1
|
Pfeffer PL. The first lineage determination in mammals. Dev Biol 2024; 513:12-30. [PMID: 38761966 DOI: 10.1016/j.ydbio.2024.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/15/2024] [Accepted: 05/16/2024] [Indexed: 05/20/2024]
Abstract
This review describes in detail the morphological, cytoskeletal and gene expression events leading to the gene regulatory network bifurcation point of trophoblast and inner cell mass cells in a variety of mammalian preimplantation embryos. The interrelated processes of compaction and polarity establishment are discussed in terms of how they affect YAP/WWTR activity and the location and fate of cells. Comparisons between mouse, human, cattle, pig and rabbit embryos suggest a conserved role for YAP/WWTR signalling in trophoblast induction in eutherian animals though the mechanisms for, and timing of, YAP/WWTR activation differs among species. Downstream targets show further differences, with the trophoblast marker GATA3 being a direct target in all examined mammals, while CDX2-positive and SOX2-negative regulation varies.
Collapse
Affiliation(s)
- Peter L Pfeffer
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand.
| |
Collapse
|
2
|
Skory RM. Revisiting trophectoderm-inner cell mass lineage segregation in the mammalian preimplantation embryo. Hum Reprod 2024; 39:1889-1898. [PMID: 38926157 DOI: 10.1093/humrep/deae142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
In the first days of life, cells of the mammalian embryo segregate into two distinct lineages, trophectoderm and inner cell mass. Unlike nonmammalian species, mammalian development does not proceed from predetermined factors in the oocyte. Rather, asymmetries arise de novo in the early embryo incorporating cues from cell position, contractility, polarity, and cell-cell contacts. Molecular heterogeneities, including transcripts and non-coding RNAs, have now been characterized as early as the 2-cell stage. However, it's debated whether these early heterogeneities bias cells toward one fate or the other or whether lineage identity arises stochastically at the 16-cell stage. This review summarizes what is known about early blastomere asymmetries and our understanding of lineage allocation in the context of historical models. Preimplantation development is reviewed coupled with what is known about changes in morphology, contractility, and transcription factor networks. The addition of single-cell atlases of human embryos has begun to reveal key differences between human and mouse, including the timing of events and core transcription factors. Furthermore, the recent generation of blastoid models will provide valuable tools to test and understand fate determinants. Lastly, new techniques are reviewed, which may better synthesize existing knowledge with emerging data sets and reconcile models with the regulative capacity unique to the mammalian embryo.
Collapse
Affiliation(s)
- Robin M Skory
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
3
|
Otsuka T, Shimojo H, Sasaki H. Daughter cells inherit YAP localization from mother cells in early preimplantation embryos. Dev Growth Differ 2023; 65:360-369. [PMID: 37309238 DOI: 10.1111/dgd.12870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/30/2023] [Accepted: 06/08/2023] [Indexed: 06/14/2023]
Abstract
The first stage of cell differentiation during mouse development is the differentiation into the trophectoderm and inner cell mass, which occurs during the 8-32-cell stages of preimplantation embryos. This differentiation is regulated by the Hippo signaling pathway. At the 32-cell stage, embryos establish a position-dependent distribution of the Hippo pathway coactivator, Yes-associated protein 1 (YAP, encoded by Yap1). The outer and inner cells showed nuclear and cytoplasmic localization of YAP, respectively. However, the process by which embryos establish position-dependent YAP localization remains elusive. Here, we established a YAP-reporter mouse line, Yap1mScarlet , and examined YAP-mScarlet protein dynamics during the 8-32-cell stages using live imaging. During mitosis, YAP-mScarlet diffused throughout the cells. YAP-mScarlet dynamics in daughter cells varied depending on the cell division patterns. YAP-mScarlet localization in daughter cells at the completion of cell division coincided with that in mother cells. Experimental manipulation of YAP-mScarlet localization in mother cells also altered its localization in daughter cells upon completion of cell division. In daughter cells, YAP-mScarlet localization gradually changed to the final pattern. In some divisions during the 8-16-cell stages, the cytoplasmic YAP-mScarlet localization preceded cell internalization. These results suggest that cell position is not a primary determinant of YAP localization and that the Hippo signaling status of the mother cell is inherited by the daughter cells, which likely contributes to the stabilization of the cell fate specification process beyond cell division.
Collapse
Affiliation(s)
- Tomoaki Otsuka
- Laboratory for Embryogenesis, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Hiromi Shimojo
- Laboratory for Embryogenesis, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Hiroshi Sasaki
- Laboratory for Embryogenesis, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| |
Collapse
|
4
|
Gahurova L, Tomankova J, Cerna P, Bora P, Kubickova M, Virnicchi G, Kovacovicova K, Potesil D, Hruska P, Zdrahal Z, Anger M, Susor A, Bruce AW. Spatial positioning of preimplantation mouse embryo cells is regulated by mTORC1 and m 7G-cap-dependent translation at the 8- to 16-cell transition. Open Biol 2023; 13:230081. [PMID: 37553074 PMCID: PMC10409569 DOI: 10.1098/rsob.230081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 07/18/2023] [Indexed: 08/10/2023] Open
Abstract
Preimplantation mouse embryo development involves temporal-spatial specification and segregation of three blastocyst cell lineages: trophectoderm, primitive endoderm and epiblast. Spatial separation of the outer-trophectoderm lineage from the two other inner-cell-mass (ICM) lineages starts with the 8- to 16-cell transition and concludes at the 32-cell stages. Accordingly, the ICM is derived from primary and secondary contributed cells; with debated relative EPI versus PrE potencies. We report generation of primary but not secondary ICM populations is highly dependent on temporal activation of mammalian target of Rapamycin (mTOR) during 8-cell stage M-phase entry, mediated via regulation of the 7-methylguanosine-cap (m7G-cap)-binding initiation complex (EIF4F) and linked to translation of mRNAs containing 5' UTR terminal oligopyrimidine (TOP-) sequence motifs, as knockdown of identified TOP-like motif transcripts impairs generation of primary ICM founders. However, mTOR inhibition-induced ICM cell number deficits in early blastocysts can be compensated by the late blastocyst stage, after inhibitor withdrawal; compensation likely initiated at the 32-cell stage when supernumerary outer cells exhibit molecular characteristics of inner cells. These data identify a novel mechanism specifically governing initial spatial segregation of mouse embryo blastomeres, that is distinct from those directing subsequent inner cell formation, contributing to germane segregation of late blastocyst lineages.
Collapse
Affiliation(s)
- Lenka Gahurova
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
- Laboratory of Biochemistry and Molecular Biology of Germ Cells, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
| | - Jana Tomankova
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Pavlina Cerna
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Pablo Bora
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Michaela Kubickova
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Giorgio Virnicchi
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Kristina Kovacovicova
- Laboratory of Cell Division Control, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic
| | - David Potesil
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Pavel Hruska
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Zbynek Zdrahal
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Martin Anger
- Laboratory of Cell Division Control, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
- Department of Genetics and Reproduction, Central European Institute of Technology, Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic
| | - Andrej Susor
- Laboratory of Biochemistry and Molecular Biology of Germ Cells, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 27721 Liběchov, Czech Republic
| | - Alexander W. Bruce
- Laboratory of Early Mammalian Developmental Biology (LEMDB), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| |
Collapse
|
5
|
Domingo-Muelas A, Skory RM, Moverley AA, Ardestani G, Pomp O, Rubio C, Tetlak P, Hernandez B, Rhon-Calderon EA, Navarro-Sánchez L, García-Pascual CM, Bissiere S, Bartolomei MS, Sakkas D, Simón C, Plachta N. Human embryo live imaging reveals nuclear DNA shedding during blastocyst expansion and biopsy. Cell 2023; 186:3166-3181.e18. [PMID: 37413989 PMCID: PMC11170958 DOI: 10.1016/j.cell.2023.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/05/2023] [Accepted: 06/05/2023] [Indexed: 07/08/2023]
Abstract
Proper preimplantation development is essential to assemble a blastocyst capable of implantation. Live imaging has uncovered major events driving early development in mouse embryos; yet, studies in humans have been limited by restrictions on genetic manipulation and lack of imaging approaches. We have overcome this barrier by combining fluorescent dyes with live imaging to reveal the dynamics of chromosome segregation, compaction, polarization, blastocyst formation, and hatching in the human embryo. We also show that blastocyst expansion mechanically constrains trophectoderm cells, causing nuclear budding and DNA shedding into the cytoplasm. Furthermore, cells with lower perinuclear keratin levels are more prone to undergo DNA loss. Moreover, applying trophectoderm biopsy, a mechanical procedure performed clinically for genetic testing, increases DNA shedding. Thus, our work reveals distinct processes underlying human development compared with mouse and suggests that aneuploidies in human embryos may not only originate from chromosome segregation errors during mitosis but also from nuclear DNA shedding.
Collapse
Affiliation(s)
- Ana Domingo-Muelas
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Igenomix Foundation and Carlos Simon Foundation, Spain
| | - Robin M Skory
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Adam A Moverley
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; University College London, London WC1E 6BT, UK
| | | | - Oz Pomp
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Piotr Tetlak
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Blake Hernandez
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eric A Rhon-Calderon
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | - Stephanie Bissiere
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marisa S Bartolomei
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Carlos Simón
- Igenomix Foundation and Carlos Simon Foundation, Spain; Department of Pediatrics Obstetrics & Gynecology, University of Valencia, Valencia 46010, Spain; INCLIVA Health Research Institute, Valencia 46010, Spain; Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Nicolas Plachta
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
6
|
Lamba A, Zernicka-Goetz M. The role of polarization and early heterogeneities in the mammalian first cell fate decision. Curr Top Dev Biol 2023; 154:169-196. [PMID: 37100517 DOI: 10.1016/bs.ctdb.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
The first cell fate decision is the process by which cells of an embryo take on distinct lineage identities for the first time, representing the beginning of patterning during development. In mammals, this process separates an embryonic inner cell mass lineage (future new organism) from an extra-embryonic trophectoderm lineage (future placenta), and in the mouse, this is classically attributed to the consequences of apical-basal polarity. The mouse embryo acquires this polarity at the 8-cell stage, indicated by cap-like protein domains on the apical surface of each cell; those cells which retain polarity over subsequent divisions are specified as trophectoderm, and the rest as inner cell mass. Recent research has advanced our knowledge of this process - this review will discuss mechanisms behind the establishment of polarity and distribution of the apical domain, different factors affecting the first cell fate decision including heterogeneities between cells of the very early embryo, and the conservation of developmental mechanisms across species, including human.
Collapse
Affiliation(s)
- Adiyant Lamba
- Mammalian Embryo and Stem Cell Group, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Magdalena Zernicka-Goetz
- Mammalian Embryo and Stem Cell Group, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.
| |
Collapse
|
7
|
Erkhembaatar M, Yamamoto I, Inoguchi F, Taki K, Yamagishi S, Delaney L, Nishibe M, Abe T, Kiyonari H, Hanashima C, Naka‐kaneda H, Ihara D, Katsuyama Y. Involvement of Strawberry Notch homologue 1 in neurite outgrowth of cortical neurons. Dev Growth Differ 2022; 64:379-394. [DOI: 10.1111/dgd.12802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 06/15/2022] [Accepted: 06/15/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Munkhsoyol Erkhembaatar
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Iroha Yamamoto
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Fuduki Inoguchi
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Kosuke Taki
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Satoru Yamagishi
- Department of Anatomy & Neuroscience Hamamatsu University School of Medicine, Hamamatsu Shizuoka Japan
- Preeminent Medical Photonics Education & Research Center Hamamatsu University School of Medicine, Hamamatsu Shizuoka Japan
| | - Leanne Delaney
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
- Department of Microbiology and Immunology Dalhousie University, PO Box 15000 Halifax Nova Scotia Canada
| | - Mariko Nishibe
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Takaya Abe
- Animal Resource Development Unit, Biosystem Dynamics Group, Division of Bio‐Function Dynamics Imaging Center for Life Science Technologies CDB RIKEN Kobe Japan
| | - Hiroshi Kiyonari
- Animal Resource Development Unit, Biosystem Dynamics Group, Division of Bio‐Function Dynamics Imaging Center for Life Science Technologies CDB RIKEN Kobe Japan
| | - Carina Hanashima
- Department of Biology, Faculty of Education and Integrated Arts and Sciences Waseda University Tokyo Japan
| | - Hayato Naka‐kaneda
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Dai Ihara
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| | - Yu Katsuyama
- Division of Neuroanatomy, Department of Anatomy Shiga University of Medical Science Shiga Japan
| |
Collapse
|
8
|
Mashiko D, Ikeda Z, Tokoro M, Hatano Y, Yao T, Kobayashi TJ, Fukunaga N, Asada Y, Yamagata K. Asynchronous division at 4-8-cell stage of preimplantation embryos affects live birth through ICM/TE differentiation. Sci Rep 2022; 12:9411. [PMID: 35672442 PMCID: PMC9174281 DOI: 10.1038/s41598-022-13646-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/18/2022] [Indexed: 11/30/2022] Open
Abstract
To improve the performance of assisted reproductive technology, it is necessary to find an indicator that can identify and select embryos that will be born or be aborted. We searched for indicators of embryo selection by comparing born/abort mouse embryos. We found that asynchronous embryos during the 4-8-cell stage were predisposed to be aborted. In asynchronous mouse embryos, the nuclear translocation of YAP1 in some blastomeres and compaction were delayed, and the number of ICMs was reduced. Hence, it is possible that asynchronous embryos have abnormal differentiation. When the synchrony of human embryos was observed, it was confirmed that embryos that did not reach clinical pregnancy had asynchrony as in mice. This could make synchrony a universal indicator common to all animal species.
Collapse
Affiliation(s)
- Daisuke Mashiko
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, 649-6493, Japan
| | - Zenki Ikeda
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, 649-6493, Japan
| | - Mikiko Tokoro
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, 649-6493, Japan
- Asada Institute for Reproductive Medicine, Asada Ladies Clinic, Nagoya, Aichi, 450-0002, Japan
| | - Yu Hatano
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, 649-6493, Japan
| | - Tatsuma Yao
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, 649-6493, Japan
- Research and Development Center, Fuso Pharmaceutical Industries, Ltd., Joto, Osaka, 536-8523, Japan
| | - Tetsuya J Kobayashi
- Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
| | - Noritaka Fukunaga
- Asada Institute for Reproductive Medicine, Asada Ladies Clinic, Nagoya, Aichi, 450-0002, Japan
| | - Yoshimasa Asada
- Asada Institute for Reproductive Medicine, Asada Ladies Clinic, Nagoya, Aichi, 450-0002, Japan
| | - Kazuo Yamagata
- Graduate School of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, 649-6493, Japan.
| |
Collapse
|
9
|
Gauster M, Moser G, Wernitznig S, Kupper N, Huppertz B. Early human trophoblast development: from morphology to function. Cell Mol Life Sci 2022; 79:345. [PMID: 35661923 PMCID: PMC9167809 DOI: 10.1007/s00018-022-04377-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/13/2022] [Accepted: 05/13/2022] [Indexed: 12/18/2022]
Abstract
Human pregnancy depends on the proper development of the embryo prior to implantation and the implantation of the embryo into the uterine wall. During the pre-implantation phase, formation of the morula is followed by internalization of blastomeres that differentiate into the pluripotent inner cell mass lineage, while the cells on the surface undergo polarization and differentiate into the trophectoderm of the blastocyst. The trophectoderm mediates apposition and adhesion of the blastocyst to the uterine epithelium. These processes lead to a stable contact between embryonic and maternal tissues, resulting in the formation of a new organ, the placenta. During implantation, the trophectoderm cells start to differentiate and form the basis for multiple specialized trophoblast subpopulations, all of which fulfilling specific key functions in placentation. They either differentiate into polar cells serving typical epithelial functions, or into apolar invasive cells that adapt the uterine wall to progressing pregnancy. The composition of these trophoblast subpopulations is crucial for human placenta development and alterations are suggested to result in placenta-associated pregnancy pathologies. This review article focuses on what is known about very early processes in human reproduction and emphasizes on morphological and functional aspects of early trophoblast differentiation and subpopulations.
Collapse
Affiliation(s)
- Martin Gauster
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Gerit Moser
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Stefan Wernitznig
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Nadja Kupper
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria
| | - Berthold Huppertz
- Division of Cell Biology, Histology and Embryology, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6, 8010, Graz, Austria.
| |
Collapse
|
10
|
Pomp O, Lim HYG, Skory RM, Moverley AA, Tetlak P, Bissiere S, Plachta N. A monoastral mitotic spindle determines lineage fate and position in the mouse embryo. Nat Cell Biol 2022; 24:155-167. [PMID: 35102267 DOI: 10.1038/s41556-021-00826-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 11/30/2021] [Indexed: 12/11/2022]
Abstract
During mammalian development, the first asymmetric cell divisions segregate cells into inner and outer positions of the embryo to establish the pluripotent and trophectoderm lineages. Typically, polarity components differentially regulate the mitotic spindle via astral microtubule arrays to trigger asymmetric division patterns. However, early mouse embryos lack centrosomes, the microtubule-organizing centres (MTOCs) that usually generate microtubule asters. Thus, it remains unknown whether spindle organization regulates lineage segregation. Here we find that heterogeneities in cell polarity in the early 8-cell-stage mouse embryo trigger the assembly of a highly asymmetric spindle organization. This spindle arises in an unusual modular manner, forming a single microtubule aster from an apically localized, non-centrosomal MTOC, before joining it to the rest of the spindle apparatus. When fully assembled, this 'monoastral' spindle triggers spatially asymmetric division patterns to segregate cells into inner and outer positions. Moreover, the asymmetric inheritance of spindle components causes differential cell polarization to determine pluripotent versus trophectoderm lineage fate.
Collapse
Affiliation(s)
- Oz Pomp
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hui Yi Grace Lim
- Institute of Molecular and Cell Biology, ASTAR, Singapore, Singapore
| | - Robin M Skory
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Adam A Moverley
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Piotr Tetlak
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Stephanie Bissiere
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nicolas Plachta
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
11
|
Thowfeequ S, Stower MJ, Srinivas S. Epithelial dynamics during early mouse development. Curr Opin Genet Dev 2022; 72:110-117. [PMID: 34929609 PMCID: PMC7615355 DOI: 10.1016/j.gde.2021.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 11/03/2022]
Abstract
The first epithelia to arise in an organism face the challenge of maintaining the integrity of the newly formed tissue, while exhibiting the behavioral flexibility required for morphogenetic processes to occur effectively. Epithelial cells integrate biochemical and biomechanical cues, both intrinsic and extrinsic, in order to bring about the molecular changes which determine their morphology, behavior and fate. In this review we highlight recent advances in our understanding of the various dynamic processes that the emergent epithelial cells undergo during the first seven days of mouse development and speculate what the future holds in understanding the mechanistic bases for these processes through integrative approaches.
Collapse
Affiliation(s)
- Shifaan Thowfeequ
- University of Oxford, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford, OX1 3QX, UK
| | - Matthew J Stower
- University of Oxford, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford, OX1 3QX, UK
| | - Shankar Srinivas
- University of Oxford, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford, OX1 3QX, UK.
| |
Collapse
|
12
|
Gu B, Bradshaw B, Zhu M, Sun Y, Hopyan S, Rossant J. Live imaging YAP signalling in mouse embryo development. Open Biol 2022; 12:210335. [PMID: 35042406 PMCID: PMC8767199 DOI: 10.1098/rsob.210335] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
YAP protein is a critical regulator of mammalian embryonic development. By generating a near-infrared fusion YAP reporter mouse line, we have achieved high-resolution live imaging of YAP localization during mouse embryonic development. We have validated the reporter by demonstrating its predicted responses to blocking LATS kinase activity or blocking cell polarity. By time lapse imaging preimplantation embryos, we revealed a mitotic reset behaviour of YAP nuclear localization. We also demonstrated deep tissue live imaging in post-implantation embryos and revealed an intriguing nuclear YAP pattern in migrating cells. The YAP fusion reporter mice and imaging methods will open new opportunities for understanding dynamic YAP signalling in vivo in many different situations.
Collapse
Affiliation(s)
- Bin Gu
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4
| | - Brian Bradshaw
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4
| | - Min Zhu
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.,Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G8
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G8.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G9.,Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada M5S 3G4
| | - Sevan Hopyan
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.,Division of Orthopaedic Surgery, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada M5G 1X8
| | - Janet Rossant
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| |
Collapse
|
13
|
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: 6] [Impact Index Per Article: 3.0] [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.
Collapse
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
| |
Collapse
|
14
|
Cell fate determination and Hippo signaling pathway in preimplantation mouse embryo. Cell Tissue Res 2021; 386:423-444. [PMID: 34586506 DOI: 10.1007/s00441-021-03530-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 09/20/2021] [Indexed: 10/20/2022]
Abstract
First cell fate determination plays crucial roles in cell specification during early phases of embryonic development. Three classical concepts have been proposed to explain the lineage specification mechanism of the preimplantation embryo: inside-outside, pre-patterning, and polarity models. Transcriptional effectors of the Hippo signal pathway are YAP and TAZ activators that can create a shuttle between the cytoplasm and the nucleus. Despite different localizations of YAP in the cell, it determines the fate of ICM and TE. How the decisive cue driving factors that determine YAP localization are coordinated remains a central unanswered question. How can an embryonic cell find its position? The objective of this review is to summarize the molecular and mechanical aspects in cell fate decision during mouse preimplantation embryonic development. The findings will reveal the relationship between cell-cell adhesion, cell polarity, and determination of cell fate during early embryonic development in mice and elucidate the inducing/inhibiting mechanisms that are involved in cell specification following zygotic genome activation and compaction processes. With future studies, new biophysical and chemical cues in the cell fate determination will impart significant spatiotemporal effects on early embryonic development. The achieved knowledge will provide important information to the development of new approaches to be used in infertility treatment and increase the success of pregnancy.
Collapse
|
15
|
Stower MJ, Srinivas S. Advances in live imaging early mouse development: exploring the researcher's interdisciplinary toolkit. Development 2021; 148:dev199433. [PMID: 34897401 PMCID: PMC7615354 DOI: 10.1242/dev.199433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Live imaging is an important part of the developmental biologist's armoury of methods. In the case of the mouse embryo, recent advances in several disciplines including embryo culture, microscopy hardware and computational analysis have all contributed to our ability to probe dynamic events during early development. Together, these advances have provided us with a versatile and powerful 'toolkit', enabling us not only to image events during mouse embryogenesis, but also to intervene with them. In this short Spotlight article, we summarise advances and challenges in using live imaging specifically for understanding early mouse embryogenesis.
Collapse
Affiliation(s)
- Matthew J. Stower
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| | - Shankar Srinivas
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3QX, UK
| |
Collapse
|
16
|
Abstract
The cytoskeleton - comprising actin filaments, microtubules and intermediate filaments - serves instructive roles in regulating cell function and behaviour during development. However, a key challenge in cell and developmental biology is to dissect how these different structures function and interact in vivo to build complex tissues, with the ultimate aim to understand these processes in a mammalian organism. The preimplantation mouse embryo has emerged as a primary model system for tackling this challenge. Not only does the mouse embryo share many morphological similarities with the human embryo during its initial stages of life, it also permits the combination of genetic manipulations with live-imaging approaches to study cytoskeletal dynamics directly within an intact embryonic system. These advantages have led to the discovery of novel cytoskeletal structures and mechanisms controlling lineage specification, cell-cell communication and the establishment of the first forms of tissue architecture during development. Here we highlight the diverse organization and functions of each of the three cytoskeletal filaments during the key events that shape the early mammalian embryo, and discuss how they work together to perform key developmental tasks, including cell fate specification and morphogenesis of the blastocyst. Collectively, these findings are unveiling a new picture of how cells in the early embryo dynamically remodel their cytoskeleton with unique spatial and temporal precision to drive developmental processes in the rapidly changing in vivo environment.
Collapse
|
17
|
Firmin J, Maître JL. Morphogenesis of the human preimplantation embryo: bringing mechanics to the clinics. Semin Cell Dev Biol 2021; 120:22-31. [PMID: 34253437 DOI: 10.1016/j.semcdb.2021.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/15/2021] [Accepted: 07/01/2021] [Indexed: 12/19/2022]
Abstract
During preimplantation development, the human embryo forms the blastocyst, the structure enabling uterine implantation. The blastocyst consists of an epithelial envelope, the trophectoderm, encompassing a fluid-filled lumen, the blastocoel, and a cluster of pluripotent stem cells, the inner cell mass. This specific architecture is crucial for the implantation and further development of the human embryo. Furthermore, the morphology of the human embryo is a prime determinant for clinicians to assess the implantation potential of in vitro fertilized human embryos, which constitutes a key aspect of assisted reproduction technology. Therefore, it is crucial to understand how the human embryo builds the blastocyst. As any material, the human embryo changes shape under the action of forces. Here, we review recent advances in our understanding of the mechanical forces shaping the blastocyst. We discuss the cellular processes responsible for generating morphogenetic forces that were studied mostly in the mouse and review the literature on human embryos to see which of them may be conserved. Based on the specific morphological defects commonly observed in clinics during human preimplantation development, we discuss how mechanical forces and their underlying cellular processes may be affected. Together, we propose that bringing tissue mechanics to the clinics will advance our understanding of human preimplantation development, as well as our ability to help infertile couples to have babies.
Collapse
Affiliation(s)
- Julie Firmin
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR3215, INSERM, U934 Paris, France
| | - Jean-Léon Maître
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR3215, INSERM, U934 Paris, France.
| |
Collapse
|
18
|
Liebisch T, Drusko A, Mathew B, Stelzer EHK, Fischer SC, Matthäus F. Cell fate clusters in ICM organoids arise from cell fate heredity and division: a modelling approach. Sci Rep 2020; 10:22405. [PMID: 33376253 PMCID: PMC7772343 DOI: 10.1038/s41598-020-80141-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/17/2020] [Indexed: 01/13/2023] Open
Abstract
During the mammalian preimplantation phase, cells undergo two subsequent cell fate decisions. During the first decision, the trophectoderm and the inner cell mass are formed. Subsequently, the inner cell mass segregates into the epiblast and the primitive endoderm. Inner cell mass organoids represent an experimental model system, mimicking the second cell fate decision. It has been shown that cells of the same fate tend to cluster stronger than expected for random cell fate decisions. Three major processes are hypothesised to contribute to the cell fate arrangements: (1) chemical signalling; (2) cell sorting; and (3) cell proliferation. In order to quantify the influence of cell proliferation on the observed cell lineage type clustering, we developed an agent-based model accounting for mechanical cell-cell interaction, i.e. adhesion and repulsion, cell division, stochastic cell fate decision and cell fate heredity. The model supports the hypothesis that initial cell fate acquisition is a stochastically driven process, taking place in the early development of inner cell mass organoids. Further, we show that the observed neighbourhood structures can emerge solely due to cell fate heredity during cell division.
Collapse
Affiliation(s)
- Tim Liebisch
- Faculty of Biological Sciences and Frankfurt Institute for Advanced Studies (FIAS), Goethe Universität Frankfurt am Main, Ruth-Moufang-Straße 1, 60438, Frankfurt, Germany.
| | - Armin Drusko
- Faculty of Biological Sciences and Frankfurt Institute for Advanced Studies (FIAS), Goethe Universität Frankfurt am Main, Ruth-Moufang-Straße 1, 60438, Frankfurt, Germany
| | - Biena Mathew
- Faculty of Biological Sciences and Buchmann Institute for Molecular Life Sciences (BMLS), Goethe Universität Frankfurt am Main, Max-von-Laue Str. 15, 60438, Frankfurt, Germany
| | - Ernst H K Stelzer
- Faculty of Biological Sciences and Buchmann Institute for Molecular Life Sciences (BMLS), Goethe Universität Frankfurt am Main, Max-von-Laue Str. 15, 60438, Frankfurt, Germany
| | - Sabine C Fischer
- Center for Computational and Theoretical Biology (CCTB), Julius-Maximilians-Universität Würzburg, Campus Hubland Nord 32, 97074, Würzburg, Germany
| | - Franziska Matthäus
- Faculty of Biological Sciences and Frankfurt Institute for Advanced Studies (FIAS), Goethe Universität Frankfurt am Main, Ruth-Moufang-Straße 1, 60438, Frankfurt, Germany
| |
Collapse
|
19
|
Tokuoka Y, Yamada TG, Mashiko D, Ikeda Z, Hiroi NF, Kobayashi TJ, Yamagata K, Funahashi A. 3D convolutional neural networks-based segmentation to acquire quantitative criteria of the nucleus during mouse embryogenesis. NPJ Syst Biol Appl 2020; 6:32. [PMID: 33082352 PMCID: PMC7575569 DOI: 10.1038/s41540-020-00152-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/11/2020] [Indexed: 12/13/2022] Open
Abstract
During embryogenesis, cells repeatedly divide and dynamically change their positions in three-dimensional (3D) space. A robust and accurate algorithm to acquire the 3D positions of the cells would help to reveal the mechanisms of embryogenesis. To acquire quantitative criteria of embryogenesis from time-series 3D microscopic images, image processing algorithms such as segmentation have been applied. Because the cells in embryos are considerably crowded, an algorithm to segment individual cells in detail and accurately is needed. To quantify the nuclear region of every cell from a time-series 3D fluorescence microscopic image of living cells, we developed QCANet, a convolutional neural network-based segmentation algorithm for 3D fluorescence bioimages. We demonstrated that QCANet outperformed 3D Mask R-CNN, which is currently considered as the best algorithm of instance segmentation. We showed that QCANet can be applied not only to developing mouse embryos but also to developing embryos of two other model species. Using QCANet, we were able to extract several quantitative criteria of embryogenesis from 11 early mouse embryos. We showed that the extracted criteria could be used to evaluate the differences between individual embryos. This study contributes to the development of fundamental approaches for assessing embryogenesis on the basis of extracted quantitative criteria.
Collapse
Affiliation(s)
- Yuta Tokuoka
- Department of Biosciences and Informatics, Keio University, Kanagawa, 223-8522, Japan
| | - Takahiro G Yamada
- Department of Biosciences and Informatics, Keio University, Kanagawa, 223-8522, Japan
| | - Daisuke Mashiko
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493, Japan
| | - Zenki Ikeda
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493, Japan
| | - Noriko F Hiroi
- Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, Yamaguchi, 756-0884, Japan
| | - Tetsuya J Kobayashi
- Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
| | - Kazuo Yamagata
- Faculty of Biology-Oriented Science and Technology, Kindai University, Wakayama, 649-6493, Japan
| | - Akira Funahashi
- Department of Biosciences and Informatics, Keio University, Kanagawa, 223-8522, Japan.
| |
Collapse
|
20
|
Otsuki J, Iwasaki T, Enatsu N, Katada Y, Furuhashi K, Shiotani M. The inclusion of blastomeres into the inner cell mass in early-stage human embryos depends on the sequence of cell cleavages during the fourth division. PLoS One 2020; 15:e0240936. [PMID: 33075059 PMCID: PMC7571684 DOI: 10.1371/journal.pone.0240936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 10/06/2020] [Indexed: 10/26/2022] Open
Abstract
The fate of the ICM in humans is still unknown, due to the ethical difficulties surrounding experimentation in this field. In this study we have explored the existing time-lapse recording data of embryos in the early stages of development, taking advantage of the large refractile bodies (RBs) within blastomeres as cellular markers. Our study found that the cellular composition of the ICM in humans is largely determined at the time of the fourth division and blastomeres which cleave first to fourth, during the fourth division from 8 cells to 16 cells, have the potential to be incorporated in the ICM.
Collapse
Affiliation(s)
- Junko Otsuki
- Assisted Reproductive Technology Center, Okayama University, Okayama, Japan
- Hanabusa Women’s Clinic, Kobe, Hyogo, Japan
- * E-mail:
| | | | | | | | | | | |
Collapse
|
21
|
Saiz N, Hadjantonakis AK. Coordination between patterning and morphogenesis ensures robustness during mouse development. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190562. [PMID: 32829684 PMCID: PMC7482220 DOI: 10.1098/rstb.2019.0562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2020] [Indexed: 12/11/2022] Open
Abstract
The mammalian preimplantation embryo is a highly tractable, self-organizing developmental system in which three cell types are consistently specified without the need for maternal factors or external signals. Studies in the mouse over the past decades have greatly improved our understanding of the cues that trigger symmetry breaking in the embryo, the transcription factors that control lineage specification and commitment, and the mechanical forces that drive morphogenesis and inform cell fate decisions. These studies have also uncovered how these multiple inputs are integrated to allocate the right number of cells to each lineage despite inherent biological noise, and as a response to perturbations. In this review, we summarize our current understanding of how these processes are coordinated to ensure a robust and precise developmental outcome during early mouse development. This article is part of a discussion meeting issue 'Contemporary morphogenesis'.
Collapse
Affiliation(s)
- Néstor Saiz
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | | |
Collapse
|
22
|
Leonavicius K, Royer C, Miranda AMA, Tyser RCV, Kip A, Srinivas S. Spatial protein analysis in developing tissues: a sampling-based image processing approach. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190560. [PMID: 32829691 PMCID: PMC7482225 DOI: 10.1098/rstb.2019.0560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2020] [Indexed: 11/19/2022] Open
Abstract
Advances in fluorescence microscopy approaches have made it relatively easy to generate multi-dimensional image volumes and have highlighted the need for flexible image analysis tools for the extraction of quantitative information from such data. Here we demonstrate that by focusing on simplified feature-based nuclear segmentation and probabilistic cytoplasmic detection we can create a tool that is able to extract geometry-based information from diverse mammalian tissue images. Our open-source image analysis platform, called 'SilentMark', can cope with three-dimensional noisy images and with crowded fields of cells to quantify signal intensity in different cellular compartments. Additionally, it provides tissue geometry related information, which allows one to quantify protein distribution with respect to marked regions of interest. The lightweight SilentMark algorithms have the advantage of not requiring multiple processors, graphics cards or training datasets and can be run even with just several hundred megabytes of memory. This makes it possible to use the method as a Web application, effectively eliminating setup hurdles and compatibility issues with operating systems. We test this platform on mouse pre-implantation embryos, embryonic stem cell-derived embryoid bodies and mouse embryonic heart, and relate protein localization to tissue geometry. This article is part of a discussion meeting issue 'Contemporary morphogenesis'.
Collapse
|
23
|
Royer C, Leonavicius K, Kip A, Fortin D, Nandi K, Vincent A, Jones C, Child T, Coward K, Graham C, Srinivas S. Establishment of a relationship between blastomere geometry and YAP localisation during compaction. Development 2020; 147:dev.189449. [PMID: 32928909 PMCID: PMC7561472 DOI: 10.1242/dev.189449] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 09/07/2020] [Indexed: 01/08/2023]
Abstract
Precise patterning within the three-dimensional context of tissues, organs and embryos implies that cells can sense their relative position. During preimplantation development, outside and inside cells rely on apicobasal polarity and the Hippo pathway to choose their fate. Despite recent findings suggesting that mechanosensing might be central to this process, the relationship between blastomere geometry (i.e. shape and position) and the Hippo pathway effector YAP remains unknown. We used a highly quantitative approach to analyse information on the geometry and YAP localisation of individual blastomeres of mouse and human embryos. We identified the proportion of exposed cell surface area as most closely correlating with the nuclear localisation of YAP. To test this relationship, we developed several hydrogel-based approaches to alter blastomere geometry in cultured embryos. Unbiased clustering analyses of blastomeres from such embryos revealed that this relationship emerged during compaction. Our results therefore pinpoint the time during early embryogenesis when cells acquire the ability to sense changes in geometry and provide a new framework for how cells might integrate signals from different membrane domains to assess their relative position within the embryo. Highlighted Article: Localisation of YAP, a key factor during the first cell fate decision, is linked to individual blastomere geometry within the three-dimentional environment of the preimplantation embryo.
Collapse
Affiliation(s)
- Christophe Royer
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Karolis Leonavicius
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Annemarie Kip
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Deborah Fortin
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Kirtirupa Nandi
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Anna Vincent
- Oxford Fertility, Institute of Reproductive Sciences, Oxford OX4 2HW, UK
| | - Celine Jones
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford OX3 9DU, UK
| | - Tim Child
- Oxford Fertility, Institute of Reproductive Sciences, Oxford OX4 2HW, UK.,Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford OX3 9DU, UK
| | - Kevin Coward
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford OX3 9DU, UK
| | - Chris Graham
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford OX3 9DU, UK
| | - Shankar Srinivas
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| |
Collapse
|
24
|
Microfabricated Device for High-Resolution Imaging of Preimplantation Embryos. Methods Mol Biol 2020. [PMID: 32944900 DOI: 10.1007/978-1-0716-0958-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The mouse preimplantation embryo is an excellent system for studying how mammalian cells organize dynamically into increasingly complex structures. Accessible to experimental and genetic manipulations, its normal or perturbed development can be scrutinized ex vivo by real-time imaging from fertilization to late blastocyst stage. High-resolution imaging of multiple embryos at the same time can be compromised by embryos displacement during imaging. We have developed an inexpensive and easy-to-produce imaging device that facilitates greatly the imaging of preimplantation embryo. In this chapter, we describe the different steps of production and storage of the imaging device as well as its use for live imaging of mouse preimplantation embryos expressing fluorescent reporters from genetically modified alleles or after in vitro transcribed mRNA transfer by microinjection or electroporation.
Collapse
|
25
|
Mechanical regulation of cell size, fate, and behavior during asymmetric cell division. Curr Opin Cell Biol 2020; 67:9-16. [PMID: 32768924 DOI: 10.1016/j.ceb.2020.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/15/2020] [Accepted: 07/06/2020] [Indexed: 01/03/2023]
Abstract
Asymmetric cell division (ACD) is an evolutionary conserved mechanism used by prokaryotes and eukaryotes alike to generate cell diversity. ACD can be manifested in biased segregation of macromolecules or differential partitioning of cell organelles. Cells are also constantly subject to extrinsic or intrinsic mechanical forces, influencing cell behavior and fate. During ACD, cell intrinsic forces generated through the spatiotemporal regulation of the actomyosin cytoskeleton can influence sibling cell size. External mechanical stresses are further translated by transcriptional coactivators or mechanically gated ion channels. Here, we will discuss recent literature, exploring how mechanical cues influence various aspects of ACD and stem cell behavior, and how these mechanical cues contribute to cell fate decisions.
Collapse
|
26
|
Płusa B, Piliszek A. Common principles of early mammalian embryo self-organisation. Development 2020; 147:147/14/dev183079. [PMID: 32699138 DOI: 10.1242/dev.183079] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Pre-implantation mammalian development unites extreme plasticity with a robust outcome: the formation of a blastocyst, an organised multi-layered structure ready for implantation. The process of blastocyst formation is one of the best-known examples of self-organisation. The first three cell lineages in mammalian development specify and arrange themselves during the morphogenic process based on cell-cell interactions. Despite decades of research, the unifying principles driving early mammalian development are still not fully defined. Here, we discuss the role of physical forces, and molecular and cellular mechanisms, in driving self-organisation and lineage formation that are shared between eutherian mammals.
Collapse
Affiliation(s)
- Berenika Płusa
- Faculty of Biology, Medicine and Health (FBMH), Division of Developmental Biology & Medicine, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Anna Piliszek
- Department of Experimental Embryology, Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, Jastrzebiec, Postepu 36A, 05-552 Magdalenka, Poland
| |
Collapse
|
27
|
Toyooka Y. Trophoblast lineage specification in the mammalian preimplantation embryo. Reprod Med Biol 2020; 19:209-221. [PMID: 32684820 PMCID: PMC7360972 DOI: 10.1002/rmb2.12333] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/31/2020] [Accepted: 06/02/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The establishment of the trophectoderm (TE) and the inner cell mass (ICM) is the first cell lineage segregation that occurs in mammalian preimplantation development. TE will contribute to the placenta while ICM cells give rise to the epiblast (EPI) and primitive endoderm (PrE). There are two historical models for TE/ICM segregation: the positional (inside-outside) model and the polarity model, but both models alone cannot explain the mechanism of TE/ICM segregation. METHODS This article discusses a current possible model based on recent studies including the finding through live-cell imaging of the expression patterns of caudal type homeobox 2 (Cdx2), a key transcription factor of TE differentiation in the mouse embryo. RESULTS It was observed that a part of outer Cdx2-expressing blastomeres was internalized at the around 20- to 30-cell stage, downregulates Cdx2, ceases TE differentiation, and participates in ICM lineages. CONCLUSION The early blastomere, which starts differentiation toward the TE cell fate, still has plasticity and can change its fate. Differentiation potency of all blastomeres until approximately the 32-cell stage is presumably not irreversibly restricted even if they show heterogeneity in their epigenetic modifications or gene expression patterns.
Collapse
Affiliation(s)
- Yayoi Toyooka
- Center for iPS Cell Research and Application (CiRA)Kyoto UniversityKyotoJapan
| |
Collapse
|
28
|
Murrow LM, Gartner ZJ. Balancing Act: Cell Polarity and Shape Compete to Ensure Robust Development. Dev Cell 2020; 51:545-547. [PMID: 31794715 DOI: 10.1016/j.devcel.2019.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this issue of Developmental Cell, Niwayama et al. (2019) describe a model in which cell polarity and cell shape compete to determine the orientation of cell division in the pre-implantation mouse embryo. This model explains how simple cell-intrinsic rules lead to robust tissue-level morphogenesis and lineage segregation.
Collapse
Affiliation(s)
- Lyndsay M Murrow
- Department of Pharmaceutical Chemistry and Center for Cellular Construction, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Zev J Gartner
- Department of Pharmaceutical Chemistry and Center for Cellular Construction, University of California, San Francisco, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, University of California, San Francisco, San Francisco, CA 94158, USA.
| |
Collapse
|
29
|
White MD, Plachta N. Specification of the First Mammalian Cell Lineages In Vivo and In Vitro. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035634. [PMID: 31615786 DOI: 10.1101/cshperspect.a035634] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Our understanding of how the first mammalian cell lineages arise has been shaped largely by studies of the preimplantation mouse embryo. Painstaking work over many decades has begun to reveal how a single totipotent cell is transformed into a multilayered structure representing the foundations of the body plan. Here, we review how the first lineage decision is initiated by epigenetic regulation but consolidated by the integration of morphological features and transcription factor activity. The establishment of pluripotent and multipotent stem cell lines has enabled deeper analysis of molecular and epigenetic regulation of cell fate decisions. The capability to assemble these stem cells into artificial embryos is an exciting new avenue of research that offers a long-awaited window into cell fate specification in the human embryo. Together, these approaches are poised to profoundly increase our understanding of how the first lineage decisions are made during mammalian embryonic development.
Collapse
Affiliation(s)
- Melanie D White
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673
| | - Nicolas Plachta
- Institute of Molecular and Cell Biology, A*STAR, Singapore 138673
| |
Collapse
|
30
|
Niwayama R, Moghe P, Liu YJ, Fabrèges D, Buchholz F, Piel M, Hiiragi T. A Tug-of-War between Cell Shape and Polarity Controls Division Orientation to Ensure Robust Patterning in the Mouse Blastocyst. Dev Cell 2019; 51:564-574.e6. [PMID: 31735668 PMCID: PMC6892278 DOI: 10.1016/j.devcel.2019.10.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 07/04/2019] [Accepted: 10/14/2019] [Indexed: 01/08/2023]
Abstract
Oriented cell division patterns tissues by modulating cell position and fate. While cell geometry, junctions, cortical tension, and polarity are known to control division orientation, relatively little is known about how these are coordinated to ensure robust patterning. Here, we systematically characterize cell division, volume, and shape changes during mouse pre-implantation development by in toto live imaging. The analysis leads us to a model in which the apical domain competes with cell shape to determine division orientation. Two key predictions of the model are verified experimentally: when outside cells of the 16-cell embryo are released from cell shape asymmetry, the axis of division is guided by the apical domain. Conversely, orientation cues from the apical domain can be overcome by applied shape asymmetry in the 8-cell embryo. We propose that such interplay between cell shape and polarity in controlling division orientation ensures robust patterning of the blastocyst and possibly other tissues. Cell division, volume, and shape changes are characterized by in toto embryo imaging Cell shape and the apical domain compete to determine division orientation Two key predictions of the model are verified experimentally The tug-of-war mechanism ensures robust cell allocation and patterning
Collapse
Affiliation(s)
- Ritsuya Niwayama
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Prachiti Moghe
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Yan-Jun Liu
- UMR 144 Institut Curie, Institut Pierre Gilles de Gennes for Microfluidics, Paris, France
| | - Dimitri Fabrèges
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Frank Buchholz
- Medical Systems Biology, UCC, University Hospital and Medical Faculty Carl Gustav Carus, TU Dresden, Dresden, Germany
| | - Matthieu Piel
- UMR 144 Institut Curie, Institut Pierre Gilles de Gennes for Microfluidics, Paris, France
| | - Takashi Hiiragi
- European Molecular Biology Laboratory (EMBL), Heidelberg, Germany; Institute for Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, Japan.
| |
Collapse
|
31
|
Menchero S, Rollan I, Lopez-Izquierdo A, Andreu MJ, Sainz de Aja J, Kang M, Adan J, Benedito R, Rayon T, Hadjantonakis AK, Manzanares M. Transitions in cell potency during early mouse development are driven by Notch. eLife 2019; 8:42930. [PMID: 30958266 PMCID: PMC6486152 DOI: 10.7554/elife.42930] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 04/07/2019] [Indexed: 12/11/2022] Open
Abstract
The Notch signalling pathway plays fundamental roles in diverse developmental processes in metazoans, where it is important in driving cell fate and directing differentiation of various cell types. However, we still have limited knowledge about the role of Notch in early preimplantation stages of mammalian development, or how it interacts with other signalling pathways active at these stages such as Hippo. By using genetic and pharmacological tools in vivo, together with image analysis of single embryos and pluripotent cell culture, we have found that Notch is active from the 4-cell stage. Transcriptomic analysis in single morula identified novel Notch targets, such as early naïve pluripotency markers or transcriptional repressors such as TLE4. Our results reveal a previously undescribed role for Notch in driving transitions during the gradual loss of potency that takes place in the early mouse embryo prior to the first lineage decisions. We start life as a single cell, which immediately begins to divide to form an embryo that will eventually contain all the different kinds of cells found in the adult body. During the first few rounds of cell division, embryonic cells can become any type of adult cells, but also form the placenta, the organ that sustains the embryo while in the womb. As cells keep on dividing, they lose this ability, called potency, and they take on more specific and inflexible roles. The first choice embryonic cells must make is whether to become part of the placenta or part of the future body. These types of decisions are controlled by molecular cascades known as signalling pathways, which relay information from the cells surface to its control centre. There, specific genes get turned on or off in response to an outside signal. Previous research showed that two signalling pathways, Hippo and Notch, help separate placenta cells from those that will form the rest of the body. However, it was not known whether the two pathways worked independently, or if they were overlapping. Menchero et al. therefore wanted to find out when exactly the Notch pathway started to be active, and examine how it helped cells to either become the placenta or part of the future body. Experiments with developing mouse embryos showed that the Notch pathway was activated after the very first two cell divisions, when the embryo consists of only four cells. Genetic manipulations combined with drug treatments that changed the activity of the Notch pathway confirmed that Notch and Hippo acted independently at this stage. Further, larger-scale analysis of gene activity in these embryos also revealed that Notch signalling was working in a previously unknown way: it turned off the genes that maintain potency, pushing the cells to become more specialised. Ultimately, identifying this new mode of action for the Notch pathway in the early embryo may help to understand how the signalling cascade acts in other types of processes. This knowledge could be useful, for example, to push embryonic cells grown in the laboratory towards a desired fate.
Collapse
Affiliation(s)
- Sergio Menchero
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Isabel Rollan
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | | | - Maria Jose Andreu
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Julio Sainz de Aja
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Minjung Kang
- Developmental Biology Program, Sloan Kettering Institute, New York, United States
| | - Javier Adan
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Rui Benedito
- Molecular Genetics of Angiogenesis Group, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Teresa Rayon
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | | | - Miguel Manzanares
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| |
Collapse
|
32
|
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.
Collapse
Affiliation(s)
- Hui Ting Zhang
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany;
| | - Takashi Hiiragi
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany;
| |
Collapse
|
33
|
Pfeffer PL. Building Principles for Constructing a Mammalian Blastocyst Embryo. BIOLOGY 2018; 7:biology7030041. [PMID: 30041494 PMCID: PMC6164496 DOI: 10.3390/biology7030041] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/16/2022]
Abstract
The self-organisation of a fertilised egg to form a blastocyst structure, which consists of three distinct cell lineages (trophoblast, epiblast and hypoblast) arranged around an off-centre cavity, is unique to mammals. While the starting point (the zygote) and endpoint (the blastocyst) are similar in all mammals, the intervening events have diverged. This review examines and compares the descriptive and functional data surrounding embryonic gene activation, symmetry-breaking, first and second lineage establishment, and fate commitment in a wide range of mammalian orders. The exquisite detail known from mouse embryogenesis, embryonic stem cell studies and the wealth of recent single cell transcriptomic experiments are used to highlight the building principles underlying early mammalian embryonic development.
Collapse
Affiliation(s)
- Peter L Pfeffer
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand.
| |
Collapse
|
34
|
White MD, Zenker J, Bissiere S, Plachta N. Instructions for Assembling the Early Mammalian Embryo. Dev Cell 2018; 45:667-679. [DOI: 10.1016/j.devcel.2018.05.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 01/23/2018] [Accepted: 05/10/2018] [Indexed: 12/15/2022]
|
35
|
Mihajlović AI, Bruce AW. The first cell-fate decision of mouse preimplantation embryo development: integrating cell position and polarity. Open Biol 2018; 7:rsob.170210. [PMID: 29167310 PMCID: PMC5717349 DOI: 10.1098/rsob.170210] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 10/27/2017] [Indexed: 12/18/2022] Open
Abstract
During the first cell-fate decision of mouse preimplantation embryo development, a population of outer-residing polar cells is segregated from a second population of inner apolar cells to form two distinct cell lineages: the trophectoderm and the inner cell mass (ICM), respectively. Historically, two models have been proposed to explain how the initial differences between these two cell populations originate and ultimately define them as the two stated early blastocyst stage cell lineages. The 'positional' model proposes that cells acquire distinct fates based on differences in their relative position within the developing embryo, while the 'polarity' model proposes that the differences driving the lineage segregation arise as a consequence of the differential inheritance of factors, which exhibit polarized subcellular localizations, upon asymmetric cell divisions. Although these two models have traditionally been considered separately, a growing body of evidence, collected over recent years, suggests the existence of a large degree of compatibility. Accordingly, the main aim of this review is to summarize the major historical and more contemporarily identified events that define the first cell-fate decision and to place them in the context of both the originally proposed positional and polarity models, thus highlighting their functional complementarity in describing distinct aspects of the developmental programme underpinning the first cell-fate decision in mouse embryogenesis.
Collapse
Affiliation(s)
- Aleksandar I Mihajlović
- Laboratory of Developmental Biology and Genetics (LDB&G), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Alexander W Bruce
- Laboratory of Developmental Biology and Genetics (LDB&G), Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 31, 37005 České Budějovice, Czech Republic
| |
Collapse
|
36
|
Simon CS, Hadjantonakis AK, Schröter C. Making lineage decisions with biological noise: Lessons from the early mouse embryo. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e319. [PMID: 29709110 DOI: 10.1002/wdev.319] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 02/09/2018] [Accepted: 03/13/2018] [Indexed: 12/18/2022]
Abstract
Understanding how individual cells make fate decisions that lead to the faithful formation and homeostatic maintenance of tissues is a fundamental goal of contemporary developmental and stem cell biology. Seemingly uniform populations of stem cells and multipotent progenitors display a surprising degree of heterogeneity, primarily originating from the inherent stochastic nature of molecular processes underlying gene expression. Despite this heterogeneity, lineage decisions result in tissues of a defined size and with consistent proportions of differentiated cell types. Using the early mouse embryo as a model we review recent developments that have allowed the quantification of molecular intercellular heterogeneity during cell differentiation. We first discuss the relationship between these heterogeneities and developmental cellular potential. We then review recent theoretical approaches that formalize the mechanisms underlying fate decisions in the inner cell mass of the blastocyst stage embryo. These models build on our extensive knowledge of the genetic control of fate decisions in this system and will become essential tools for a rigorous understanding of the connection between noisy molecular processes and reproducible outcomes at the multicellular level. We conclude by suggesting that cell-to-cell communication provides a mechanism to exploit and buffer intercellular variability in a self-organized process that culminates in the reproducible formation of the mature mammalian blastocyst stage embryo that is ready for implantation into the maternal uterus. This article is categorized under: Gene Expression and Transcriptional Hierarchies > Cellular Differentiation Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics Gene Expression and Transcriptional Hierarchies > Quantitative Methods and Models.
Collapse
Affiliation(s)
- Claire S Simon
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Anna-Katerina Hadjantonakis
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Christian Schröter
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| |
Collapse
|
37
|
Zenker J, White MD, Gasnier M, Alvarez YD, Lim HYG, Bissiere S, Biro M, Plachta N. Expanding Actin Rings Zipper the Mouse Embryo for Blastocyst Formation. Cell 2018; 173:776-791.e17. [DOI: 10.1016/j.cell.2018.02.035] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/20/2017] [Accepted: 02/15/2018] [Indexed: 01/08/2023]
|
38
|
Klimczewska K, Kasperczuk A, Suwińska A. The Regulative Nature of Mammalian Embryos. Curr Top Dev Biol 2018; 128:105-149. [DOI: 10.1016/bs.ctdb.2017.10.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
39
|
Our First Choice: Cellular and Genetic Underpinnings of Trophectoderm Identity and Differentiation in the Mammalian Embryo. Curr Top Dev Biol 2018; 128:59-80. [DOI: 10.1016/bs.ctdb.2017.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
40
|
Cell Polarity-Dependent Regulation of Cell Allocation and the First Lineage Specification in the Preimplantation Mouse Embryo. Curr Top Dev Biol 2018; 128:11-35. [DOI: 10.1016/bs.ctdb.2017.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
41
|
Transcriptional Regulation and Genes Involved in First Lineage Specification During Preimplantation Development. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2018; 229:31-46. [PMID: 29177763 DOI: 10.1007/978-3-319-63187-5_4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The successful development from a single-cell zygote into a complex multicellular organism requires precise coordination of multiple cell-fate decisions. The very first of these is lineage specification into the inner cell mass (ICM) and trophectoderm (TE) during mammalian preimplantation development. In mouse embryos, transcription factors (TFs) such as Oct4, Sox2, and Nanog are enriched in cells of ICM, which gives rise to the fetus and yolk sac. Conversely, TFs such as Cdx2 and Eomes become highly upregulated in TE, which contribute to the placenta. Here, we review the current understanding of key transcriptional control mechanisms and genes responsible for these distinct differences during the first cell lineage specification. In particular, we highlight recent insights gained through advances in genome manipulation, live imaging, single-cell transcriptomics, and loss-of-function studies.
Collapse
|
42
|
|
43
|
Abstract
During the very first days of mammalian development, the embryo forms a structure called the blastocyst. The blastocyst consists of two cell types: the trophectoderm (TE), which implants the embryo in the uterus and the inner cell mass (ICM), which gives rise to all cells of the mammalian body. Previous works identified how cells differentiate according to their position within the embryo: TE for surface cells and ICM for internal cells. It is therefore essential to understand how cells acquire their position in the first place. During the formation of the blastocyst, cells distort and relocate as a consequence of forces that are generated by the cells themselves. Recently, several important studies have identified the forces and cellular mechanisms leading to the shaping of the ICM. Here, I describe how these studies led us to understand how contractile forces shape the mammalian embryo to position and differentiate the ICM.
Collapse
Affiliation(s)
- Jean-Léon Maître
- Institut Curie, PSL Research University, CNRS UMR3215 Inserm U934, 26 rue d'Ulm, 75248 Paris, France - Équipe mécanique du développement mammifère, Unité Génétique et Biologie du Développement, Institut Curie, 26 rue d'Ulm, 75248 Paris cedex 05, France
| |
Collapse
|
44
|
A Tale of Division and Polarization in the Mammalian Embryo. Dev Cell 2017; 40:215-216. [PMID: 28171743 DOI: 10.1016/j.devcel.2017.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first cell fate choice in mouse development is the segregation of the embryonic inner cell mass and the extra-embryonic trophectoderm. In this issue of Developmental Cell, Korotkevic and colleagues (2017) show that the interplay between cell polarization and cell-cell contact drives the segregation of these lineages, providing a framework for self-organization in development.
Collapse
|
45
|
Maître JL. Mechanics of blastocyst morphogenesis. Biol Cell 2017; 109:323-338. [DOI: 10.1111/boc.201700029] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/28/2017] [Accepted: 06/28/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Jean-Léon Maître
- Institut Curie; PSL Research University; CNRS UMR3215, INSERM U934; Paris France
| |
Collapse
|
46
|
Korotkevich E, Niwayama R, Courtois A, Friese S, Berger N, Buchholz F, Hiiragi T. The Apical Domain Is Required and Sufficient for the First Lineage Segregation in the Mouse Embryo. Dev Cell 2017; 40:235-247.e7. [PMID: 28171747 PMCID: PMC5300053 DOI: 10.1016/j.devcel.2017.01.006] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/10/2016] [Accepted: 01/09/2017] [Indexed: 11/29/2022]
Abstract
Mammalian development begins with segregation of the extra-embryonic trophectoderm from the embryonic lineage in the blastocyst. While cell polarity and adhesion play key roles, the decisive cue driving this lineage segregation remains elusive. Here, to study symmetry breaking, we use a reduced system in which isolated blastomeres recapitulate the first lineage segregation. We find that in the 8-cell stage embryo, the apical domain recruits a spindle pole to ensure its differential distribution upon division. Daughter cells that inherit the apical domain adopt trophectoderm fate. However, the fate of apolar daughter cells depends on whether their position within the embryo facilitates apical domain formation by Cdh1-independent cell contact. Finally, we develop methods for transplanting apical domains and show that acquisition of this domain is not only required but also sufficient for the first lineage segregation. Thus, we provide mechanistic understanding that reconciles previous models for symmetry breaking in mouse development. A reduced system was established to study symmetry breaking in mouse development 8-cell stage blastomeres acquire the capacity to self-organize the apical domain The apical domain is required and sufficient for the first lineage segregation Contact asymmetry specifies cell fate, leading to self-organized embryo patterning
Collapse
Affiliation(s)
- Ekaterina Korotkevich
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Ritsuya Niwayama
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Aurélien Courtois
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Stefanie Friese
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Nicolas Berger
- Medical Systems Biology, UCC, University Hospital and Medical Faculty Carl Gustav Carus, TU Dresden, 01062 Dresden, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Frank Buchholz
- Medical Systems Biology, UCC, University Hospital and Medical Faculty Carl Gustav Carus, TU Dresden, 01062 Dresden, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Takashi Hiiragi
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
| |
Collapse
|
47
|
Forceful patterning in mouse preimplantation embryos. Semin Cell Dev Biol 2017; 71:129-136. [PMID: 28577924 DOI: 10.1016/j.semcdb.2017.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/16/2017] [Accepted: 05/21/2017] [Indexed: 12/22/2022]
Abstract
The generation of a functional organism from a single, fertilized ovum requires the spatially coordinated regulation of diverse cell identities. The establishment and precise arrangement of differentiated cells in developing embryos has, historically, been extensively studied by geneticists and developmental biologists. While chemical gradients and genetic regulatory networks are widely acknowledged to play significant roles in embryo patterning, recent studies have highlighted that mechanical forces generated by, and exerted on, embryos are also crucial for the proper control of cell differentiation and morphogenesis. Here we review the most recent findings in murine preimplantation embryogenesis on the roles of cortical tension in the coupling of cell-fate determination and cell positioning in 8-16-cell-stage embryos. These basic principles of mechanochemical coupling in mouse embryos can be applied to other pattern formation phenomena that rely on localized modifications of cell polarity proteins and actin cytoskeletal components and activities.
Collapse
|
48
|
Posfai E, Petropoulos S, de Barros FRO, Schell JP, Jurisica I, Sandberg R, Lanner F, Rossant J. Position- and Hippo signaling-dependent plasticity during lineage segregation in the early mouse embryo. eLife 2017; 6:22906. [PMID: 28226240 PMCID: PMC5370188 DOI: 10.7554/elife.22906] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/13/2017] [Indexed: 12/16/2022] Open
Abstract
The segregation of the trophectoderm (TE) from the inner cell mass (ICM) in the mouse blastocyst is determined by position-dependent Hippo signaling. However, the window of responsiveness to Hippo signaling, the exact timing of lineage commitment and the overall relationship between cell commitment and global gene expression changes are still unclear. Single-cell RNA sequencing during lineage segregation revealed that the TE transcriptional profile stabilizes earlier than the ICM and prior to blastocyst formation. Using quantitative Cdx2-eGFP expression as a readout of Hippo signaling activity, we assessed the experimental potential of individual blastomeres based on their level of Cdx2-eGFP expression and correlated potential with gene expression dynamics. We find that TE specification and commitment coincide and occur at the time of transcriptional stabilization, whereas ICM cells still retain the ability to regenerate TE up to the early blastocyst stage. Plasticity of both lineages is coincident with their window of sensitivity to Hippo signaling. DOI:http://dx.doi.org/10.7554/eLife.22906.001 In female mammals, conception is a complex process that involves several stages. First, an egg is released from the ovary and travels along a tube called the oviduct, where sperm from a male may fertilize it. If the egg is fertilized, the newly formed embryo moves into the womb, where it will then implant into the walls. In mice, it takes around four days for the embryo to implant and during this time, the cells in the embryo divide several times and start to specialize to form distinct cell types called lineages. The first two lineages to form are known as the inner cell mass and the trophectoderm. The inner cell mass forms a ball of cells within the embryo and contains the precursors of all cells that build the animal’s body. The trophectoderm forms a layer that surrounds the inner cell mass and will become part of the placenta (the organ that supplies the embryo with nutrients while it is in the womb). The embryo can organize these lineages without any instructions from the mother. However, it is still not clear when the cells start to differ from each other, and when they ‘commit’ to stay in these lineages. Cells in the inner cell mass and trophectoderm have different gene expression profiles, meaning that many genes display different levels of activity in these two lineages. Posfai et al. use a technique called single-cell RNA sequencing to analyse gene activity as the inner cell mass and trophectoderm form in mouse embryos. By measuring changes in gene activity, it is possible to track their development and show which genes change expression levels when each lineage specifies and commits. The experiments reveal that the inner cell mass and trophectoderm lineages develop at different times. As the inner cell mass forms, cells adopt the inner cell mass ‘identity’ before they commit to remaining in this lineage, revealing a window of time where different signals could still change the fate of the cells. However, when the early trophectoderm cells show the first signs of specialization, they also commit to their new identity at the same time. These findings suggest that the different timings at which these cell lineages form might provide embryos with the means to organize their own cells. An important future challenge is to understand exactly how the cells commit to their fate. DOI:http://dx.doi.org/10.7554/eLife.22906.002
Collapse
Affiliation(s)
- Eszter Posfai
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | - Sophie Petropoulos
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.,Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden.,Division of Obstetrics and Gynecology, Karolinska Universitetssjukhuset, Stockholm, Sweden
| | | | - John Paul Schell
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.,Division of Obstetrics and Gynecology, Karolinska Universitetssjukhuset, Stockholm, Sweden
| | - Igor Jurisica
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, Canada.,Departments of Medical Biophysics and Computer Science, University of Toronto, Toronto, Canada.,Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Rickard Sandberg
- Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden.,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Fredrik Lanner
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.,Division of Obstetrics and Gynecology, Karolinska Universitetssjukhuset, Stockholm, Sweden
| | - Janet Rossant
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada
| |
Collapse
|
49
|
Holmes WR, Reyes de Mochel NS, Wang Q, Du H, Peng T, Chiang M, Cinquin O, Cho K, Nie Q. Gene Expression Noise Enhances Robust Organization of the Early Mammalian Blastocyst. PLoS Comput Biol 2017; 13:e1005320. [PMID: 28114387 PMCID: PMC5293272 DOI: 10.1371/journal.pcbi.1005320] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/06/2017] [Accepted: 12/19/2016] [Indexed: 12/18/2022] Open
Abstract
A critical event in mammalian embryo development is construction of an inner cell mass surrounded by a trophoectoderm (a shell of cells that later form extraembryonic structures). We utilize multi-scale, stochastic modeling to investigate the design principles responsible for robust establishment of these structures. This investigation makes three predictions, each supported by our quantitative imaging. First, stochasticity in the expression of critical genes promotes cell plasticity and has a critical role in accurately organizing the developing mouse blastocyst. Second, asymmetry in the levels of noise variation (expression fluctuation) of Cdx2 and Oct4 provides a means to gain the benefits of noise-mediated plasticity while ameliorating the potentially detrimental effects of stochasticity. Finally, by controlling the timing and pace of cell fate specification, the embryo temporally modulates plasticity and creates a time window during which each cell can continually read its environment and adjusts its fate. These results suggest noise has a crucial role in maintaining cellular plasticity and organizing the blastocyst. A critical event in mammalian embryo development is construction of a mass of embryonic stem cells surrounded by a distinct shell that later forms the placenta along with other structures. Despite sustained investigation, multiple hypotheses for what is responsible for this organization persist and it remains unclear what is responsible for the robust organization (remarkable ability for embryos to pattern correctly) of these structures. Here, we utilize multi-scale, stochastic modeling along with fluorescence imaging to investigate the factors that contribute to the incredible robustness of this organizational process. Results point to two factors that contribute to this robustness: 1) the timing and pace of cell fate specification and 2) stochastic gene regulatory effects. The former creates a window of time during which each cell can continually read their environment and adjust their gene expressions (and consequently fate) in response to dynamic rearrangements of cells arising from cell divisions and motions. The latter improves cell plasticity, providing the capability for cells to adjust to changes in their local environment. Fluorescence imaging results demonstrate that the magnitude and structure of gene expression variations match those predicted to promote organizational robustness.
Collapse
Affiliation(s)
- William R. Holmes
- Department of Physics and Astronomy, Vanderbilt University, Nashville TN, United States of America
| | - Nabora Soledad Reyes de Mochel
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States of America
| | - Qixuan Wang
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Mathematics, University of California, Irvine, Irvine, CA, United States of America
| | - Huijing Du
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Mathematics, University of California, Irvine, Irvine, CA, United States of America
| | - Tao Peng
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Mathematics, University of California, Irvine, Irvine, CA, United States of America
| | - Michael Chiang
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States of America
| | - Olivier Cinquin
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States of America
| | - Ken Cho
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States of America
- * E-mail: (QN); (KC)
| | - Qing Nie
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, United States of America
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States of America
- Department of Mathematics, University of California, Irvine, Irvine, CA, United States of America
- * E-mail: (QN); (KC)
| |
Collapse
|
50
|
Munevver S, Findikli N, Bahceci M. New Horizons/Developments in Time-Lapse Morphokinetic Analysis of Mammalian Embryos. Hum Reprod 2016. [DOI: 10.1002/9781118849613.ch8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|