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Glazenburg MM, Hettema NM, Laan L, Remy O, Laloux G, Brunet T, Chen X, Tee YH, Wen W, Rizvi MS, Jolly MK, Riddell M. Perspectives on polarity - exploring biological asymmetry across scales. J Cell Sci 2024; 137:jcs261987. [PMID: 38441500 DOI: 10.1242/jcs.261987] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024] Open
Abstract
In this Perspective, Journal of Cell Science invited researchers working on cell and tissue polarity to share their thoughts on unique, emerging or open questions relating to their field. The goal of this article is to feature 'voices' from scientists around the world and at various career stages, to bring attention to innovative and thought-provoking topics of interest to the cell biology community. These voices discuss intriguing questions that consider polarity across scales, evolution, development and disease. What can yeast and protists tell us about the evolution of cell and tissue polarity in animals? How are cell fate and development influenced by emerging dynamics in cell polarity? What can we learn from atypical and extreme polarity systems? How can we arrive at a more unified biophysical understanding of polarity? Taken together, these pieces demonstrate the broad relevance of the fascinating phenomenon of cell polarization to diverse fundamental biological questions.
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Affiliation(s)
- Marieke Margaretha Glazenburg
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2629 HZ, The Netherlands
| | - Nynke Marije Hettema
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2629 HZ, The Netherlands
| | - Liedewij Laan
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2629 HZ, The Netherlands
| | - Ophélie Remy
- Institut de Duve, UCLouvain, 75 avenue Hippocrate, 1200 Brussels, Belgium
| | - Géraldine Laloux
- Institut de Duve, UCLouvain, 75 avenue Hippocrate, 1200 Brussels, Belgium
| | - Thibaut Brunet
- Institut Pasteur, Université Paris-Cité, CNRS UMR 3691, Evolutionary Cell Biology and Evolution of Morphogenesis Unit, 25-28 rue du docteur Roux, 75015 Paris, France
| | - Xin Chen
- Howard Hughes Medical Institute and Department of Biology, Johns Hopkins University, Levi Hall 137, 3400 North Charles Street, Baltimore, MD 21218-2685, USA
| | - Yee Han Tee
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Wenyu Wen
- Department of Neurosurgery, Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Mohd Suhail Rizvi
- Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Sangareddy 502284, India
| | - Mohit Kumar Jolly
- Department of Bioengineering, Indian Institute of Science, Bangalore 560012, India
| | - Meghan Riddell
- Department of Physiology and Department of Obstetrics and Gynecology, University of Alberta, Edmonton, AB, T6G 2S2, Canada
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Lee SY, Robertson C, Diot A, Meuray V, Bourdon JC, Bissell MJ. Δ133p53 coordinates ECM-driven morphogenesis and gene expression in three-dimensional mammary epithelial acini. J Cell Sci 2022; 135:jcs259673. [PMID: 36239052 PMCID: PMC9687550 DOI: 10.1242/jcs.259673] [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: 12/09/2021] [Accepted: 09/24/2022] [Indexed: 11/20/2022] Open
Abstract
Growing evidence indicates that p53 (encoded by TP53) has a crucial role in normal tissue development. The role of the canonical p53 (p53α) and its 12 isoforms in development and homeostasis of healthy tissue remains poorly understood. Here, we demonstrate that the Δ133p53 isoforms, the three short isoforms of p53, respond specifically to laminin-111 and play an important regulatory role in formation of mammary organoids in concert with p53α. We demonstrate that down-modulation of Δ133p53 isoforms leads to changes in gene expression of the extracellular matrix molecules fibronectin (FN), EDA+-FN, laminin α5 and laminin α3 in human breast epithelial cells. These changes resulted in increased actin stress fibers and enhanced migratory behavior of cells in two-dimensional culture. We found that α5β1-integrin coupled with the extracellularly deposited EDA+-FN activates the Akt signaling pathway in three-dimensional (3D) culture when Δ133p53 is dysregulated. Cells that do not express detectable Δ133p53 isoforms or express low levels of these isoforms failed to form polarized structures in 3D. These results uncover that Δ133p53 isoforms coordinate expression and deposition of organ-specific ECM molecules that are critical for maintenance of tissue architecture and function.
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Affiliation(s)
- Sun-Young Lee
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Claire Robertson
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Material Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Alexandra Diot
- Jacqui Wood Cancer Centre, School of Medicine, University of Dundee, Dundee DD1 9SY, UK
| | - Valerie Meuray
- Jacqui Wood Cancer Centre, School of Medicine, University of Dundee, Dundee DD1 9SY, UK
| | | | - Mina J. Bissell
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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Cravo J, van den Heuvel S. Tissue polarity and PCP protein function: C. elegans as an emerging model. Curr Opin Cell Biol 2019; 62:159-167. [PMID: 31884395 DOI: 10.1016/j.ceb.2019.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/14/2019] [Accepted: 11/19/2019] [Indexed: 12/14/2022]
Abstract
Polarity is the basis for the generation of cell diversity, as well as the organization, morphogenesis, and functioning of tissues. Studies in Caenorhabditis elegans have provided much insight into PAR-protein mediated polarity; however, the molecules and mechanisms critical for cell polarization within the plane of epithelia have been identified in other systems. Tissue polarity in C. elegans is organized by Wnt-signaling with some resemblance to the Wnt/planar cell polarity (PCP) pathway, but lacking core PCP protein functions. Nonetheless, recent studies revealed that conserved PCP proteins regulate directed cell migratory events in C. elegans, such as convergent extension movements and neurite formation and guidance. Here, we discuss the latest insights and use of C. elegans as a PCP model.
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Affiliation(s)
- Janine Cravo
- Developmental Biology, Department of Biology, Faculty of Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands
| | - Sander van den Heuvel
- Developmental Biology, Department of Biology, Faculty of Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, the Netherlands.
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Hirashima T, Adachi T. Polarized cellular mechano-response system for maintaining radial size in developing epithelial tubes. Development 2019; 146:dev.181206. [PMID: 31619390 PMCID: PMC6918744 DOI: 10.1242/dev.181206] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/07/2019] [Indexed: 12/31/2022]
Abstract
Size control in biological tissues involves multicellular communication via mechanical forces during development. Although fundamental cellular behaviours in response to mechanical stimuli underlie size maintenance during morphogenetic processes, the mechanisms underpinning the cellular mechano-response system that maintains size along an axis of a polarized tissue remain elusive. Here, we show how the diameter of an epithelial tube is maintained during murine epididymal development by combining quantitative imaging, mechanical perturbation and mathematical modelling. We found that epithelial cells counteract compressive forces caused by cell division exclusively along the circumferential axis of the tube to produce polarized contractile forces, eventually leading to an oriented cell rearrangement. Moreover, a mathematical model that includes the polarized mechano-responsive regime explains how the diameter of proliferating tubes is maintained. Our findings pave the way for an improved understanding of the cellular response to mechanical forces that involves collective multicellular behaviours for organizing diverse tissue morphologies. Summary: Polarized cellular constriction responding to mechanical stress controls the diameter of a developing epithelial tube during murine epididymal development.
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Affiliation(s)
- Tsuyoshi Hirashima
- Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, 6068501, Kyoto, Japan .,Institute for Frontier Life and Medical Sciences, Kyoto University, 6068501, Kyoto, Japan
| | - Taiji Adachi
- Institute for Frontier Life and Medical Sciences, Kyoto University, 6068501, Kyoto, Japan
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Abstract
Cadherin EGF LAG seven-pass G-type receptors 1, 2 and 3 (CELSR1-3) form a family of three atypical cadherins with multiple functions in epithelia and in the nervous system. During the past decade, evidence has accumulated for a key role of CELSR1 in epithelial planar cell polarity (PCP), and for CELSR2 and CELSR3 in ciliogenesis and neural development, especially neuron migration and axon guidance in the central, peripheral and enteric nervous systems. Phenotypes in mutant mice indicate that CELSR proteins work in concert with FZD3 and FZD6, but several questions remain. Apart from PCP signaling pathways implicating CELSR1 that begin to be unraveled, little is known about other signals generated by CELSR2 and CELSR3. A crucial question concerns the putative ligands that trigger signaling, in particular what is the role of WNT factors. Another critical issue is the identification of novel intracellular pathways and effectors that relay and transmit signals in receptive cells? Answers to those questions should further our understanding of the role of those important molecules not only in development but also in regeneration and disease.
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Avilés EC, Goodrich LV. Configuring a robust nervous system with Fat cadherins. Semin Cell Dev Biol 2017; 69:91-101. [PMID: 28603077 DOI: 10.1016/j.semcdb.2017.06.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/26/2017] [Accepted: 06/07/2017] [Indexed: 01/14/2023]
Abstract
Atypical Fat cadherins represent a small but versatile group of signaling molecules that influence proliferation and tissue polarity. With huge extracellular domains and intracellular domains harboring many independent protein interaction sites, Fat cadherins are poised to translate local cell adhesion events into a variety of cell behaviors. The need for such global coordination is particularly prominent in the nervous system, where millions of morphologically diverse neurons are organized into functional networks. As we learn more about their biological functions and molecular properties, increasing evidence suggests that Fat cadherins mediate contact-induced changes that ultimately impose a structure to developing neuronal circuits.
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Farley RD. Book lung development in embryos of the cobweb spider, Parasteatoda tepidariorum C. L. Koch, 1841 (Araneomorphae, Theridiidae). Arthropod Struct Dev 2016; 45:562-584. [PMID: 27693811 DOI: 10.1016/j.asd.2016.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/19/2016] [Accepted: 09/22/2016] [Indexed: 06/06/2023]
Abstract
Light and transmission electron microscopy were used to study the development of book lungs in embryos of the spider Parasteatoda tepidariorum. There is a bilateral cluster of temporary lamellae that form just posterior to the second opisthosomal (O2) limb buds. These lamellae are replaced by advanced embryo (AE) book lungs that continue into postembryonic stages. Results herein agree with earlier suggestions that the O2 limb buds become the AE book lungs. Each O2 limb bud merges with the ventral surface of the O2 segment, where the limb bud/book lung is internalized by covering with epidermis. A strand of tissue (entapophysis) from the epidermis at the posterior opisthosoma provides precursor cells for the book lung lamellae, and possibly entapophysis cells induce limb bud cells to align and produce lamellae. Electron micrographs show the different modes (I-III) of lumen formation. The result is a spiracle, atrium and alternating air and hemolymph channels. A hypothesis is presented for the role of precursor cell polarity in producing the planar tissue polarity of the channels. Some type of apical/apical affinity results in air channels, while basal/basal affinity results in hemolymph channels. Strong basal/basal affinity is likely as opposed cells in hemolymph channels extend basal processes that span the channel and start pillar trabeculae that continue in postembryonic stages.
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Affiliation(s)
- Roger D Farley
- Department of Biology, University of California, Riverside, CA 92521, USA.
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Li L, Chen J, Xiong G, St Clair DK, Xu W, Xu R. Increased ROS production in non-polarized mammary epithelial cells induces monocyte infiltration in 3D culture. J Cell Sci 2016; 130:190-202. [PMID: 27656113 DOI: 10.1242/jcs.186031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 08/17/2016] [Indexed: 02/01/2023] Open
Abstract
Loss of epithelial cell polarity promotes cell invasion and cancer dissemination. Therefore, identification of factors that disrupt polarized acinar formation is crucial. Reactive oxygen species (ROS) drive cancer progression and promote inflammation. Here, we show that the non-polarized breast cancer cell line T4-2 generates significantly higher ROS levels than polarized S1 and T4R cells in three-dimensional (3D) culture, accompanied by induction of the nuclear factor κB (NF-κB) pathway and cytokine expression. Minimizing ROS in T4-2 cells with antioxidants reestablished basal polarity and inhibited cell proliferation. Introducing constitutively activated RAC1 disrupted cell polarity and increased ROS levels, indicating that RAC1 is a crucial regulator that links cell polarity and ROS generation. We also linked monocyte infiltration with disruption of polarized acinar structure using a 3D co-culture system. Gain- and loss-of-function experiments demonstrated that increased ROS in non-polarized cells is necessary and sufficient to enhance monocyte recruitment. ROS also induced cytokine expression and NF-κB activity. These results suggest that increased ROS production in mammary epithelial cell leads to disruption of cell polarity and promotes monocyte infiltration.
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Affiliation(s)
- Linzhang Li
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province 130021, China.,Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Jie Chen
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Gaofeng Xiong
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Daret K St Clair
- Toxicology and Cancer Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Wei Xu
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, Jilin Province 130021, China
| | - Ren Xu
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA .,Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40536, USA
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Abstract
Frizzled proteins are the principal receptors for the Wnt family of ligands. They mediate canonical Wnt signaling together with Lrp5 and Lrp6 coreceptors. In conjunction with Celsr, Vangl, and a small number of additional membrane and membrane-associated proteins, they also play a central role in tissue polarity/planar cell polarity (PCP) signaling. Targeted mutations in 9 of the 10 mammalian Frizzled genes have revealed their roles in an extraordinarily diverse set of developmental and homeostatic processes, including morphogenetic movements responsible for palate, ventricular septum, ocular furrow, and neural tube closure; survival of thalamic neurons; bone formation; central nervous system (CNS) angiogenesis and blood-brain barrier formation and maintenance; and a wide variety of processes that orient subcellular, cellular, and multicellular structures relative to the body axes. The last group likely reflects the mammalian equivalent of tissue polarity/PCP signaling, as defined in Drosophila, and it includes CNS axon guidance, hair follicle and tongue papilla orientation, and inner ear sensory hair bundle orientation. Frizzled receptors are ubiquitous among multicellular animals and, with other signaling molecules, they very likely evolved to permit the development of the complex tissue architectures that provide multicellular animals with their enormous selective advantage.
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Affiliation(s)
- Yanshu Wang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hao Chang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Amir Rattner
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jeremy Nathans
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Chang H, Smallwood PM, Williams J, Nathans J. The spatio-temporal domains of Frizzled6 action in planar polarity control of hair follicle orientation. Dev Biol 2015; 409:181-193. [PMID: 26517967 DOI: 10.1016/j.ydbio.2015.10.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 10/16/2015] [Indexed: 12/26/2022]
Abstract
In mammals, hair follicles cover most of the body surface and exhibit precise and stereotyped orientations relative to the body axes. Follicle orientation is controlled by the planar cell polarity (PCP; or, more generally, tissue polarity) system, as determined by the follicle mis-orientation phenotypes observed in mice with PCP gene mutations. The present study uses conditional knockout alleles of the PCP genes Frizzled6 (Fz6), Vangl1, and Vangl2, together with a series of Cre drivers to interrogate the spatio-temporal domains of PCP gene action in the developing mouse epidermis required for follicle orientation. Fz6 is required starting between embryonic day (E)11.5 and E12.5. Eliminating Fz6 in either the anterior or the posterior halves of the embryo or in either the feet or the torso leads to follicle mis-orientation phenotypes that are limited to the territories associated with Fz6 loss, implying either that PCP signaling is required for communicating polarity information on a local but not a global scale, or that there are multiple independent sources of global polarity information. Eliminating Fz6 in most hair follicle cells or in the inter-follicular epidermis at E15.5 suggests that PCP signaling in developing follicles is not required to maintain their orientation. The asymmetric arrangement of Merkel cells around the base of each guard hair follicle dependents on Fz6 expression in the epidermis but not in differentiating Merkel cells. These experiments constrain current models of PCP signaling and the flow of polarity information in mammalian skin.
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Affiliation(s)
- Hao Chang
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - Philip M Smallwood
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - John Williams
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States
| | - Jeremy Nathans
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States.
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Nübler-Jung K. Insect epidermis: disturbance of supracellular tissue polarity does not prevent the expression of cell polarity. ACTA ACUST UNITED AC 1987; 196:286-289. [PMID: 28305549 DOI: 10.1007/bf00395951] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/1986] [Accepted: 07/21/1986] [Indexed: 11/24/2022]
Abstract
The insect integument displays planar tissue polarity in the uniform orientation of polarized cuticular structures. In a body segment, for example, the denticles and bristles produced by the constituent epidermal cells point posteriorly. Colchicine can abolish this uniform orientation while still allowing individual cells to form orientated cuticular structures and thereby to express cell polarity. This suggests that an individual cell in a sheet can establish planar polarity without reference to some kind of covert supracellular cue (such as a morphogen gradient) in the epidermis as a whole. The results also indicate that colchicine interferes - directly or indirectly - with the mechanisms involved in aligning the polarity axes of individual cells into a common orientation, thereby generating supracellular or tissue polarity.
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Affiliation(s)
- Katharina Nübler-Jung
- Institut für Biologie I (Zoologie), Albert-Ludwigs-Universität Freiburg, Albertstraße 21 a, D-7800, Freiburg i.Br., Federal Republic of Germany
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Nübler-Jung K, Grau V. Pattern control in insect segments: superimposed features of the pattern may be subject to different control mechanisms. ACTA ACUST UNITED AC 1987; 196:290-294. [PMID: 28305550 DOI: 10.1007/bf00395952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/1986] [Accepted: 01/26/1987] [Indexed: 10/26/2022]
Abstract
The integument of an insect segment displays two distinct pattern features which are based on different properties of the constituent epidermal cells. Normally, the uniform orientation of epidermal cell polarities ("polarity pattern") is strictly correlated with the sequence of differentiated cells ("differentiation pattern"). Here it is reported that in the integument of the cotton bug Dysdercus epidermal cells can adopt orientations that do not correlate with the pigmentation pattern and which are not compatible with the gradient model. The results indicate that different features of a composite pattern can be independently controlled.
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Affiliation(s)
- Katharina Nübler-Jung
- Institut für Biologie I (Zoologie), Albert-Ludwigs-Universität Freiburg, Albertstraße 21 a, D-7800, Freiburg i.Br., Federal Republic of Germany
| | - Veronika Grau
- Institut für Biologie I (Zoologie), Albert-Ludwigs-Universität Freiburg, Albertstraße 21 a, D-7800, Freiburg i.Br., Federal Republic of Germany
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