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Iwanaga R, Yahagi N, Hakeda‐Suzuki S, Suzuki T. Cell adhesion and actin dynamics factors promote axonal extension and synapse formation in transplanted Drosophila photoreceptor cells. Dev Growth Differ 2024; 66:205-218. [PMID: 38403285 PMCID: PMC11457513 DOI: 10.1111/dgd.12916] [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: 11/24/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/27/2024]
Abstract
Vision is formed by the transmission of light stimuli to the brain through axons extending from photoreceptor cells. Damage to these axons leads to loss of vision. Despite research on neural circuit regeneration through transplantation, achieving precise axon projection remains challenging. To achieve optic nerve regeneration by transplantation, we employed the Drosophila visual system. We previously established a transplantation method for Drosophila utilizing photoreceptor precursor cells extracted from the eye disc. However, little axonal elongation of transplanted cells into the brain, the lamina, was observed. We verified axonal elongation to the lamina by modifying the selection process for transplanted cells. Moreover, we focused on N-cadherin (Ncad), a cell adhesion factor, and Twinstar (Tsr), which has been shown to promote actin reorganization and induce axon elongation in damaged nerves. Overexpression of Ncad and tsr promoted axon elongation to the lamina, along with presynaptic structure formation in the elongating axons. Furthermore, overexpression of Neurexin-1 (Nrx-1), encoding a protein identified as a synaptic organizer, was found to not only promote presynapse formation but also enhance axon elongation. By introducing Ncad, tsr, and Nrx-1, we not only successfully achieved axonal projection of transplanted cells to the brain beyond the retina, but also confirmed the projection of transplanted cells into a deeper ganglion, the medulla. The present study offers valuable insights to realize regeneration through transplantation in a more complex nervous system.
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Affiliation(s)
- Riku Iwanaga
- School of Life Science and Technology, Tokyo Institute of TechnologyYokahamaJapan
| | - Nagisa Yahagi
- School of Life Science and Technology, Tokyo Institute of TechnologyYokahamaJapan
| | - Satoko Hakeda‐Suzuki
- School of Life Science and Technology, Tokyo Institute of TechnologyYokahamaJapan
- Research Initiatives and Promotion OrganizationYokohama National UniversityYokohamaJapan
| | - Takashi Suzuki
- School of Life Science and Technology, Tokyo Institute of TechnologyYokahamaJapan
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2
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Sun X, Decker J, Sanchez-Luege N, Rebay I. Inter-plane feedback coordinates cell morphogenesis and maintains 3D tissue organization in the Drosophila pupal retina. Development 2024; 151:dev201757. [PMID: 38533736 PMCID: PMC11006395 DOI: 10.1242/dev.201757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 01/12/2024] [Indexed: 03/28/2024]
Abstract
How complex organs coordinate cellular morphogenetic events to achieve three-dimensional (3D) form is a central question in development. The question is uniquely tractable in the late Drosophila pupal retina, where cells maintain stereotyped contacts as they elaborate the specialized cytoskeletal structures that pattern the apical, basal and longitudinal planes of the epithelium. In this study, we combined cell type-specific genetic manipulation of the cytoskeletal regulator Abelson (Abl) with 3D imaging to explore how the distinct cellular morphogenetic programs of photoreceptors and interommatidial pigment cells (IOPCs) organize tissue pattern to support retinal integrity. Our experiments show that photoreceptor and IOPC terminal differentiation is unexpectedly interdependent, connected by an intercellular feedback mechanism that coordinates and promotes morphogenetic change across orthogonal tissue planes to ensure correct 3D retinal pattern. We propose that genetic regulation of specialized cellular differentiation programs combined with inter-plane mechanical feedback confers spatial coordination to achieve robust 3D tissue morphogenesis.
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Affiliation(s)
- Xiao Sun
- Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Jacob Decker
- Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Nicelio Sanchez-Luege
- Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Ilaria Rebay
- Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA
- Ben May Department for Cancer Research, University of Chicago, Chicago, IL 60637, USA
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3
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Gazsó-Gerhát G, Gombos R, Tóth K, Kaltenecker P, Szikora S, Bíró J, Csapó E, Asztalos Z, Mihály J. FRL and DAAM are required for lateral adhesion of interommatidial cells and patterning of the retinal floor. Development 2023; 150:dev201713. [PMID: 37997920 PMCID: PMC10690107 DOI: 10.1242/dev.201713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 10/17/2023] [Indexed: 11/25/2023]
Abstract
Optical insulation of the unit eyes (ommatidia) is an important prerequisite of precise sight with compound eyes. Separation of the ommatidia is ensured by pigment cells that organize into a hexagonal lattice in the Drosophila eye, forming thin walls between the facets. Cell adhesion, mediated by apically and latero-basally located junctional complexes, is crucial for stable attachment of these cells to each other and the basal lamina. Whereas former studies have focused on the formation and remodelling of the cellular connections at the apical region, here, we report a specific alteration of the lateral adhesion of the lattice cells, leaving the apical junctions largely unaffected. We found that DAAM and FRL, two formin-type cytoskeleton regulatory proteins, play redundant roles in lateral adhesion of the interommatidial cells and patterning of the retinal floor. We show that formin-dependent cortical actin assembly is crucial for latero-basal sealing of the ommatidial lattice. We expect that the investigation of these previously unreported eye phenotypes will pave the way toward a better understanding of the three-dimensional aspects of compound eye development.
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Affiliation(s)
- Gabriella Gazsó-Gerhát
- Institute of Genetics, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged H-6726, Hungary
- Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged H-6726, Hungary
| | - Rita Gombos
- Institute of Genetics, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged H-6726, Hungary
| | - Krisztina Tóth
- Institute of Genetics, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged H-6726, Hungary
| | - Péter Kaltenecker
- Institute of Genetics, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged H-6726, Hungary
| | - Szilárd Szikora
- Institute of Genetics, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged H-6726, Hungary
| | - Judit Bíró
- Aktogen Hungary Ltd., Szeged H-6726, Hungary
| | - Enikő Csapó
- Aktogen Hungary Ltd., Szeged H-6726, Hungary
| | - Zoltán Asztalos
- Institute of Biochemistry, HUN-REN Biological Research Centre, Szeged H-6726, Hungary
| | - József Mihály
- Institute of Genetics, HUN-REN Biological Research Centre, Temesvári krt. 62, Szeged H-6726, Hungary
- Department of Genetics, University of Szeged, Szeged H-6726, Hungary
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Sun X, Decker J, Sanchez-Luege N, Rebay I. Orthogonal coupling of a 3D cytoskeletal scaffold coordinates cell morphogenesis and maintains tissue organization in the Drosophila pupal retina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.531386. [PMID: 36945525 PMCID: PMC10028844 DOI: 10.1101/2023.03.06.531386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
How complex three-dimensional (3D) organs coordinate cellular morphogenetic events to achieve the correct final form is a central question in development. The question is uniquely tractable in the late Drosophila pupal retina where cells maintain stereotyped contacts as they elaborate the specialized cytoskeletal structures that pattern the apical, basal and longitudinal planes of the epithelium. In this study, we combined cell type-specific genetic manipulation of the cytoskeletal regulator Abelson (Abl) with 3D imaging to explore how the distinct cellular morphogenetic programs of photoreceptors and interommatidial pigment cells coordinately organize tissue pattern to support retinal integrity. Our experiments revealed an unanticipated intercellular feedback mechanism whereby correct cellular differentiation of either cell type can non-autonomously induce cytoskeletal remodeling in the other Abl mutant cell type, restoring retinal pattern and integrity. We propose that genetic regulation of specialized cellular differentiation programs combined with inter-plane mechanical feedback confers spatial coordination to achieve robust 3D tissue morphogenesis.
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5
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Skouloudaki K, Papadopoulos DK, Hurd TW. The Molecular Network of YAP/Yorkie at the Cell Cortex and their Role in Ocular Morphogenesis. Int J Mol Sci 2020; 21:ijms21228804. [PMID: 33233821 PMCID: PMC7699867 DOI: 10.3390/ijms21228804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 12/11/2022] Open
Abstract
During development, the precise control of tissue morphogenesis requires changes in the cell number, size, shape, position, and gene expression, which are driven by both chemical and mechanical cues from the surrounding microenvironment. Such physical and architectural features inform cells about their proliferative and migratory capacity, enabling the formation and maintenance of complex tissue architecture. In polarised epithelia, the apical cell cortex, a thin actomyosin network that lies directly underneath the apical plasma membrane, functions as a platform to facilitate signal transmission between the external environment and downstream signalling pathways. One such signalling pathway culminates in the regulation of YES-associated protein (YAP) and TAZ transcriptional co-activators and their sole Drosophila homolog, Yorkie, to drive proliferation and differentiation. Recent studies have demonstrated that YAP/Yorkie exhibit a distinct function at the apical cell cortex. Here, we review recent efforts to understand the mechanisms that regulate YAP/Yki at the apical cell cortex of epithelial cells and how normal and disturbed YAP-actomyosin networks are involved in eye development and disease.
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Hebbar S, Schuhmann K, Shevchenko A, Knust E. Hydroxylated sphingolipid biosynthesis regulates photoreceptor apical domain morphogenesis. J Cell Biol 2020; 219:211460. [PMID: 33048164 PMCID: PMC7557679 DOI: 10.1083/jcb.201911100] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 08/07/2020] [Accepted: 09/08/2020] [Indexed: 01/04/2023] Open
Abstract
Apical domains of epithelial cells often undergo dramatic changes during morphogenesis to form specialized structures, such as microvilli. Here, we addressed the role of lipids during morphogenesis of the rhabdomere, the microvilli-based photosensitive organelle of Drosophila photoreceptor cells. Shotgun lipidomics analysis performed on mutant alleles of the polarity regulator crumbs, exhibiting varying rhabdomeric growth defects, revealed a correlation between increased abundance of hydroxylated sphingolipids and abnormal rhabdomeric growth. This could be attributed to an up-regulation of fatty acid hydroxylase transcription. Indeed, direct genetic perturbation of the hydroxylated sphingolipid metabolism modulated rhabdomere growth in a crumbs mutant background. One of the pathways targeted by sphingolipid metabolism turned out to be the secretory route of newly synthesized Rhodopsin, a major rhabdomeric protein. In particular, altered biosynthesis of hydroxylated sphingolipids impaired apical trafficking via Rab11, and thus apical membrane growth. The intersection of lipid metabolic pathways with apical domain growth provides a new facet to our understanding of apical growth during morphogenesis.
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Mishra M, Knust E. Analysis of the Drosophila Compound Eye with Light and Electron Microscopy. Methods Mol Biol 2019; 1834:345-364. [PMID: 30324454 DOI: 10.1007/978-1-4939-8669-9_22] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The Drosophila compound eye is composed of about 750 units, called ommatidia, which are arranged in a highly regular pattern. Eye development proceeds in a stereotypical fashion, where epithelial cells of the eye imaginal discs are specified, recruited, and differentiated in a sequential order that leads to the highly precise structure of an adult eye. Even small perturbations, for example in signaling pathways that control proliferation, cell death, or differentiation, can impair the regular structure of the eye, which can be easily detected and analyzed. In addition, the Drosophila eye has proven to be an ideal model for studying the genetic control of neurodegeneration, since the eye is not essential for viability. Several human neurodegeneration diseases have been modeled in the fly, leading to a better understanding of the function/misfunction of the respective gene. In many cases, the genes involved and their functions are conserved between flies and human. More strikingly, when ectopically expressed in the fly eye some human genes, even those without a Drosophila counterpart, can induce neurodegeneration, detectable by aberrant phototaxis, impaired electrophysiology, or defects in eye morphology and retinal histology. These defects are often rather subtle alteration in shape, size, or arrangement of the cells, and can be easily scored at the ultrastructural level. This chapter aims to provide an overview regarding the analysis of the retina by light and electron microscopy.
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Affiliation(s)
- Monalisa Mishra
- National Institute of Technology Rourkela (NITR), Rourkela, Odisha, India
| | - Elisabeth Knust
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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8
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Structure, dynamics, and biochemical characterization of ADF/cofilin Twinstar from Drosophilamelanogaster. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:885-898. [PMID: 29709602 DOI: 10.1016/j.bbapap.2018.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 04/25/2018] [Accepted: 04/25/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Twinstar is an ADF/cofilin family protein, which is expressed by the tsr gene in Drosophila melanogaster. Twinstar is one of the main regulators of actin cytoskeleton remodelling and is essential for vital cellular processes like cytokinesis and endocytosis. METHODS We have characterized the structure and dynamics of Twinstar by solution NMR spectroscopy, the interaction of Twinstar with rabbit muscle actin by ITC, and biochemical activities of Twinstar through different biochemical assays using fluorescence spectroscopy and ultra-centrifugation. RESULTS The solution structure of Twinstar shows characteristic ADF-H fold with well-formed G/F-site and F-site for interaction with actin. The structure possesses an extended F-loop, which is rigid at the base, but flexible towards its apical region. Twinstar shares similar dynamics for the G/F-site with C. elegans homologs, UNC-60A and UNC-60B. However, the dynamics of its F-loop are different from its C. elegans homologs. Twinstar shows strong affinity for ADP-G-Actin and ATP-G-Actin with Kds of ~7.6 nM and ~0.4 μM, respectively. It shows mild F-actin depolymerizing activity and stable interaction with F-actin with a Kd of ~5.0 μM. It inhibits the rate of the nucleotide exchange in a dose dependent manner. CONCLUSION On the basis of structure, dynamics, and biochemical activity, Twinstar can be taken to execute its biochemical role by facilitating directional growth and maintenance of length of actin filaments. GENERAL SIGNIFICANCE This study characterizes the structure, backbone dynamics, and biochemical activities of Twinstar of Drosophila, which provides an insight into the regulation of actin dynamics in the member of phylum insecta.
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9
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Twinstar/cofilin is required for regulation of epithelial integrity and tissue growth in Drosophila. Oncogene 2016; 35:5144-54. [DOI: 10.1038/onc.2016.46] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 01/12/2016] [Accepted: 02/08/2016] [Indexed: 12/14/2022]
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Wang D, Naydenov NG, Feygin A, Baranwal S, Kuemmerle JF, Ivanov AI. Actin-Depolymerizing Factor and Cofilin-1 Have Unique and Overlapping Functions in Regulating Intestinal Epithelial Junctions and Mucosal Inflammation. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:844-58. [PMID: 26878213 DOI: 10.1016/j.ajpath.2015.11.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/28/2015] [Accepted: 11/18/2015] [Indexed: 12/29/2022]
Abstract
The actin cytoskeleton is a crucial regulator of the intestinal mucosal barrier, controlling the assembly and function of epithelial adherens and tight junctions (AJs and TJs). Junction-associated actin filaments are dynamic structures that undergo constant turnover. Members of the actin-depolymerizing factor (ADF) and cofilin protein family play key roles in actin dynamics by mediating filament severing and polymerization. We examined the roles of ADF and cofilin-1 in regulating the structure and functions of AJs and TJs in the intestinal epithelium. Knockdown of either ADF or cofilin-1 by RNA interference increased the paracellular permeability of human colonic epithelial cell monolayers to small ions. Additionally, cofilin-1, but not ADF, depletion increased epithelial permeability to large molecules. Loss of either ADF or cofilin-1 did not affect the steady-state morphology of AJs and TJs but attenuated de novo junctional assembly. The observed defects in AJ and TJ formation were accompanied by delayed assembly of the perijunctional filamentous actin belt. A total loss of ADF expression in mice did not result in a defective mucosal barrier or in spontaneous gut inflammation. However, ADF-null mice demonstrated increased intestinal permeability and exaggerated inflammation during dextran sodium sulfate-induced colitis. Our findings demonstrate novel roles for ADF and cofilin-1 in regulating the remodeling and permeability of epithelial junctions, as well as the role of ADF in limiting the severity of intestinal inflammation.
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Affiliation(s)
- Dongdong Wang
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Nayden G Naydenov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Alex Feygin
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - Somesh Baranwal
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
| | - John F Kuemmerle
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Andrei I Ivanov
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia; Virginia Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, Virginia; VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia.
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Ohashi K. Roles of cofilin in development and its mechanisms of regulation. Dev Growth Differ 2015; 57:275-90. [DOI: 10.1111/dgd.12213] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 02/06/2023]
Affiliation(s)
- Kazumasa Ohashi
- Department of Biomolecular Sciences; Graduate School of Life Sciences; Tohoku University; Sendai Miyagi 980-8578 Japan
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12
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Grego-Bessa J, Hildebrand J, Anderson KV. Morphogenesis of the mouse neural plate depends on distinct roles of cofilin 1 in apical and basal epithelial domains. Development 2015; 142:1305-14. [PMID: 25742799 DOI: 10.1242/dev.115493] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The genetic control of mammalian epithelial polarity and dynamics can be studied in vivo at cellular resolution during morphogenesis of the mouse neural tube. The mouse neural plate is a simple epithelium that is transformed into a columnar pseudostratified tube over the course of ∼ 24 h. Apical F-actin is known to be important for neural tube closure, but the precise roles of actin dynamics in the neural epithelium are not known. To determine how the organization of the neural epithelium and neural tube closure are affected when actin dynamics are blocked, we examined the cellular basis of the neural tube closure defect in mouse mutants that lack the actin-severing protein cofilin 1 (CFL1). Although apical localization of the adherens junctions, the Par complex, the Crumbs complex and SHROOM3 is normal in the mutants, CFL1 has at least two distinct functions in the apical and basal domains of the neural plate. Apically, in the absence of CFL1 myosin light chain does not become phosphorylated, indicating that CFL1 is required for the activation of apical actomyosin required for neural tube closure. On the basal side of the neural plate, loss of CFL1 has the opposite effect on myosin: excess F-actin and myosin accumulate and the ectopic myosin light chain is phosphorylated. The basal accumulation of F-actin is associated with the assembly of ectopic basal tight junctions and focal disruptions of the basement membrane, which eventually lead to a breakdown of epithelial organization.
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Affiliation(s)
- Joaquim Grego-Bessa
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Jeffrey Hildebrand
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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Gurudev N, Yuan M, Knust E. chaoptin, prominin, eyes shut and crumbs form a genetic network controlling the apical compartment of Drosophila photoreceptor cells. Biol Open 2014; 3:332-41. [PMID: 24705015 PMCID: PMC4021355 DOI: 10.1242/bio.20147310] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The apical surface of epithelial cells is often highly specialised to fulfil cell type-specific functions. Many epithelial cells expand their apical surface by forming microvilli, actin-based, finger-like membrane protrusions. The apical surface of Drosophila photoreceptor cells (PRCs) forms tightly packed microvilli, which are organised into the photosensitive rhabdomeres. As previously shown, the GPI-anchored adhesion protein Chaoptin is required for the stability of the microvilli, whereas the transmembrane protein Crumbs is essential for proper rhabdomere morphogenesis. Here we show that chaoptin synergises with crumbs to ensure optimal rhabdomere width. In addition, reduction of crumbs ameliorates morphogenetic defects observed in PRCs mutant for prominin and eyes shut, known antagonists of chaoptin. These results suggest that these four genes provide a balance of adhesion and anti-adhesion to maintain microvilli development and maintenance. Similar to crumbs mutant PRCs, PRCs devoid of prominin or eyes shut undergo light-dependent retinal degeneration. Given the observation that human orthologues of crumbs, prominin and eyes shut result in progressive retinal degeneration and blindness, the Drosophila eye is ideally suited to unravel the genetic and cellular mechanisms that ensure morphogenesis of PRCs and their maintenance under light-mediated stress.
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Affiliation(s)
- Nagananda Gurudev
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
| | - Michaela Yuan
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
| | - Elisabeth Knust
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
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Jin K, Ren DD, Chi FL, Yang JM, Huang YB, Li W. Changes in ADF/destrin expression in the development of hair cells following Atoh1-induced ectopic regeneration. Exp Ther Med 2013; 6:177-183. [PMID: 23935742 PMCID: PMC3735608 DOI: 10.3892/etm.2013.1089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Accepted: 04/08/2013] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to investigate the effects of actin depolymerizing factor (ADF)/destrin and position changes of kinetosomes in the development of hair cells following Atoh1-induced ectopic regeneration in the basilar membrane of mice. We observed through immunofluorescence at various time-points the expression of ADF/destrin and the specific kinetosome marker, γ-tubulin, in hair cells following ectopic regeneration induced by adenovirus transfection, overexpression of Atoh1 and in vitro culture. Changes of ADF/destrin distribution and kinetosome position during in vitro culture of new hair cells [Myo7a(+)] following Atoh1-induced ectopic regeneration are consistent with the changes in ADF/destrin expression and the polar migration of kinetosomes in hair cells of the cochlear sensory epithelium in normal development. ADF/destrin is involved in the development of the auditory epithelium and the development and structural rearrangement of ectopically regenerated hair cells in mammals. The kinetosomes of hair cells following Atoh1-induced ectopic regeneration show positional changes in vitro at different time-points.
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Affiliation(s)
- Kai Jin
- Department of Otolaryngology, Otology and Skull Base Surgery
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15
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Szarama KB, Gavara N, Petralia RS, Chadwick RS, Kelley MW. Thyroid hormone increases fibroblast growth factor receptor expression and disrupts cell mechanics in the developing organ of corti. BMC DEVELOPMENTAL BIOLOGY 2013; 13:6. [PMID: 23394545 PMCID: PMC3598248 DOI: 10.1186/1471-213x-13-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 01/29/2013] [Indexed: 01/13/2023]
Abstract
Background Thyroid hormones regulate growth and development. However, the molecular mechanisms by which thyroid hormone regulates cell structural development are not fully understood. The mammalian cochlea is an intriguing system to examine these mechanisms, as cellular structure plays a key role in tissue development, and thyroid hormone is required for the maturation of the cochlea in the first postnatal week. Results In hypothyroid conditions, we found disruptions in sensory outer hair cell morphology and fewer microtubules in non-sensory supporting pillar cells. To test the functional consequences of these cytoskeletal defects on cell mechanics, we combined atomic force microscopy with live cell imaging. Hypothyroidism stiffened outer hair cells and supporting pillar cells, but pillar cells ultimately showed reduced cell stiffness, in part from a lack of microtubules. Analyses of changes in transcription and protein phosphorylation suggest that hypothyroidism prolonged expression of fibroblast growth factor receptors, and decreased phosphorylated Cofilin. Conclusions These findings demonstrate that thyroid hormones may be involved in coordinating the processes that regulate cytoskeletal dynamics and suggest that manipulating thyroid hormone sensitivity might provide insight into the relationship between cytoskeletal formation and developing cell mechanical properties.
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Affiliation(s)
- Katherine B Szarama
- Section on Developmental Neuroscience, Laboratory of Cochlear Development, National Institute on Deafness and other Communication Disorders, National Institutes of Health, Bethesda, MD, USA.
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Abstract
INTRODUCTION Calpains represent a family of neutral, calcium-dependent proteases, which modify the function of their target proteins by partial truncation. These proteases have been implicated in numerous cell functions, including cell division, proliferation, migration, and death. In the CNS, where µ-calpain and m-calpain are the main calpain isoforms, their activation has been linked to synaptic plasticity as well as to neurodegeneration. This review will focus on the role of calpains in synaptic plasticity and discuss the possibility of developing methods to manipulate calpain activity for therapeutic purposes. AREAS COVERED This review covers the literature showing how calpains are implicated in synaptic plasticity and in a number of conditions associated with learning impairment. The possibility of developing new drugs targeting these enzymes for treating these conditions is discussed. EXPERT OPINION As evidence accumulates that calpain activation participates in neurodegeneration and cancer, there is interest in developing therapeutic approaches using direct or indirect calpain inhibition. In particular, a peptide derived from the calpain truncation site of mGluR1α was shown to decrease neurodegeneration following neonatal hypoxia/ischemia. More selective approaches need to be developed to target calpain or some of its substrates for therapeutic indications associated with deregulation of synaptic plasticity.
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Affiliation(s)
- Michel Baudry
- Western University of Health Sciences, Graduate College of Biomedical Sciences, Basic Medical Sciences, COMP , 309 E 2nd St, Pomona, CA 91766, USA.
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Abstract
The Drosophila compound eye is a regular structure, in which about 750 units, called ommatidia, are arranged in a highly regular pattern. Eye development proceeds in a stereotypical fashion, where epithelial cells of the eye imaginal discs are specified, recruited, and differentiated in a sequential order that leads to the highly precise structure of an adult eye. Even small perturbations, for example in signaling pathways that control proliferation, cell death, or differentiation, can impair the regular structure of the eye, which can be easily detected and analyzed. In addition, the Drosophila eye has proven to be an ideal model for studying the genetic control of neurodegeneration, since the eye is not essential for viability. Several human neurodegeneration diseases have been modeled in the fly, leading to a better understanding of the function/misfunction of the respective gene. In many cases, the genes involved and their function are conserved between flies and human. More strikingly, when ectopically expressed in the fly eye some human genes without a Drosophila counterpart can induce neurodegeneration, detectable by aberrant phototaxis, impaired electrophysiology, or defects in eye morphology. These defects are often rather subtle alteration in shape, size, or arrangement of the cells, and can be easily scored at the ultrastructural level. This chapter aims to provide an overview regarding the analysis of the retina by various means.
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Affiliation(s)
- Monalisa Mishra
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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Siudeja K, Grzeschik NA, Rana A, de Jong J, Sibon OCM. Cofilin/Twinstar phosphorylation levels increase in response to impaired coenzyme a metabolism. PLoS One 2012; 7:e43145. [PMID: 22912811 PMCID: PMC3422318 DOI: 10.1371/journal.pone.0043145] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/19/2012] [Indexed: 11/19/2022] Open
Abstract
Coenzyme A (CoA) is a pantothenic acid-derived metabolite essential for many fundamental cellular processes including energy, lipid and amino acid metabolism. Pantothenate kinase (PANK), which catalyses the first step in the conversion of pantothenic acid to CoA, has been associated with a rare neurodegenerative disorder PKAN. However, the consequences of impaired PANK activity are poorly understood. Here we use Drosophila and human neuronal cell cultures to show how PANK deficiency leads to abnormalities in F-actin organization. Cells with reduced PANK activity are characterized by abnormally high levels of phosphorylated cofilin, a conserved actin filament severing protein. The increased levels of phospho-cofilin coincide with morphological changes of PANK-deficient Drosophila S2 cells and human neuronal SHSY-5Y cells. The latter exhibit also markedly reduced ability to form neurites in culture--a process that is strongly dependent on actin remodeling. Our results reveal a novel and conserved link between a metabolic biosynthesis pathway, and regulation of cellular actin dynamics.
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Affiliation(s)
| | | | | | | | - Ody C. M. Sibon
- Department of Cell Biology, Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- * E-mail:
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Marrone AK, Kucherenko MM, Rishko VM, Shcherbata HR. New dystrophin/dystroglycan interactors control neuron behavior in Drosophila eye. BMC Neurosci 2011; 12:93. [PMID: 21943192 PMCID: PMC3217851 DOI: 10.1186/1471-2202-12-93] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 09/26/2011] [Indexed: 01/09/2023] Open
Abstract
Background The Dystrophin Glycoprotein Complex (DGC) is a large multi-component complex that is well known for its function in muscle tissue. When the main components of the DGC, Dystrophin (Dys) and Dystroglycan (Dg) are affected cognitive impairment and mental retardation in addition to muscle degeneration can occur. Previously we performed an array of genetic screens using a Drosophila model for muscular dystrophy in order to find novel DGC interactors aiming to elucidate the signaling role(s) in which the complex is involved. Since the function of the DGC in the brain and nervous system has not been fully defined, we have here continued to analyze the DGC modifiers' function in the developing Drosophila brain and eye. Results Given that disruption of Dys and Dg leads to improper photoreceptor axon projections into the lamina and eye neuron elongation defects during development, we have determined the function of previously screened components and their genetic interaction with the DGC in this tissue. Our study first found that mutations in chif, CG34400, Nrk, Lis1, capt and Cam cause improper axon path-finding and loss of SP2353, Grh, Nrk, capt, CG34400, vimar, Lis1 and Cam cause shortened rhabdomere lengths. We determined that Nrk, mbl, capt and Cam genetically interact with Dys and/or Dg in these processes. It is notable that most of the neuronal DGC interacting components encountered are involved in regulation of actin dynamics. Conclusions Our data indicate possible DGC involvement in the process of cytoskeletal remodeling in neurons. The identification of new components that interact with the DGC not only helps to dissect the mechanism of axon guidance and eye neuron differentiation but also provides a great opportunity for understanding the signaling mechanisms by which the cell surface receptor Dg communicates via Dys with the actin cytoskeleton.
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Affiliation(s)
- April K Marrone
- Max Planck Institute for biophysical chemistry, Research group of Gene Expression and Signaling, Am Fassberg 11, 37077, Goettingen, Germany
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Galy A, Schenck A, Sahin HB, Qurashi A, Sahel JA, Diebold C, Giangrande A. CYFIP dependent actin remodeling controls specific aspects of Drosophila eye morphogenesis. Dev Biol 2011; 359:37-46. [PMID: 21884694 DOI: 10.1016/j.ydbio.2011.08.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 08/11/2011] [Accepted: 08/15/2011] [Indexed: 12/20/2022]
Abstract
Cell rearrangements shape organs and organisms using molecular pathways and cellular processes that are still poorly understood. Here we investigate the role of the Actin cytoskeleton in the formation of the Drosophila compound eye, which requires extensive remodeling and coordination between different cell types. We show that CYFIP/Sra-1, a member of the WAVE/SCAR complex and regulator of Actin remodeling, controls specific aspects of eye architecture: rhabdomere extension, rhabdomere terminal web organization, adherens junctions, retina depth and basement membrane integrity. We demonstrate that some phenotypes manifest independently, due to defects in different cell types. Mutations in WAVE/SCAR and in ARP2/3 complex subunits but not in WASP, another major regulator of Actin nucleation, phenocopy CYFIP defects. Thus, the CYFIP-SCAR-ARP2/3 pathway orchestrates specific tissue remodeling processes.
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Affiliation(s)
- Anne Galy
- Fovea-Pharmaceuticals, Institut de la vision, 17 rue Moreau 75012 Paris, France
| | - Annette Schenck
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Donders Institute for Brain, Cognition and Behaviour & Radboud University Nijmegen Medical Center, 6525 GA Nijmegen, The Netherlands.
| | - H Bahar Sahin
- Department of Molecular Biology and Genetics, Bogazici University, Bebek, Istanbul, Turkey
| | - Abrar Qurashi
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - José-Alain Sahel
- INSERM, U968, Université Pierre et Marie Curie-Paris 6, UM80, Institut de la Vision, CNRS, UMR-7210, Fondation Ophtalmologique Adolphe de Rothschild, Paris, France; Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Céline Diebold
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UDS, BP 10142, 67404 Illkirch, CU de Strasbourg, France
| | - Angela Giangrande
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/UDS, BP 10142, 67404 Illkirch, CU de Strasbourg, France.
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Kuure S, Cebrian C, Machingo Q, Lu BC, Chi X, Hyink D, D'Agati V, Gurniak C, Witke W, Costantini F. Actin depolymerizing factors cofilin1 and destrin are required for ureteric bud branching morphogenesis. PLoS Genet 2010; 6:e1001176. [PMID: 21060807 PMCID: PMC2965756 DOI: 10.1371/journal.pgen.1001176] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 09/22/2010] [Indexed: 01/10/2023] Open
Abstract
The actin depolymerizing factors (ADFs) play important roles in several cellular processes that require cytoskeletal rearrangements, such as cell migration, but little is known about the in vivo functions of ADFs in developmental events like branching morphogenesis. While the molecular control of ureteric bud (UB) branching during kidney development has been extensively studied, the detailed cellular events underlying this process remain poorly understood. To gain insight into the role of actin cytoskeletal dynamics during renal branching morphogenesis, we studied the functional requirements for the closely related ADFs cofilin1 (Cfl1) and destrin (Dstn) during mouse development. Either deletion of Cfl1 in UB epithelium or an inactivating mutation in Dstn has no effect on renal morphogenesis, but simultaneous lack of both genes arrests branching morphogenesis at an early stage, revealing considerable functional overlap between cofilin1 and destrin. Lack of Cfl1 and Dstn in the UB causes accumulation of filamentous actin, disruption of normal epithelial organization, and defects in cell migration. Animals with less severe combinations of mutant Cfl1 and Dstn alleles, which retain one wild-type Cfl1 or Dstn allele, display abnormalities including ureter duplication, renal hypoplasia, and abnormal kidney shape. The results indicate that ADF activity, provided by either cofilin1 or destrin, is essential in UB epithelial cells for normal growth and branching. Development of the ureter and collecting ducts of the kidney requires extensive growth and branching of an epithelial tube, the ureteric bud. While many genes that control this process are known, the cellular events that underlie renal morphogenesis remain poorly understood. Many cellular changes that might contribute to ureteric bud morphogenesis, such as migration and changes in shape, involve the actin cytoskeleton. Actin depolymerizing factors (ADFs) are important for changes in the organization of the cytoskeleton in cultured cells, but the roles of the ADF genes in vivo remain to be fully elucidated. Here, we examine the importance of the ADFs cofilin1 and destrin in ureteric bud branching and find that lack of both genes arrests this process at an early stage, while lesser reductions in ADF gene dosage cause more subtle defects in kidney development. This finding may help us to understand the origins of certain congenital malformations in humans.
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Affiliation(s)
- Satu Kuure
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Cristina Cebrian
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Quentin Machingo
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Benson C. Lu
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Xuan Chi
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
| | - Deborah Hyink
- Department of Medicine, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Vivette D'Agati
- Department of Pathology, Columbia University Medical Center, New York, New York, United States of America
| | | | - Walter Witke
- Institute of Genetics, University of Bonn, Bonn, Germany
| | - Frank Costantini
- Department of Genetics and Development, Columbia University Medical Center, New York, New York, United States of America
- * E-mail:
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Syntrophin-2 is required for eye development in Drosophila. Exp Cell Res 2009; 316:272-85. [PMID: 19836389 DOI: 10.1016/j.yexcr.2009.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/07/2009] [Accepted: 10/07/2009] [Indexed: 11/23/2022]
Abstract
Syntrophins are components of the dystrophin glycoprotein complex (DGC), which is encoded by causative genes of muscular dystrophies. The DGC is thought to play roles not only in linking the actin cytoskeleton to the extracellular matrix, providing stability to the cell membrane, but also in signal transduction. Because of their binding to a variety of different molecules, it has been suggested that syntrophins are adaptor proteins recruiting signaling proteins to membranes and the DGC. However, critical roles in vivo remain elusive. Drosophila Syntrophin-2 (Syn2) is an orthologue of human gamma 1/gamma 2-syntrophins. Western immunoblot analysis here showed Syn2 to be expressed throughout development, with especially high levels in the adult head. Morphological aberrations were observed in Syn2 knockdown adult flies, with lack of retinal elongation and malformation of rhabdomeres. Furthermore, Syn2 knockdown flies exhibited excessive apoptosis in third instar larvae and alterations in the actin localization in the pupal retinae. Genetic crosses with a collection of Drosophila deficiency stocks allowed us to identify seven genomic regions, deletions of which caused enhancement of the rough eye phenotype induced by Syn2 knockdown. This information should facilitate identification of Syn2 regulators in Drosophila and clarification of roles of Syn2 in eye development.
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Function of Drosophila mob2 in photoreceptor morphogenesis. Cell Tissue Res 2009; 338:377-89. [DOI: 10.1007/s00441-009-0878-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Accepted: 09/03/2009] [Indexed: 01/11/2023]
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Wu P, Qi D, Chen L, Zhang H, Zhang X, Qin JG, Hu S. Gene discovery from an ovary cDNA library of oriental river prawn Macrobrachium nipponense by ESTs annotation. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2008; 4:111-20. [PMID: 20403747 DOI: 10.1016/j.cbd.2008.12.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 12/09/2008] [Accepted: 12/09/2008] [Indexed: 12/16/2022]
Abstract
The oriental river prawn, Macrobrachium nipponense, is an important crustacean species in aquaculture. However, early gonad maturity is a ubiquitous problem which devalues the product quality. While husbandry and nutritional management have achieved little success in tackling this issue, a molecular approach may discover the genes involved in reproduction and development, which will provide the basic knowledge on reproductive control. In this study, a high-quality cDNA library of prawn was constructed from the ovary tissue. A total of 3294 successful sequencing reactions yielded 3256 expressed sequence tags (ESTs) longer than 100 bp. The cluster and assembly analyses yielded 1514 unique sequences including 414 contigs and 1168 singletons. About 719 (47.49%) unique sequences were identified as orthologs of genes from other organisms. By sequence comparability analysis, 28 important genes including cathepsin B, chromobox protein, Cdc2, cyclin B, DEAD box protein and ADF/cofilin protein were expressed. These genes may be involved in reproductive and developmental functions in prawn. Peritrophin consisting of cortical rods was also found in this species. The identification of these EST sequences in M. nipponense would improve our understanding on the genes that regulate reproduction and development in prawn species. This study also lays the groundwork for development of molecular markers related to ovary development in other prawn species.
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Affiliation(s)
- Ping Wu
- College of Life Science, East China Normal University, Shanghai 200062, PR China
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