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Expression and Function of Toll Pathway Components in the Early Development of the Wasp Nasonia vitripennis. J Dev Biol 2022; 10:jdb10010007. [PMID: 35225961 PMCID: PMC8883978 DOI: 10.3390/jdb10010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/20/2022] [Accepted: 01/22/2022] [Indexed: 11/22/2022] Open
Abstract
The Toll signaling pathway is the main source of embryonic DV polarity in the fly Drosophila melanogaster. This pathway appears to have been co-opted from an ancestral innate immunity system within the insects and has been deployed in different ways among insect taxa. Here we report the expression and function of homologs of the important components of the D. melanogaster Toll pathway in the wasp Nasonia vitripennis. We found homologs for all the components; many components had one or more additional paralogs in the wasp relative the fly. We also found significant deviations in expression patterns of N. vitripennis homologs. Finally, we provide some preliminary functional analyses of the N. vitripennis homologs, where we find a mixture of conservation and divergence of function.
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2
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Pechmann M, Kenny NJ, Pott L, Heger P, Chen YT, Buchta T, Özüak O, Lynch J, Roth S. Striking parallels between dorsoventral patterning in Drosophila and Gryllus reveal a complex evolutionary history behind a model gene regulatory network. eLife 2021; 10:e68287. [PMID: 33783353 PMCID: PMC8051952 DOI: 10.7554/elife.68287] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 12/18/2022] Open
Abstract
Dorsoventral pattering relies on Toll and BMP signalling in all insects studied so far, with variations in the relative contributions of both pathways. Drosophila and the beetle Tribolium share extensive dependence on Toll, while representatives of more distantly related lineages like the wasp Nasonia and bug Oncopeltus rely more strongly on BMP signalling. Here, we show that in the cricket Gryllus bimaculatus, an evolutionarily distant outgroup, Toll has, like in Drosophila, a direct patterning role for the ventral half of the embryo. In addition, Toll polarises BMP signalling, although this does not involve the conserved BMP inhibitor Sog/Chordin. Finally, Toll activation relies on ovarian patterning mechanisms with striking similarity to Drosophila. Our data suggest two surprising hypotheses: (1) that Toll's patterning function in Gryllus and Drosophila is the result of convergent evolution or (2) a Drosophila-like system arose early in insect evolution and was extensively altered in multiple independent lineages.
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Affiliation(s)
- Matthias Pechmann
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
| | | | - Laura Pott
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
| | - Peter Heger
- Regional Computing Centre (RRZK), University of CologneKölnGermany
| | - Yen-Ta Chen
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
| | - Thomas Buchta
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
| | - Orhan Özüak
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
| | - Jeremy Lynch
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
| | - Siegfried Roth
- Institute for Zoology/Developmental Biology, Biocenter, University of CologneKölnGermany
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Hammond A, Karlsson X, Morianou I, Kyrou K, Beaghton A, Gribble M, Kranjc N, Galizi R, Burt A, Crisanti A, Nolan T. Regulating the expression of gene drives is key to increasing their invasive potential and the mitigation of resistance. PLoS Genet 2021; 17:e1009321. [PMID: 33513149 PMCID: PMC7886172 DOI: 10.1371/journal.pgen.1009321] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 02/16/2021] [Accepted: 12/22/2020] [Indexed: 12/27/2022] Open
Abstract
Homing-based gene drives use a germline source of nuclease to copy themselves at specific target sites in a genome and bias their inheritance. Such gene drives can be designed to spread and deliberately suppress populations of malaria mosquitoes by impairing female fertility. However, strong unintended fitness costs of the drive and a propensity to generate resistant mutations can limit a gene drive’s potential to spread. Alternative germline regulatory sequences in the drive element confer improved fecundity of carrier individuals and reduced propensity for target site resistance. This is explained by reduced rates of end-joining repair of DNA breaks from parentally deposited nuclease in the embryo, which can produce heritable mutations that reduce gene drive penetrance. We tracked the generation and selection of resistant mutations over the course of a gene drive invasion of a population. Improved gene drives show faster invasion dynamics, increased suppressive effect and later onset of target site resistance. Our results show that regulation of nuclease expression is as important as the choice of target site when developing a robust homing-based gene drive for population suppression. Gene drives are selfish genetic elements that are able to drastically bias their own inheritance. They can rapidly invade populations, even starting from a very low frequency. Recent advances have allowed the engineering of gene drives deliberately designed to spread genetic traits of choice into populations of malaria-transmitting mosquito species–for example traits that impair a mosquito’s ability to reproduce or its ability to transmit parasites. The class of gene drive in question uses a very precise cutting and copying mechanism, termed ‘homing’, that allows it to increase its numbers in the cells that go on to form sperm or eggs, thereby increasing the chances that a copy of the gene drive is transmitted to offspring. However, while this type of gene drive can rapidly invade a mosquito population, mosquitoes can also eventually become resistant to the gene drive in some cases. Here we show that restricting the cutting activity of the gene drive to the germline tissue is crucial to maintaining its potency and we illustrate how failure to restrict this activity can lead to the generation of mutations that can make mosquitoes resistant to the gene drive.
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Affiliation(s)
- Andrew Hammond
- Department of Life Sciences, Imperial College London, London, United Kingdom
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Xenia Karlsson
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ioanna Morianou
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Kyros Kyrou
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Andrea Beaghton
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Matthew Gribble
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Nace Kranjc
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Roberto Galizi
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Austin Burt
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Andrea Crisanti
- Department of Life Sciences, Imperial College London, London, United Kingdom
- University of Padova, Padova, Italy
- * E-mail: (AC); (TN)
| | - Tony Nolan
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail: (AC); (TN)
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4
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Shin S, Hong JH, Na Y, Lee M, Qian WJ, Kim VN, Kim JS. Development of Multiplexed Immuno-N-Terminomics to Reveal the Landscape of Proteolytic Processing in Early Embryogenesis of Drosophila melanogaster. Anal Chem 2020; 92:4926-4934. [DOI: 10.1021/acs.analchem.9b05035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Sanghee Shin
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Ji Hye Hong
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Yongwoo Na
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Mihye Lee
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan-si, Chungcheongnam-do 31151, Korea
| | - Wei-Jun Qian
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - V. Narry Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | - Jong-Seo Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
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Schloop AE, Bandodkar PU, Reeves GT. Formation, interpretation, and regulation of the Drosophila Dorsal/NF-κB gradient. Curr Top Dev Biol 2019; 137:143-191. [PMID: 32143742 DOI: 10.1016/bs.ctdb.2019.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The morphogen gradient of the transcription factor Dorsal in the early Drosophila embryo has become one of the most widely studied tissue patterning systems. Dorsal is a Drosophila homolog of mammalian NF-κB and patterns the dorsal-ventral axis of the blastoderm embryo into several tissue types by spatially regulating upwards of 100 zygotic genes. Recent studies using fluorescence microscopy and live imaging have quantified the Dorsal gradient and its target genes, which has paved the way for mechanistic modeling of the gradient. In this review, we describe the mechanisms behind the initiation of the Dorsal gradient and its regulation of target genes. The main focus of the review is a discussion of quantitative and computational studies of the Dl gradient system, including regulation of the Dl gradient. We conclude with a discussion of potential future directions.
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Affiliation(s)
- Allison E Schloop
- Genetics Program, North Carolina State University, Raleigh, NC, United States
| | - Prasad U Bandodkar
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, United States
| | - Gregory T Reeves
- Genetics Program, North Carolina State University, Raleigh, NC, United States; Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, United States.
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Anthoney N, Foldi I, Hidalgo A. Toll and Toll-like receptor signalling in development. Development 2018; 145:145/9/dev156018. [DOI: 10.1242/dev.156018] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ABSTRACT
The membrane receptor Toll and the related Toll-like receptors (TLRs) are best known for their universal function in innate immunity. However, Toll/TLRs were initially discovered in a developmental context, and recent studies have revealed that Toll/TLRs carry out previously unanticipated functions in development, regulating cell fate, cell number, neural circuit connectivity and synaptogenesis. Furthermore, knowledge of their molecular mechanisms of action is expanding and has highlighted that Toll/TLRs function beyond the canonical NF-κB pathway to regulate cell-to-cell communication and signalling at the synapse. Here, we provide an overview of Toll/TLR signalling and discuss how this signalling pathway regulates various aspects of development across species.
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Affiliation(s)
- Niki Anthoney
- NeuroDevelopment Group, School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Istvan Foldi
- NeuroDevelopment Group, School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Alicia Hidalgo
- NeuroDevelopment Group, School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
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Yang C, Wang L, Zhang H, Yi Q, Wang L, Wang H, Song L. The first CUB-domain containing serine protease from Chlamys farreri which might be involved in larval development and immune response. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 76:163-168. [PMID: 28619282 DOI: 10.1016/j.dci.2017.05.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 06/07/2023]
Abstract
Serine proteases (SPs) are one of the most well understood enzyme families, which play an important role in regulating many physiological events. In the present study, one CUB-domain containing serine protease was identified from Chlamys farreri (designated as CfCUBSP). The full-length cDNA of CfCUBSP was of 3181 bp with an open reading frame of 2688 bp encoding a polypeptide of 896 amino acids. CfCUBSP shared closer phylogenetic relationship with those multi-domain SPs which consisted of one SP domain, and different numbers of CUB domain and LDLa domain than other SPs. The mRNA transcripts of CfCUBSP were detected in all developmental stages with the highest expression level in fertilized eggs and the lowest in trochophore larvae. In adult scallop, the CfCUBSP mRNA could be detected in all examined tissues with the highest level in hepatopancreas, and CfCUBSP protein was dominantly located in the gills, hepatopancreas, gonad and kidney. The mRNA expression of CfCUBSP in hemocytes was significantly up-regulated after the stimulation of lipopolysaccharide (LPS), peptidoglycan (PGN) and β-glucan (GLU) (P < 0.05). All the results collectively indicated that CfCUBSP was a primitive member of the invertebrate SPs which might be involved in larval development and immune response against Gram-negative (G-) and Gram-positive (G+) bacteria and fungus in scallop.
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Affiliation(s)
- Chuanyan Yang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Leilei Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Huan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Qilin Yi
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Hao Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
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Yan A, Ren C, Chen T, Jiang X, Sun H, Hu C. Identification and functional characterization of a novel antistasin/WAP-like serine protease inhibitor from the tropical sea cucumber, Stichopus monotuberculatus. FISH & SHELLFISH IMMUNOLOGY 2016; 59:203-212. [PMID: 27989867 DOI: 10.1016/j.fsi.2016.10.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 06/06/2023]
Abstract
A novel antistasin/WAP-like serine protease inhibitor, named as StmAW-SPI, was identified from sea cucumber (Stichopus monotuberculatus) and functionally characterized in this study. The full-length cDNA of StmAW-SPI is 1917 bp in length with a 72 bp 5'-untranslated region (UTR), a 294 bp 3'-UTR and a 1551 bp open reading frame (ORF) encoding a protein of 516 amino acids with a deduced molecular weight of 54.56 kDa. The StmAW-SPI protein has 5-fold internal repeats (IRs) of antistasin domain and 6-fold IRs of WAP domain. For the gene structure, StmAW-SPI contains 10 exons separated by 9 introns. The StmAW-SPI mRNA expression pattern was determined using quantitative real-time PCR. The highest level of StmAW-SPI was found in the intestine, followed by coelomocytes, gonad, body wall and respiratory tree. The StmAW-SPI expressions were significantly up-regulated after polyriboinosinic polyribocytidylic acid [Poly (I:C)] or lipopolysaccharides (LPS) challenge in in vitro experiments performed in primary coelomocytes. In addition, the serine protease inhibitory activity and bacterial protease inhibitory activity of StmAW-SPI were examined, and the antibacterial activity was also demonstrated in this study. Our study, as a whole, suggested that StmAW-SPI might play a critical role in the innate immune defense of sea cucumber against microbial infections, by not only inactivating the serine protease but also inhibiting the growth of pathogens.
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Affiliation(s)
- Aifen Yan
- College of Medicine, Foshan University, Foshan, 528000, PR China.
| | - Chunhua Ren
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, PR China.
| | - Ting Chen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, PR China.
| | - Xiao Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China.
| | - Hongyan Sun
- College of Marine Science, South China Agricultural University, Guangzhou, 510642, PR China.
| | - Chaoqun Hu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, PR China.
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9
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Veillard F, Troxler L, Reichhart JM. Drosophila melanogaster clip-domain serine proteases: Structure, function and regulation. Biochimie 2015; 122:255-69. [PMID: 26453810 DOI: 10.1016/j.biochi.2015.10.007] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/05/2015] [Indexed: 01/22/2023]
Abstract
Mammalian chymotrypsin-like serine proteases (SPs) are one of the best-studied family of enzymes with roles in a wide range of physiological processes, including digestion, blood coagulation, fibrinolysis and humoral immunity. Extracellular SPs can form cascades, in which one protease activates the zymogen of the next protease in the chain, to amplify physiological or pathological signals. These extracellular SPs are generally multi-domain proteins, with pro-domains that are involved in protein-protein interactions critical for the sequential organization of the cascades, the control of their intensity and their proper localization. Far less is known about invertebrate SPs than their mammalian counterparts. In insect genomes, SPs and their proteolytically inactive homologs (SPHs) constitute large protein families. In addition to the chymotrypsin fold, many of these proteins contain additional structural domains, often with conserved mammalian orthologues. However, the largest group of arthropod SP regulatory modules is the clip domains family, which has only been identified in arthropods. The clip-domain SPs are extracellular and have roles in the immune response and embryonic development. The powerful reverse-genetics tools in Drosophila melanogaster have been essential to identify the functions of clip-SPs and their organization in sequential cascades. This review focuses on the current knowledge of Drosophila clip-SPs and presents, when necessary, data obtained in other insect models. We will first cover the biochemical and structural features of clip domain SPs and SPHs. Clip-SPs are implicated in three main biological processes: the control of the dorso-ventral patterning during embryonic development; the activation of the Toll-mediated response to microbial infections and the prophenoloxydase cascade, which triggers melanization. Finally, we review the regulation of SPs and SPHs, from specificity of activation to inhibition by endogenous or pathogen-encoded inhibitors.
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Affiliation(s)
- Florian Veillard
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France.
| | - Laurent Troxler
- CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Jean-Marc Reichhart
- Faculté des Sciences de la Vie, Université de Strasbourg, Strasbourg, France
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Vera A, Recabal A, Saldivia N, Stanic K, Torrejón M, Montecinos H, Caprile T. Interaction between SCO-spondin and low density lipoproteins from embryonic cerebrospinal fluid modulates their roles in early neurogenesis. Front Neuroanat 2015; 9:72. [PMID: 26074785 PMCID: PMC4446542 DOI: 10.3389/fnana.2015.00072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/14/2015] [Indexed: 01/20/2023] Open
Abstract
During early stages of development, encephalic vesicles are composed by a layer of neuroepithelial cells surrounding a central cavity filled with embryonic cerebrospinal fluid (eCSF). This fluid contains several morphogens that regulate proliferation and differentiation of neuroepithelial cells. One of these neurogenic factors is SCO-spondin, a giant protein secreted to the eCSF from early stages of development. Inhibition of this protein in vivo or in vitro drastically decreases the neurodifferentiation process. Other important neurogenic factors of the eCSF are low density lipoproteins (LDL), the depletion of which generates a 60% decrease in mesencephalic explant neurodifferentiation. The presence of several LDL receptor class A (LDLrA) domains (responsible for LDL binding in other proteins) in the SCO-spondin sequence suggests a possible interaction between both molecules. This possibility was analyzed using three different experimental approaches: (1) Bioinformatics analyses of the SCO-spondin region, that contains eight LDLrA domains in tandem, and of comparisons with the LDL receptor consensus sequence; (2) Analysis of the physical interactions of both molecules through immunohistochemical colocalization in embryonic chick brains and through the immunoprecipitation of LDL with anti-SCO-spondin antibodies; and (3) Analysis of functional interactions during the neurodifferentiation process when these molecules were added to a culture medium of mesencephalic explants. The results revealed that LDL and SCO-spondin interact to form a complex that diminishes the neurogenic capacities that both molecules have separately. Our work suggests that the eCSF is an active signaling center with a complex regulation system that allows for correct brain development.
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Affiliation(s)
- América Vera
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Antonia Recabal
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Natalia Saldivia
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Karen Stanic
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Marcela Torrejón
- Faculty of Biological Sciences, Department of Biochemistry and Molecular Biology, University of Concepción Concepción, Chile
| | - Hernán Montecinos
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
| | - Teresa Caprile
- Department of Cell Biology, Faculty of Biological Sciences, University of Concepción Concepción, Chile
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11
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Mineo A, Furriols M, Casanova J. Accumulation of the Drosophila Torso-like protein at the blastoderm plasma membrane suggests that it translocates from the eggshell. Development 2015; 142:1299-304. [PMID: 25758463 DOI: 10.1242/dev.117630] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The eggshell serves as a depository for proteins that play an important role in early embryonic development. In particular, the Drosophila eggshell is responsible for transferring asymmetries from the egg chamber to specify the regions at both ends of the embryo through the uneven activation of the Torso (Tor) receptor in its membrane. This process relies on the restricted expression of the gene torso-like (tsl) in subpopulations of follicle cells during oogenesis and its protein accumulation at both poles of the eggshell, but it is not known how this signal is transmitted to the embryo. Here, we show that Tsl accumulates at the embryonic plasma membrane, even in the absence of the Tor receptor. However, during oogenesis, we detected Tsl accumulation only at the eggshell. These results suggest that there is a two-step mechanism to transfer the asymmetric positional cues from the egg chamber into the early embryo: initial anchoring of Tsl at the eggshell as it is secreted, followed by its later translocation to the egg plasma membrane, where it enables Tor receptor activation. Translocation of anchored determinants from the eggshell might then regulate the spatial and temporal control of early embryonic developmental processes.
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Affiliation(s)
- Alessandro Mineo
- Institut de Biologia Molecular de Barcelona (CSIC), Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Catalonia, Spain
| | - Marc Furriols
- Institut de Biologia Molecular de Barcelona (CSIC), Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Catalonia, Spain
| | - Jordi Casanova
- Institut de Biologia Molecular de Barcelona (CSIC), Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Catalonia, Spain
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12
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Stein DS, Stevens LM. Maternal control of the Drosophila dorsal-ventral body axis. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2014; 3:301-30. [PMID: 25124754 DOI: 10.1002/wdev.138] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 03/24/2014] [Accepted: 04/07/2014] [Indexed: 12/14/2022]
Abstract
UNLABELLED The pathway that generates the dorsal-ventral (DV) axis of the Drosophila embryo has been the subject of intense investigation over the previous three decades. The initial asymmetric signal originates during oogenesis by the movement of the oocyte nucleus to an anterior corner of the oocyte, which establishes DV polarity within the follicle through signaling between Gurken, the Drosophila Transforming Growth Factor (TGF)-α homologue secreted from the oocyte, and the Drosophila Epidermal Growth Factor Receptor (EGFR) that is expressed by the follicular epithelium cells that envelop the oocyte. Follicle cells that are not exposed to Gurken follow a ventral fate and express Pipe, a sulfotransferase that enzymatically modifies components of the inner vitelline membrane layer of the eggshell, thereby transferring DV spatial information from the follicle to the egg. These ventrally sulfated eggshell proteins comprise a localized cue that directs the ventrally restricted formation of the active Spätzle ligand within the perivitelline space between the eggshell and the embryonic membrane. Spätzle activates Toll, a transmembrane receptor in the embryonic membrane. Transmission of the Toll signal into the embryo leads to the formation of a ventral-to-dorsal gradient of the transcription factor Dorsal within the nuclei of the syncytial blastoderm stage embryo. Dorsal controls the spatially specific expression of a large constellation of zygotic target genes, the Dorsal gene regulatory network, along the embryonic DV circumference. This article reviews classic studies and integrates them with the details of more recent work that has advanced our understanding of the complex pathway that establishes Drosophila embryo DV polarity. For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST The authors have declared no conflicts of interest for this article.
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Affiliation(s)
- David S Stein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
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13
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Stein D, Cho YS, Stevens LM. Localized serine protease activity and the establishment of Drosophila embryonic dorsoventral polarity. Fly (Austin) 2013; 7:161-7. [PMID: 24047959 DOI: 10.4161/fly.25141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Drosophila embryo dorsoventral polarity is established by a maternally encoded signal transduction pathway in which three sequentially acting serine proteases, Gastrulation Defective, Snake and Easter, generate the ligand that activates the Toll receptor on the ventral side of the embryo. The spatial regulation of this pathway depends upon ventrally restricted expression of the Pipe sulfotransferase in the ovarian follicle during egg formation. Several recent observations have advanced our understanding of the mechanism regulating the spatially restricted activation of Toll. First, several protein components of the vitelline membrane layer of the eggshell have been determined to be targets of Pipe-mediated sulfation. Second, the processing of Easter by Snake has been identified as the first Pipe-dependent, ventrally-restricted processing event in the pathway. Finally, Gastrulation Defective has been shown to undergo Pipe-dependent, ventral localization within the perivitelline space and to facilitate Snake-mediated processing of Easter. Together, these observations suggest that Gastrulation Defective, localized on the interior ventral surface of the eggshell in association with Pipe-sulfated eggshell proteins, recruits and mediates an interaction between Snake and Easter. This event leads to ventrally-restricted processing and activation of Easter and consequently, localized formation of the Toll ligand, and Toll activation.
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Affiliation(s)
- David Stein
- Section of Molecular Cell and Developmental Biology; Institute for Cellular and Molecular Biology; University of Texas at Austin; Austin, TX USA
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14
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Carter JM, Baker SC, Pink R, Carter DRF, Collins A, Tomlin J, Gibbs M, Breuker CJ. Unscrambling butterfly oogenesis. BMC Genomics 2013; 14:283. [PMID: 23622113 PMCID: PMC3654919 DOI: 10.1186/1471-2164-14-283] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 04/05/2013] [Indexed: 12/16/2022] Open
Abstract
Background Butterflies are popular model organisms to study physiological mechanisms
underlying variability in oogenesis and egg provisioning in response to
environmental conditions. Nothing is known, however, about; the
developmental mechanisms governing butterfly oogenesis, how polarity in the
oocyte is established, or which particular maternal effect genes regulate
early embryogenesis. To gain insights into these developmental mechanisms
and to identify the conserved and divergent aspects of butterfly oogenesis,
we analysed a de novo ovarian transcriptome of the Speckled Wood
butterfly Pararge aegeria (L.), and compared the results with known
model organisms such as Drosophila melanogaster and Bombyx
mori. Results A total of 17306 contigs were annotated, with 30% possibly novel or highly
divergent sequences observed. Pararge aegeria females expressed
74.5% of the genes that are known to be essential for D.
melanogaster oogenesis. We discuss the genes involved in all
aspects of oogenesis, including vitellogenesis and choriogenesis, plus those
implicated in hormonal control of oogenesis and transgenerational hormonal
effects in great detail. Compared to other insects, a number of significant
differences were observed in; the genes involved in stem cell maintenance
and differentiation in the germarium, establishment of oocyte polarity, and
in several aspects of maternal regulation of zygotic development. Conclusions This study provides valuable resources to investigate a number of divergent
aspects of butterfly oogenesis requiring further research. In order to fully
unscramble butterfly oogenesis, we also now also have the resources to
investigate expression patterns of oogenesis genes under a range of
environmental conditions, and to establish their function.
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Affiliation(s)
- Jean-Michel Carter
- Evolutionary Developmental Biology Research Group, Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, OX3 0BP, UK
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15
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Grondona JM, Hoyo-Becerra C, Visser R, Fernández-Llebrez P, López-Ávalos MD. The subcommissural organ and the development of the posterior commissure. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 296:63-137. [PMID: 22559938 DOI: 10.1016/b978-0-12-394307-1.00002-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Growing axons navigate through the developing brain by means of axon guidance molecules. Intermediate targets producing such signal molecules are used as guideposts to find distal targets. Glial, and sometimes neuronal, midline structures represent intermediate targets when axons cross the midline to reach the contralateral hemisphere. The subcommissural organ (SCO), a specialized neuroepithelium located at the dorsal midline underneath the posterior commissure, releases SCO-spondin, a large glycoprotein belonging to the thrombospondin superfamily that shares molecular domains with axonal pathfinding molecules. Several evidences suggest that the SCO could be involved in the development of the PC. First, both structures display a close spatiotemporal relationship. Second, certain mutants lacking an SCO present an abnormal PC. Third, some axonal guidance molecules are expressed by SCO cells. Finally, SCO cells, the Reissner's fiber (the aggregated form of SCO-spondin), or synthetic peptides from SCO-spondin affect the neurite outgrowth or neuronal aggregation in vitro.
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Affiliation(s)
- Jesús M Grondona
- Departamento de Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, Spain.
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16
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Affiliation(s)
- P Jallepalli
- The Dept of Molecular Biology and Genetics, Johns Hopkins University, Baltimore, MD 21205, USA
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17
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Ge LQ, Cheng Y, Wu JC, Jahn GC. Proteomic analysis of insecticide triazophos-induced mating-responsive proteins of Nilaparvata lugens Stål (Hemiptera: Delphacidae). J Proteome Res 2011; 10:4597-612. [PMID: 21800909 DOI: 10.1021/pr200414g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is a classic example of a resurgent pest induced by insecticides. It has been demonstrated that triazophos treatment causes an increase in the content of male accessory gland proteins (Acps) that can be transferred to females via mating, influencing female reproduction. However, the mechanism of this type of insecticide-induced Acps in males and the subsequent stimulation of reproduction in females are not well understood. To identify changes in the types of Acps and reproductive proteins in mated females, we conducted a comparative proteomic analysis. Six samples were categorized into four different groups: (1) untreated unmated males compared to treated unmated males (UUM vs TUM); (2) treated unmated males compared to treated mated males (TUM vs TMM); (3) untreated unmated females compared to treated unmated females (UUF vs TUF); (4) treated unmated females compared to treated mated females (TUF vs TMF). Protein expression changes among the four different groups were examined by two-dimensional gel electrophoresis (2-DE) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Of the 500-600 reproducibly detected protein spots on each gel, 107 protein spots were differentially expressed between the four different groups. Of the 63 proteins identified by LC-MS/MS analysis, 38 were up-regulated and 25 were down-regulated in the four different groups. Some novel proteins related to fecundity were observed including spermatogenesis-associated protein 5, testis development protein NYD-SP6, arginine kinase, actin-5C, vitellogenin, and ovarian serine protease nudel. The elevated expression of novel fecundity proteins in six samples of N. lugens females and males due to exposure to triazophos was confirmed by quantitative real-time PCR (qRT-PCR). The results suggest that these proteins may participate in the reproductive process of N. lugens adult females and males. Our findings fill a gap in understanding the relationship between insecticide-treated males and the stimulated reproduction of N. lugens females.
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Affiliation(s)
- Lin-Quan Ge
- School of Plant Protection, Yangzhou University , Yangzhou 225009, PR China
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18
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Valanne S, Wang JH, Rämet M. The Drosophila Toll signaling pathway. THE JOURNAL OF IMMUNOLOGY 2011; 186:649-56. [PMID: 21209287 DOI: 10.4049/jimmunol.1002302] [Citation(s) in RCA: 589] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The identification of the Drosophila melanogaster Toll pathway cascade and the subsequent characterization of TLRs have reshaped our understanding of the immune system. Ever since, Drosophila NF-κB signaling has been actively studied. In flies, the Toll receptors are essential for embryonic development and immunity. In total, nine Toll receptors are encoded in the Drosophila genome, including the Toll pathway receptor Toll. The induction of the Toll pathway by gram-positive bacteria or fungi leads to the activation of cellular immunity as well as the systemic production of certain antimicrobial peptides. The Toll receptor is activated when the proteolytically cleaved ligand Spatzle binds to the receptor, eventually leading to the activation of the NF-κB factors Dorsal-related immunity factor or Dorsal. In this study, we review the current literature on the Toll pathway and compare the Drosophila and mammalian NF-κB pathways.
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Affiliation(s)
- Susanna Valanne
- Laboratory of Experimental Immunology, Institute of Medical Technology, University of Tampere, 33014 Tampere, Finland
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19
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Activation of Snake in a serine protease cascade that defines the dorsoventral axis is atypical and pipe-independent in Drosophila embryos. FEBS Lett 2010; 584:3557-60. [PMID: 20638387 DOI: 10.1016/j.febslet.2010.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/07/2010] [Accepted: 07/12/2010] [Indexed: 11/20/2022]
Abstract
During Drosophila embryogenesis, establishment of ventral and lateral cell fates requires spatial regulation of an extracellular serine protease cascade composed of Nudel, Gastrulation Defective (GD), Snake, and Easter. Pipe, a sulfotransferase expressed ventrally during oogenesis, sulfates secreted targets that somehow confer positive spatial input to this cascade. Nudel and GD activation are pipe-independent, while Easter activation requires pipe. The effect of pipe on Snake activation has been unknown. Here we show that Snake activation is cascade-dependent but pipe-independent. These findings support a conclusion that Snake's activation of Easter is the first spatially regulated step in the dorsoventral protease cascade.
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20
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Ventura G, Furriols M, Martín N, Barbosa V, Casanova J. closca, a new gene required for both Torso RTK activation and vitelline membrane integrity. Germline proteins contribute to Drosophila eggshell composition. Dev Biol 2010; 344:224-32. [PMID: 20457146 DOI: 10.1016/j.ydbio.2010.05.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 04/29/2010] [Accepted: 05/01/2010] [Indexed: 11/29/2022]
Abstract
The Drosophila eggshell is a specialised extracellular matrix (ECM) that surrounds and protects the oocyte and the embryo until its eclosion. In addition, the vitelline membrane, the innermost layer of the eggshell, holds the local determinant required to activate the Torso RTK pathway, which establishes the embryonic terminal regions. Here we report the identification and characterisation of closca, a gene encoding a new member of a group of proteins that act non-redundantly in vitelline membrane biogenesis and in Torso signalling. We also show that the Nasrat protein, another member of this group, is incorporated into the vitelline membrane, thereby indicating that the eggshell is a shared ECM that receives contributions from both follicle cells and the germline. This observation also provides a new scenario that accounts for the long known contribution of germline products to vitelline membrane biogenesis and to the follicle cell-dependent activation of the Torso receptor.
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Affiliation(s)
- Gemma Ventura
- Institut de Biologia Molecular de Barcelona (CSIC) and Institut de Recerca de Biomèdica, Barcelona, Spain
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21
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22
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Zhang Z, Stevens LM, Stein D. Sulfation of eggshell components by Pipe defines dorsal-ventral polarity in the Drosophila embryo. Curr Biol 2009; 19:1200-5. [PMID: 19540119 DOI: 10.1016/j.cub.2009.05.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 10/20/2022]
Abstract
Drosophila embryonic dorsal-ventral (DV) polarity is controlled by a group of sequentially acting serine proteases located in the fluid-filled perivitelline space between the embryonic membrane and the eggshell, which generate the ligand for the Toll receptor on the ventral side of the embryo. Spatial control of the protease cascade relies on the Pipe sulfotransferase, a fly homolog of vertebrate glycosaminoglycan-modifying enzymes, which is expressed in ventral cells of the follicular epithelium surrounding the developing oocyte. Here we show that the vitelline membrane-like (VML) protein undergoes Pipe-dependent sulfation and, consistent with a role in conveying positional information from the egg chamber to the embryo, becomes incorporated into the eggshell at a position corresponding to the location of the follicle cells from which it was secreted. Although VML influences embryonic DV pattern in a sensitized genetic background, VML is not essential for DV axis formation, suggesting that there is redundancy in the composition of the Pipe enzymatic target. Correspondingly, we find that additional structural components of the vitelline membrane undergo Pipe-dependent sulfation. In identifying the elusive targets of Pipe, this work points to the vitelline membrane as the source of signals that generate the Drosophila DV axis.
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Affiliation(s)
- Zhenyu Zhang
- Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
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23
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LeMosy EK. Proteolytic regulatory mechanisms in the formation of extracellular morphogen gradients. ACTA ACUST UNITED AC 2006; 78:243-55. [PMID: 17061259 DOI: 10.1002/bdrc.20074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Growth factors are secreted into the extracellular space, where they encounter soluble inhibitors, extracellular matrix glycoproteins and proteoglycans, and proteolytic enzymes that can each modulate the spatial distribution, activity state, and receptor interactions of these signaling molecules. During development, morphogenetic gradients of these growth factors pattern fields of cells responsive to different levels of signaling, creating such structures as the branched pattern of airways and vasculature, and the arrangement of digits in the hand. This review focuses specifically on the roles of proteolytic enzymes and their regulators in the generation of such activity gradients. Evidence from Drosophila developmental pathways provides a detailed understanding of general mechanisms underlying proteolytic control of morphogen gradients, while recent studies of several mammalian growth factors illustrate the relevance of this proteolytic control to human development and disease.
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Affiliation(s)
- Ellen K LeMosy
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia 30912, USA.
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24
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Carneiro K, Fontenele M, Negreiros E, Lopes E, Bier E, Araujo H. Graded maternal short gastrulation protein contributes to embryonic dorsal-ventral patterning by delayed induction. Dev Biol 2006; 296:203-18. [PMID: 16781701 DOI: 10.1016/j.ydbio.2006.04.453] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 04/04/2006] [Accepted: 04/19/2006] [Indexed: 10/24/2022]
Abstract
Establishment of the dorsal-ventral (DV) axis of the Drosophila embryo depends on ventral activation of the maternal Toll pathway, which creates a gradient of the NFkB/c-rel-related transcription factor dorsal. Signaling through the maternal BMP pathway also alters the dorsal gradient, probably by regulating degradation of the IkB homologue Cactus. The BMP4 homologue decapentaplegic (dpp) and the BMP antagonist short gastrulation (sog) are expressed by follicle cells during mid-oogenesis, but it is unknown how they affect embryonic patterning following fertilization. Here, we provide evidence that maternal Sog and Dpp proteins are secreted into the perivitelline space where they remain until early embryogenesis to modulate Cactus degradation, enabling their dual function in patterning the eggshell and embryo. We find that metalloproteases encoded by tolloid (tld) and tolkin (tok), which cleave Sog, are expressed by follicle cells and are required to generate DV asymmetry in the Dpp signal. Expression of tld and tok is ventrally restricted by the TGF-alpha ligand encoded by gurken, suggesting that signaling via the EGF receptor pathway may regulate embryonic patterning through two independent mechanisms: by restricting the expression of pipe and thereby activation of Toll signaling and by spatially regulating BMP activity.
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Affiliation(s)
- K Carneiro
- Department of Histology and Embryology, Universidade Federal do Rio de Janeiro, CCS, Bl. F, Sala F2-031, Av. Brig. Trompowski, s/n, 21949-900 Rio de Janeiro, RJ, Brazil
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25
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Zhu L, Song L, Chang Y, Xu W, Wu L. Molecular cloning, characterization and expression of a novel serine proteinase inhibitor gene in bay scallops (Argopecten irradians, Lamarck 1819). FISH & SHELLFISH IMMUNOLOGY 2006; 20:320-31. [PMID: 16005644 DOI: 10.1016/j.fsi.2005.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Revised: 02/01/2005] [Accepted: 05/11/2005] [Indexed: 05/03/2023]
Abstract
Serine protease inhibitors, critical regulators of endogenous proteases, are found in all multicellular organisms and play crucial roles in host physiological and immunological effector mechanisms. The first mollusk serine proteinase inhibitor (designated AISPI) cDNA was obtained from the bay scallop Argopecten irradians by randomly sequencing a whole tissue cDNA library and rapid amplification of cDNA ends (RACE). The full-length cDNA of the scallop serine protease inhibitor was 1020 bp, consisting of a 5'-terminal untranslated region (UTR) of 39 bp, a 3'-terminal UTR of 147 bp with a canonical polyadenylation signal sequence AATAAA and a poly(A) tail, and an open reading frame of 834 bp. The AISPI cDNA encoded a polypeptide of 278 amino acids with a putative signal peptide of 22 amino acids and a mature protein of 256 amino acids. The deduced amino-acid sequence of AISPI contained six tandem and homologous domains similar to that of Kazal-type serine protease inhibitors, including the conserved sequence C-X(7)-C-X(6)-Y-X(3)-C-X(2,3)-C and six cysteine residues responsible for the formation of disulfide bridges, indicating that the AISPI protein from bay scallop should be a member of the Kazal-type serine protease inhibitor family. The temporal expression of AISPI was measured by semi-quantitative RT-PCR after injury or bacterial challenge. After the adductor muscle was wounded or injected with Vibrio anguillarum, the expression of AISPI mRNA in hemolymph was up-regulated and reached the maximum level at 8 and 16 h, respectively, and then progressively dropped back to the original level. The results indicated that AISPI could play an important role in injury healing and immune response in mollusks as it could be induced by injury and bacterial challenge.
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Affiliation(s)
- Ling Zhu
- Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, P.R. China
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26
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Zhu X, Sen J, Stevens L, Goltz JS, Stein D. Drosophila pipe protein activity in the ovary and the embryonic salivary gland does not require heparan sulfate glycosaminoglycans. Development 2005; 132:3813-22. [PMID: 16049108 DOI: 10.1242/dev.01962] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Drosophila pipe gene encodes ten related proteins that exhibit amino acid sequence similarity to vertebrate heparan sulfate 2-O-sulfotransferase. One of the Pipe isoforms, which is expressed in the ventral follicular epithelium, is a key determinant of embryonic dorsoventral polarity, suggesting that Pipe-mediated sulfation of a heparan sulfate proteoglycan provides a spatial cue for dorsoventral axis formation. We used several approaches to investigate this possibility in the work described here. We determined the nucleotide alterations in 11 different pipe alleles. Ten of the mutations specifically affect the pipe isoform that is expressed in the ovary. Among these ten mutations, two alter an amino acid in the putative binding site for 3'-phosphoadenosine 5'-phosphosulfate, the universal sulfate donor. Using Alcian Blue, a histochemical stain that detects sulfated glycans, we observed a novel, pipe-dependent macromolecule in the embryonic salivary glands. Genes known to participate in the formation of heparan sulfate in Drosophila are not required for the production of this material. To investigate whether a heparan sulfate proteoglycan is involved in pipe function in dorsoventral patterning, we generated females carrying follicle cell clones mutant for heparan sulfate synthesis-related genes. Embryos from follicles with mutant clones did not exhibit a dorsalized phenotype. Taken together, our data provide evidence that Pipe acts as a sulfotransferase, but argue against the hypothesis that the target of Pipe is a heparan sulfate glycosaminoglycan.
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Affiliation(s)
- Xianjun Zhu
- Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
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27
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Gilboa L, Forbes A, Tazuke SI, Fuller MT, Lehmann R. Germ line stem cell differentiation in Drosophila requires gap junctions and proceeds via an intermediate state. Development 2004; 130:6625-34. [PMID: 14660550 DOI: 10.1242/dev.00853] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Gap junctions coordinate processes ranging from muscle contraction to ovarian follicle development. Here we show that the gap junction protein Zero population growth (Zpg) is required for germ cell differentiation in the Drosophila ovary. In the absence of Zpg the stem cell daughter destined to differentiate dies. The zpg phenotype is novel, and we used this phenotype to genetically dissect the process of stem cell maintenance and differentiation. Our findings suggest that germ line stem cells differentiate upon losing contact with their niche, that gap junction mediated cell-cell interactions are required for germ cell differentiation, and that in Drosophila germ line stem cell differentiation to a cystoblast is gradual.
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Affiliation(s)
- Lilach Gilboa
- Developmental Genetics Program, Skirball Institute at NYU School of Medicine and Howard Hughes Medical Institute, 540 First Avenue, New York, NY 10016, USA
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28
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Affiliation(s)
- Qingyu Wu
- Department of Cardiovascular Research, Berlex Biosciences, Richmond, California 94806, USA
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29
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Gonçalves-Mendes N, Simon-Chazottes D, Creveaux I, Meiniel A, Guénet JL, Meiniel R. Mouse SCO-spondin, a gene of the thrombospondin type 1 repeat (TSR) superfamily expressed in the brain. Gene 2003; 312:263-70. [PMID: 12909363 DOI: 10.1016/s0378-1119(03)00622-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
SCO-spondin is specifically expressed in the subcommissural organ (SCO), a secretory ependymal differentiation lining the roof of the third ventricular cavity of the brain. When released into the cerebro-spinal fluid (CSF), SCO-spondin aggregates and forms Reissner's fiber (RF), a structure present in the central canal of the spinal cord. SCO-spondin belongs to the superfamily of proteins exhibiting conserved motifs called TSRs for 'thrombospondin type 1 repeats' and involved in axonal pathfinding during development. The mouse SCO-spondin coding sequence was searched by alignement of the coding bovine SCO-spondin sequence with the mouse whole genome shotgun (WGS) supercontig (NW 000250). Compared to the bovine, mouse SCO-spondin shows 66.8% identity of amino acids. This extracellular matrix glycoprotein has a modular arrangement of several conserved domains including 25 TSRs, 10 low-density lipoprotein receptor (LDLr) type A repeats and cystein-rich regions in the -NH2 and -COOH ends. The spatio-temporal expression of SCO-spondin was analyzed using specific antisera and an homospecific SCO-spondin riboprobe. In the adult, the patterns obtained by in situ hybridization (ISH) and immunohistochemistry correlated well in the SCO, while Reissner's fiber and the ampulla caudalis were immunoreactive only. In the fetus, both the immuno and ISH reactions appeared between 14 and 15 days post coïtum (dpc) in the SCO anlage. In addition, the mouse SCO-spondin gene was located at chromosome 6, between marker D6Mit352 and D6Mit119, in a conserved syntenic region.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Brain/embryology
- Brain/growth & development
- Cattle
- Cell Adhesion Molecules, Neuronal/genetics
- Cell Adhesion Molecules, Neuronal/metabolism
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Gene Expression Regulation, Developmental
- Humans
- Immunohistochemistry
- In Situ Hybridization
- Mice
- Molecular Sequence Data
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Radiation Hybrid Mapping
- Repetitive Sequences, Nucleic Acid/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Thrombospondin 1/genetics
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Affiliation(s)
- Nicolas Gonçalves-Mendes
- UMR INSERM 384, Faculté de Médecine de Clermont-Ferrand, 28 Place Henri Dunant, 63001 Clermont-Ferrand, France
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30
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Tadros W, Houston SA, Bashirullah A, Cooperstock RL, Semotok JL, Reed BH, Lipshitz HD. Regulation of maternal transcript destabilization during egg activation in Drosophila. Genetics 2003; 164:989-1001. [PMID: 12871909 PMCID: PMC1462612 DOI: 10.1093/genetics/164.3.989] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In animals, the transfer of developmental control from maternal RNAs and proteins to zygotically derived products occurs at the midblastula transition. This is accompanied by the destabilization of a subset of maternal transcripts. In Drosophila, maternal transcript destabilization occurs in the absence of fertilization and requires specific cis-acting instability elements. We show here that egg activation is necessary and sufficient to trigger transcript destabilization. We have identified 13 maternal-effect lethal loci that, when mutated, result in failure of maternal transcript degradation. All mutants identified are defective in one or more additional processes associated with egg activation. These include vitelline membrane reorganization, cortical microtubule depolymerization, translation of maternal mRNA, completion of meiosis, and chromosome condensation (the S-to-M transition) after meiosis. The least pleiotropic class of transcript destabilization mutants consists of three genes: pan gu, plutonium, and giant nuclei. These three genes regulate the S-to-M transition at the end of meiosis and are thought to be required for the maintenance of cyclin-dependent kinase (CDK) activity during this cell cycle transition. Consistent with a possible functional connection between this S-to-M transition and transcript destabilization, we show that in vitro-activated eggs, which exhibit aberrant postmeiotic chromosome condensation, fail to initiate transcript degradation. Several genetic tests exclude the possibility that reduction of CDK/cyclin complex activity per se is responsible for the failure to trigger transcript destabilization in these mutants. We propose that the trigger for transcript destabilization occurs coincidently with the S-to-M transition at the end of meiosis and that pan gu, plutonium, and giant nuclei regulate maternal transcript destabilization independent of their role in cell cycle regulation.
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Affiliation(s)
- Wael Tadros
- Program in Developmental Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
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31
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Imler JL, Hoffmann JA. Toll receptors in Drosophila: a family of molecules regulating development and immunity. Curr Top Microbiol Immunol 2003; 270:63-79. [PMID: 12467244 DOI: 10.1007/978-3-642-59430-4_4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In recent years, Toll-like receptors (TLRs) have emerged as key receptors which detect microbes and initiate an inflammatory response. The Toll receptor was originally identified and characterized 14 years ago for its role in the embryonic development of the fruit-fly Drosophila melanogaster. Subsequently, it was also shown to be an essential component of the signaling pathway mediating the anti-fungal host defense in this model organism. New factors involved in the activation of the Toll receptor or in intracytoplasmic signaling during the immune response in Drosophila have recently been identified. The existence of significant functional differences between mammalian TLRs and Drosophila Toll receptors is also becoming apparent.
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Affiliation(s)
- J L Imler
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire, 15 rue Descartes, 67000 Strasbourg, France.
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Meiniel A, Meiniel R, Gonçalves-Mendes N, Creveaux I, Didier R, Dastugue B. The thrombospondin type 1 repeat (TSR) and neuronal differentiation: roles of SCO-spondin oligopeptides on neuronal cell types and cell lines. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 230:1-39. [PMID: 14692680 DOI: 10.1016/s0074-7696(03)30001-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SCO-spondin is a large glycoprotein secreted by ependymal cells of the subcommissural organ. It shares functional domains called thrombospondin type 1 repeats (TSRs) with a number of developmental proteins expressed in the central nervous system, and involved in axonal pathfinding. Also, SCO-spondin is highly conserved in the chordate phylum and its multiple domain organization is probably a chordate innovation. The putative involvement of SCO-spondin in neuron/glia interaction in the course of development is assessed in various cell culture systems. SCO-spondin interferes with several developmental processes, including neuronal survival, neurite extension, neuronal aggregation, and fasciculation. The TSR motifs, and especially the WSGWSSCSVSCG sequence, are most important in these neuronal responses. Integrins and growth factor receptors may cooperate as integrative signals. We discuss the putative involvement of the subcommissural organ/Reissner's fiber complex in developmental events, as a particular extracellular signaling system.
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Affiliation(s)
- Annie Meiniel
- INSERUM UMR 384 et Laboratoire de Biochimie médicale, F-63001 Clermont-Ferrand, France
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33
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Chang AJ, Morisato D. Regulation of Easter activity is required for shaping the Dorsal gradient in the Drosophila embryo. Development 2002; 129:5635-45. [PMID: 12421704 DOI: 10.1242/dev.00161] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Dorsoventral polarity of the Drosophila embryo requires maternal spätzle-Toll signaling to establish a nuclear gradient of Dorsal protein. The shape of this gradient is altered in embryos produced by females carrying dominant alleles of easter (ea(D)). The easter gene encodes a serine protease that generates processed Spätzle, which is proposed to act as the Toll ligand. By examining the expression domains of the zygotic genes zen, sog, rho and twist, which are targets of nuclear Dorsal, we show that the slope of the Dorsal gradient is progressively flattened in stronger ea(D) alleles. In the wild-type embryo, activated Easter is found in a high M(r) complex called Ea-X, which is hypothesized to contain a protease inhibitor. In ea(D) embryo extracts, we detect an Easter form corresponding to the free catalytic domain, which is never observed in wild type. These mutant ea(D) proteins retain protease activity, as determined by the production of processed Spätzle both in the embryo and in cultured Drosophila cells. These experiments suggest that the ea(D) mutations interfere with inactivation of catalytic Easter, and imply that this negative regulation is essential for generating the wild-type shape of the Dorsal gradient.
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Affiliation(s)
- Andy J Chang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
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Tazuke SI, Schulz C, Gilboa L, Fogarty M, Mahowald AP, Guichet A, Ephrussi A, Wood CG, Lehmann R, Fuller MT. A germline-specific gap junction protein required for survival of differentiating early germ cells. Development 2002; 129:2529-39. [PMID: 11973283 DOI: 10.1242/dev.129.10.2529] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Germ cells require intimate associations and signals from the surrounding somatic cells throughout gametogenesis. The zero population growth (zpg) locus of Drosophila encodes a germline-specific gap junction protein, Innexin 4, that is required for survival of differentiating early germ cells during gametogenesis in both sexes. Animals with a null mutation in zpg are viable but sterile and have tiny gonads. Adult zpg-null gonads contain small numbers of early germ cells, resembling stem cells or early spermatogonia or oogonia, but lack later stages of germ cell differentiation. In the male, Zpg protein localizes to the surface of spermatogonia, primarily on the sides adjacent to the somatic cyst cells. In the female, Zpg protein localizes to germ cell surfaces, both those adjacent to surrounding somatic cells and those adjacent to other germ cells. We propose that Zpg-containing gap junctional hemichannels in the germ cell plasma membrane may connect with hemichannels made of other innexin isoforms on adjacent somatic cells. Gap junctional intercellular communication via these channels may mediate passage of crucial small molecules or signals between germline and somatic support cells required for survival and differentiation of early germ cells in both sexes.
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Affiliation(s)
- Salli I Tazuke
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329, USA.
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35
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Turcotte CL, Hashimoto C. Evidence for a glycosaminoglycan on the nudel protein important for dorsoventral patterning of the drosophila embryo. Dev Dyn 2002; 224:51-7. [PMID: 11984873 DOI: 10.1002/dvdy.10081] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dorsoventral patterning of the Drosophila embryo requires Nudel, a large mosaic protein with a protease domain. Previous studies have implicated Nudel's protease domain as the trigger of a proteolytic cascade that activates the Toll signaling pathway to establish dorsoventral polarity in the embryo. However, the function of other regions of Nudel has been unclear. By using two-dimensional gel electrophoresis and site-directed mutagenesis, we have obtained evidence that the N-terminal region of Nudel contains a site for glycosaminoglycan (GAG) attachment that is required for dorsoventral patterning. Disruption of this site blocks a disulfide-based association between N- and C-terminal Nudel polypeptides and proteolytic activation of Nudel's protease domain. We discuss how a GAG chain on Nudel might be required for Nudel protease activation.
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Affiliation(s)
- Cynthia L Turcotte
- Department of Cell Biology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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Jiménez G, González-Reyes A, Casanova J. Cell surface proteins Nasrat and Polehole stabilize the Torso-like extracellular determinant in Drosophila oogenesis. Genes Dev 2002; 16:913-8. [PMID: 11959840 PMCID: PMC152353 DOI: 10.1101/gad.223902] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Structural cell-surface and extracellular-matrix proteins modulate intercellular signaling events during development, but how this is achieved remains largely unknown. Here we identify a novel family of Drosophila proteins, Nasrat and Polehole, that coat the oocyte surface and play two roles: They mediate assembly of the eggshell, and act in the Torso RTK signaling pathway that specifies the terminal regions of the embryo. Nasrat and Polehole are essential for extracellular accumulation of Torso-like, a factor secreted during oogenesis that initiates Torso receptor activation. Stabilization of secreted factors by specialized pericellular proteins may be a general mechanism during signaling and developmental patterning.
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Affiliation(s)
- Gerardo Jiménez
- Instituto de Biología Molecular de Barcelona (CSIC), 08034 Barcelona, Spain.
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37
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Abstract
Genetic screens in Drosophila melanogaster have helped elucidate the process of axis formation during early embryogenesis. Axis formation in the D. melanogaster embryo involves the use of two fundamentally different mechanisms for generating morphogenetic activity: patterning the anteroposterior axis by diffusion of a transcription factor within the syncytial embryo and specification of the dorsoventral axis through a signal transduction cascade. Identification of Drosophila genes involved in axis formation provides a launch-pad for comparative studies that examine the evolution of axis specification in different insects. Additionally, there is similarity between axial patterning mechanisms elucidated genetically in Drosophila and those demonstrated for chordates such as Xenopus. In this review we examine the postfertilization mechanisms underlying axis specification in Drosophila. Comparative data are then used to ask whether aspects of axis formation might be derived or ancestral.
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Affiliation(s)
- S Lall
- Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois 60637, USA
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38
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Goff DJ, Nilson LA, Morisato D. Establishment of dorsal-ventral polarity of theDrosophilaegg requirescapicuaaction in ovarian follicle cells. Development 2001; 128:4553-62. [PMID: 11714680 DOI: 10.1242/dev.128.22.4553] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The dorsal-ventral pattern of the Drosophila egg is established during oogenesis. Epidermal growth factor receptor (Egfr) signaling within the follicular epithelium is spatially regulated by the dorsally restricted distribution of its presumptive ligand, Gurken. As a consequence, pipe is transcribed in a broad ventral domain to initiate the Toll signaling pathway in the embryo, resulting in a gradient of Dorsal nuclear translocation. We show that expression of pipe RNA requires the action of fettucine (fet) in ovarian follicle cells. Loss of maternal fet activity produces a dorsalized eggshell and embryo. Although similar mutant phenotypes are observed with regulators of Egfr signaling, genetic analysis suggests that fet acts downstream of this event. The fet mutant phenotype is rescued by a transgene of capicua (cic), which encodes an HMG-box transcription factor. We show that Cic protein is initially expressed uniformly in ovarian follicle cell nuclei, and is subsequently downregulated on the dorsal side. Earlier studies described a requirement for cic in repressing zygotic target genes of both the torso and Toll pathways in the embryo. Our experiments reveal that cic controls dorsal-ventral patterning by regulating pipe expression in ovarian follicle cells, before its previously described role in interpreting the Dorsal gradient.
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Affiliation(s)
- D J Goff
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
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39
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Weiss JB, Suyama KL, Lee HH, Scott MP. Jelly belly: a Drosophila LDL receptor repeat-containing signal required for mesoderm migration and differentiation. Cell 2001; 107:387-98. [PMID: 11701128 DOI: 10.1016/s0092-8674(01)00540-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Inductive interactions subdivide the Drosophila mesoderm into visceral, somatic, and heart muscle precursors. The muscle precursors form organs by executing tissue-specific migrations and cell fusions. We identified a novel gene, jelly belly (jeb), which is required for visceral mesoderm development. jeb encodes a secreted protein that contains an LDL receptor repeat. In jeb mutants, visceral mesoderm precursors form, but they fail to migrate or differentiate normally; no visceral muscles develop. Jeb protein is produced in somatic muscle precursors and taken up by visceral muscle precursors. jeb reveals a signaling process in which somatic muscle precursors support the proper migration and differentiation of visceral muscle cells. Later in embryogenesis, jeb is transcribed in neurons and Jeb protein is found in axons.
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Affiliation(s)
- J B Weiss
- Department of Developmental Biology, Howard Hughes Medical Institute, Beckman Center B300, 279 Campus Drive, Stanford University School of Medicine, Stanford, CA 94305, USA.
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40
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Freeman MR, Doe CQ. Moving muscle. Jeb signaling in Drosophila. Dev Cell 2001; 1:587-8. [PMID: 11709176 DOI: 10.1016/s1534-5807(01)00080-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A recent study identifies a novel nonautonomous signaling pathway that regulates cell migration and differentiation in early Drosophila mesodermal tissues.
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Affiliation(s)
- M R Freeman
- Institutes of Neuroscience and Molecular Biology/HHMI, University of Oregon, Eugene, OR 97403, USA
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41
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Andrenacci D, Cernilogar FM, Taddel C, Rotoli D, Cavaliere V, Graziani F, Gargiulo G. Specific domains drive VM32E protein distribution and integration in Drosophila eggshell layers. J Cell Sci 2001; 114:2819-29. [PMID: 11683415 DOI: 10.1242/jcs.114.15.2819] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A study was made of the localization and assembly of the VM32E protein, a putative vitelline membrane component of the Drosophila eggshell. The results highlight some unique features of this protein compared with the other proteins of the same gene family. At the time of its synthesis (stage 10), the VM32E protein is not detectable in polar follicle cells. However, it is able to move in the extracellular space around the oocyte and, by stage 11 is uniformly distributed in the vitelline membrane. During the terminal stages of oogenesis the VM32E protein is partially released from the vitelline membrane and becomes localized in the endochorion layer also. By analyzing transgenic flies carrying variously truncated VM32E proteins, we could identify the protein domains required for the proper assembly of the VM32E protein in the eggshell. The highly conserved vitelline membrane domain is implicated in the early interactions with other components and is required for cross-linking VM32E protein in the vitelline membrane. The terminal carboxylic domain is necessary for localization to the endochorion layer. Protein with the C-end domain deleted is localized solely to the vitelline membrane and cross-linked only in laid eggs, as occurs for the other vitelline membrane proteins.
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Affiliation(s)
- D Andrenacci
- Dipartimento di Biologia Evoluzionistica Sperimentale, Bologna, Italy
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42
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Dissing M, Giordano H, DeLotto R. Autoproteolysis and feedback in a protease cascade directing Drosophila dorsal-ventral cell fate. EMBO J 2001; 20:2387-93. [PMID: 11350927 PMCID: PMC125460 DOI: 10.1093/emboj/20.10.2387] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Three serine protease zymogens, Gastrulation defective (GD), Snake (Snk) and Easter (Ea), and a nerve growth factor-like growth factor ligand precursor, Spaetzle, are required for specification of dorsal- ventral cell fate during Drosophila embryogenesis. The proteases have been proposed to function in a sequential activation cascade within the extracellular compartment called the perivitelline space. We examined biochemical interactions between these four proteins using a heterologous co-expression system. The results indicate that the three proteases do function in a sequential activation cascade, that GD becomes active and initiates the cascade and that interaction between GD and Snk is sufficient for GD to cleave itself autoproteolytically. The proteolytically active form of Ea cleaves GD at a different position, revealing biochemical feedback in the pathway. Both GD and Snk bind to heparin-Sepharose, providing a link between the pipe-defined ventral prepattern and the protease cascade. Our results suggest a model of the cascade in which initiation is by relief from inhibition, and spatial regulation of activity is due to interaction with sulfated proteoglycans.
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Affiliation(s)
| | - Heidi Giordano
- Department of Genetics, Institute of Molecular Biology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark
Present address: Tularik Inc., Two Corporate Drive, South San Francisco, CA 94080, USA Corresponding author e-mail:
| | - Robert DeLotto
- Department of Genetics, Institute of Molecular Biology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark
Present address: Tularik Inc., Two Corporate Drive, South San Francisco, CA 94080, USA Corresponding author e-mail:
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43
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Abstract
Dorsal-ventral polarity of the Drosophila embryo is established by a nuclear gradient of Dorsal protein, generated by successive gurken-Egfr and spätzle-Toll signaling. Overexpression of extracellular Spätzle dramatically reshapes the Dorsal gradient: the normal single peak is broadened and then refined to two distinct peaks of nuclear Dorsal, to produce two ventral furrows. This partial axis duplication, which mimics the ventralized phenotype caused by reduced gurken-Egfr signaling, arises from events in the perivitelline fluid of the embryo and occurs at the level of Spätzle processing or Toll activation. The production of two Dorsal peaks is addressed by a model that invokes action of a diffusible inhibitor, which is proposed to normally regulate the slope of the Dorsal gradient.
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Affiliation(s)
- D Morisato
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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44
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Casali A, Casanova J. The spatial control of Torso RTK activation: a C-terminal fragment of the Trunk protein acts as a signal for Torso receptor in the Drosophila embryo. Development 2001; 128:1709-15. [PMID: 11290307 DOI: 10.1242/dev.128.9.1709] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Regulated activation of receptor tyrosine kinases depends on both the presence of the receptors at the cell surface and on the availability of their ligands. In Drosophila, the torso tyrosine kinase receptor is distributed along the surface of the embryo but it is only activated at the poles by a diffusible extracellular ligand generated at each pole that is trapped by the receptor, thereby impeding further diffusion. Although it is known that this signal depends on the activity of several genes, such as torso-like and trunk, it is still unclear how is generated. The identification of the signal responsible for the torso receptor activation is an essential step towards understanding the mechanism that regulates the local restriction of torso signalling. Here we report that a fragment containing the carboxy-terminal 108 amino acids of the trunk protein retains trunk activity and is sufficient to activate torso signalling. We also show that this fragment bypasses the requirements for the other genes involved in the activation of the torso receptor. These results suggest that a cleaved form of the trunk protein acts as a signal for the torso receptor. We therefore propose that the restricted activation of the torso receptor is defined by the spatial control of the proteolytic processing of the trunk protein.
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Affiliation(s)
- A Casali
- Institut de Biologia Molecular de Barcelona, CSIC, C/ Jordi Girona 18-26, Spain
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45
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Kim DR, Sharmin S, Inoue M, Kido H. Cloning and expression of novel mosaic serine proteases with and without a transmembrane domain from human lung. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1518:204-9. [PMID: 11267681 DOI: 10.1016/s0167-4781(01)00184-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Two cDNAs encoding novel mosaic proteins with a serine protease domain and potential regulatory modules, consisting of a protein kinase substrate and a low-density lipoprotein receptor, were cloned from a human lung cDNA library by PCR. One with a transmembrane domain (MSPL) and the other without one (MSPS) comprise 581 and 537 amino acids, respectively. Except for the C-terminal ends, the two isoforms had an identical serine protease domain exhibiting 42, 39 and 43% identity with those of plasma kallikrein, hepsin and transmembrane protease serine 2, respectively. Both genes were predominantly expressed in human lung, placenta, pancreas and prostate.
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Affiliation(s)
- D R Kim
- Division of Enzyme Chemistry, Institute for Enzyme Research, The University of Tokushima, 770-8503, Tokushima, Japan
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46
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Meiniel A. SCO-spondin, a glycoprotein of the subcommissural organ/Reissner's fiber complex: evidence of a potent activity on neuronal development in primary cell cultures. Microsc Res Tech 2001; 52:484-95. [PMID: 11241859 DOI: 10.1002/1097-0029(20010301)52:5<484::aid-jemt1034>3.0.co;2-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the cattle, SCO-spondin was shown to be a brain-secreted glycoprotein specifically expressed in the subcommissural organ (SCO), an ependymal differentiation located in the roof of the Sylvian aqueduct. Furthermore, SCO-spondin makes part of Reissner's fiber (RF), a structure present in the central canal of the spinal cord. Sequencing of overlaping cDNA inserts after successive screening of a cattle SCO cDNA expression library allowed characterization of the complete sequence of this novel protein. Conserved domains were identified including twenty-six thrombospondin type 1 repeats (TSRs), nine low-density lipoprotein receptor LDLr type A domains (LDLRA), two epidermal growth factor EGF-like domains, and homologies to mucins and the von Willebrand factor were found in the amino- and carboxy- termini. In addition, SCO-spondin shows a unique arrangement "in mosaic" of these domains. The putative function of SCO-spondin in neuronal differentiation is discussed regarding these features and homologies with other developmental molecules of the central nervous system exhibiting TSR domains, and involved in axonal guidance.To correlate molecular and functional features of SCO-spondin, we tested the effect of oligopeptides whose sequences include highly conserved regions of the TSRs, LDLRA repeats, and a potent site of attachment to glycosaminoglycan, on cortical and spinal cord neurons in primary cell cultures. Peptides corresponding to SCO-spondin TSRs markedly increased adhesivity and neuritic outgrowth of cortical neurons and induced disaggregation of spinal cord neurons. Thus, SCO-spondin is a candidate to interfere with neuronal development and/or axonal guidance during ontogenesis of the central nervous system in modulating side-to-side and side-to-substratum interactions, and in promoting neuritic outgrowth. RF proper has a wide range of activity on neuronal differentiation, including survival, aggregation, and disaggregation effects and neurite extension of cortical and spinal cord neurones "in vitro." Thus, the SCO/RF complex may interact with developmental processes of the central nervous system including the posterior commissure and spinal cord differentiation.
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Affiliation(s)
- A Meiniel
- Laboratoire de Biochimie médicale et INSERM U384 28, Place Henri Dunant, 63001 Clermont-Ferrand cedex, France.
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47
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Sergeev P, Streit A, Heller A, Steinmann-Zwicky M. The Drosophila dorsoventral determinant PIPE contains ten copies of a variable domain homologous to mammalian heparan sulfate 2-sulfotransferase. Dev Dyn 2001; 220:122-32. [PMID: 11169845 DOI: 10.1002/1097-0177(2000)9999:9999<::aid-dvdy1094>3.0.co;2-a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In Drosophila, the gene PIPE is expressed in follicle cells, the somatic cells that surround the forming egg during maturation, specifically on one side of the egg chamber. This asymmetry establishes the dorsoventral axis of the future embryo. Through the action of PIPE, the ligand SPATZLE, that is located in the perivitelline fluid of the embryo, is activated ventrally. This signal activates TOLL, a membrane-bound receptor. According to present knowledge, PIPE encodes two different transcripts, one of which restored ventral pattern elements to embryos when introduced into mutant pipe females. Here we show that PIPE is far more complex than previously reported. It encodes not two, but at least ten different transcripts, two of which are localized to ventral follicle cells. The transcripts contain one of ten copies of a variable domain, all homologous to heparan sulfate 2-sulfotransferase, an enzyme known to modify heparan sulfate proteoglycans, which are molecules that can bind ligands. The complex gene structure of PIPE thus evolved by duplications of one exon, a strategy used by genes of the immunoglobulin superfamily to generate molecular diversity. We show that PIPE transcripts can be eliminated by RNAi, although in this method double-stranded RNA is injected in embryos, while PIPE transcripts appear in the adult ovary. Our data suggest that at least two different PIPE transcripts redundantly provide the ventralizing PIPE function. 3' of PIPE we identified an enhancer element that drives a lacZ reporter gene specifically in ventral follicle cells. Since PIPE transcripts are found in salivary glands, and since expression of salivary gland genes is dependent on signaling molecules, we speculate that PIPE became localized to ventral follicle cells by a preexisting control system after acquiring a follicle cell enhancer.
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Affiliation(s)
- P Sergeev
- Zoological Institute, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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48
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Hahn M, Bishop J. Expression pattern of Drosophila ret suggests a common ancestral origin between the metamorphosis precursors in insect endoderm and the vertebrate enteric neurons. Proc Natl Acad Sci U S A 2001; 98:1053-8. [PMID: 11158593 PMCID: PMC14707 DOI: 10.1073/pnas.98.3.1053] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The RET gene, encoding a receptor tyrosine kinase, is unusual among human protooncogenes in that its mutant alleles are implicated in a developmental defect involving enteric neurons as well as in tumorigenesis. The cells affected in both types of disorders are derived from the neural crest. Targeted disruption of mouse ret has revealed an additional role in kidney development. Here we report the analysis of a ret homolog in Drosophila melanogaster, an arthropod with no neural crest. Drosophila ret (D-ret) encodes a protein of 1,235 amino acids that has all of the domains identified in the vertebrate ret, including a cadherin motif. During embryogenesis, D-ret mRNA is first detected in the yolk sac at the late gastrula stage. In the postgastrula, D-ret is expressed in the foregut neurons, excretory system, peripheral ganglia, and the central nervous system. Thus, despite the wide divergence of early embryonic fate maps between vertebrates and invertebrates, D-ret is expressed in cells that are presumed to be the functional equivalents of the ret-expressing cells in vertebrates. Unexpectedly, D-ret is also expressed in the imaginal islands of the endodermal gut. These cells are proliferation-competent precursors for adult midgut that are diffusely embedded in the growth-arrested juvenile gut. These ret-expressing nonneuronal cells are strikingly analogous to vertebrate enteric neurons in their topography, but not in their cell fate. Our finding suggests a previously unrecognized phylogenetic relationship between the ret-expressing cells in vertebrates and the precursor reserves of metamorphosing insects.
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Affiliation(s)
- M Hahn
- G. W. Hooper Foundation, University of California, San Francisco, CA 94143-0552, USA
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49
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Expression pattern of Drosophila ret suggests a common ancestral origin between the metamorphosis precursors in insect endoderm and the vertebrate enteric neurons. Proc Natl Acad Sci U S A 2001. [PMID: 11158593 PMCID: PMC14707 DOI: 10.1073/pnas.021558598] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The RET gene, encoding a receptor tyrosine kinase, is unusual among human protooncogenes in that its mutant alleles are implicated in a developmental defect involving enteric neurons as well as in tumorigenesis. The cells affected in both types of disorders are derived from the neural crest. Targeted disruption of mouse ret has revealed an additional role in kidney development. Here we report the analysis of a ret homolog in Drosophila melanogaster, an arthropod with no neural crest. Drosophila ret (D-ret) encodes a protein of 1,235 amino acids that has all of the domains identified in the vertebrate ret, including a cadherin motif. During embryogenesis, D-ret mRNA is first detected in the yolk sac at the late gastrula stage. In the postgastrula, D-ret is expressed in the foregut neurons, excretory system, peripheral ganglia, and the central nervous system. Thus, despite the wide divergence of early embryonic fate maps between vertebrates and invertebrates, D-ret is expressed in cells that are presumed to be the functional equivalents of the ret-expressing cells in vertebrates. Unexpectedly, D-ret is also expressed in the imaginal islands of the endodermal gut. These cells are proliferation-competent precursors for adult midgut that are diffusely embedded in the growth-arrested juvenile gut. These ret-expressing nonneuronal cells are strikingly analogous to vertebrate enteric neurons in their topography, but not in their cell fate. Our finding suggests a previously unrecognized phylogenetic relationship between the ret-expressing cells in vertebrates and the precursor reserves of metamorphosing insects.
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Wakabayashi-Ito N, Belvin MP, Bluestein DA, Anderson KV. fusilli, an essential gene with a maternal role in Drosophila embryonic dorsal-ventral patterning. Dev Biol 2001; 229:44-54. [PMID: 11133153 DOI: 10.1006/dbio.2000.9954] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Drosophila fusilli (fus) gene was identified in a genetic screen for dominant maternal enhancers of an unusual dorsalizing mutation in the cactus gene, cact(E10). While females that are heterozygous for the cact(E10) allele produce embryos with wild-type dorsal-ventral patterning, more than 90% of the embryos produced by females that are heterozygous for both cact(E10) and the fus(1) mutation are weakly dorsalized. Loss of fusilli activity causes lethality during embryogenesis but not dorsal-ventral patterning defects, indicating that fusilli is important in more than one developmental process. The fusilli gene encodes a protein with RNA binding motifs related to those in mammalian hnRNP F and H, which play roles in regulated RNA splicing. The fusilli RNA is not present in the oocyte or early embryo, and germ-line clones of fusilli mutations have no maternal effect on dorsal-ventral patterning, indicating that the fusilli maternal effect does not depend on germ-line expression of the gene. Because the fusilli RNA is present in ovarian follicle cells, we propose that fusilli acts downstream of the Drosophila EGF receptor to control the biogenesis of follicle cell transcripts that control the initial dorsal-ventral asymmetry of the embryo.
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Affiliation(s)
- N Wakabayashi-Ito
- Division of Genetics, University of California, Berkeley, California 94720-3200, USA
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