1
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Merle M, Friedman L, Chureau C, Shoushtarizadeh A, Gregor T. Precise and scalable self-organization in mammalian pseudo-embryos. Nat Struct Mol Biol 2024; 31:896-902. [PMID: 38491138 DOI: 10.1038/s41594-024-01251-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 02/08/2024] [Indexed: 03/18/2024]
Abstract
Gene expression is inherently noisy, posing a challenge to understanding how precise and reproducible patterns of gene expression emerge in mammals. Here we investigate this phenomenon using gastruloids, a three-dimensional in vitro model for early mammalian development. Our study reveals intrinsic reproducibility in the self-organization of gastruloids, encompassing growth dynamics and gene expression patterns. We observe a remarkable degree of control over gene expression along the main body axis, with pattern boundaries positioned with single-cell precision. Furthermore, as gastruloids grow, both their physical proportions and gene expression patterns scale proportionally with system size. Notably, these properties emerge spontaneously in self-organizing cell aggregates, distinct from many in vivo systems constrained by fixed boundary conditions. Our findings shed light on the intricacies of developmental precision, reproducibility and size scaling within a mammalian system, suggesting that these phenomena might constitute fundamental features of multicellularity.
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Affiliation(s)
- Mélody Merle
- Department of Developmental and Stem Cell Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, Paris, France
| | - Leah Friedman
- Department of Developmental and Stem Cell Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, Paris, France
| | - Corinne Chureau
- Department of Developmental and Stem Cell Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, Paris, France
| | - Armin Shoushtarizadeh
- Department of Developmental and Stem Cell Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, Paris, France
| | - Thomas Gregor
- Department of Developmental and Stem Cell Biology, CNRS UMR3738 Paris Cité, Institut Pasteur, Paris, France.
- Joseph Henry Laboratories of Physics & Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
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2
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Fan D, Cong Y, Liu J, Zhang H, Du Z. Spatiotemporal analysis of mRNA-protein relationships enhances transcriptome-based developmental inference. Cell Rep 2024; 43:113928. [PMID: 38461413 DOI: 10.1016/j.celrep.2024.113928] [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: 08/08/2023] [Revised: 01/31/2024] [Accepted: 02/22/2024] [Indexed: 03/12/2024] Open
Abstract
Elucidating the complex relationships between mRNA and protein expression at high spatiotemporal resolution is critical for unraveling multilevel gene regulation and enhancing mRNA-based developmental analyses. In this study, we conduct a single-cell analysis of mRNA and protein expression of transcription factors throughout C. elegans embryogenesis. Initially, cellular co-presence of mRNA and protein is low, increasing to a medium-high level (73%) upon factoring in delayed protein synthesis and long-term protein persistence. These factors substantially affect mRNA-protein concordance, leading to potential inaccuracies in mRNA-reliant gene detection and specificity characterization. Building on the learned relationship, we infer protein presence from mRNA expression and demonstrate its utility in identifying tissue-specific genes and elucidating relationships between genes and cells. This approach facilitates identifying the role of sptf-1/SP7 in neuronal lineage development. Collectively, this study provides insights into gene expression dynamics during rapid embryogenesis and approaches for improving the efficacy of transcriptome-based developmental analyses.
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Affiliation(s)
- Duchangjiang Fan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yulin Cong
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jinyi Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Haoye Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuo Du
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
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3
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Waliman M, Johnson RL, Natesan G, Tan S, Santella A, Hong RL, Shah PK. Automated Cell Lineage Reconstruction using Label-Free 4D Microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.20.576449. [PMID: 38328064 PMCID: PMC10849476 DOI: 10.1101/2024.01.20.576449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Here we describe embGAN, a deep learning pipeline that addresses the challenge of automated cell detection and tracking in label-free 3D time lapse imaging. embGAN requires no manual data annotation for training, learns robust detections that exhibits a high degree of scale invariance and generalizes well to images acquired in multiple labs on multiple instruments.
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Affiliation(s)
- Matthew Waliman
- Department of Electrical and Computer Engineering, University of California, Los Angeles, California, United States of America
| | - Ryan L Johnson
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California, United State of America
| | - Gunalan Natesan
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California, United State of America
| | - Shiqin Tan
- Department of Computational and Systems Biology, University of California, Los Angeles, California, United States of America
| | - Anthony Santella
- Molecular Cytology Core, Memorial Sloan Kettering Cancer Center, New York, New York, United States of America
| | - Ray L Hong
- Department of Biology, California State University, Northridge, California, United States of America
| | - Pavak K Shah
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California, United State of America
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, California, United States of America
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4
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Natesan G, Hamilton T, Deeds EJ, Shah PK. Novel metrics reveal new structure and unappreciated heterogeneity in Caenorhabditis elegans development. PLoS Comput Biol 2023; 19:e1011733. [PMID: 38113280 PMCID: PMC10763962 DOI: 10.1371/journal.pcbi.1011733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 01/03/2024] [Accepted: 12/04/2023] [Indexed: 12/21/2023] Open
Abstract
High throughput experimental approaches are increasingly allowing for the quantitative description of cellular and organismal phenotypes. Distilling these large volumes of complex data into meaningful measures that can drive biological insight remains a central challenge. In the quantitative study of development, for instance, one can resolve phenotypic measures for single cells onto their lineage history, enabling joint consideration of heritable signals and cell fate decisions. Most attempts to analyze this type of data, however, discard much of the information content contained within lineage trees. In this work we introduce a generalized metric, which we term the branch edit distance, that allows us to compare any two embryos based on phenotypic measurements in individual cells. This approach aligns those phenotypic measurements to the underlying lineage tree, providing a flexible and intuitive framework for quantitative comparisons between, for instance, Wild-Type (WT) and mutant developmental programs. We apply this novel metric to data on cell-cycle timing from over 1300 WT and RNAi-treated Caenorhabditis elegans embryos. Our new metric revealed surprising heterogeneity within this data set, including subtle batch effects in WT embryos and dramatic variability in RNAi-induced developmental phenotypes, all of which had been missed in previous analyses. Further investigation of these results suggests a novel, quantitative link between pathways that govern cell fate decisions and pathways that pattern cell cycle timing in the early embryo. Our work demonstrates that the branch edit distance we propose, and similar metrics like it, have the potential to revolutionize our quantitative understanding of organismal phenotype.
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Affiliation(s)
- Gunalan Natesan
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California, United States of America
| | - Timothy Hamilton
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, United States of America
| | - Eric J. Deeds
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, United States of America
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, California, United States of America
| | - Pavak K. Shah
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, California, United States of America
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, California, United States of America
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5
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Natesan G, Hamilton T, Deeds EJ, Shah PK. Novel metrics reveal new structure and unappreciated heterogeneity in C. elegans development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.12.540617. [PMID: 37292606 PMCID: PMC10245744 DOI: 10.1101/2023.05.12.540617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
High throughput experimental approaches are increasingly allowing for the quantitative description of cellular and organismal phenotypes. Distilling these large volumes of complex data into meaningful measures that can drive biological insight remains a central challenge. In the quantitative study of development, for instance, one can resolve phenotypic measures for single cells onto their lineage history, enabling joint consideration of heritable signals and cell fate decisions. Most attempts to analyze this type of data, however, discard much of the information content contained within lineage trees. In this work we introduce a generalized metric, which we term the branch distance, that allows us to compare any two embryos based on phenotypic measurements in individual cells. This approach aligns those phenotypic measurements to the underlying lineage tree, providing a flexible and intuitive framework for quantitative comparisons between, for instance, Wild-Type (WT) and mutant developmental programs. We apply this novel metric to data on cell-cycle timing from over 1300 WT and RNAi-treated Caenorhabditis elegans embryos. Our new metric revealed surprising heterogeneity within this data set, including subtle batch effects in WT embryos and dramatic variability in RNAi-induced developmental phenotypes, all of which had been missed in previous analyses. Further investigation of these results suggests a novel, quantitative link between pathways that govern cell fate decisions and pathways that pattern cell cycle timing in the early embryo. Our work demonstrates that the branch distance we propose, and similar metrics like it, have the potential to revolutionize our quantitative understanding of organismal phenotype.
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Affiliation(s)
- Gunalan Natesan
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA
| | - Timothy Hamilton
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, CA
| | - Eric J. Deeds
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, CA
| | - Pavak K. Shah
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA
- Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, CA
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6
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Xu Y, Cheng Y, Chen AT, Bao Z. A compound PCP scheme underlies sequential rosettes-based cell intercalation. Development 2023; 150:dev201493. [PMID: 36975724 PMCID: PMC10263146 DOI: 10.1242/dev.201493] [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: 11/29/2022] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
The formation of sequential rosettes is a type of collective cell behavior recently discovered in the Caenorhabditis elegans embryo that mediates directional cell migration through sequential formation and resolution of multicellular rosettes involving the migrating cell and its neighboring cells along the way. Here, we show that a planar cell polarity (PCP)-based polarity scheme regulates sequential rosettes, which is distinct from the known mode of PCP regulation in multicellular rosettes during the process of convergent extension. Specifically, non-muscle myosin (NMY) localization and edge contraction are perpendicular to that of Van Gogh as opposed to colocalizing with Van Gogh. Further analyses suggest a two-component polarity scheme: one being the canonical PCP pathway with MIG-1/Frizzled and VANG-1/Van Gogh localized to the vertical edges, the other being MIG-1/Frizzled and NMY-2 localized to the midline/contracting edges. The NMY-2 localization and contraction of the midline edges also required LAT-1/Latrophilin, an adhesion G protein-coupled receptor that has not been shown to regulate multicellular rosettes. Our results establish a distinct mode of PCP-mediated cell intercalation and shed light on the versatile nature of the PCP pathway.
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Affiliation(s)
- Yichi Xu
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA
| | - Yunsheng Cheng
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA
| | - Allison T. Chen
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY 10065, USA
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7
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Azuma Y, Okada H, Onami S. Systematic analysis of cell morphodynamics in C. elegans early embryogenesis. FRONTIERS IN BIOINFORMATICS 2023; 3:1082531. [PMID: 37026092 PMCID: PMC10070942 DOI: 10.3389/fbinf.2023.1082531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 03/07/2023] [Indexed: 04/08/2023] Open
Abstract
The invariant cell lineage of Caenorhabditis elegans allows unambiguous assignment of the identity for each cell, which offers a unique opportunity to study developmental dynamics such as the timing of cell division, dynamics of gene expression, and cell fate decisions at single-cell resolution. However, little is known about cell morphodynamics, including the extent to which they are variable between individuals, mainly due to the lack of sufficient amount and quality of quantified data. In this study, we systematically quantified the cell morphodynamics in 52 C. elegans embryos from the two-cell stage to mid-gastrulation at the high spatiotemporal resolution, 0.5 μm thickness of optical sections, and 30-second intervals of recordings. Our data allowed systematic analyses of the morphological features. We analyzed sphericity dynamics and found a significant increase at the end of metaphase in every cell, indicating the universality of the mitotic cell rounding. Concomitant with the rounding, the volume also increased in most but not all cells, suggesting less universality of the mitotic swelling. Combining all features showed that cell morphodynamics was unique for each cell type. The cells before the onset of gastrulation could be distinguished from all the other cell types. Quantification of reproducibility in cell-cell contact revealed that variability in division timings and cell arrangements produced variability in contacts between the embryos. However, the area of such contacts occupied less than 5% of the total area, suggesting the high reproducibility of spatial occupancies and adjacency relationships of the cells. By comparing the morphodynamics of identical cells between the embryos, we observed diversity in the variability between cells and found it was determined by multiple factors, including cell lineage, cell generation, and cell-cell contact. We compared the variabilities of cell morphodynamics and cell-cell contacts with those in ascidian Phallusia mammillata embryos. The variabilities were larger in C. elegans, despite smaller differences in embryo size and number of cells at each developmental stage.
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8
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Xiao L, Fan D, Qi H, Cong Y, Du Z. Defect-buffering cellular plasticity increases robustness of metazoan embryogenesis. Cell Syst 2022; 13:615-630.e9. [PMID: 35882226 DOI: 10.1016/j.cels.2022.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/14/2022] [Accepted: 06/30/2022] [Indexed: 01/26/2023]
Abstract
Developmental processes are intrinsically robust so as to preserve a normal-like state in response to genetic and environmental fluctuations. However, the robustness and potential phenotypic plasticity of individual developing cells under genetic perturbations remain to be systematically evaluated. Using large-scale gene perturbation, live imaging, lineage tracing, and single-cell phenomics, we quantified the phenotypic landscape of C. elegans embryogenesis in >2,000 embryos following individual knockdown of over 750 conserved genes. We observed that cellular genetic systems are not sufficiently robust to single-gene perturbations across all cells; rather, gene knockdowns frequently induced cellular defects. Dynamic phenotypic analyses revealed many cellular defects to be transient, with cells exhibiting phenotypic plasticity that serves to alleviate, correct, and accommodate the defects. Moreover, potential developmentally related cell modules may buffer the phenotypic effects of individual cell position changes. Our findings reveal non-negligible contributions of cellular plasticity and multicellularity as compensatory strategies to increase developmental robustness.
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Affiliation(s)
- Long Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Duchangjiang Fan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huan Qi
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yulin Cong
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuo Du
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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9
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Guan G, Zhao Z, Tang C. Delineating mechanisms and design principles of Caenorhabditis elegans embryogenesis using in toto high-resolution imaging data and computational modeling. Comput Struct Biotechnol J 2022; 20:5500-5515. [PMID: 36284714 PMCID: PMC9562942 DOI: 10.1016/j.csbj.2022.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 11/19/2022] Open
Abstract
The nematode (roundworm) Caenorhabditis elegans is one of the most popular animal models for the study of developmental biology, as its invariant development and transparent body enable in toto cellular-resolution fluorescence microscopy imaging of developmental processes at 1-min intervals. This has led to the development of various computational tools for the systematic and automated analysis of imaging data to delineate the molecular and cellular processes throughout the embryogenesis of C. elegans, such as those associated with cell lineage, cell migration, cell morphology, and gene activity. In this review, we first introduce C. elegans embryogenesis and the development of techniques for tracking cell lineage and reconstructing cell morphology during this process. We then contrast the developmental modes of C. elegans and the customized technologies used for studying them with the ones of other animal models, highlighting its advantage for studying embryogenesis with exceptional spatial and temporal resolution. This is followed by an examination of the physical models that have been devised—based on accurate determinations of developmental processes afforded by analyses of imaging data—to interpret the early embryonic development of C. elegans from subcellular to intercellular levels of multiple cells, which focus on two key processes: cell polarization and morphogenesis. We subsequently discuss how quantitative data-based theoretical modeling has improved our understanding of the mechanisms of C. elegans embryogenesis. We conclude by summarizing the challenges associated with the acquisition of C. elegans embryogenesis data, the construction of algorithms to analyze them, and the theoretical interpretation.
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10
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Shah P, Bao Z, Zaidel-Bar R. Visualizing and quantifying molecular and cellular processes in C. elegans using light microscopy. Genetics 2022; 221:6619563. [PMID: 35766819 DOI: 10.1093/genetics/iyac068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 04/14/2022] [Indexed: 11/14/2022] Open
Abstract
Light microscopes are the cell and developmental biologists' "best friend", providing a means to see structures and follow dynamics from the protein to the organism level. A huge advantage of C. elegans as a model organism is its transparency, which coupled with its small size means that nearly every biological process can be observed and measured with the appropriate probe and light microscope. Continuous improvement in microscope technologies along with novel genome editing techniques to create transgenic probes have facilitated the development and implementation of a dizzying array of methods for imaging worm embryos, larvae and adults. In this review we provide an overview of the molecular and cellular processes that can be visualized in living worms using light microscopy. A partial inventory of fluorescent probes and techniques successfully used in worms to image the dynamics of cells, organelles, DNA, and protein localization and activity is followed by a practical guide to choosing between various imaging modalities, including widefield, confocal, lightsheet, and structured illumination microscopy. Finally, we discuss the available tools and approaches, including machine learning, for quantitative image analysis tasks, such as colocalization, segmentation, object tracking, and lineage tracing. Hopefully, this review will inspire worm researchers who have not yet imaged their worms to begin, and push those who are imaging to go faster, finer, and longer.
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Affiliation(s)
- Pavak Shah
- Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles 90095, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Ronen Zaidel-Bar
- Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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11
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Niu B, Nguyen Bach T, Chen X, Raghunath Chandratre K, Isaac Murray J, Zhao Z, Zhang M. Computational modeling and analysis of the morphogenetic domain signaling networks regulating C. elegans embryogenesis. Comput Struct Biotechnol J 2022; 20:3653-3666. [PMID: 35891777 PMCID: PMC9289785 DOI: 10.1016/j.csbj.2022.05.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 11/03/2022] Open
Abstract
Caenorhabditis elegans, often referred to as the ‘roundworm’, provides a powerful model for studying cell autonomous and cell–cell interactions through the direct observation of embryonic development in vivo. By leveraging the precisely mapped cell lineage at single cell resolution, we are able to study at a systems level how early embryonic cells communicate across morphogenetic domains for the coordinated processes of gene expressions and collective cellular behaviors that regulate tissue morphogenesis. In this study, we developed a computational framework for the exploration of the morphogenetic domain cell signaling networks that may regulate C. elegans gastrulation and embryonic organogenesis. We demonstrated its utility by producing the following results, i) established a virtual reference model of developing C. elegans embryos through the spatiotemporal alignment of individual embryo cell nuclear imaging samples; ii) integrated the single cell spatiotemporal gene expression profile with the established virtual embryo model by data pooling; iii) trained a Machine Learning model (Random Forest Regression), which predicts accurately the spatial positions of the cells given their gene expression profiles for a given developmental time (e.g. total cell number of the embryo); iv) enabled virtual 4-dimensional tomographic graphical modeling of single cell data; v) inferred the biology signaling pathways that act in each of morphogenetic domains by meta-data analysis. It is intriguing that the morphogenetic domain cell signaling network seems to involve some crosstalk of multiple biology signaling pathways during the formation of tissue boundary pattern. Lastly, we developed the Software tool ‘Embryo aligner version 1.0’ and provided it as an Open Source program to the research community for virtual embryo modeling, and phenotype perturbation analyses (https://github.com/csniuben/embryo_aligner/wiki and https://bioinfo89.github.io/C.elegansEmbryonicOrganogenesisweb/).
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12
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Wang Z, Xu Y, Wang D, Yang J, Bao Z. Hierarchical deep reinforcement learning reveals a modular mechanism of cell movement. NAT MACH INTELL 2022; 4:73-83. [DOI: 10.1038/s42256-021-00431-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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13
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A 4D single-cell protein atlas of transcription factors delineates spatiotemporal patterning during embryogenesis. Nat Methods 2021; 18:893-902. [PMID: 34312566 DOI: 10.1038/s41592-021-01216-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 06/17/2021] [Indexed: 12/27/2022]
Abstract
Complex biological processes such as embryogenesis require precise coordination of cell differentiation programs across both space and time. Using protein-fusion fluorescent reporters and four-dimensional live imaging, we present a protein expression atlas of transcription factors (TFs) mapped onto developmental cell lineages during Caenorhabditis elegans embryogenesis, at single-cell resolution. This atlas reveals a spatiotemporal combinatorial code of TF expression, and a cascade of lineage-specific, tissue-specific and time-specific TFs that specify developmental states. The atlas uncovers regulators of embryogenesis, including an unexpected role of a skin specifier in neurogenesis and the critical function of an uncharacterized TF in convergent muscle differentiation. At the systems level, the atlas provides an opportunity to model cell state-fate relationships, revealing a lineage-dependent state diversity within functionally related cells and a winding trajectory of developmental state progression. Collectively, this single-cell protein atlas represents a valuable resource for elucidating metazoan embryogenesis at the molecular and systems levels.
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14
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Jud MC, Lowry J, Padilla T, Clifford E, Yang Y, Fennell F, Miller AK, Hamill D, Harvey AM, Avila-Zavala M, Shao H, Nguyen Tran N, Bao Z, Bowerman B. A genetic screen for temperature-sensitive morphogenesis-defective Caenorhabditis elegans mutants. G3-GENES GENOMES GENETICS 2021; 11:6169531. [PMID: 33713117 PMCID: PMC8133775 DOI: 10.1093/g3journal/jkab026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/18/2021] [Indexed: 11/21/2022]
Abstract
Morphogenesis involves coordinated cell migrations and cell shape changes that generate tissues and organs, and organize the body plan. Cell adhesion and the cytoskeleton are important for executing morphogenesis, but their regulation remains poorly understood. As genes required for embryonic morphogenesis may have earlier roles in development, temperature-sensitive embryonic-lethal mutations are useful tools for investigating this process. From a collection of ∼200 such Caenorhabditis elegans mutants, we have identified 17 that have highly penetrant embryonic morphogenesis defects after upshifts from the permissive to the restrictive temperature, just prior to the cell shape changes that mediate elongation of the ovoid embryo into a vermiform larva. Using whole genome sequencing, we identified the causal mutations in seven affected genes. These include three genes that have roles in producing the extracellular matrix, which is known to affect the morphogenesis of epithelial tissues in multicellular organisms: the rib-1 and rib-2 genes encode glycosyltransferases, and the emb-9 gene encodes a collagen subunit. We also used live imaging to characterize epidermal cell shape dynamics in one mutant, or1219ts, and observed cell elongation defects during dorsal intercalation and ventral enclosure that may be responsible for the body elongation defects. These results indicate that our screen has identified factors that influence morphogenesis and provides a platform for advancing our understanding of this fundamental biological process.
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Affiliation(s)
- Molly C Jud
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Josh Lowry
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Thalia Padilla
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Erin Clifford
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Yuqi Yang
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Francesca Fennell
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Alexander K Miller
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Danielle Hamill
- Department of Zoology, Ohio Wesleyan University, Delaware, OH, 43015, USA
| | - Austin M Harvey
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Martha Avila-Zavala
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Hong Shao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Nhan Nguyen Tran
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
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15
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Structural and developmental principles of neuropil assembly in C. elegans. Nature 2021; 591:99-104. [PMID: 33627875 PMCID: PMC8385650 DOI: 10.1038/s41586-020-03169-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 11/12/2020] [Indexed: 01/31/2023]
Abstract
Neuropil is a fundamental form of tissue organization within the brain1, in which densely packed neurons synaptically interconnect into precise circuit architecture2,3. However, the structural and developmental principles that govern this nanoscale precision remain largely unknown4,5. Here we use an iterative data coarse-graining algorithm termed 'diffusion condensation'6 to identify nested circuit structures within the Caenorhabditis elegans neuropil, which is known as the nerve ring. We show that the nerve ring neuropil is largely organized into four strata that are composed of related behavioural circuits. The stratified architecture of the neuropil is a geometrical representation of the functional segregation of sensory information and motor outputs, with specific sensory organs and muscle quadrants mapping onto particular neuropil strata. We identify groups of neurons with unique morphologies that integrate information across strata and that create neural structures that cage the strata within the nerve ring. We use high resolution light-sheet microscopy7,8 coupled with lineage-tracing and cell-tracking algorithms9,10 to resolve the developmental sequence and reveal principles of cell position, migration and outgrowth that guide stratified neuropil organization. Our results uncover conserved structural design principles that underlie the architecture and function of the nerve ring neuropil, and reveal a temporal progression of outgrowth-based on pioneer neurons-that guides the hierarchical development of the layered neuropil. Our findings provide a systematic blueprint for using structural and developmental approaches to understand neuropil organization within the brain.
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Hutchison LAD, Berger B, Kohane IS. Meta-analysis of Caenorhabditis elegans single-cell developmental data reveals multi-frequency oscillation in gene activation. Bioinformatics 2020; 36:4047-4057. [PMID: 31860066 PMCID: PMC7332571 DOI: 10.1093/bioinformatics/btz864] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 09/23/2019] [Accepted: 12/18/2019] [Indexed: 02/06/2023] Open
Abstract
MOTIVATION The advent of in vivo automated techniques for single-cell lineaging, sequencing and analysis of gene expression has begun to dramatically increase our understanding of organismal development. We applied novel meta-analysis and visualization techniques to the EPIC single-cell-resolution developmental gene expression dataset for Caenorhabditis elegans from Bao, Murray, Waterston et al. to gain insights into regulatory mechanisms governing the timing of development. RESULTS Our meta-analysis of the EPIC dataset revealed that a simple linear combination of the expression levels of the developmental genes is strongly correlated with the developmental age of the organism, irrespective of the cell division rate of different cell lineages. We uncovered a pattern of collective sinusoidal oscillation in gene activation, in multiple dominant frequencies and in multiple orthogonal axes of gene expression, pointing to the existence of a coordinated, multi-frequency global timing mechanism. We developed a novel method based on Fisher's Discriminant Analysis to identify gene expression weightings that maximally separate traits of interest, and found that remarkably, simple linear gene expression weightings are capable of producing sinusoidal oscillations of any frequency and phase, adding to the growing body of evidence that oscillatory mechanisms likely play an important role in the timing of development. We cross-linked EPIC with gene ontology and anatomy ontology terms, employing Fisher's Discriminant Analysis methods to identify previously unknown positive and negative genetic contributions to developmental processes and cell phenotypes. This meta-analysis demonstrates new evidence for direct linear and/or sinusoidal mechanisms regulating the timing of development. We uncovered a number of previously unknown positive and negative correlations between developmental genes and developmental processes or cell phenotypes. Our results highlight both the continued relevance of the EPIC technique, and the value of meta-analysis of previously published results. The presented analysis and visualization techniques are broadly applicable across developmental and systems biology. AVAILABILITY AND IMPLEMENTATION Analysis software available upon request. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
| | - Bonnie Berger
- MIT Computer Science and AI Lab, Cambridge, MA 02139, USA
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17
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Establishment of a morphological atlas of the Caenorhabditis elegans embryo using deep-learning-based 4D segmentation. Nat Commun 2020; 11:6254. [PMID: 33288755 PMCID: PMC7721714 DOI: 10.1038/s41467-020-19863-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 11/02/2020] [Indexed: 01/17/2023] Open
Abstract
The invariant development and transparent body of the nematode Caenorhabditis elegans enables complete delineation of cell lineages throughout development. Despite extensive studies of cell division, cell migration and cell fate differentiation, cell morphology during development has not yet been systematically characterized in any metazoan, including C. elegans. This knowledge gap substantially hampers many studies in both developmental and cell biology. Here we report an automatic pipeline, CShaper, which combines automated segmentation of fluorescently labeled membranes with automated cell lineage tracing. We apply this pipeline to quantify morphological parameters of densely packed cells in 17 developing C. elegans embryos. Consequently, we generate a time-lapse 3D atlas of cell morphology for the C. elegans embryo from the 4- to 350-cell stages, including cell shape, volume, surface area, migration, nucleus position and cell-cell contact with resolved cell identities. We anticipate that CShaper and the morphological atlas will stimulate and enhance further studies in the fields of developmental biology, cell biology and biomechanics. The systematic characterization of C. elegans morphology during development has yet to be performed. Here, the authors produce a 3D atlas of C. elegans morphology from 17 embryos and 54 developmental stages, using an automated pipeline, CShaper (combining segmentation of fluorescently labeled membranes with automated cell lineage tracing).
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Abstract
Biclustering is an important exploratory analysis tool that simultaneously clusters rows (e.g., samples) and columns (e.g., variables) of a data matrix. Checkerboard-like biclusters reveal intrinsic associations between rows and columns. However, most existing methods rely on Gaussian assumptions and only apply to matrix data. In practice, non-Gaussian and/or multi-way tensor data are frequently encountered. A new CO-clustering method via Regularized Alternating Least Squares (CORALS) is proposed, which generalizes biclustering to non-Gaussian data and multi-way tensor arrays. Non-Gaussian data are modeled with single-parameter exponential family distributions and co-clusters are identified in the natural parameter space via sparse CANDECOMP/PARAFAC tensor decomposition. A regularized alternating (iteratively reweighted) least squares algorithm is devised for model fitting and a deflation procedure is exploited to automatically determine the number of co-clusters. Comprehensive simulation studies and three real data examples demonstrate the efficacy of the proposed method. The data and code are publicly available.
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Affiliation(s)
- Gen Li
- Department of Biostatistics, Columbia University. New York, NY 10032
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19
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Li X, Zhao Z, Xu W, Fan R, Xiao L, Ma X, Du Z. Systems Properties and Spatiotemporal Regulation of Cell Position Variability during Embryogenesis. Cell Rep 2020; 26:313-321.e7. [PMID: 30625313 DOI: 10.1016/j.celrep.2018.12.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 11/06/2018] [Accepted: 12/11/2018] [Indexed: 12/15/2022] Open
Abstract
An intriguing question in developmental biology is how do developmental processes achieve high reproducibility among individuals? An in-depth analysis of information contained in phenotypic variability provides an important perspective to address this question. In this work, we present a quantitative and functional analysis of cell position variability during Caenorhabditis elegans embryogenesis. We find that cell position variability is highly deterministic and regulated by intrinsic and extrinsic mechanisms. Positional variability is determined by cell lineage identity and is coupled to diverse developmental properties of cells, including embryonic localization, cell contact, and left-right symmetry. Temporal dynamics of cell position variability are highly concordant, and fate specification contributes to a systems-wide reduction of variability that could provide a buffering strategy. Positional variability is stringently regulated throughout embryogenesis and cell-cell junctions function to restrict variability. Our results provide insight into systems properties and spatiotemporal control of cellular variability during development.
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Affiliation(s)
- Xiaoyu Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiguang Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weina Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rong Fan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Long Xiao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuehua Ma
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhuo Du
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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20
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Wang Z, Wang D, Li C, Xu Y, Li H, Bao Z. Deep reinforcement learning of cell movement in the early stage of C.elegans embryogenesis. Bioinformatics 2019; 34:3169-3177. [PMID: 29701853 DOI: 10.1093/bioinformatics/bty323] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/24/2018] [Indexed: 02/02/2023] Open
Abstract
Motivation Cell movement in the early phase of Caenorhabditis elegans development is regulated by a highly complex process in which a set of rules and connections are formulated at distinct scales. Previous efforts have demonstrated that agent-based, multi-scale modeling systems can integrate physical and biological rules and provide new avenues to study developmental systems. However, the application of these systems to model cell movement is still challenging and requires a comprehensive understanding of regulatory networks at the right scales. Recent developments in deep learning and reinforcement learning provide an unprecedented opportunity to explore cell movement using 3D time-lapse microscopy images. Results We present a deep reinforcement learning approach within an agent-based modeling system to characterize cell movement in the embryonic development of C.elegans. Our modeling system captures the complexity of cell movement patterns in the embryo and overcomes the local optimization problem encountered by traditional rule-based, agent-based modeling that uses greedy algorithms. We tested our model with two real developmental processes: the anterior movement of the Cpaaa cell via intercalation and the rearrangement of the superficial left-right asymmetry. In the first case, the model results suggested that Cpaaa's intercalation is an active directional cell movement caused by the continuous effects from a longer distance (farther than the length of two adjacent cells), as opposed to a passive movement caused by neighbor cell movements. In the second case, a leader-follower mechanism well explained the collective cell movement pattern in the asymmetry rearrangement. These results showed that our approach to introduce deep reinforcement learning into agent-based modeling can test regulatory mechanisms by exploring cell migration paths in a reverse engineering perspective. This model opens new doors to explore the large datasets generated by live imaging. Availability and implementation Source code is available at https://github.com/zwang84/drl4cellmovement. Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Zi Wang
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA
| | - Dali Wang
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA.,Environmental Science Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Chengcheng Li
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA
| | - Yichi Xu
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY, USA
| | - Husheng Li
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, TN, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY, USA
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21
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Patel DS, Xu N, Lu H. Digging deeper: methodologies for high-content phenotyping in Caenorhabditis elegans. Lab Anim (NY) 2019; 48:207-216. [PMID: 31217565 DOI: 10.1038/s41684-019-0326-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 05/17/2019] [Indexed: 11/09/2022]
Abstract
Deep phenotyping is an emerging conceptual paradigm and experimental approach aimed at measuring and linking many aspects of a phenotype to understand its underlying biology. To date, deep phenotyping has been applied mostly in cultured cells and used less in multicellular organisms. However, in the past decade, it has increasingly been recognized that deep phenotyping could lead to a better understanding of how genetics, environment and stochasticity affect the development, physiology and behavior of an organism. The nematode Caenorhabditis elegans is an invaluable model system for studying how genes affect a phenotypic trait, and new technologies have taken advantage of the worm's physical attributes to increase the throughput and informational content of experiments. Coupling of these technical advancements with computational and analytical tools has enabled a boom in deep-phenotyping studies of C. elegans. In this Review, we highlight how these new technologies and tools are digging into the biological origins of complex, multidimensional phenotypes.
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Affiliation(s)
- Dhaval S Patel
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Nan Xu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
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22
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Breimann L, Preusser F, Preibisch S. Light-microscopy methods in C. elegans research. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.coisb.2018.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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23
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Chen L, Ho VWS, Wong MK, Huang X, Chan LY, Ng HCK, Ren X, Yan H, Zhao Z. Establishment of Signaling Interactions with Cellular Resolution for Every Cell Cycle of Embryogenesis. Genetics 2018; 209:37-49. [PMID: 29567658 PMCID: PMC5937172 DOI: 10.1534/genetics.118.300820] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 03/19/2018] [Indexed: 11/18/2022] Open
Abstract
Intercellular signaling interactions play a key role in breaking fate symmetry during animal development. Identification of signaling interactions at cellular resolution is technically challenging, especially in a developing embryo. Here, we develop a platform that allows automated inference and validation of signaling interactions for every cell cycle of Caenorhabditis elegans embryogenesis. This is achieved by the generation of a systems-level cell contact map, which consists of 1114 highly confident intercellular contacts, by modeling analysis and is validated through cell membrane labeling coupled with cell lineage analysis. We apply the map to identify cell pairs between which a Notch signaling interaction takes place. By generating expression patterns for two ligands and two receptors of the Notch signaling pathway with cellular resolution using the automated expression profiling technique, we are able to refine existing and identify novel Notch interactions during C. elegans embryogenesis. Targeted cell ablation followed by cell lineage analysis demonstrates the roles of signaling interactions during cell division in breaking fate symmetry. Finally, we describe the development of a website that allows online access to the cell-cell contact map for mapping of other signaling interactions by the community. The platform can be adapted to establish cellular interactions from any other signaling pathway.
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Affiliation(s)
- Long Chen
- Department of Electronic Engineering, City University of Hong Kong, China
| | | | - Ming-Kin Wong
- Department of Biology, Hong Kong Baptist University, China
| | - Xiaotai Huang
- School of Computer Science and Technology, Xidian University, Xi'an, 710126 China
| | - Lu-Yan Chan
- Department of Biology, Hong Kong Baptist University, China
| | | | - Xiaoliang Ren
- Department of Biology, Hong Kong Baptist University, China
| | - Hong Yan
- Department of Electronic Engineering, City University of Hong Kong, China
| | - Zhongying Zhao
- Department of Biology, Hong Kong Baptist University, China
- State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, China
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24
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Murray JI. Systems biology of embryonic development: Prospects for a complete understanding of the Caenorhabditis elegans embryo. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e314. [PMID: 29369536 DOI: 10.1002/wdev.314] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/01/2017] [Accepted: 12/12/2017] [Indexed: 01/07/2023]
Abstract
The convergence of developmental biology and modern genomics tools brings the potential for a comprehensive understanding of developmental systems. This is especially true for the Caenorhabditis elegans embryo because its small size, invariant developmental lineage, and powerful genetic and genomic tools provide the prospect of a cellular resolution understanding of messenger RNA (mRNA) expression and regulation across the organism. We describe here how a systems biology framework might allow large-scale determination of the embryonic regulatory relationships encoded in the C. elegans genome. This framework consists of two broad steps: (a) defining the "parts list"-all genes expressed in all cells at each time during development and (b) iterative steps of computational modeling and refinement of these models by experimental perturbation. Substantial progress has been made towards defining the parts list through imaging methods such as large-scale green fluorescent protein (GFP) reporter analysis. Imaging results are now being augmented by high-resolution transcriptome methods such as single-cell RNA sequencing, and it is likely the complete expression patterns of all genes across the embryo will be known within the next few years. In contrast, the modeling and perturbation experiments performed so far have focused largely on individual cell types or genes, and improved methods will be needed to expand them to the full genome and organism. This emerging comprehensive map of embryonic expression and regulatory function will provide a powerful resource for developmental biologists, and would also allow scientists to ask questions not accessible without a comprehensive picture. This article is categorized under: Invertebrate Organogenesis > Worms Technologies > Analysis of the Transcriptome Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics.
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Affiliation(s)
- John Isaac Murray
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
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25
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Shah PK, Santella A, Jacobo A, Siletti K, Hudspeth AJ, Bao Z. An In Toto Approach to Dissecting Cellular Interactions in Complex Tissues. Dev Cell 2017; 43:530-540.e4. [PMID: 29161596 DOI: 10.1016/j.devcel.2017.10.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 09/01/2017] [Accepted: 10/20/2017] [Indexed: 11/27/2022]
Abstract
Single-cell measurements have broadened our understanding of heterogeneity in biology, yet have been limited to mostly observational studies of normal or globally perturbed systems. Typically, perturbations are utilized in an open-ended approach wherein an endpoint is assayed during or after the biological event of interest. Here we describe ShootingStar, a platform for perturbation analysis in vivo, which combines live imaging, real-time image analysis, and automated optical perturbations. ShootingStar builds a quantitative record of the state of the sample being analyzed, which is used to automate the identification of target cells for perturbation, as well as to validate the impacts of the perturbation. We used ShootingStar to dissect the cellular basis of development, morphogenesis, and polarity in the lateral line of Danio rerio and the embryo of Caenorhabditis elegans. ShootingStar can be extended to diverse optical manipulations and enables more robust and informative single-cell perturbations in complex tissues.
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Affiliation(s)
- Pavak Kirit Shah
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065 USA
| | - Anthony Santella
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065 USA
| | - Adrian Jacobo
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - Kimberly Siletti
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - A J Hudspeth
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065 USA.
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26
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Jin Y, Qi YB. Building stereotypic connectivity: mechanistic insights into structural plasticity from C. elegans. Curr Opin Neurobiol 2017; 48:97-105. [PMID: 29182952 DOI: 10.1016/j.conb.2017.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 11/07/2017] [Accepted: 11/14/2017] [Indexed: 01/10/2023]
Abstract
The ability of neurons to modify or remodel their synaptic connectivity is critical for the function of neural circuitry throughout the life of an animal. Understanding the mechanisms underlying neuronal structural changes is central to our knowledge of how the nervous system is shaped for complex behaviors and how it further adapts to developmental and environmental demands. Caenorhabditis elegans provides a powerful model for examining developmental processes and for discovering mechanisms controlling neural plasticity. Recent findings have identified conserved themes underlying neural plasticity in development and under environmental stress.
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Affiliation(s)
- Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Yingchuan B Qi
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
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An Observation-Driven Agent-Based Modeling and Analysis Framework for C. elegans Embryogenesis. PLoS One 2016; 11:e0166551. [PMID: 27851808 PMCID: PMC5113041 DOI: 10.1371/journal.pone.0166551] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 10/31/2016] [Indexed: 11/19/2022] Open
Abstract
With cutting-edge live microscopy and image analysis, biologists can now systematically track individual cells in complex tissues and quantify cellular behavior over extended time windows. Computational approaches that utilize the systematic and quantitative data are needed to understand how cells interact in vivo to give rise to the different cell types and 3D morphology of tissues. An agent-based, minimum descriptive modeling and analysis framework is presented in this paper to study C. elegans embryogenesis. The framework is designed to incorporate the large amounts of experimental observations on cellular behavior and reserve data structures/interfaces that allow regulatory mechanisms to be added as more insights are gained. Observed cellular behaviors are organized into lineage identity, timing and direction of cell division, and path of cell movement. The framework also includes global parameters such as the eggshell and a clock. Division and movement behaviors are driven by statistical models of the observations. Data structures/interfaces are reserved for gene list, cell-cell interaction, cell fate and landscape, and other global parameters until the descriptive model is replaced by a regulatory mechanism. This approach provides a framework to handle the ongoing experiments of single-cell analysis of complex tissues where mechanistic insights lag data collection and need to be validated on complex observations.
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28
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Zhao H, Wang DD, Chen L, Liu X, Yan H. Identifying Multi-Dimensional Co-Clusters in Tensors Based on Hyperplane Detection in Singular Vector Spaces. PLoS One 2016; 11:e0162293. [PMID: 27598575 PMCID: PMC5012624 DOI: 10.1371/journal.pone.0162293] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 08/19/2016] [Indexed: 11/18/2022] Open
Abstract
Co-clustering, often called biclustering for two-dimensional data, has found many applications, such as gene expression data analysis and text mining. Nowadays, a variety of multi-dimensional arrays (tensors) frequently occur in data analysis tasks, and co-clustering techniques play a key role in dealing with such datasets. Co-clusters represent coherent patterns and exhibit important properties along all the modes. Development of robust co-clustering techniques is important for the detection and analysis of these patterns. In this paper, a co-clustering method based on hyperplane detection in singular vector spaces (HDSVS) is proposed. Specifically in this method, higher-order singular value decomposition (HOSVD) transforms a tensor into a core part and a singular vector matrix along each mode, whose row vectors can be clustered by a linear grouping algorithm (LGA). Meanwhile, hyperplanar patterns are extracted and successfully supported the identification of multi-dimensional co-clusters. To validate HDSVS, a number of synthetic and biological tensors were adopted. The synthetic tensors attested a favorable performance of this algorithm on noisy or overlapped data. Experiments with gene expression data and lineage data of embryonic cells further verified the reliability of HDSVS to practical problems. Moreover, the detected co-clusters are well consistent with important genetic pathways and gene ontology annotations. Finally, a series of comparisons between HDSVS and state-of-the-art methods on synthetic tensors and a yeast gene expression tensor were implemented, verifying the robust and stable performance of our method.
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Affiliation(s)
- Hongya Zhao
- Industrial Center, Shenzhen Polytechnic, Shenzhen, China
| | - Debby D. Wang
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
- Caritas Institute of Higher Education, New Territories, Hong Kong
| | - Long Chen
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
- * E-mail:
| | - Xinyu Liu
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
| | - Hong Yan
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong
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29
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Jelier R, Kruger A, Swoger J, Zimmermann T, Lehner B. Compensatory Cell Movements Confer Robustness to Mechanical Deformation during Embryonic Development. Cell Syst 2016; 3:160-171. [DOI: 10.1016/j.cels.2016.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/30/2016] [Accepted: 07/07/2016] [Indexed: 12/17/2022]
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30
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Zacharias AL, Murray JI. Combinatorial decoding of the invariant C. elegans embryonic lineage in space and time. Genesis 2016; 54:182-97. [PMID: 26915329 PMCID: PMC4840027 DOI: 10.1002/dvg.22928] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 02/18/2016] [Accepted: 02/22/2016] [Indexed: 12/19/2022]
Abstract
Understanding how a single cell, the zygote, can divide and differentiate to produce the diverse animal cell types is a central goal of developmental biology research. The model organism Caenorhabditis elegans provides a system that enables a truly comprehensive understanding of this process across all cells. Its invariant cell lineage makes it possible to identify all of the cells in each individual and compare them across organisms. Recently developed methods automate the process of cell identification, allowing high-throughput gene expression characterization and phenotyping at single cell resolution. In this Review, we summarize the sequences of events that pattern the lineage including establishment of founder cell identity, the signaling pathways that diversify embryonic fate, and the regulators involved in patterning within these founder lineages before cells adopt their terminal fates. We focus on insights that have emerged from automated approaches to lineage tracking, including insights into mechanisms of robustness, context-specific regulation of gene expression, and temporal coordination of differentiation. We suggest a model by which lineage history produces a combinatorial code of transcription factors that act, often redundantly, to ensure terminal fate.
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Affiliation(s)
- Amanda L. Zacharias
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104 USA
| | - John Isaac Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104 USA
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31
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Lemaire P, Piette J. Tunicates: exploring the sea shores and roaming the open ocean. A tribute to Thomas Huxley. Open Biol 2016; 5:150053. [PMID: 26085517 PMCID: PMC4632506 DOI: 10.1098/rsob.150053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This review is a tribute to the remarkable contributions of Thomas Huxley to the biology of tunicates, the likely sister group of vertebrates. In 1851, the great biologist and philosopher published two landmark papers on pelagic tunicates in the Philosophical Transactions of the Royal Society. They were dedicated to the description of the adult anatomy and life cycle of thaliaceans and appendicularians, the pelagic relatives of ascidians. In the first part of this review, we discuss the novel anatomical observations and evolutionary hypotheses made by Huxley, which would have a lasting influence on tunicate biology. We also briefly comment on the more philosophical reflections of Huxley on individuality. In the second part, we stress the originality and relevance of past and future studies of tunicates in the resolution of major biological issues. In particular, we focus on the complex relationship between genotype and phenotype and the phenomenon of developmental system drift. We propose that more than 150 years after Huxley's papers, tunicate embryos are still worth studying in their own right, independently of their evolutionary proximity to vertebrates, as they provide original and crucial insights into the process of animal evolution. Tunicates are still at the forefront of biological research.
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Affiliation(s)
- Patrick Lemaire
- Centre de Recherches de Biochimie Macromoléculaire. UMR 5237, Centre National de la Recherche Scientifique, Université de Montpellier, 1919 Route de Mende, 34293, Montpellier cedex 5, France
| | - Jacques Piette
- Centre de Recherches de Biochimie Macromoléculaire. UMR 5237, Centre National de la Recherche Scientifique, Université de Montpellier, 1919 Route de Mende, 34293, Montpellier cedex 5, France
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Santella A, Kovacevic I, Herndon LA, Hall DH, Du Z, Bao Z. Digital development: a database of cell lineage differentiation in C. elegans with lineage phenotypes, cell-specific gene functions and a multiscale model. Nucleic Acids Res 2016; 44:D781-5. [PMID: 26503254 PMCID: PMC4702815 DOI: 10.1093/nar/gkv1119] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/09/2015] [Accepted: 10/12/2015] [Indexed: 11/16/2022] Open
Abstract
Developmental systems biology is poised to exploit large-scale data from two approaches: genomics and live imaging. The combination of the two offers the opportunity to map gene functions and gene networks in vivo at single-cell resolution using cell tracking and quantification of cellular phenotypes. Here we present Digital Development (http://www.digital-development.org), a database of cell lineage differentiation with curated phenotypes, cell-specific gene functions and a multiscale model. The database stores data from recent systematic studies of cell lineage differentiation in the C. elegans embryo containing ∼ 200 conserved genes, 1400 perturbed cell lineages and 600,000 digitized single cells. Users can conveniently browse, search and download four categories of phenotypic and functional information from an intuitive web interface. This information includes lineage differentiation phenotypes, cell-specific gene functions, differentiation landscapes and fate choices, and a multiscale model of lineage differentiation. Digital Development provides a comprehensive, curated, multidimensional database for developmental biology. The scale, resolution and richness of biological information presented here facilitate exploration of gene-specific and systems-level mechanisms of lineage differentiation in Metazoans.
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Affiliation(s)
| | | | | | - David H Hall
- Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Zhuo Du
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhirong Bao
- Sloan Kettering Institute, New York, NY 10065, USA
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Du Z, Santella A, He F, Shah PK, Kamikawa Y, Bao Z. The Regulatory Landscape of Lineage Differentiation in a Metazoan Embryo. Dev Cell 2015; 34:592-607. [PMID: 26321128 DOI: 10.1016/j.devcel.2015.07.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 05/21/2015] [Accepted: 07/28/2015] [Indexed: 11/19/2022]
Abstract
Elucidating the mechanism of cell lineage differentiation is critical for our understanding of development and fate manipulation. Here we combined systematic perturbation and direct lineaging to map the regulatory landscape of lineage differentiation in early C. elegans embryogenesis. High-dimensional phenotypic analysis of 204 essential genes in 1,368 embryos revealed that cell lineage differentiation follows a canalized landscape with barriers shaped by lineage distance and genetic robustness. We assigned function to 201 genes in regulating lineage differentiation, including 175 switches of binary fate choices. We generated a multiscale model that connects gene networks and cells to the experimentally mapped landscape. Simulations showed that the landscape topology determines the propensity of differentiation and regulatory complexity. Furthermore, the model allowed us to identify the chromatin assembly complex CAF-1 as a context-specific repressor of Notch signaling. Our study presents a systematic survey of the regulatory landscape of lineage differentiation of a metazoan embryo.
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Affiliation(s)
- Zhuo Du
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA.
| | - Anthony Santella
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Fei He
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Pavak K Shah
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Yuko Kamikawa
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Zhirong Bao
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA.
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Ho VWS, Wong MK, An X, Guan D, Shao J, Ng HCK, Ren X, He K, Liao J, Ang Y, Chen L, Huang X, Yan B, Xia Y, Chan LLH, Chow KL, Yan H, Zhao Z. Systems-level quantification of division timing reveals a common genetic architecture controlling asynchrony and fate asymmetry. Mol Syst Biol 2015; 11:814. [PMID: 26063786 PMCID: PMC4501849 DOI: 10.15252/msb.20145857] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Coordination of cell division timing is crucial for proper cell fate specification and tissue growth. However, the differential regulation of cell division timing across or within cell types during metazoan development remains poorly understood. To elucidate the systems-level genetic architecture coordinating division timing, we performed a high-content screening for genes whose depletion produced a significant reduction in the asynchrony of division between sister cells (ADS) compared to that of wild-type during Caenorhabditis elegans embryogenesis. We quantified division timing using 3D time-lapse imaging followed by computer-aided lineage analysis. A total of 822 genes were selected for perturbation based on their conservation and known roles in development. Surprisingly, we find that cell fate determinants are not only essential for establishing fate asymmetry, but also are imperative for setting the ADS regardless of cellular context, indicating a common genetic architecture used by both cellular processes. The fate determinants demonstrate either coupled or separate regulation between the two processes. The temporal coordination appears to facilitate cell migration during fate specification or tissue growth. Our quantitative dataset with cellular resolution provides a resource for future analyses of the genetic control of spatial and temporal coordination during metazoan development.
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Affiliation(s)
- Vincy Wing Sze Ho
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Ming-Kin Wong
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Xiaomeng An
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Daogang Guan
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jiaofang Shao
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Hon Chun Kaoru Ng
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Xiaoliang Ren
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Kan He
- Department of Biology, Hong Kong Baptist University, Hong Kong, China Center for Stem Cell and Translational Medicine, School of Life Sciences Anhui University, Hefei, China
| | - Jinyue Liao
- Division of Life Science and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yingjin Ang
- Division of Life Science and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Long Chen
- Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China
| | - Xiaotai Huang
- Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China
| | - Bin Yan
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yiji Xia
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Leanne Lai Hang Chan
- Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China
| | - King Lau Chow
- Division of Life Science and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hong Yan
- Department of Electronic Engineering, City University of Hong Kong, Hong Kong, China
| | - Zhongying Zhao
- Department of Biology, Hong Kong Baptist University, Hong Kong, China State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong, China
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WormGUIDES: an interactive single cell developmental atlas and tool for collaborative multidimensional data exploration. BMC Bioinformatics 2015; 16:189. [PMID: 26051157 PMCID: PMC4459063 DOI: 10.1186/s12859-015-0627-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/23/2015] [Indexed: 01/15/2023] Open
Abstract
Background Imaging and image analysis advances are yielding increasingly complete and complicated records of cellular events in tissues and whole embryos. The ability to follow hundreds to thousands of cells at the individual level demands a spatio-temporal data infrastructure: tools to assemble and collate knowledge about development spatially in a manner analogous to geographic information systems (GIS). Just as GIS indexes items or events based on their spatio-temporal or 4D location on the Earth these tools would organize knowledge based on location within the tissues or embryos. Developmental processes are highly context-specific, but the complexity of the 4D environment in which they unfold is a barrier to assembling an understanding of any particular process from diverse sources of information. In the same way that GIS aids the understanding and use of geo-located large data sets, software can, with a proper frame of reference, allow large biological data sets to be understood spatially. Intuitive tools are needed to navigate the spatial structure of complex tissue, collate large data sets and existing knowledge with this spatial structure and help users derive hypotheses about developmental mechanisms. Results Toward this goal we have developed WormGUIDES, a mobile application that presents a 4D developmental atlas for Caenorhabditis elegans. The WormGUIDES mobile app enables users to navigate a 3D model depicting the nuclear positions of all cells in the developing embryo. The identity of each cell can be queried with a tap, and community databases searched for available information about that cell. Information about ancestry, fate and gene expression can be used to label cells and craft customized visualizations that highlight cells as potential players in an event of interest. Scenes are easily saved, shared and published to other WormGUIDES users. The mobile app is available for Android and iOS platforms. Conclusion WormGUIDES provides an important tool for examining developmental processes and developing mechanistic hypotheses about their control. Critically, it provides the typical end user with an intuitive interface for developing and sharing custom visualizations of developmental processes. Equally important, because users can select cells based on their position and search for information about them, the app also serves as a spatially organized index into the large body of knowledge available to the C. elegans community online. Moreover, the app can be used to create and publish the result of exploration: interactive content that brings other researchers and students directly to the spatio-temporal point of insight. Ultimately the app will incorporate a detailed time lapse record of cell shape, beginning with neurons. This will add the key ability to navigate and understand the developmental events that result in the coordinated and precise emergence of anatomy, particularly the wiring of the nervous system.
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Kyoda K, Tohsato Y, Ho KHL, Onami S. Biological Dynamics Markup Language (BDML): an open format for representing quantitative biological dynamics data. ACTA ACUST UNITED AC 2014; 31:1044-52. [PMID: 25414366 PMCID: PMC4382901 DOI: 10.1093/bioinformatics/btu767] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 11/13/2014] [Indexed: 01/08/2023]
Abstract
Motivation: Recent progress in live-cell imaging and modeling techniques has resulted in generation of a large amount of quantitative data (from experimental measurements and computer simulations) on spatiotemporal dynamics of biological objects such as molecules, cells and organisms. Although many research groups have independently dedicated their efforts to developing software tools for visualizing and analyzing these data, these tools are often not compatible with each other because of different data formats. Results: We developed an open unified format, Biological Dynamics Markup Language (BDML; current version: 0.2), which provides a basic framework for representing quantitative biological dynamics data for objects ranging from molecules to cells to organisms. BDML is based on Extensible Markup Language (XML). Its advantages are machine and human readability and extensibility. BDML will improve the efficiency of development and evaluation of software tools for data visualization and analysis. Availability and implementation: A specification and a schema file for BDML are freely available online at http://ssbd.qbic.riken.jp/bdml/. Contact:sonami@riken.jp Supplementary Information:Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Koji Kyoda
- Laboratory for Developmental Dynamics, RIKEN Quantitative Biology Center, Kobe 650-0047, Japan and
| | - Yukako Tohsato
- Laboratory for Developmental Dynamics, RIKEN Quantitative Biology Center, Kobe 650-0047, Japan and
| | - Kenneth H L Ho
- Laboratory for Developmental Dynamics, RIKEN Quantitative Biology Center, Kobe 650-0047, Japan and
| | - Shuichi Onami
- Laboratory for Developmental Dynamics, RIKEN Quantitative Biology Center, Kobe 650-0047, Japan and National Bioscience Database Center, Japan Science and Technology Agency, Tokyo 102-0081, Japan
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Krüger AV, Jelier R, Dzyubachyk O, Zimmerman T, Meijering E, Lehner B. Comprehensive single cell-resolution analysis of the role of chromatin regulators in early C. elegans embryogenesis. Dev Biol 2014; 398:153-62. [PMID: 25446273 DOI: 10.1016/j.ydbio.2014.10.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 09/12/2014] [Accepted: 10/17/2014] [Indexed: 11/19/2022]
Abstract
Chromatin regulators are widely expressed proteins with diverse roles in gene expression, nuclear organization, cell cycle regulation, pluripotency, physiology and development, and are frequently mutated in human diseases such as cancer. Their inhibition often results in pleiotropic effects that are difficult to study using conventional approaches. We have developed a semi-automated nuclear tracking algorithm to quantify the divisions, movements and positions of all nuclei during the early development of Caenorhabditis elegans and have used it to systematically study the effects of inhibiting chromatin regulators. The resulting high dimensional datasets revealed that inhibition of multiple regulators, including F55A3.3 (encoding FACT subunit SUPT16H), lin-53 (RBBP4/7), rba-1 (RBBP4/7), set-16 (MLL2/3), hda-1 (HDAC1/2), swsn-7 (ARID2), and let-526 (ARID1A/1B) affected cell cycle progression and caused chromosome segregation defects. In contrast, inhibition of cir-1 (CIR1) accelerated cell division timing in specific cells of the AB lineage. The inhibition of RNA polymerase II also accelerated these division timings, suggesting that normal gene expression is required to delay cell cycle progression in multiple lineages in the early embryo. Quantitative analyses of the dataset suggested the existence of at least two functionally distinct SWI/SNF chromatin remodeling complex activities in the early embryo, and identified a redundant requirement for the egl-27 and lin-40 MTA orthologs in the development of endoderm and mesoderm lineages. Moreover, our dataset also revealed a characteristic rearrangement of chromatin to the nuclear periphery upon the inhibition of multiple general regulators of gene expression. Our systematic, comprehensive and quantitative datasets illustrate the power of single cell-resolution quantitative tracking and high dimensional phenotyping to investigate gene function. Furthermore, the results provide an overview of the functions of essential chromatin regulators during the early development of an animal.
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Affiliation(s)
- Angela V Krüger
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), Dr. Aiguader 88, 08003 Barcelona, Spain; University Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Rob Jelier
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), Dr. Aiguader 88, 08003 Barcelona, Spain; University Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Oleh Dzyubachyk
- Biomedical Imaging Group Rotterdam, Departments of Medical Informatics and Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Timo Zimmerman
- Advanced Light Microscopy Facility, Centre for Genomic Regulation (CRG), Dr. Aiguader 88, 08003 Barcelona, Spain
| | - Erik Meijering
- Biomedical Imaging Group Rotterdam, Departments of Medical Informatics and Radiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Ben Lehner
- EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation (CRG), Dr. Aiguader 88, 08003 Barcelona, Spain; University Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys 23, 08010 Barcelona, Spain.
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Xu C, Su Z. Identification of genes driving lineage divergence from single-cell gene expression data in C. elegans. Dev Biol 2014; 393:236-244. [PMID: 25050933 DOI: 10.1016/j.ydbio.2014.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 07/09/2014] [Accepted: 07/11/2014] [Indexed: 11/25/2022]
Abstract
The nematode Caenorhabditis elegans (C. elegans) is an ideal model organism to study the cell fate specification mechanisms during embryogenesis. It is generally believed that cell fate specification in C. elegans is mainly mediated by lineage-based mechanisms, where the specification paths are driven forward by a succession of asymmetric cell divisions. However, little is known about how each binary decision is made by gene regulatory programs. In this study, we endeavor to obtain a global understanding of cell lineage/fate divergence processes during the early embryogenesis of C. elegans. We reanalyzed the EPIC data set, which traced the expression level of reporter genes at single-cell resolution on a nearly continuous time scale up to the 350-cell stage in C. elegans embryos. We examined the expression patterns for a total of 131 genes from 287 embryos with high quality image recordings, among which 86 genes have replicate embryos. Our results reveal that during early embryogenesis, divergence between sister lineages could be largely explained by a few genes. We predicted genes driving lineage divergence and explored their expression patterns in sister lineages. Moreover, we found that divisions leading to fate divergence are associated with a large number of genes being differentially expressed between sister lineages. Interestingly, we found that the developmental paths of lineages could be differentiated by a small set of genes. Therefore, our results support the notion that the cell fate patterns in C. elegans are achieved through stepwise binary decisions punctuated by cell divisions. Our predicted genes driving lineage divergence provide good starting points for future detailed characterization of their roles in the embryogenesis in this important model organism.
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Affiliation(s)
- Chen Xu
- Department of Bioinformatics and Genomics, The University of North Carolina at Charlotte, 351 Bioinformatics Building, 9201 University City Blvd, Charlotte, NC 28223, USA.
| | - Zhengchang Su
- Department of Bioinformatics and Genomics, The University of North Carolina at Charlotte, 351 Bioinformatics Building, 9201 University City Blvd, Charlotte, NC 28223, USA.
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Pantazis P, Supatto W. Advances in whole-embryo imaging: a quantitative transition is underway. Nat Rev Mol Cell Biol 2014; 15:327-39. [DOI: 10.1038/nrm3786] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Callander DC, Alcorn MR, Birsoy B, Rothman JH. Natural reversal of left-right gut/gonad asymmetry in C. elegans males is independent of embryonic chirality. Genesis 2014; 52:581-7. [PMID: 24585712 DOI: 10.1002/dvg.22762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 01/25/2023]
Abstract
Anatomical left-right (L/R) asymmetry in C. elegans is established in the four-cell embryo as a result of anteroposterior skewing of transverse mitotic spindles with a defined handedness. This event creates a chiral embryo and ultimately an adult body plan with fixed L/R positioning of internal organs and components of the nervous system. While this "dextral" configuration is invariant in hermaphrodites, it can be reversed by physical manipulation of the early embryo or by mutations that interfere with mitotic spindle orientation, which leads to viable, mirror-reversed (sinistral) animals. During normal development of the C. elegans male, the gonad develops on the right of the midline, with the gut bilaterally apposed on the left. However, we found that in males of the laboratory N2 strain and Hawaiian ("Hw") wild isolate, the gut/gonad asymmetry is frequently reversed in a temperature-dependent manner, independent of normal embryonic chirality. We also observed sporadic errors in gonad migration occurring naturally during early larval stages of these and other wild strains; however, the incidence of such errors does not correlate with the frequency of L/R gut/gonad reversals in these strains. Analysis of N2/Hw hybrids and recombinant inbred advanced intercross lines (RIAILs) indicate that the L/R organ reversals are likely to result from recessively acting variations in multiple genes. Thus, unlike the highly reproducible L/R asymmetries of most structures in hermaphrodites, the L/R asymmetry of the male C. elegans body plan is less rigidly determined and subject to natural variation that is influenced by a multiplicity of genes.
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Affiliation(s)
- Davon C Callander
- Department of Molecular, Cellular and Developmental Biology and Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California; Department of Computer Science, University of California Santa Barbara, Santa Barbara, California
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Du Z, Santella A, He F, Tiongson M, Bao Z. De novo inference of systems-level mechanistic models of development from live-imaging-based phenotype analysis. Cell 2014; 156:359-72. [PMID: 24439388 PMCID: PMC3998820 DOI: 10.1016/j.cell.2013.11.046] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 09/25/2013] [Accepted: 11/11/2013] [Indexed: 12/21/2022]
Abstract
Elucidation of complex phenotypes for mechanistic insights presents a significant challenge in systems biology. We report a strategy to automatically infer mechanistic models of cell fate differentiation based on live-imaging data. We use cell lineage tracing and combinations of tissue-specific marker expression to assay progenitor cell fate and detect fate changes upon genetic perturbation. Based on the cellular phenotypes, we further construct a model for how fate differentiation progresses in progenitor cells and predict cell-specific gene modules and cell-to-cell signaling events that regulate the series of fate choices. We validate our approach in C. elegans embryogenesis by perturbing 20 genes in over 300 embryos. The result not only recapitulates current knowledge but also provides insights into gene function and regulated fate choice, including an unexpected self-renewal. Our study provides a powerful approach for automated and quantitative interpretation of complex in vivo information.
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Affiliation(s)
- Zhuo Du
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Anthony Santella
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Fei He
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Michael Tiongson
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA.
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