domain. Our time-lapse studies demonstrate that this distal-lateral domain is incorporated into the AVE together with cells in which Cer1 expression begins only after implantation. Thus, the AVE is formed from both part of an ancestral population of Cerl-expressing cells and cells that acquire Cer1 expression later. Finally, we demonstrate that when the AVE shifts asymmetrically to establish the anterior pole, this occurs towards the region where the earlier postimplantation expression of Cer1 was strongest. Together, these results suggest that the orientation of the anterior-posterior axis is already anticipated before AVE migration.
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Affiliation(s)
- Maria-Elena Torres-Padilla
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Lucy Richardson
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Paulina Kolasinska
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Sigolène M. Meilhac
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Merlin Verena Luetke-Eversloh
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Magdalena Zernicka-Goetz
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
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27
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Perea-Gomez A, Meilhac SM, Piotrowska-Nitsche K, Gray D, Collignon J, Zernicka-Goetz M. Regionalization of the mouse visceral endoderm as the blastocyst transforms into the egg cylinder. BMC DEVELOPMENTAL BIOLOGY 2007; 7:96. [PMID: 17705827 PMCID: PMC1978209 DOI: 10.1186/1471-213x-7-96] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Accepted: 08/16/2007] [Indexed: 11/22/2022]
Abstract
Background Reciprocal interactions between two extra-embryonic tissues, the extra-embryonic ectoderm and the visceral endoderm, and the pluripotent epiblast, are required for the establishment of anterior-posterior polarity in the mouse. After implantation, two visceral endoderm cell types can be distinguished, in the embryonic and extra-embryonic regions of the egg cylinder. In the embryonic region, the specification of the anterior visceral endoderm (AVE) is central to the process of anterior-posterior patterning. Despite recent advances in our understanding of the molecular interactions underlying the differentiation of the visceral endoderm, little is known about how cells colonise the three regions of the tissue. Results As a first step, we performed morphological observations to understand how the extra-embryonic region of the egg cylinder forms from the blastocyst. Our analysis suggests a new model for the formation of this region involving cell rearrangements such as folding of the extra-embryonic ectoderm at the early egg cylinder stage. To trace visceral endoderm cells, we microinjected mRNAs encoding fluorescent proteins into single surface cells of the inner cell mass of the blastocyst and analysed the distribution of labelled cells at E5.0, E5.5 and E6.5. We found that at E5.0 the embryonic and extra-embryonic regions of the visceral endoderm do not correspond to distinct cellular compartments. Clusters of labelled cells may span the junction between the two regions even after the appearance of histological and molecular differences at E5.5. We show that in the embryonic region cell dispersion increases after the migration of the AVE. At this time, visceral endoderm cell clusters tend to become oriented parallel to the junction between the embryonic and extra-embryonic regions. Finally we investigated the origin of the AVE and demonstrated that this anterior signalling centre arises from more than a single precursor between E3.5 and E5.5. Conclusion We propose a new model for the formation of the extra-embryonic region of the egg cylinder involving a folding of the extra-embryonic ectoderm. Our analyses of the pattern of labelled visceral endoderm cells indicate that distinct cell behaviour in the embryonic and extra-embryonic regions is most apparent upon AVE migration. We also demonstrate the polyclonal origin of the AVE. Taken together, these studies lead to further insights into the formation of the extra-embryonic tissues as they first develop after implantation.
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Affiliation(s)
- Aitana Perea-Gomez
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
- Institut Jacques Monod CNRS UMR 7592, Université Paris 6 and Paris 7, 2 place Jussieu, 75005 Paris, France
| | - Sigolène M Meilhac
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
- Department of Developmental Biology, CNRS URA2578, Pasteur Institute, 25 rue du Dr Roux, 75015 Paris, France
| | - Karolina Piotrowska-Nitsche
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
- Division of Neuroscience Yerkes National Primate Research Center, Emory University School of Medicine, 954 Gatewood Rd., Atlanta, Georgia 30329, USA
| | - Dionne Gray
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
- Department of Anatomy, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Jérôme Collignon
- Institut Jacques Monod CNRS UMR 7592, Université Paris 6 and Paris 7, 2 place Jussieu, 75005 Paris, France
| | - Magdalena Zernicka-Goetz
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK
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28
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Westerling T, Kuuluvainen E, Mäkelä TP. Cdk8 is essential for preimplantation mouse development. Mol Cell Biol 2007; 27:6177-82. [PMID: 17620419 PMCID: PMC1952144 DOI: 10.1128/mcb.01302-06] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Cdk8 kinase and associated proteins form a nonessential transcriptional repressor module of the Mediator in the budding yeast Saccharomyces cerevisiae. Genetic analyses of this module have demonstrated functions ranging from environmental responses in budding yeast to organogenesis and development in worms, flies, and zebrafish. Here we have investigated the function of mammalian Cdk8 using mice harboring a gene trap insertion at the Cdk8 locus inactivating this kinase. No phenotypes were noted in heterozygote Cdk8+/- mice, but intercrossing these did not produce homozygous Cdk8-/- offspring. Developmental analysis demonstrated a requirement for Cdk8 prior to implantation at embryonic days 2.5 to 3.0. Cdk8-/- preimplantation embryos had fragmented blastomeres and did not proceed to compaction. As Cdk8 deficiency in cultured metazoan cells did not affect cell viability, the results suggest that transcriptional repression of genes critical for early-cell-fate determination underlies the requirement of Cdk8 in embryogenesis.
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Affiliation(s)
- Thomas Westerling
- Genome-Scale Biology Program and Institute of Biomedicine, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014 Helsinki, Finland
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29
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Abstract
During early mouse embryogenesis, temporal and spatial regulation of gene expression and cell signalling influences lineage specification, embryonic polarity, the patterning of tissue progenitors and the morphogenetic movement of cells and tissues. Uniquely in mammals, the extraembryonic tissues are the source of signals for lineage specification and tissue patterning. Here we discuss recent discoveries about the lead up to gastrulation, including early manifestations of asymmetry, coordination of cell and tissue movements and the interactions of transcription factors and signalling activity for lineage allocation and germ-layer specification.
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Affiliation(s)
- Patrick P L Tam
- Embryology Unit, Children's Medical Research Institute and Faculty of Medicine, University of Sydney, Westmead, NSW 2145, Australia.
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30
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Novel gene expression patterns along the proximo-distal axis of the mouse embryo before gastrulation. BMC DEVELOPMENTAL BIOLOGY 2007; 7:8. [PMID: 17302988 PMCID: PMC1821012 DOI: 10.1186/1471-213x-7-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Accepted: 02/15/2007] [Indexed: 01/29/2023]
Abstract
BACKGROUND To date, the earliest stage at which the orientation of the anterior-posterior axis in the mouse embryo is distinguishable by asymmetric gene expression is shortly after E5.5. At E5.5, prospective anterior markers are expressed at the distal tip of the embryo, whereas prospective posterior markers are expressed more proximally, close to the boundary with the extraembryonic region. RESULTS To contribute to elucidating the mechanisms underlying the events involved in early patterning of the mouse embryo, we have carried out a microarray screen to identify novel genes that are differentially expressed between the distal and proximal parts of the E5.5 embryo. Secondary screening of resulting candidates by in situ hybridisation at E5.5 and E6.5 revealed novel expression patterns for known and previously uncharacterised genes, including Peg10, Ctsz1, Cubilin, Jarid1b, Ndrg1, Sfmbt2, Gjb5, Talia and Plet1. The previously undescribed gene Talia and recently identified Plet1 are expressed specifically in the distal-most part of the extraembryonic ectoderm, adjacent to the epiblast, and are therefore potential candidates for regulating early patterning events. Talia and the previously described gene XE7 define a gene family highly conserved among metazoans and with a predicted protein structure suggestive of a post-transcriptional regulative function, whilst Plet1 appears to be mammal-specific and of unknown function. CONCLUSION Our approach has allowed us to compare expression between dissected parts of the egg cylinder and has identified multiple genes with novel expression patterns at this developmental stage. These genes are potential candidates for regulating tissue interactions following implantation.
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31
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Lewis SL, Tam PPL. Definitive endoderm of the mouse embryo: formation, cell fates, and morphogenetic function. Dev Dyn 2006; 235:2315-29. [PMID: 16752393 DOI: 10.1002/dvdy.20846] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The endoderm is one of the primary germ layers but, in comparison to ectoderm and mesoderm, has received less attention. The definitive endoderm forms during gastrulation and replaces the extraembryonic visceral endoderm. It participates in the complex morphogenesis of the gut tube and contributes to the associated visceral organs. This review highlights the role of the definitive endoderm as a source of patterning cues for the morphogenesis of other germ-layer tissues, such as the anterior neurectoderm and the pharyngeal region, and also emphasizes the intricate patterning that the endoderm itself undergoes enabling the acquisition of regionalized cell fates.
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Affiliation(s)
- Samara L Lewis
- Embryology Unit, Children's Medical Research Institute, University of Sydney, Sydney, NSW, Australia
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32
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Niakan KK, Davis EC, Clipsham RC, Jiang M, Dehart DB, Sulik KK, McCabe ERB. Novel role for the orphan nuclear receptor Dax1 in embryogenesis, different from steroidogenesis. Mol Genet Metab 2006; 88:261-71. [PMID: 16466956 DOI: 10.1016/j.ymgme.2005.12.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Accepted: 12/15/2005] [Indexed: 11/26/2022]
Abstract
Cytomegalic adrenal hypoplasia congenita (AHC) is an X-linked disease caused by mutations in DAX1-encoding gene NR0B1, previously thought to function primarily in steroidogenesis. We sought to determine the expression pattern for Dax1 along with known network partners in early embryogenesis and to determine a steroidogenic capacity for the embryo prior to the establishment of the urogenital ridge at embryonic day 9 (E9). Here, we report that murine Dax1 is a unique marker in early embryonic development, distinguishing the extraembryonic (proximal) endoderm from the remainder of the developing embryo. We showed that Wilms tumor 1, steroidogenic factor 1, and estrogen receptor beta were expressed throughout the embryo, but the progesterone, estrogen alpha and androgen receptors, cytochrome P450 (Cyp11a1) and Nur77 were not observed in any of the embryonic layers. Lack of Cyp11A1 expression at this stage confirmed an absence of inherent steroidogenic capacity for the early embryo. The role of Nr0b1 in embryonic stem (ES) cells was investigated using siRNA knockdown, resulting in differentiation toward endoderm-like fate. Nr0b1 conditional knockout in ES cells led to differentiation, confirming our knockdown results. Our investigations suggest that Nr0b1 functions in a novel role in the maintenance of a relatively undifferentiated state. Our results further suggest that the failure of conventional murine Nr0b1 knockout attempts may be due to disregulated differentiation.
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Affiliation(s)
- Kathy K Niakan
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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33
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Moorthy PP, Kumar AA, Devaraj H. Expression of the Gas7 gene and Oct4 in embryonic stem cells of mice. Stem Cells Dev 2006; 14:664-70. [PMID: 16433621 DOI: 10.1089/scd.2005.14.664] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Oct4 is a stem cell expression marker, and persistence of its expression retains pluripotency in embryonic stem (ES) cells. Our results indicate a pattern of gradual decrease in Oct4 expression, which is prominent in the blastocyst and markedly reduced in the gastrula and neurula. The presence of POU transcription factor-like domain in Gas7 prompted us to look for its expression in the early embryonic cells. We have observed high expression of the Gas7 protein in blastocysts that gradually decreased in the neurula stages. The localization of Gas7 was initially seen throughout the blastocyst, but was later confined to dorsal ectodermal regions of the neurula, conforming with its role in neuronal differentiation. Our data reveal that Gas7 might play a role in cellular migration and cell protection in the ES cells of mouse embryo.
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Affiliation(s)
- P P Moorthy
- Unit of Biochemistry, Department of Zoology, University of Madras, Chennai-600 025, Tamil Nadu, India
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34
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Chazaud C, Yamanaka Y, Pawson T, Rossant J. Early Lineage Segregation between Epiblast and Primitive Endoderm in Mouse Blastocysts through the Grb2-MAPK Pathway. Dev Cell 2006; 10:615-24. [PMID: 16678776 DOI: 10.1016/j.devcel.2006.02.020] [Citation(s) in RCA: 657] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 02/17/2006] [Accepted: 02/20/2006] [Indexed: 10/24/2022]
Abstract
It has been thought that early inner cell mass (ICM) is a homogeneous population and that cell position in the ICM leads to the formation of two lineages, epiblast (EPI) and primitive endoderm (PE), by E4.5. Here, however, we show that the ICM at E3.5 is already heterogeneous. The EPI- and PE-specific transcription factors, Nanog and Gata6, were expressed in the ICM in a random "salt and pepper" pattern, as early as E3.5, in a mutually exclusive manner. Lineage tracing showed predominant lineage restriction of single ICM cells at E3.5 to either lineage. In embryos lacking Grb2 where no PE forms, Gata6 expression was lost and all ICM cells were Nanog positive. We propose a model in which the ICM develops as a mosaic of EPI and PE progenitors at E3.5, dependent on Grb2-Ras-MAP kinase signaling, followed by later segregation of the progenitors into the appropriate cell layers.
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Affiliation(s)
- Claire Chazaud
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G1X5, Canada
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35
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Richardson L, Torres-Padilla ME, Zernicka-Goetz M. Regionalised signalling within the extraembryonic ectoderm regulates anterior visceral endoderm positioning in the mouse embryo. Mech Dev 2006; 123:288-96. [PMID: 16517131 DOI: 10.1016/j.mod.2006.01.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 01/17/2006] [Accepted: 01/22/2006] [Indexed: 11/26/2022]
Abstract
The development of the anterior-posterior (AP) axis in the mammalian embryo is controlled by interactions between embryonic and extraembryonic tissues. It is well established that one of these extraembryonic tissues, the anterior visceral endoderm (AVE), can repress posterior cell fate and that signalling from the other, the extraembryonic ectoderm (ExE), is required for posterior patterning. Here, we show that signals from the prospective posterior ExE repress AVE gene expression and affect the distribution of the AVE cells. Surgical ablation of the prospective posterior, but not the anterior, extraembryonic region at 5.5 days of development (E5.5) perturbs the characteristic distal-to-anterior distribution of AVE cells and leads to a dramatic expansion of the AVE domain. Time-lapse imaging studies show that this increase is due to the ectopic expression of an AVE marker, which results in a symmetrical positioning of the AVE. Surgical ablation of this same ExE region after the distal-to-anterior migration has already commenced, at E5.75, does not affect the localisation of the AVE, indicating that this effect takes place within a short time window. Conversely, transplanting the prospective posterior, but not the anterior, extraembryonic region onto isolated E5.5 embryonic explants drastically reduces the AVE domain. Further, transplantation experiments demonstrate that the signalling regulating AVE gene expression originates from the posterior ExE, rather than its surrounding VE. Together, our results show that signals emanating from the future posterior ExE within a temporal window both restrict the AVE domain and promote its specific positioning. This indicates for the first time that the ExE is already regionalised a day before the onset of gastrulation in order to correctly set the orientation of the AP axis of the mouse embryo. We propose a reciprocal function of the posterior ExE and the AVE in establishing a balance between the antagonistic activities of these two tissues, essential for AP patterning.
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Affiliation(s)
- Lucy Richardson
- The Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
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36
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Moore CA, Zernicka-Goetz M. PAR-1 and the microtubule-associated proteins CLASP2 and dynactin-p50 have specific localisation on mouse meiotic and first mitotic spindles. Reproduction 2005; 130:311-20. [PMID: 16123238 DOI: 10.1530/rep.1.00651] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The site of second meiotic division, marked by the second polar body, is an important reference point in the early mouse embryo. To study its formation, we look at the highly asymmetric meiotic divisions. For extrusion of the small polar bodies during meiosis, the spindles must be located cortically. The positioning of meiotic spindles is known to involve the actin cytoskeleton, but whether microtubules are also involved is not clear. In this study we investigated the patterns of localisation of microtubule regulatory proteins in mouse oocytes. PAR-1 is a member of the PAR (partitioning-defective) family with known roles in regulation of microtubule stability and spindle positioning in other model systems. Here we show its specific localisation on mouse meiotic and first mitotic spindles. In addition, the microtubule-associated proteins CLASP2 (a CLIP associating protein) and dynactin-p50 are found on kinetochores and a subset of microtubule-organising centres. Thus we show specific localisation of microtubule regulatory proteins in mouse oocytes, which could indicate roles in meiotic spindle organisation.
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Affiliation(s)
- Catherine A Moore
- University of Cambridge, The Wellcome Trust/Cancer Research UK Gurdon Institute of Cancer and Developmental Biology, Tennis Court Road, Cambridge CB2 1QR, UK
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37
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Mackay GE, West JD. Fate of tetraploid cells in 4n<-->2n chimeric mouse blastocysts. Mech Dev 2005; 122:1266-81. [PMID: 16274964 DOI: 10.1016/j.mod.2005.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 09/02/2005] [Accepted: 09/08/2005] [Indexed: 10/25/2022]
Abstract
Previous studies have shown that tetraploid (4n) cells rarely contribute to the derivatives of the epiblast lineage of mid-gestation 4n<-->2n mouse chimeras. The aim of the present study was to determine when and how 4n cells were excluded from the epiblast lineage of such chimeras. The contributions of GFP-positive cells to different tissues of 4n<-->2n chimeric blastocysts labelled with tauGFP were analysed at E3.5 and E4.5 using confocal microscopy. More advanced E5.5 and E7.5 chimeric blastocysts were analysed after a period of diapause to allow further growth without implantation. Tetraploid cells were not initially excluded from the epiblast in 4n<-->2n chimeric blastocysts and they contributed to all four blastocyst tissues at all of the blastocyst stages examined. Four steps affected the allocation and fate of 4n cells in chimeras, resulting in their exclusion from the epiblast lineage by mid-gestation. (1) Fewer 4n cells were allocated to the inner cell mass than trophectoderm. (2) The blastocyst cavity tended to form among the 4n cells, causing more 4n cells to be allocated to the hypoblast and mural trophectoderm than the epiblast and polar trophectoderm, respectively. (3) 4n cells were depleted from the hypoblast and mural trophectoderm, where initially they were relatively enriched. (4) After implantation 4n cells must be lost preferentially from the epiblast lineage. Relevance of these results to the aetiology of human confined placental mosaicism and possible implications for the interpretation of mouse tetraploid complementation studies of the site of gene action are discussed.
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Affiliation(s)
- Gillian E Mackay
- Division of Reproductive and Developmental Sciences, Genes and Development Group, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, Scotland, UK
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38
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Piotrowska-Nitsche K, Zernicka-Goetz M. Spatial arrangement of individual 4-cell stage blastomeres and the order in which they are generated correlate with blastocyst pattern in the mouse embryo. Mech Dev 2005; 122:487-500. [PMID: 15804563 DOI: 10.1016/j.mod.2004.11.014] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Revised: 11/24/2004] [Accepted: 11/24/2004] [Indexed: 11/29/2022]
Abstract
In the unperturbed development of the mouse embryo one of the 2-cell blastomeres tends to contribute its progeny predominantly to the embryonic and the other to the abembryonic part of the blastocyst. However, a significant minority of embryos (20-30%) do not show this correlation. In this study, we have used non-invasive lineage tracing to determine whether development of blastocyst pattern shows any correlation with the orientation and order of the second cleavage divisions that result in specific positioning of blastomeres at the 4-cell stage. Although the orientation and order of the second cleavages are not predetermined, in the great majority (80%) of embryos the spatial arrangement of 4-cell blastomeres is consistent with one of the second cleavages occurring meridionally and the other equatorially or obliquely with respect to the polar body. In such cleaving embryos, one of the 2-cell stage blastomeres tends to contribute to embryonic while the other contributes predominantly to abembryonic part of the blastocyst. Thus, in these embryos the outcome of the first cleavage tends to correlate with the orientation of the blastocyst embryonic-abembryonic axis. However, the order of blastomere divisions predicts a specific polarity for this axis only when the earlier 2-cell blastomere to divide does so meridionally. In contrast to the above two groups, in those embryos in which both second cleavage divisions occur in a similar orientation, either meridionally or equatorially, we do not observe any tendency for the 2-cell blastomeres to contribute to specific blastocyst parts. We find that all these groups of embryos develop to term with similar success, with the exception of those in which both second cleavage divisions occur equatorially whose development can be compromised. We conclude that the orientations and order of the second cleavages are not predetermined; they correlate with the development of blastocyst patterning; and that the majority, but not all, of these cleavage patterns allow equally successful development.
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39
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Abstract
A growing body of evidence indicates that although the early mouse embryo retains flexibility in responding to perturbations, its patterning is initiated at the earliest developmental stages. There are a few spatial cues that are able to influence the pattern of cleavage divisions: one of these lies in the vicinity of the previous meiotic division, the second is associated with the sperm entry and, related to this, the third is the cell shape. Furthermore, the first cleavage separates the zygote into two cells that tend to follow distinguishable fates: one contributes mainly to the embryonic part of the blastocyst, and the other to the abembryonic. The cumulative effect of the early asymmetries generated through cleavage might lead to asymmetric interactions between the first lineages of cells. This could influence development of patterning after implantation. These early polarity cues serve to bias patterning and not as definitive determinants.
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Affiliation(s)
- Magdalena Zernicka-Goetz
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK.
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40
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Malter HE, Cohen J, Pieczenik G. Combinatorial peptide library binding of mammalian spermatozoa identifies a ligand (HIPRT) in the axin protein: putative identification of a sperm surface axin binding protein and intriguing developmental implications. Reprod Biomed Online 2005; 10:355-62. [PMID: 15820042 DOI: 10.1016/s1472-6483(10)61796-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The identification of components in cell-cell interactions is an important research goal in reproductive and developmental biology. Such interactions are critical to gamete development, fertilization, implantation and basic development. Several proteins involved with sperm-oocyte interaction and other developmentally important phenomena have been identified. However, these are obviously only a subset of the molecular components involved in such complex cell-cell interactions. One method that has been used to identify binding partners for particular molecular targets is the use of combinatorial libraries accessible on phage surfaces. For the most part, this technique has mainly been applied to screen specific target moieties. However, in some cases whole-cell screening has been attempted. This study describes the first report of screening intact, living mammalian gametes using a proprietary whole-cell combinatorial library binding and analysis protocol. Results from the first screening protocol of mouse spermatozoa strongly identified a putative sperm-binding ligand using proprietary bioinformatic analysis. This amino acid sequence (HIPRT) precisely corresponds with a previously characterized highly conserved protein-protein interaction site in the axin protein. This sequence is found within the binding site for a known sperm surface protein, glycogen synthase kinase-3. This result not only provides proof of the utility of this technique to identify cell surface ligands in mammalian gametes, but it also suggests a potential role for spermatozoa in facilitating developmental axis formation in mammalian embryos.
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Affiliation(s)
- Henry E Malter
- Tyho-Galileo Research Laboratories, 101 Old Short Hills Road, Suite 501, West Orange, NJ 07052, USA
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41
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Abstract
In mammalian embryos, molecular cross-talk with extraembryonic tissues is essential to elaborate the primary body axes. Here, we review a series of reciprocal interactions that occur shortly after implantation in the uterus, and discuss how they are integrated in a complex signaling network to establish antero-posterior and dorso-ventral polarity. At the heart of this signaling network is the TGFbeta-related protein Nodal which acts on extraembryonic tissues to induce positive and negative feedback regulators at opposite poles of the egg cylinder. This likely results in an activity gradient which is instrumental to pattern the embryo proper.
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Affiliation(s)
- Siew-Lan Ang
- Division of Developmental Neurobiology, NIMR, The Ridgeway, Mill Hill, London NW7 1AA, UK.
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42
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Abstract
Embryonic patterning of the mouse during gastrulation and early organogenesis engenders the specification of anterior versus posterior structures and body laterality by the interaction of signalling and modulating activities. A group of cells in the mouse gastrula, characterised by the expression of a repertoire of "organiser" genes, acts as a source and the conduit for allocation of the axial mesoderm, floor plate and definitive endoderm. The organiser and its derivatives provide the antagonistic activity that modulates WNT and TGFbeta signalling. Recent findings show that the organiser activity is augmented by morphogenetic activity of the extraembryonic and embryonic endoderm, suggesting embryonic patterning is not solely the function of the organiser.
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Affiliation(s)
- Lorraine Robb
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Vic. 3050, Australia
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43
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Abstract
The main aim of the gastrulation process is commonly regarded to be the generation of the definitive germ layers known as mesoderm, endoderm and ectoderm. Here we discuss how the topography of gene expression, cellular migration and proliferative activity in the preliminary germ layers (hypoblast and epiblast) of the rabbit embryo reveal the sequence of events that establishes the three major body axes. We present a testable model in which a combination of cellular movement in the hypoblast with a morphogen gradient created by the (extraembryonic) trophoblast creates morphological polarity in the embryo and, hence, the co-ordinates for germ layer formation.
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Affiliation(s)
- Jan Idkowiak
- Department of Anatomy and Cell Biology, Martin-Luther University, Grosse Steinstrasse 56, 06097 Halle, Germany
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44
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Rossant J. Lineage development and polar asymmetries in the peri-implantation mouse blastocyst. Semin Cell Dev Biol 2004; 15:573-81. [PMID: 15271303 DOI: 10.1016/j.semcdb.2004.04.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The early events of mouse embryogenesis lead to the formation of three distinct cell lineages by the blastocyst: the pluripotent epiblast and the two extraembryonic lineages, the trophoblast and primitive endoderm. Segregation of the lineages depends on the relative levels of expression of key transcription factors, whose localized expression must be controlled by the earlier events of compaction and polarization of the morula. Soon after lineage specification, the two extraembryonic lineages show evidence of early polarities that may relate to the polarity of the postimplantation embryo at gastrulation. The exact relationship between lineage segregation, preimplantation polarities and the postimplantation axes remain to be determined but are now open to molecular and cellular investigation.
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Affiliation(s)
- Janet Rossant
- Samuel Lunenfeld Research Institute, Mount Sinal Hospital, Toronto, Ont, Canada.
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45
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Cervera RP, Garcia-Ximénez F. Subzonal Older Adult Fibroblast Insertion in Both In Vivo–Fertilized and Nuclear Transfer Rabbit Zygotes and Embryos: Effects on Further In Vitro Embryo Development. CLONING AND STEM CELLS 2004; 6:315-26. [PMID: 15671676 DOI: 10.1089/clo.2004.6.315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the present work, we evaluated the effect on further in vitro embryo development of inserting rabbit adult fibroblasts into in vivo-fertilized rabbit embryos. To this end, we inserted either 4 or 15-20 rabbit adult fibroblasts in two different early embryo stages of development, 1-cell stage and 4-8-cell stage embryos. We observed that fibroblast insertion not only did not negatively affect further embryo development, but also may have exerted a positive effect on development on it. Therefore, in forthcoming works were where we intend to study a possible cell helper role on early embryo development. The early embryo microenvironment may reprogram somatic cell gene expression of fibroblasts inserted within the embryo, making them suitable as nuclear donors.
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Affiliation(s)
- R P Cervera
- Laboratory of Animal Reproduction and Biotechnology (LARB-UPV), Polytechnic University of Valencia, Camino de Vera 14, 46071 Valencia, Spain.
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46
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Lu CC, Robertson EJ. Multiple roles for Nodal in the epiblast of the mouse embryo in the establishment of anterior-posterior patterning. Dev Biol 2004; 273:149-59. [PMID: 15302604 DOI: 10.1016/j.ydbio.2004.06.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Revised: 06/08/2004] [Accepted: 06/10/2004] [Indexed: 11/19/2022]
Abstract
The TGFbeta family member Nodal has been shown to be involved in a variety of processes in development, including early axis formation. Here, we use a conditional gene inactivation strategy to show a specific requirement for Nodal in the epiblast. Complete inactivation of the Nodal locus in the epiblast using the Sox2-Cre deleter strain results in a failure to establish global anterior-posterior patterning, a phenotype that resembles the Nodal null phenotype. By contrast, mosaic inactivation of Nodal in the epiblast using the Mox2-Cre (MORE) deleter strain affects formation of the anterior mesendoderm and subsequent anterior neurectoderm patterning. Furthermore, ES cell chimera experiments indicate that Nodal-deficient ES cells preferentially populate the anterior compartment of the epiblast, suggesting that cell mixing in the epiblast is not random and that Nodal signaling mediates a novel anterior-posterior cell-sorting process within the epiblast before gastrulation.
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Affiliation(s)
- Cindy C Lu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
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47
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Abstract
Recent studies have revealed asymmetries in the mouse zygote and preimplantation embryo, well before the establishment of anterior-posterior polarity after implantation. Whether these asymmetries are causally related to embryonic patterning or are coincidental outcomes of the topology of normal development remains uncertain.
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Affiliation(s)
- Janet Rossant
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Ontario M5G 1X5, Canada.
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48
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Prodon F, Prulière G, Chenevert J, Sardet C. [Establishment and expression of embryonic axes: comparisons between different model organisms]. Med Sci (Paris) 2004; 20:526-38. [PMID: 15190470 DOI: 10.1051/medsci/2004205526] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In an accompanying article (C. Sardet et al. m/s 2004; 20 : 414-423) we reviewed determinants of polarity in early development and the mechanisms which regulate their localization and expression. Such determinants have for the moment been identified in only a few species: the insect Drosophila melanogaster, the worm Caenorhabditis elegans, the frog Xenopus laevis and the ascidians Ciona intestinalis and Holocynthia roretzi. Although oogenesis, fertilization, and cell divisions in these embryos differ considerably, with respect to early polarities certain common themes emerge, such as the importance of cortical mRNAs, the PAR polarity proteins, and reorganizations mediated by the cytoskeleton. Here we highlight similarities and differences in axis establishment between these species, describing them in a chronological order from oocyte to gastrula, and add two more classical model organisms, sea urchin and mouse, to complete the comparisons depicted in the form of a Poster which can be downloaded from the site http://biodev.obs-vlfr.fr/biomarcell.
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Affiliation(s)
- François Prodon
- BioMarCell, Laboratoire de biologie du développement, UMR 7009 CNRS-UPMC, Observatoire, Station zoologique, 06230 Villefranche-sur-Mer, France
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49
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50
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Wang QT, Piotrowska K, Ciemerych MA, Milenkovic L, Scott MP, Davis RW, Zernicka-Goetz M. A genome-wide study of gene activity reveals developmental signaling pathways in the preimplantation mouse embryo. Dev Cell 2004; 6:133-44. [PMID: 14723853 DOI: 10.1016/s1534-5807(03)00404-0] [Citation(s) in RCA: 406] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The preimplantation development of the mammalian embryo encompasses a series of critical events: the transition from oocyte to embryo, the first cell divisions, the establishment of cellular contacts, the first lineage differentiation-all the first subtle steps toward a future body plan. Here, we use microarrays to explore gene activity during preimplantation development. We reveal robust and dynamic patterns of stage-specific gene activity that fall into two major phases, one up to the 2-cell stage (oocyte-to-embryo transition) and one after the 4-cell stage (cellular differentiation). The mouse oocyte and early embryo express components of multiple signaling pathways including those downstream of Wnt, BMP, and Notch, indicating that conserved regulators of cell fate and pattern formation are likely to function at the earliest embryonic stages. Overall, these data provide a detailed temporal profile of gene expression that reveals the richness of signaling processes in early mammalian development.
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Affiliation(s)
- Q Tian Wang
- Department of Biochemistry and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
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