1
|
McDaniel C, Simsek MF, Chandel AS, Özbudak EM. Spatiotemporal control of pattern formation during somitogenesis. Sci Adv 2024; 10:eadk8937. [PMID: 38277458 PMCID: PMC10816718 DOI: 10.1126/sciadv.adk8937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 12/27/2023] [Indexed: 01/28/2024]
Abstract
Spatiotemporal patterns widely occur in biological, chemical, and physical systems. Particularly, embryonic development displays a diverse gamut of repetitive patterns established in many tissues and organs. Branching treelike structures in lungs, kidneys, livers, pancreases, and mammary glands as well as digits and bones in appendages, teeth, and palates are just a few examples. A fascinating instance of repetitive patterning is the sequential segmentation of the primary body axis, which is conserved in all vertebrates and many arthropods and annelids. In these species, the body axis elongates at the posterior end of the embryo containing an unsegmented tissue. Meanwhile, segments sequentially bud off from the anterior end of the unsegmented tissue, laying down an exquisite repetitive pattern and creating a segmented body plan. In vertebrates, the paraxial mesoderm is sequentially divided into somites. In this review, we will discuss the most prominent models, the most puzzling experimental data, and outstanding questions in vertebrate somite segmentation.
Collapse
Affiliation(s)
- Cassandra McDaniel
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Systems Biology and Physiology Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - M. Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Angad Singh Chandel
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Systems Biology and Physiology Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Ertuğrul M. Özbudak
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| |
Collapse
|
2
|
Simsek MF, Özbudak EM. A design logic for sequential segmentation across organisms. FEBS J 2023; 290:5086-5093. [PMID: 37422856 PMCID: PMC10774455 DOI: 10.1111/febs.16899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/24/2023] [Accepted: 07/06/2023] [Indexed: 07/11/2023]
Abstract
Multitudes of organisms display metameric compartmentalization of their body plan. Segmentation of these compartments happens sequentially in diverse phyla. In several sequentially segmenting species, periodically active molecular clocks and signaling gradients have been found. The clocks are proposed to control the timing of segmentation, while the gradients are proposed to instruct the positions of segment boundaries. However, the identity of the clock and gradient molecules differs across species. Furthermore, sequential segmentation of a basal chordate, Amphioxus, continues at late stages when the small tail bud cell population cannot establish long-range signaling gradients. Thus, it remains to be explained how a conserved morphological trait (i.e., sequential segmentation) is achieved by using different molecules or molecules with different spatial profiles. Here, we first focus on sequential segmentation of somites in vertebrate embryos and then draw parallels with other species. Thereafter, we propose a candidate design principle that has the potential to answer this puzzling question.
Collapse
Affiliation(s)
- M Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, OH, USA
| | - Ertuğrul M Özbudak
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, OH, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, OH, USA
| |
Collapse
|
3
|
Abstract
In vitro models to study human somitogenesis, the formation of the segmented body plan, have so far been limited.1 Two papers in Nature now report the creation of pluripotent stem cell (PSC)-derived 3D culture systems that recapitulate the formation of somite-like structures and help gain insights into this developmental process.2,3.
Collapse
Affiliation(s)
- M Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Ertuğrul M Özbudak
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
| |
Collapse
|
4
|
Abstract
Metazoan embryos develop from a single cell into three-dimensional structured organisms while groups of genetically identical cells attain specialized identities. Cells of the developing embryo both create and accurately interpret morphogen gradients to determine their positions and make specific decisions in response. Here, we first cover intellectual roots of morphogen and positional information concepts. Focusing on animal embryos, we then provide a review of current understanding on how morphogen gradients are established and how their spans are controlled. Lastly, we cover how gradients evolve in time and space during development, and how they encode information to control patterning. In sum, we provide a list of patterning principles for morphogen gradients and review recent advances in quantitative methodologies elucidating information provided by morphogens.
Collapse
Affiliation(s)
- M. Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Ertuğrul M. Özbudak
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| |
Collapse
|
5
|
Simsek MF, Özbudak EM. A 3-D Tail Explant Culture to Study Vertebrate Segmentation in Zebrafish. J Vis Exp 2021. [PMID: 34279500 DOI: 10.3791/61981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Vertebrate embryos pattern their major body axis as repetitive somites, the precursors of vertebrae, muscle, and skin. Somites progressively segment from the presomitic mesoderm (PSM) as the tail end of the embryo elongates posteriorly. Somites form with regular periodicity and scale in size. Zebrafish is a popular model organism as it is genetically tractable and has transparent embryos that allow for live imaging. Nevertheless, during somitogenesis, fish embryos are wrapped around a large, rounding yolk. This geometry limits live imaging of PSM tissue in zebrafish embryos, particularly at higher resolutions that require a close objective working distance. Here, we present a flattened 3-D tissue culture method for live imaging of zebrafish tail explants. Tail explants mimic intact embryos by displaying a proportional slowdown of axis elongation and shortening of rostrocaudal somite lengths. We are further able to stall axis elongation speed through explant culture. This, for the first time, enables us to untangle the chemical input of signaling gradients from the mechanistic input of axial elongation. In future studies, this method can be combined with a microfluidic setup to allow time-controlled pharmaceutical perturbations or screening of vertebrate segmentation without any drug penetration concerns.
Collapse
Affiliation(s)
- M Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center; Department of Genetics, Albert Einstein College of Medicine;
| | - Ertugrul M Özbudak
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center; Department of Pediatrics, University of Cincinnati College of Medicine; Department of Genetics, Albert Einstein College of Medicine
| |
Collapse
|
6
|
Simsek MF, Özbudak EM. Spatial Fold Change of FGF Signaling Encodes Positional Information for Segmental Determination in Zebrafish. Cell Rep 2019; 24:66-78.e8. [PMID: 29972792 PMCID: PMC6063364 DOI: 10.1016/j.celrep.2018.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 05/08/2018] [Accepted: 06/05/2018] [Indexed: 01/15/2023] Open
Abstract
Signal gradients encode instructive information for numerous decision-making processes during embryonic development. A striking example of precise, scalable tissue-level patterning is the segmentation of somites—the precursors of the vertebral column—during which the fibroblast growth factor (FGF), Wnt, and retinoic acid (RA) pathways establish spatial gradients. Despite decades of studies proposing roles for all three pathways, the dynamic feature of these gradients that encodes instructive information determining segment sizes remained elusive. We developed a non-elongating tail explant system, integrated quantitative measurements with computational modeling, and tested alternative models to show that positional information is encoded solely by spatial fold change (SFC) in FGF signal output. Neighboring cells measure SFC to accurately position the determination front and thus determine segment size. The SFC model successfully recapitulates results of spatiotemporal perturbation experiments on both explants and intact embryos, and it shows that Wnt signaling acts permissively upstream of FGF signaling and that RA gradient is dispensable. Simsek et al. use an elongation-arrested 3D explant system, integrated with quantitative measurements and computational modeling, to show that positional information for segmentation is encoded solely by spatial fold change (SFC) in FGF signal output. Neighboring cells measure SFC to accurately determine somite segment sizes. Wnt signaling acts permissively upstream of FGF signaling.
Collapse
Affiliation(s)
- M Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ertuğrul M Özbudak
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| |
Collapse
|
7
|
Keskin S, Simsek MF, Vu HT, Yang C, Devoto SH, Ay A, Özbudak EM. Regulatory Network of the Scoliosis-Associated Genes Establishes Rostrocaudal Patterning of Somites in Zebrafish. iScience 2019; 12:247-259. [PMID: 30711748 PMCID: PMC6360518 DOI: 10.1016/j.isci.2019.01.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 12/31/2018] [Accepted: 01/16/2019] [Indexed: 12/22/2022] Open
Abstract
Gene regulatory networks govern pattern formation and differentiation during embryonic development. Segmentation of somites, precursors of the vertebral column among other tissues, is jointly controlled by temporal signals from the segmentation clock and spatial signals from morphogen gradients. To explore how these temporal and spatial signals are integrated, we combined time-controlled genetic perturbation experiments with computational modeling to reconstruct the core segmentation network in zebrafish. We found that Mesp family transcription factors link the temporal information of the segmentation clock with the spatial action of the fibroblast growth factor signaling gradient to establish rostrocaudal (head to tail) polarity of segmented somites. We further showed that cells gradually commit to patterning by the action of different genes at different spatiotemporal positions. Our study provides a blueprint of the zebrafish segmentation network, which includes evolutionarily conserved genes that are associated with the birth defect congenital scoliosis in humans. A core network establishes rostrocaudal polarity of segmented somites in zebrafish mesp genes link the segmentation clock with the FGF signaling gradient Gradual patterning is done by the action of different genes at different positions
Collapse
Affiliation(s)
- Sevdenur Keskin
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - M Fethullah Simsek
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Ha T Vu
- Departments of Biology and Mathematics, Colgate University, Hamilton, NY 13346, USA
| | - Carlton Yang
- Departments of Biology and Mathematics, Colgate University, Hamilton, NY 13346, USA
| | - Stephen H Devoto
- Department of Biology, Wesleyan University, Middletown, CT 06459, USA
| | - Ahmet Ay
- Departments of Biology and Mathematics, Colgate University, Hamilton, NY 13346, USA.
| | - Ertuğrul M Özbudak
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| |
Collapse
|
8
|
Abstract
It has been long recognized that the cell membrane is heterogeneous on scales ranging from a couple of molecules to micrometers in size and hence diffusion of receptors is length scale dependent. This heterogeneity modulates many cell-membrane-associated processes requiring transient spatiotemporal separation of components. The transient increase in local concentration of interacting signal components enables robust signaling in an otherwise thermally noisy system. Understanding how lipids and proteins self-organize and interact with the cell cortex requires quantifying the motion of the components. Multi-length scale diffusion measurements by single particle tracking, fluorescence correlation spectroscopy (FCS) or related techniques are able to identify components being transiently trapped in nanodomains, from freely moving one and from ones with reduced long-scale diffusion due to interaction with the cell cortex. One particular implementation of multi-length scale diffusion measurements is the combination of FCS with a spatially resolved detector, such as a camera and two-dimensional extended excitation profile. The main advantages of this approach are that all length scales are interrogated simultaneously, uniquely permits quantifying changes to the membrane structure caused by extrenal or internal perturbations. Here, we review how combining total internal reflection microscopy (TIRF) with FC resolves the membrane organization in living cells. We show how to implement the method, which requires only a few seconds of data acquisition to quantify membrane nanodomains, or the spacing of membrane fences caused by the actin cortex. The choice of diffusing fluorescent probe determines which membrane heterogeneity is detected. We review the instrument, sample preparation, experimental and computational requirements to perform such measurements, and discuss the potential and limitations. The discussion includes examples of spatial and temporal comparisons of the membrane structure in response to perturbations demonstrating the complex cell physiology.
Collapse
Affiliation(s)
- Weixiang Jin
- Dept. of Physics, 239 Fronczak Hall, University at Buffalo, SUNY, Buffalo, NY 14260-1500, United States
| | - M Fethullah Simsek
- Dept. of Physics, 239 Fronczak Hall, University at Buffalo, SUNY, Buffalo, NY 14260-1500, United States
| | - Arnd Pralle
- Dept. of Physics, 239 Fronczak Hall, University at Buffalo, SUNY, Buffalo, NY 14260-1500, United States.
| |
Collapse
|
9
|
Huang H, Simsek MF, Jin W, Pralle A. Effect of receptor dimerization on membrane lipid raft structure continuously quantified on single cells by camera based fluorescence correlation spectroscopy. PLoS One 2015; 10:e0121777. [PMID: 25811483 PMCID: PMC4374828 DOI: 10.1371/journal.pone.0121777] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 02/10/2015] [Indexed: 02/07/2023] Open
Abstract
Membrane bound cell signaling is modulated by the membrane ultra-structure, which itself may be affected by signaling. However, measuring the interaction of membrane proteins with membrane structures in intact cells in real-time poses considerable challenges. In this paper we present a non-destructive fluorescence method that quantifies these interactions in single cells, and is able to monitor the same cell continuously to observe small changes. This approach combines total internal fluorescence microscopy with fluorescence correlation spectroscopy to measure the protein's diffusion and molecular concentration in different sized areas simultaneously. It correctly differentiates proteins interacting with membrane fences from proteins interacting with cholesterol-stabilized domains, or lipid rafts. This method detects small perturbations of the membrane ultra-structure or of a protein's tendency to dimerize. Through continuous monitoring of single cells, we demonstrate how dimerization of GPI-anchored proteins increases their association with the structural domains. Using a dual-color approach we study the effect of dimerization of one GPI-anchored protein on another type of GPI-anchored protein expressed in the same cell. Scans over the cell surface reveal a correlation between cholesterol stabilized domains and membrane cytoskeleton.
Collapse
Affiliation(s)
- Heng Huang
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
| | - M. Fethullah Simsek
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
| | - Weixiang Jin
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
| | - Arnd Pralle
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
- Department of Biophysics and Physiology, University at Buffalo the State University of New York, Buffalo, New York, United States of America
- * E-mail:
| |
Collapse
|