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Jindra M. František Sehnal: A project that worked out. J Insect Physiol 2023; 145:104475. [PMID: 36623749 DOI: 10.1016/j.jinsphys.2023.104475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
František Sehnal was a prominent and inspiring figure in many areas of insect science, most notably endocrinology, developmental biology, silk research, and recently insect interactions with genetically modified crops. In this article, I will briefly overview Sehnal's research and other academic and educational activities. I would also like to share my personal experience with František Sehnal as a mentor who drafted, in 1990, a plan for my doctoral thesis: to identify a receptor for juvenile hormone. The project ended up taking more than two decades to complete. While František has passed away, his legacy stays.
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Affiliation(s)
- Marek Jindra
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice 370 05, Czech Republic.
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2
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Tumova S, Jindra M. Ligand-dependent protein interactions of the juvenile hormone receptor captured in real time. FEBS J 2023. [PMID: 36609881 DOI: 10.1111/febs.16719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/28/2022] [Accepted: 01/05/2023] [Indexed: 01/09/2023]
Abstract
Juvenile hormone (JH) signalling provides vital regulatory functions during insect development via transcriptional regulation of genes critical for the progression of metamorphosis and oogenesis. Despite the importance of JH signalling, the underlying molecular mechanisms remain largely unknown. Our current understanding of the pathway depends on static end-point information and suffers from the lack of time-resolved data. Here, we have addressed the dynamic aspect of JH signalling by monitoring in real time the interactions of insect JH receptor proteins. Use of two tags that reconstitute a functional luciferase when in proximity enabled us to follow the rapid assembly of a JH receptor heterodimer from basic helix-loop-helix/Per-Arnt-SIM (bHLH-PAS) proteins, methoprene-tolerant (Met) and taiman (Tai), upon specific JH binding to Met. On a similar timescale (minutes), the dissociation of Met-Met complexes occurred, again strictly dependent on Met interaction with specific agonist ligands. To resolve questions regarding the regulatory role of the chaperone Hsp90/83 in the JHR complex formation, we used the same technique to demonstrate that the Met-Hsp83 complex persisted in the agonist absence but readily dissociated upon specific binding of JH to Met. Preincubation with the Hsp90 inhibitor geldanamycin showed that the chaperone interaction protected Met from degradation and was critical for Met to produce the active signalling dimer with Tai. Thus, the JH receptor functions appear to be governed by principles similar to those regulating the aryl hydrocarbon receptor, the closest vertebrate homologue of the arthropod JH receptor.
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Affiliation(s)
- Sarka Tumova
- Institute of Entomology, Biology Center of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Marek Jindra
- Institute of Entomology, Biology Center of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic
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3
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Milacek M, Bittova L, Tumova S, Luksan O, Hanus R, Kyjakova P, Machara A, Marek A, Jindra M. Binding of de novo synthesized radiolabeled juvenile hormone (JH III) by JH receptors from the Cuban subterranean termite Prorhinotermes simplex and the German cockroach Blattella germanica. Insect Biochem Mol Biol 2021; 139:103671. [PMID: 34656795 DOI: 10.1016/j.ibmb.2021.103671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/11/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Juvenile hormone (JH) controls insect reproduction and development through an intracellular receptor complex comprising two bHLH-PAS proteins, the JH-binding Methoprene-tolerant (Met) and its partner Taiman (Tai). Many hemimetabolous insects including cockroaches strictly depend on JH for stimulation of vitellogenesis. In termites, the eusocial hemimetabolans, JH also regulates the development of caste polyphenism. Studies addressing the agonist ligand binding to recombinant JH receptors currently include three species belonging to two holometabolous insect orders, but none that would represent any of the hemimetabolous orders. Here, we examined JH receptors in two representatives of Blattodea, the cockroach Blattella germanica and the termite Prorhinotermes simplex. To test the JH-binding capacity of Met proteins from these species, we performed chemical synthesis and tritium labeling of the natural blattodean JH homolog, JH III. Our improved protocol increased the yield and specific activity of [10-3H]JH III relative to formerly available preparations. Met proteins from both species specifically bound [3H]JH III with high affinity, whereas Met variants mutated at a critical position within the ligand-binding domain were incapable of such binding. Furthermore, JH III and the synthetic JH mimic fenoxycarb stimulated dimerization between Met and Tai components of the respective JH receptors of both species. These data present primary evidence for agonist binding by JH receptors in any hemimetabolous species and provide a molecular basis for JH action in cockroaches and termites.
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Affiliation(s)
- Matej Milacek
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, 370 05, Czech Republic; Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, 370 05, Czech Republic
| | - Lenka Bittova
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, 370 05, Czech Republic
| | - Sarka Tumova
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, 370 05, Czech Republic
| | - Ondrej Luksan
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, 166 10, Czech Republic
| | - Robert Hanus
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, 166 10, Czech Republic
| | - Pavlina Kyjakova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, 166 10, Czech Republic
| | - Ales Machara
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, 166 10, Czech Republic
| | - Ales Marek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, 166 10, Czech Republic.
| | - Marek Jindra
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, 370 05, Czech Republic; Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, 370 05, Czech Republic.
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4
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Jindra M, McKinstry WJ, Nebl T, Bittova L, Ren B, Shaw J, Phan T, Lu L, Low JKK, Mackay JP, Sparrow LG, Lovrecz GO, Hill RJ. Purification of an insect juvenile hormone receptor complex enables insights into its post-translational phosphorylation. J Biol Chem 2021; 297:101387. [PMID: 34758356 PMCID: PMC8683598 DOI: 10.1016/j.jbc.2021.101387] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 11/29/2022] Open
Abstract
Juvenile hormone (JH) plays vital roles in insect reproduction, development, and in many aspects of physiology. JH primarily acts at the gene-regulatory level through interaction with an intracellular receptor (JH receptor [JHR]), a ligand-activated complex of transcription factors consisting of the JH-binding protein methoprene-tolerant (MET) and its partner taiman (TAI). Initial studies indicated significance of post-transcriptional phosphorylation, subunit assembly, and nucleocytoplasmic transport of JHR in JH signaling. However, our knowledge of JHR regulation at the protein level remains rudimentary, partly because of the difficulty of obtaining purified and functional JHR proteins. Here, we present a method for high-yield expression and purification of JHR complexes from two insect species, the beetle T. castaneum and the mosquito Aedes aegypti. Recombinant JHR subunits from each species were coexpressed in an insect cell line using a baculovirus system. MET–TAI complexes were purified through affinity chromatography and anion exchange columns to yield proteins capable of binding both the hormonal ligand (JH III) and DNA bearing cognate JH-response elements. We further examined the beetle JHR complex in greater detail. Biochemical analyses and MS confirmed that T. castaneum JHR was a 1:1 heterodimer consisting of MET and Taiman proteins, stabilized by the JHR agonist ligand methoprene. Phosphoproteomics uncovered multiple phosphorylation sites in the MET protein, some of which were induced by methoprene treatment. Finally, we report a functional bipartite nuclear localization signal, straddled by phosphorylated residues, within the disordered C-terminal region of MET. Our present characterization of the recombinant JHR is an initial step toward understanding JHR structure and function.
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Affiliation(s)
- Marek Jindra
- Biology Center, Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic.
| | | | - Thomas Nebl
- CSIRO Manufacturing, CSIRO, Parkville, Victoria, Australia
| | - Lenka Bittova
- Biology Center, Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Bin Ren
- CSIRO Manufacturing, CSIRO, Parkville, Victoria, Australia
| | - Jan Shaw
- CSIRO Health and Biosecurity, CSIRO, North Ryde, New South Wales, Australia
| | - Tram Phan
- CSIRO Manufacturing, CSIRO, Parkville, Victoria, Australia
| | - Louis Lu
- CSIRO Manufacturing, CSIRO, Parkville, Victoria, Australia
| | - Jason K K Low
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Joel P Mackay
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | | | | | - Ronald J Hill
- CSIRO Health and Biosecurity, CSIRO, North Ryde, New South Wales, Australia; School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia.
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Abstract
Insect Growth Regulators (IGRs) represent advanced, bio-rational insecticides. This Special Issue reflects progress in IGR development that has been enabled by insight into the molecular principles of biosynthetic or hormone signaling pathways. The unifying principle is aiming at processes and molecular targets that are unique to arthropods and ideally to narrower insect taxa representing pests or disease vectors. While some strategies of obtaining the desired compounds for chemical intervention rely on rational, structure-based design or computational power, others exploit technologies allowing automated, high-throughput screening of large chemical libraries. All avenues leading to selective and environmentally safe pest control are valid as we face the imminent threat of the declining world insect population.
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Affiliation(s)
- Marek Jindra
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice 370 05, Czech Republic
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Jindra M, Bittova L. The juvenile hormone receptor as a target of juvenoid "insect growth regulators". Arch Insect Biochem Physiol 2020; 103:e21615. [PMID: 31502704 DOI: 10.1002/arch.21615] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 08/22/2019] [Accepted: 08/26/2019] [Indexed: 05/24/2023]
Abstract
Synthetic compounds that mimic the action of juvenile hormones (JHs) are founding members of a class of insecticides called insect growth regulators (IGRs). Like JHs, these juvenoids block metamorphosis of insect larvae to reproductive adults. Many biologically active juvenoids deviate in their chemical structure considerably from the sesquiterpenoid JHs, raising questions about the mode of action of such JH mimics. Despite the early deployment of juvenoid IGRs in the mid-1970s, their molecular effect could not be understood until recent discoveries of JH signaling through an intracellular JH receptor, namely the ligand-binding transcription factor Methoprene-tolerant (Met). Here, we briefly overview evidence defining three widely employed and chemically distinct juvenoid IGRs (methoprene, pyriproxyfen, and fenoxycarb), as agonist ligands of the JH receptor. We stress that knowledge of the target molecule is critical for using these compounds both as insecticides and as research tools.
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Affiliation(s)
- Marek Jindra
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Lenka Bittova
- Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
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Krejčová G, Danielová A, Nedbalová P, Kazek M, Strych L, Chawla G, Tennessen JM, Lieskovská J, Jindra M, Doležal T, Bajgar A. Drosophila macrophages switch to aerobic glycolysis to mount effective antibacterial defense. eLife 2019; 8:50414. [PMID: 31609200 PMCID: PMC6867711 DOI: 10.7554/elife.50414] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/12/2019] [Indexed: 12/13/2022] Open
Abstract
Macrophage-mediated phagocytosis and cytokine production represent the front lines of resistance to bacterial invaders. A key feature of this pro-inflammatory response in mammals is the complex remodeling of cellular metabolism towards aerobic glycolysis. Although the function of bactericidal macrophages is highly conserved, the metabolic remodeling of insect macrophages remains poorly understood. Here, we used adults of the fruit fly Drosophila melanogaster to investigate the metabolic changes that occur in macrophages during the acute and resolution phases of Streptococcus-induced sepsis. Our studies revealed that orthologs of Hypoxia inducible factor 1α (HIF1α) and Lactate dehydrogenase (LDH) are required for macrophage activation, their bactericidal function, and resistance to infection, thus documenting the conservation of this cellular response between insects and mammals. Further, we show that macrophages employing aerobic glycolysis induce changes in systemic metabolism that are necessary to meet the biosynthetic and energetic demands of their function and resistance to bacterial infection. Macrophages are the immune system's first line of defense against infection. These immune cells can be found in all tissues and organs, watching for signs of disease-causing agents and targeting them for destruction. Maintaining macrophages costs energy, so to minimize waste, these cells spend most of their lives in 'low power mode'. When macrophages sense harmful bacteria, they rapidly awaken and trigger a series of immune events that protect the body from infection. However, to perform these protective tasks macrophages need a sudden surge in energy. In mammals, activated macrophages get their energy from aerobic glycolysis – a series of chemical reactions normally reserved for low oxygen environments. Switching on this metabolic process requires a protein called hypoxia inducible factor 1α (HIF-1 α), which switches on the genes that macrophages need to generate energy as quickly as possible. Macrophages then maintain their energy supply by sending out chemical signals which divert glucose away from the rest of the body. Fruit flies are regularly used as a model system for studying human disease, as the mechanisms they use to defend themselves from infections are similar to human immune cells. However, it remains unclear whether their macrophages undergo the same metabolic changes during an infection. To address this question, Krejčová et al. isolated macrophages from fruit flies that had been infected with bacteria. Experiments studying the metabolism of these cells revealed that, just like human macrophages, they responded to bacteria by taking in more glucose and generating energy via aerobic glycolysis. The macrophages of these flies were also found to draw in energy from the rest of the body by raising blood sugar levels and depleting stores of glucose. Similar to human macrophages, these metabolic changes depended on HIF1α, and flies without this protein were unable to secure the level of energy needed to effectively fight off the bacteria. These findings suggest that this metabolic switch to aerobic glycolysis is a conserved mechanism that both insects and mammals use to fight off infections. This means in the future fruit flies could be used as a model organism for studying diseases associated with macrophage mis-activation, such as chronic inflammation and autoimmune diseases.
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Affiliation(s)
- Gabriela Krejčová
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Adéla Danielová
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Pavla Nedbalová
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Michalina Kazek
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Lukáš Strych
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Geetanjali Chawla
- Department of Biology, Indiana University, Bloomington, United States
| | - Jason M Tennessen
- Department of Biology, Indiana University, Bloomington, United States
| | - Jaroslava Lieskovská
- Department of Medical Biology, University of South Bohemia, Ceske Budejovice, Czech Republic.,Institute of Parasitology, Biology Centre CAS, Ceske Budejovice, Czech Republic
| | - Marek Jindra
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic.,Institute of Entomology, Biology Centre CAS, Ceske Budejovice, Czech Republic
| | - Tomáš Doležal
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Adam Bajgar
- Department of Molecular Biology and Genetics, University of South Bohemia, Ceske Budejovice, Czech Republic.,Institute of Entomology, Biology Centre CAS, Ceske Budejovice, Czech Republic
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Jindra M. Where did the pupa come from? The timing of juvenile hormone signalling supports homology between stages of hemimetabolous and holometabolous insects. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190064. [PMID: 31438814 DOI: 10.1098/rstb.2019.0064] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Insect metamorphosis boasts spectacular cases of postembryonic development when juveniles undergo massive morphogenesis before attaining the adult form and function; in moths or flies the larvae do not even remotely resemble their adult parents. A selective advantage of complete metamorphosis (holometaboly) is that within one species the two forms with different lifestyles can exploit diverse habitats. It was the environmental adaptation and specialization of larvae, primarily the delay and internalization of wing development, that eventually required an intermediate stage that we call a pupa. It is a long-held and parsimonious hypothesis that the holometabolous pupa evolved through modification of a final juvenile stage of an ancestor developing through incomplete metamorphosis (hemimetaboly). Alternative hypotheses see the pupa as an equivalent of all hemimetabolous moulting cycles (instars) collapsed into one, and consider any preceding holometabolous larval instars free-living embryos stalled in development. Discoveries on juvenile hormone signalling that controls metamorphosis grant new support to the former hypothesis deriving the pupa from a final pre-adult stage. The timing of expression of genes that repress and promote adult development downstream of hormonal signals supports homology between postembryonic stages of hemimetabolous and holometabolous insects. This article is part of the theme issue 'The evolution of complete metamorphosis'.
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Affiliation(s)
- Marek Jindra
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice 370 05, Czech Republic
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Bajgar A, Saloň I, Krejčová G, Doležal T, Jindra M, Štěpánek F. Yeast glucan particles enable intracellular protein delivery in Drosophila without compromising the immune system. Biomater Sci 2019; 7:4708-4719. [DOI: 10.1039/c9bm00539k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Glucan particles spread through the whole organism quickly, accumulate in sites of macrophage occurrence and can deliver cargo into the macrophages with a negligible effect on immune response activation.
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Affiliation(s)
- Adam Bajgar
- University of South Bohemia
- Faculty of Sciences
- Department of Molecular Biology and Genetics
- 37005 České Budějovice
- Czech Republic
| | - Ivan Saloň
- University of Chemistry and Technology Prague
- Department of Chemical Engineering
- 166 28 Prague
- Czech Republic
| | - Gabriela Krejčová
- University of South Bohemia
- Faculty of Sciences
- Department of Molecular Biology and Genetics
- 37005 České Budějovice
- Czech Republic
| | - Tomáš Doležal
- University of South Bohemia
- Faculty of Sciences
- Department of Molecular Biology and Genetics
- 37005 České Budějovice
- Czech Republic
| | - Marek Jindra
- Biology Centre CAS
- Institute of Entomology
- 37005 České Budějovice
- Czech Republic
| | - František Štěpánek
- University of Chemistry and Technology Prague
- Department of Chemical Engineering
- 166 28 Prague
- Czech Republic
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Bittova L, Jedlicka P, Dracinsky M, Kirubakaran P, Vondrasek J, Hanus R, Jindra M. Exquisite ligand stereoselectivity of a Drosophila juvenile hormone receptor contrasts with its broad agonist repertoire. J Biol Chem 2018; 294:410-423. [PMID: 30455350 PMCID: PMC6333893 DOI: 10.1074/jbc.ra118.005992] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/05/2018] [Indexed: 11/24/2022] Open
Abstract
The sesquiterpenoid juvenile hormone (JH) is vital to insect development and reproduction. Intracellular JH receptors have recently been established as basic helix-loop-helix transcription factor (bHLH)/PAS proteins in Drosophila melanogaster known as germ cell–expressed (Gce) and its duplicate paralog, methoprene-tolerant (Met). Upon binding JH, Gce/Met activates its target genes. Insects possess multiple native JH homologs whose molecular activities remain unexplored, and diverse synthetic compounds including insecticides exert JH-like effects. How the JH receptor recognizes its ligands is unknown. To determine which structural features define an active JH receptor agonist, we tested several native JHs and their nonnative geometric and optical isomers for the ability to bind the Drosophila JH receptor Gce, to induce Gce-dependent transcription, and to affect the development of the fly. Our results revealed high ligand stereoselectivity of the receptor. The geometry of the JH skeleton, dictated by two stereogenic double bonds, was the most critical feature followed by the presence of an epoxide moiety at a terminal position. The optical isomerism at carbon C11 proved less important even though Gce preferentially bound a natural JH enantiomer. The results of receptor-ligand–binding and cell-based gene activation assays tightly correlated with the ability of different geometric JH isomers to induce gene expression and morphogenetic effects in the developing insects. Molecular modeling supported the requirement for the proper double-bond geometry of JH, which appears to be its major selective mechanism. The strict stereoselectivity of Gce toward the natural hormone contrasts with the high potency of synthetic Gce agonists of disparate chemistries.
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Affiliation(s)
- Lenka Bittova
- From the Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice 370 05, Czech Republic and
| | - Pavel Jedlicka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Martin Dracinsky
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Palani Kirubakaran
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Jiri Vondrasek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Robert Hanus
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 166 10, Czech Republic
| | - Marek Jindra
- From the Biology Center of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice 370 05, Czech Republic and
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Donohoe CD, Csordás G, Correia A, Jindra M, Klein C, Habermann B, Uhlirova M. Atf3 links loss of epithelial polarity to defects in cell differentiation and cytoarchitecture. PLoS Genet 2018; 14:e1007241. [PMID: 29494583 PMCID: PMC5849342 DOI: 10.1371/journal.pgen.1007241] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/13/2018] [Accepted: 02/05/2018] [Indexed: 12/27/2022] Open
Abstract
Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or Dlg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from Dlg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity. Epithelial cells form sheets and line both the outside and inside of our body. Their proper development and function require the asymmetric distribution of cellular components from the top to the bottom, known as apicobasal polarization. As loss of polarity hallmarks a majority of cancers in humans, understanding how epithelia respond to a collapse of the apicobasal axis is of great interest. Here, we show that in the fruit fly Drosophila melanogaster the breakdown of epithelial polarity engages Activating transcription factor 3 (Atf3), a protein that directly binds the DNA and regulates gene expression. We demonstrate that many of the pathological consequences of disturbed polarity require Atf3, as its loss in this context results in normalization of cellular architecture, vesicle trafficking and differentiation. Using unbiased genome-wide approaches we identify the genetic program controlled by Atf3 and experimentally verify select candidates. Given the evolutionary conservation of Atf3 between flies and man, we believe that our findings in the Drosophila model will contribute to a better understanding of diseases stemming from compromised epithelial polarity.
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Affiliation(s)
- Colin D. Donohoe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Gábor Csordás
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Andreia Correia
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Marek Jindra
- Biology Center, Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Corinna Klein
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail:
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12
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Malá E, Vejražková E, Bielmeierová J, Jindra M, Vošmik M, Novosad J, Sobotka L. [Long Term Monitoring of Nutritional, Clinical Status and Quality of Life in Head and Neck Cancer Patients]. Klin Onkol 2015; 28:200-14. [PMID: 26062622 DOI: 10.14735/amko2015200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Malnutrition in head and neck cancer (HNC) patients decreases survival, quality of life (QOL) and oncological outcomes. The aim of the prospective three-year study was to compare QOL, clinical symptoms and variables (complications, survival and mortality rates in HNC patients). PATIENTS AND METHODS A total of 726 patients aged 55 to 72 years with treatable HNC were included from January 2004 to December 2009; these patients were randomized to either group with PEG and enteral nutrition and nonPEG group with nutritional counselling according to nutritional care. We used EORTC questionnaires QOL C-30 and Head and neck module (HN-35) for measuring of QOL. The following variables due to expectable influence on QOL (demographic data, oncological data, nutritional screening, Clinical symptom score, Karnofsky performance status score, Charlson comorbidity index) were included. Monitoring was done five times in three years. RESULTS In the first six months, we found decrease of weight and body mass index (BMI). After this critical time point and finish of oncological treatment, a marked difference in the development of patients treated with PEG. Negative factors influencing patients survival, QOL, clinical status were males aged > 63 years, hypopharyngeal cancer (stage III- IV), smoking, weight loss > 10%, BMI < 21 and disallowance of PEG. CONCLUSIONS QOL is an essential factor for cancer patients. Our study showed that nutritional intervention with early enteral nutrition may improve QOL and survival in HNC patients. The PEG group better tolerated oncological treatment, had lower incidence of complications, shorter time to re-entry of permanent increase in weight, lower rate of rehospitalization and its shorter length. We found QOL questionnaires to be very important for better understanding and communication and a key instrument for improving solution of patients difficulties during their therapy in multidisciplinary approach.
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Jindra M, Bellés X, Shinoda T. Molecular basis of juvenile hormone signaling. Curr Opin Insect Sci 2015; 11:39-46. [PMID: 28285758 DOI: 10.1016/j.cois.2015.08.004] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/13/2015] [Accepted: 08/13/2015] [Indexed: 05/23/2023]
Abstract
Despite important roles played by juvenile hormone (JH) in insects, the mechanisms underlying its action were until recently unknown. A breakthrough has been the demonstration that the bHLH-PAS protein Met is an intracellular receptor for JH. Binding of JH to Met triggers dimerization of Met with its partner protein Tai, and the resulting complex induces transcription of target genes. In addition, JH can potentiate this response by phosphorylating Met and Tai via cell membrane, second-messenger signaling. An important gene induced by the JH-Met-Tai complex is Kr-h1, which inhibits metamorphosis. Kr-h1 represses an 'adult specifier' gene E93. The action of this JH-activated pathway in maintaining the juvenile status is dispensable during early postembryonic development when larvae/nymphs lack competence to metamorphose.
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Affiliation(s)
- Marek Jindra
- Biology Center, Czech Academy of Sciences, Branisovska 31, Ceske Budejovice 37005, Czech Republic.
| | - Xavier Bellés
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Passeig Marítim 37, 08003 Barcelona, Spain
| | - Tetsuro Shinoda
- National Institute of Agrobiological Sciences, Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan
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Jindra M, Uhlirova M, Charles JP, Smykal V, Hill RJ. Genetic Evidence for Function of the bHLH-PAS Protein Gce/Met As a Juvenile Hormone Receptor. PLoS Genet 2015; 11:e1005394. [PMID: 26161662 PMCID: PMC4498814 DOI: 10.1371/journal.pgen.1005394] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 06/26/2015] [Indexed: 12/31/2022] Open
Abstract
Juvenile hormones (JHs) play a major role in controlling development and reproduction in insects and other arthropods. Synthetic JH-mimicking compounds such as methoprene are employed as potent insecticides against significant agricultural, household and disease vector pests. However, a receptor mediating effects of JH and its insecticidal mimics has long been the subject of controversy. The bHLH-PAS protein Methoprene-tolerant (Met), along with its Drosophila melanogaster paralog germ cell-expressed (Gce), has emerged as a prime JH receptor candidate, but critical evidence that this protein must bind JH to fulfill its role in normal insect development has been missing. Here, we show that Gce binds a native D. melanogaster JH, its precursor methyl farnesoate, and some synthetic JH mimics. Conditional on this ligand binding, Gce mediates JH-dependent gene expression and the hormone's vital role during development of the fly. Any one of three different single amino acid mutations in the ligand-binding pocket that prevent binding of JH to the protein block these functions. Only transgenic Gce capable of binding JH can restore sensitivity to JH mimics in D. melanogaster Met-null mutants and rescue viability in flies lacking both Gce and Met that would otherwise die at pupation. Similarly, the absence of Gce and Met can be compensated by expression of wild-type but not mutated transgenic D. melanogaster Met protein. This genetic evidence definitively establishes Gce/Met in a JH receptor role, thus resolving a long-standing question in arthropod biology.
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Affiliation(s)
- Marek Jindra
- Biology Center, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Food and Nutrition Flagship, North Ryde, New South Wales, Australia
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jean-Philippe Charles
- Centre des Sciences du Gout et de l’Alimentation (CSGA), CNRS 6265, INRA 1324, Université Bourgogne-Franche-Comté, Dijon, France
| | - Vlastimil Smykal
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Ronald J. Hill
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Food and Nutrition Flagship, North Ryde, New South Wales, Australia
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Ewer J, Jindra M. Editorial overview: Development and regulation: Departing from paradigms. Curr Opin Insect Sci 2014; 1:vii-ix. [PMID: 32846735 DOI: 10.1016/j.cois.2014.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- John Ewer
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
| | - Marek Jindra
- Biology Center ASCR, Department of Molecular Biology and Genetics, Branisovska 31, Ceske Budejovice, Czech Republic.
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Smykal V, Daimon T, Kayukawa T, Takaki K, Shinoda T, Jindra M. Importance of juvenile hormone signaling arises with competence of insect larvae to metamorphose. Dev Biol 2014; 390:221-30. [PMID: 24662045 DOI: 10.1016/j.ydbio.2014.03.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/14/2014] [Accepted: 03/17/2014] [Indexed: 11/16/2022]
Abstract
Juvenile hormone (JH) postpones metamorphosis of insect larvae until they have attained an appropriate stage and size. Then, during the final larval instar, a drop in JH secretion permits a metamorphic molt that transforms larvae to adults either directly (hemimetaboly) or via a pupal stage (holometaboly). In both scenarios, JH precludes metamorphosis by activating the Kr-h1 gene through a JH receptor, Methoprene-tolerant (Met). Removal of Met, Kr-h1, or JH itself triggers deleterious precocious metamorphosis. Although JH is thought to maintain the juvenile status throughout larval life, various methods of depleting JH failed to induce metamorphosis in early-instar larvae. To determine when does JH signaling become important for the prevention of precocious metamorphosis, we chose the hemimetabolous bug, Pyrrhocoris apterus, and the holometabolous silkworm, Bombyx mori. Both species undergo a fixed number of five larval instars. Pyrrhocoris larvae subjected to RNAi-mediated knockdown of Met or Kr-h1 underwent precocious adult development when treated during the fourth (penultimate) instar, but younger larvae proved increasingly resistant to loss of either gene. The earliest instar developing minor signs of precocious metamorphosis was the third. Therefore, the JH-response genes may not be required to maintain the larval program during the first two larval instars. Next, we examined Bombyx mod mutants that cannot synthesize authentic, epoxidized forms of JH. Although mod larvae expressed Kr-h1 mRNA at severely reduced levels since hatching, they only entered metamorphosis by pupating after four, rarely three instars. Based on findings in Pyrrhocoris and Bombyx, we propose that insect postembryonic development is initially independent of JH. Only later, when larvae gain competence to enter metamorphosis, JH signaling becomes necessary to prevent precocious metamorphosis and to optimize growth.
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Affiliation(s)
- Vlastimil Smykal
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Takaaki Daimon
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan
| | - Takumi Kayukawa
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan
| | - Keiko Takaki
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic
| | - Tetsuro Shinoda
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan
| | - Marek Jindra
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Animal, Food and Health Sciences Division, Commonwealth Scientific and Industrial Research Organization, North Ryde, NSW 2113, Australia.
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Smykal V, Bajgar A, Provaznik J, Fexova S, Buricova M, Takaki K, Hodkova M, Jindra M, Dolezel D. Juvenile hormone signaling during reproduction and development of the linden bug, Pyrrhocoris apterus. Insect Biochem Mol Biol 2014; 45:69-76. [PMID: 24361539 DOI: 10.1016/j.ibmb.2013.12.003] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/09/2013] [Accepted: 12/11/2013] [Indexed: 05/11/2023]
Abstract
Juvenile hormone (JH), a sesquiterpenoid produced by the insect corpus allatum gland (CA), prevents metamorphosis in larvae and stimulates vitellogenesis in adult females. Whether the same JH signaling pathway regulates both processes is presently unknown. Here, we employ the robust JH response during reproduction and development of the linden bug, Pyrrhocoris apterus, to compare the function of key JH-signaling genes encoding the JH receptor, Methoprene-tolerant (Met), its binding partner Taiman (Tai), and a JH-inducible protein, Krüppel-homolog 1 (Kr-h1). RNA interference (RNAi) with Met or Tai, but not Kr-h1, blocked ovarian development and suppressed vitellogenin gene expression in the fat body of females raised under reproduction-inducing conditions. Loss of Met and Tai matched the effects of CA ablation or the natural absence of JH during reproductive diapause. Stimulation of vitellogenesis by treatment of diapausing females with a JH mimic methoprene also required both Met and Tai in the fat body, whereas Kr-h1 RNAi had no effect. Therefore, the Met-Tai complex likely functions as a JH receptor during vitellogenesis. In contrast to Met and Kr-h1 that are both required for JH to prevent precocious metamorphosis in P. apterus larvae, removal of Tai disrupted larval ecdysis without causing premature adult development. Our results show that while Met operates during metamorphosis in larvae and reproduction in adult females, its partner Tai is only required for the latter. The diverse functions of JH thus likely rely on a common receptor whose actions are modulated by distinct components.
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Affiliation(s)
- Vlastimil Smykal
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Adam Bajgar
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Jan Provaznik
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Silvie Fexova
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Marcela Buricova
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Keiko Takaki
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic
| | - Magdalena Hodkova
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic
| | - Marek Jindra
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Animal, Food and Health Sciences Division, Commonwealth Scientific and Industrial Research Organization, North Ryde, NSW 2113, Australia.
| | - David Dolezel
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic; Department of Molecular Biology, Faculty of Sciences, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic.
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Rynes J, Donohoe CD, Frommolt P, Brodesser S, Jindra M, Uhlirova M. Activating transcription factor 3 regulates immune and metabolic homeostasis. Mol Cell Biol 2012; 32:3949-62. [PMID: 22851689 PMCID: PMC3457521 DOI: 10.1128/mcb.00429-12] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 07/18/2012] [Indexed: 12/20/2022] Open
Abstract
Integration of metabolic and immune responses during animal development ensures energy balance, permitting both growth and defense. Disturbed homeostasis causes organ failure, growth retardation, and metabolic disorders. Here, we show that the Drosophila melanogaster activating transcription factor 3 (Atf3) safeguards metabolic and immune system homeostasis. Loss of Atf3 results in chronic inflammation and starvation responses mounted primarily by the larval gut epithelium, while the fat body suffers lipid overload, causing energy imbalance and death. Hyperactive proinflammatory and stress signaling through NF-κB/Relish, Jun N-terminal kinase, and FOXO in atf3 mutants deregulates genes important for immune defense, digestion, and lipid metabolism. Reducing the dose of either FOXO or Relish normalizes both lipid metabolism and gene expression in atf3 mutants. The function of Atf3 is conserved, as human ATF3 averts some of the Drosophila mutant phenotypes, improving their survival. The single Drosophila Atf3 may incorporate the diversified roles of two related mammalian proteins.
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Affiliation(s)
- Jan Rynes
- Institute for Genetics and Cologne Excellence Cluster in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Department of Molecular Biology, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Colin D. Donohoe
- Institute for Genetics and Cologne Excellence Cluster in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Peter Frommolt
- Bioinformatics Core Facility, CECAD, and Cologne Center for Genomics, Cologne, Germany
| | - Susanne Brodesser
- Lipidomics Core Facility, CECAD, and Institute for Medical Microbiology, Immunology and Hygiene, Cologne, Germany
| | - Marek Jindra
- Biology Center, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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Abstract
The molecular action of juvenile hormone (JH), a regulator of vital importance to insects, was until recently regarded as a mystery. The past few years have seen an explosion of studies of JH signaling, sparked by a finding that a JH-resistance gene, Methoprene-tolerant (Met), plays a critical role in insect metamorphosis. Here, we summarize the recently acquired knowledge on the capacity of Met to bind JH, which has been mapped to a particular ligand-binding domain, thus establishing this bHLH-PAS protein as a novel type of an intracellular hormone receptor. Next, we consider the significance of JH-dependent interactions of Met with other transcription factors and signaling pathways. We examine the regulation and biological roles of genes acting downstream of JH and Met in insect metamorphosis. Finally, we discuss the current gaps in our understanding of JH action and outline directions for future research.
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Affiliation(s)
- Marek Jindra
- Biology Center, Academy of Sciences of the Czech Republic, 37005 Ceske Budejovice, Czech Republic
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20
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Affiliation(s)
- René Feyereisen
- INRA-CNRS-Université de Nice Sophia Antipolis, Sophia Antipolis, France.
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Konopova B, Smykal V, Jindra M. Common and distinct roles of juvenile hormone signaling genes in metamorphosis of holometabolous and hemimetabolous insects. PLoS One 2011; 6:e28728. [PMID: 22174880 PMCID: PMC3234286 DOI: 10.1371/journal.pone.0028728] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 11/14/2011] [Indexed: 11/18/2022] Open
Abstract
Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In either case juvenile hormone (JH) prevents metamorphosis until a larva has attained an appropriate phase of development. In holometabolous insects, JH acts through its putative receptor Methoprene-tolerant (Met) to regulate Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) genes. While Met and Kr-h1 prevent precocious metamorphosis in pre-final larval instars, BR-C specifies the pupal stage. How JH signaling operates in hemimetabolous insects is poorly understood. Here, we compare the function of Met, Kr-h1 and BR-C genes in the two types of insects. Using systemic RNAi in the hemimetabolous true bug, Pyrrhocoris apterus, we show that Met conveys the JH signal to prevent premature metamorphosis by maintaining high expression of Kr-h1. Knockdown of either Met or Kr-h1 (but not of BR-C) in penultimate-instar Pyrrhocoris larvae causes precocious development of adult color pattern, wings and genitalia. A natural fall of Kr-h1 expression in the last larval instar normally permits adult development, and treatment with an exogenous JH mimic methoprene at this time requires both Met and Kr-h1 to block the adult program and induce an extra larval instar. Met and Kr-h1 therefore serve as JH-dependent repressors of deleterious precocious metamorphic changes in both hemimetabolous and holometabolous juveniles, whereas BR-C has been recruited for a new role in specifying the holometabolous pupa. These results show that despite considerable evolutionary distance, insects with diverse developmental strategies employ a common-core JH signaling pathway to commit to adult morphogenesis.
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Affiliation(s)
- Barbora Konopova
- Biology Center, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
| | - Vlastimil Smykal
- Department of Molecular Biology, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Marek Jindra
- Biology Center, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
- * E-mail:
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Viktorinova I, Kucerova L, Bohmova M, Henry I, Jindra M, Dolezal P, Zurovcova M, Zurovec M. Characterization of two closely related α-amylase paralogs in the bark beetle, Ips typographus (L.). Arch Insect Biochem Physiol 2011; 77:179-198. [PMID: 21638308 DOI: 10.1002/arch.20433] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ips typographus (L.), the eight-spined spruce bark beetle, causes severe damage throughout Eurasian spruce forests and suitable nuclear markers are needed in order to study its population structure on a genetic level. Two closely related genes encoding α-amylase in I. typographus were characterized and named AmyA and AmyB. Both α-amylase paralogs consisted of six exons and five introns. AmyA encodes a polypeptide of 483 amino acids, whereas AmyB has two alternative transcripts encoding polypeptides of 483 and 370 amino acids. The expression levels of both genes were high during larval stage and adulthood. The AmyB transcripts were absent in the pupal stage. A modification of the allozyme staining method allowed us to detect two clusters of bands on the electrophoretic gel that may correspond to the two α-amylase genes. There was a correlation between the lack of AmyB expression in pupa and the absence of the fast migrating isozyme cluster at this stage, suggesting that the faster migrating isoforms are products of the AmyB gene, whereas the slowly migrating bands are derived from the AmyA.
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Streda R, Mardesic T, Sobotka V, Koryntová D, Hybnerová L, Jindra M, Paseková V, Slámová J, Stevíková M, Voboril J, Jelínková L, Vilímová S, Ichová J, Mádrová J, Tersová H, Masata M, Sobotková J. [Comparison of human chorionic gonadotropin (Pregnyl 10 000 IU i.m.) versus GnRH agonist (triptorelin 0,2 mg s.c.) for final oocytes maturation in the same egg donors--clinical and embryological characteristics]. Ceska Gynekol 2011; 76:113-118. [PMID: 21649994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To compare clinical and embryological characteristics in donor cycles triggered for final oocytes maturation with Pregnyl 10 000 IU i.m. versus triptorelin 0.2 mg s.c. in the same patients in two sequential stimulation cycles. The aim of the study is to decrease the risk of the development of ovarian hyperstimulation syndrome (OHSS) at high response donors by the replacement of Pregnyl 10 000 IU i.m. vs. triptorelin 0.2 mg s.c. The administration of a single dose of gonadotropin-releasing hormone agonist (triptorelin 0.2 mg s.c.) induces release of LH from the pituitary gland similarly to a spontaneous LH surge. SUBJECT Prospective cross-over trial. SETTING Sanatorium Pronatal, Praha. SUBJECT AND METHOD From August 2009 to July 2010 we analysed 24 stimulation cycles in 12 egg donors treated with GnRH antagonist protocol with recombinant FSH (follitropin beta). We identified patients with more than 15 follicles during examination by transvaginal ultrasound. When at least 3 leading follicles reached 17 mm in diameter we administrated Pregnyl 10 000 IU i.m. for final oocytes maturation and triptorelin 0.2 mg s.c in the subsequent treatment cycle. RESULTS The primary outcome measure was number of oocytes, proportion mature oocytes and fertilized oocytes. The secondary outcome were duration of FSH stimulation, total dose of gonadotropins and mean daily dose of gonadotropins. Data was analysed by paired t-test. We retrieved 17.2 +/- 8.6 vs. 15.8 +/- 5.3 (ns) oocytes, 12.6 +/- 7.3 vs. 13.0 +/- 5.4 (ns) metaphase II oocytes, proportion of metaphase II oocytes (%) was 73 vs. 83 (ns), number of fertilized oocytes 11.5 +/- 6.7 vs. 11.7 +/- 4.5 (ns), fertilization rate (%) 91 vs. 90 (ns) in Pregnyl's vs. triptorelin's group, resp. Duration of FSH stimulation (days) 12.2 +/- 0.8 vs. 12.4 +/- 0.7 (ns), total dose of gonadotropins (IU) 1744 +/- 277 vs. 1740 +/- 276 (ns), mean daily dose of gonadotropins (IU) 238 +/- 43 vs. 221 +/- 36 (ns), were not statistically different in both groups. CONCLUSIONS Number of mature oocytes and subsequent embryonic cleavage is comparable to standard hCG treatment. There are no differences in clinical and embryological characteristics in both groups. Only one patient with administration of Pregnyl 10 000 IU i.m. was treated for OHSS grade II by vaginal paracentesis. Administration of triptorelin 0.2 mg s.c. is a safe and effective approach to achieve mature oocytes in egg donation programme, where we do not take care of implantation, which has got some limitations based on several studies.
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Sekyrova P, Bohmann D, Jindra M, Uhlirova M. Interaction between Drosophila bZIP proteins Atf3 and Jun prevents replacement of epithelial cells during metamorphosis. Development 2010; 137:141-50. [PMID: 20023169 DOI: 10.1242/dev.037861] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Epithelial sheet spreading and fusion underlie important developmental processes. Well-characterized examples of such epithelial morphogenetic events have been provided by studies in Drosophila, and include embryonic dorsal closure, formation of the adult thorax and wound healing. All of these processes require the basic region-leucine zipper (bZIP) transcription factors Jun and Fos. Much less is known about morphogenesis of the fly abdomen, which involves replacement of larval epidermal cells (LECs) with adult histoblasts that divide, migrate and finally fuse to form the adult epidermis during metamorphosis. Here, we implicate Drosophila Activating transcription factor 3 (Atf3), the single ortholog of human ATF3 and JDP2 bZIP proteins, in abdominal morphogenesis. During the process of the epithelial cell replacement, transcription of the atf3 gene declines. When this downregulation is experimentally prevented, the affected LECs accumulate cell-adhesion proteins and their extrusion and replacement with histoblasts are blocked. The abnormally adhering LECs consequently obstruct the closure of the adult abdominal epithelium. This closure defect can be either mimicked and further enhanced by knockdown of the small GTPase Rho1 or, conversely, alleviated by stimulating ecdysone steroid hormone signaling. Both Rho and ecdysone pathways have been previously identified as effectors of the LEC replacement. To elicit the gain-of-function effect, Atf3 specifically requires its binding partner Jun. Our data thus identify Atf3 as a new functional partner of Drosophila Jun during development.
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Affiliation(s)
- Petra Sekyrova
- Biology Center, Czech Academy of Sciences and Department of Molecular Biology, University of South Bohemia, Ceske Budejovice 37005, Czech Republic
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Hajduskova M, Jindra M, Herman MA, Asahina M. The nuclear receptor NHR-25 cooperates with the Wnt/beta-catenin asymmetry pathway to control differentiation of the T seam cell in C. elegans. J Cell Sci 2009; 122:3051-60. [PMID: 19654209 DOI: 10.1242/jcs.052373] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Asymmetric cell divisions produce new cell types during animal development. Studies in Caenorhabditis elegans have identified major signal-transduction pathways that determine the polarity of cell divisions. How these relatively few conserved pathways interact and what modulates them to ensure the diversity of multiple tissue types is an open question. The Wnt/beta-catenin asymmetry pathway governs polarity of the epidermal T seam cell in the C. elegans tail. Here, we show that the asymmetry of T-seam-cell division and morphogenesis of the male sensory rays require NHR-25, an evolutionarily conserved nuclear receptor. NHR-25 ensures the neural fate of the T-seam-cell descendants in cooperation with the Wnt/beta-catenin asymmetry pathway. Loss of NHR-25 enhances the impact of mutated nuclear effectors of this pathway, POP-1 (TCF) and SYS-1 (beta-catenin), on T-seam-cell polarity, whereas it suppresses the effect of the same mutations on asymmetric division of the somatic gonad precursor cells. Therefore, NHR-25 can either synergize with or antagonize the Wnt/beta-catenin asymmetry pathway depending on the tissue context. Our findings define NHR-25 as a versatile modulator of Wnt/beta-catenin-dependent cell-fate decisions.
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Affiliation(s)
- Martina Hajduskova
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
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Hajduskova M, Jindra M, Herman MA, Asahina M. 08-P006 The Caenorhabditis elegans nuclear receptor NHR-25 controls epidermal T cell differentiation. Mech Dev 2009. [DOI: 10.1016/j.mod.2009.06.313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Konopova B, Jindra M. 03-P006 Juvenile hormone regulates metamorphosis of holometabolous and hemimetabolous insects through Met and Kr-h1 genes. Mech Dev 2009. [DOI: 10.1016/j.mod.2009.06.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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28
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Jindra M, Sekyrova P, bohmann D, Uhirova M. 03-P037 Interaction of ATF3 with dJun during morphogenesis of the Drosophila abdomen. Mech Dev 2009. [DOI: 10.1016/j.mod.2009.06.090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hajduskova M, Jindra M, Herman MA, Asahina M. Nuclear receptor NHR-25 interacts with Wnt/β-catenin signaling to direct differentiation of the C. elegans T cell. Dev Biol 2009. [DOI: 10.1016/j.ydbio.2009.05.473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Richards S, Gibbs RA, Weinstock GM, Brown SJ, Denell R, Beeman RW, Gibbs R, Beeman RW, Brown SJ, Bucher G, Friedrich M, Grimmelikhuijzen CJP, Klingler M, Lorenzen M, Richards S, Roth S, Schröder R, Tautz D, Zdobnov EM, Muzny D, Gibbs RA, Weinstock GM, Attaway T, Bell S, Buhay CJ, Chandrabose MN, Chavez D, Clerk-Blankenburg KP, Cree A, Dao M, Davis C, Chacko J, Dinh H, Dugan-Rocha S, Fowler G, Garner TT, Garnes J, Gnirke A, Hawes A, Hernandez J, Hines S, Holder M, Hume J, Jhangiani SN, Joshi V, Khan ZM, Jackson L, Kovar C, Kowis A, Lee S, Lewis LR, Margolis J, Morgan M, Nazareth LV, Nguyen N, Okwuonu G, Parker D, Richards S, Ruiz SJ, Santibanez J, Savard J, Scherer SE, Schneider B, Sodergren E, Tautz D, Vattahil S, Villasana D, White CS, Wright R, Park Y, Beeman RW, Lord J, Oppert B, Lorenzen M, Brown S, Wang L, Savard J, Tautz D, Richards S, Weinstock G, Gibbs RA, Liu Y, Worley K, Weinstock G, Elsik CG, Reese JT, Elhaik E, Landan G, Graur D, Arensburger P, Atkinson P, Beeman RW, Beidler J, Brown SJ, Demuth JP, Drury DW, Du YZ, Fujiwara H, Lorenzen M, Maselli V, Osanai M, Park Y, Robertson HM, Tu Z, Wang JJ, Wang S, Richards S, Song H, Zhang L, Sodergren E, Werner D, Stanke M, Morgenstern B, Solovyev V, Kosarev P, Brown G, Chen HC, Ermolaeva O, Hlavina W, Kapustin Y, Kiryutin B, Kitts P, Maglott D, Pruitt K, Sapojnikov V, Souvorov A, Mackey AJ, Waterhouse RM, Wyder S, Zdobnov EM, Zdobnov EM, Wyder S, Kriventseva EV, Kadowaki T, Bork P, Aranda M, Bao R, Beermann A, Berns N, Bolognesi R, Bonneton F, Bopp D, Brown SJ, Bucher G, Butts T, Chaumot A, Denell RE, Ferrier DEK, Friedrich M, Gordon CM, Jindra M, Klingler M, Lan Q, Lattorff HMG, Laudet V, von Levetsow C, Liu Z, Lutz R, Lynch JA, da Fonseca RN, Posnien N, Reuter R, Roth S, Savard J, Schinko JB, Schmitt C, Schoppmeier M, Schröder R, Shippy TD, Simonnet F, Marques-Souza H, Tautz D, Tomoyasu Y, Trauner J, Van der Zee M, Vervoort M, Wittkopp N, Wimmer EA, Yang X, Jones AK, Sattelle DB, Ebert PR, Nelson D, Scott JG, Beeman RW, Muthukrishnan S, Kramer KJ, Arakane Y, Beeman RW, Zhu Q, Hogenkamp D, Dixit R, Oppert B, Jiang H, Zou Z, Marshall J, Elpidina E, Vinokurov K, Oppert C, Zou Z, Evans J, Lu Z, Zhao P, Sumathipala N, Altincicek B, Vilcinskas A, Williams M, Hultmark D, Hetru C, Jiang H, Grimmelikhuijzen CJP, Hauser F, Cazzamali G, Williamson M, Park Y, Li B, Tanaka Y, Predel R, Neupert S, Schachtner J, Verleyen P, Raible F, Bork P, Friedrich M, Walden KKO, Robertson HM, Angeli S, Forêt S, Bucher G, Schuetz S, Maleszka R, Wimmer EA, Beeman RW, Lorenzen M, Tomoyasu Y, Miller SC, Grossmann D, Bucher G. The genome of the model beetle and pest Tribolium castaneum. Nature 2008; 452:949-55. [PMID: 18362917 DOI: 10.1038/nature06784] [Citation(s) in RCA: 976] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Accepted: 02/06/2008] [Indexed: 02/08/2023]
Abstract
Tribolium castaneum is a member of the most species-rich eukaryotic order, a powerful model organism for the study of generalized insect development, and an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved the ability to interact with a diverse chemical environment, as shown by large expansions in odorant and gustatory receptors, as well as P450 and other detoxification enzymes. Development in Tribolium is more representative of other insects than is Drosophila, a fact reflected in gene content and function. For example, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, some being expressed in the growth zone crucial for axial elongation in short-germ development. Systemic RNA interference in T. castaneum functions differently from that in Caenorhabditis elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.
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Affiliation(s)
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- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
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Konopova B, Jindra M. Broad-Complex acts downstream of Met in juvenile hormone signaling to coordinate primitive holometabolan metamorphosis. Development 2008; 135:559-68. [DOI: 10.1242/dev.016097] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Metamorphosis of holometabolous insects, an elaborate change of form between larval, pupal and adult stages, offers an ideal system to study the regulation of morphogenetic processes by hormonal signals. Metamorphosis involves growth and differentiation, tissue remodeling and death, all of which are orchestrated by the morphogenesis-promoting ecdysteroids and the antagonistically acting juvenile hormone (JH), whose presence precludes the metamorphic changes. How target tissues interpret this combinatorial effect of the two hormonal cues is poorly understood, mainly because JH does not prevent larval-pupal transformation in the derived Drosophila model, and because the JH receptor is unknown. We have recently used the red flour beetle Tribolium castaneum to show that JH controls entry to metamorphosis via its putative receptor Methoprene-tolerant (Met). Here, we demonstrate that Met mediates JH effects on the expression of the ecdysteroid-response gene Broad-Complex (BR-C). Using RNAi and a classical mutant, we show that Tribolium BR-C is necessary for differentiation of pupal characters. Furthermore, heterochronic combinations of retarded and accelerated phenotypes caused by impaired BR-C function suggest that besides specifying the pupal fate, BR-C operates as a temporal coordinator of hormonally regulated morphogenetic events across epidermal tissues. Similar results were also obtained when using the lacewing Chrysopa perla (Neuroptera), a member of another holometabolous group with a primitive type of metamorphosis. The tissue coordination role of BR-C may therefore be a part of the Holometabola groundplan.
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Affiliation(s)
- Barbora Konopova
- Biology Center, Czech Academy of Sciences and Department of Molecular Biology, University of South Bohemia, Branisovska 31, Ceske Budejovice 37005,Czech Republic
| | - Marek Jindra
- Biology Center, Czech Academy of Sciences and Department of Molecular Biology, University of South Bohemia, Branisovska 31, Ceske Budejovice 37005,Czech Republic
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Pilný M, Kubes T, Cizmár I, Jindra M, Sprláková A. [Trauma to the triangular fibrocartilaginous complex (TFCC)]. Acta Chir Orthop Traumatol Cech 2007; 74:258-61. [PMID: 17877942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
PURPOSE OF THE STUDY The triangular fibrocartilaginous complex (TFCC) can be injured either due to trauma or by chronic strain. Based on these findings, Palmer devised a classification system distinguishing traumatic (I) and degenerative (II) TFCC lesions. Traumatic TFCC injury may be single or involved in a combined injury of the distal radius. The aim of this study was to evaluate the results of surgical treatment in patients with traumatic TFCC injury at six-month follow-up. MATERIAL AND METHODS In the years 2000 to 2004, 23 patients with injury to the wrist were treated. The group comprised 16 men and 7 women at an average age of 34 years (range, 17 to 54 years). Nine patients were diagnosed with a distal radial fracture and 14 had no damage to the bony structures. Of these, seven showed clinical signs of TFCC injury and were indicated to acute arthroscopy of the wrist. The remaining seven, due to persisting complaints, were examined by arthroscopy within 3 months of injury. During the arthroscopic procedure, the Palmer type of injury was identified and arthroscopic treatment, open or closed, was carried out at the same stage. All patients were followed up for 6 months for pain relief and return to full physical activity. RESULTS The arthroscopic examination revealed the following TFCC lesions: 11 central ruptures (I.A), 6 ulnar tears (I.B), 4 palmar (I.C) and 2 radial (I.D) avulsions. During arthroscopy, partial resection of the disc was performed in 13 cases (I.A, I.D), and reattachment of the disc to the styloid process of the ulna was carried out in six cases (I.B). In four of these patients the intervention was done at the stage of acute lesion within 4 weeks of injury, and in two within a longer period. Four patients with type I.C injuries underwent open disc reattachment from the palmar approach. Subjective evaluation showed that 65 % of the patients had no complaints, 26 % reported pain after excessive activity and 9 % had pain associated with daily activities. Nome of the patients reported rest pain. DISCUSSION In our group, 91 % of the patients reported excellent and very good results at six months of follow-up. The two patients experiencing pain in daily activities (9 %) had type I.B. injury and were indicated for arthroscopy at a time longer than 6 weeks after injury. CONCLUSIONS TFCC lesions are wrist injuries which, if diagnosed early and treated appropriately, show good healing. If the triangular fibrocartilage complex is damaged by a central tear, disc resection gives good results. However, if the distal radioulnar ligaments are torn, their reattachment is necessary in order to prevent instability of the distal radioulnar joint. Open surgical procedures interfere with integrity of the distal radioulnar joint ligaments, which may lead to joint instability and prolonged healing.
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Affiliation(s)
- M Pilný
- Ortopedické oddelení Krajské nemocnice Pardubice
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Konopova B, Jindra M. Juvenile hormone resistance gene Methoprene-tolerant controls entry into metamorphosis in the beetle Tribolium castaneum. Proc Natl Acad Sci U S A 2007; 104:10488-93. [PMID: 17537916 PMCID: PMC1965540 DOI: 10.1073/pnas.0703719104] [Citation(s) in RCA: 228] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Besides being a spectacular developmental process, metamorphosis is key to insect success. Entry into metamorphosis is controlled by juvenile hormone (JH). In larvae, JH prevents pupal and adult morphogenesis, thus keeping the insect in its immature state. How JH signals to preclude metamorphosis is poorly understood, and a JH receptor remains unknown. One candidate for the JH receptor role is the Methoprene-tolerant (Met) Per-Arnt-Sim (PAS) domain protein [also called Resistance to JH, Rst (1)JH], whose loss confers tolerance to JH and its mimic methoprene in the fruit fly Drosophila melanogaster. However, Met deficiency does not affect the larval-pupal transition, possibly because this process does not require JH absence in Drosophila. By contrast, the red flour beetle Tribolium castaneum is sensitive to developmental regulation by JH, thus making an ideal system to examine the role of Met in the antimetamorphic JH action. Here we show that impaired function of the Met ortholog TcMet renders Tribolium resistant to the effects of ectopic JH and, in a striking contrast to Drosophila, causes early-stage beetle larvae to undergo precocious metamorphosis. This is evident as TcMet-deficient larvae pupate prematurely or develop specific heterochronic phenotypes such as pupal-like cuticular structures, appendages, and compound eyes. Our results demonstrate that TcMet functions in JH response and provide the critical evidence that the putative JH receptor Met mediates the antimetamorphic effect of JH.
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Affiliation(s)
- Barbora Konopova
- *Department of Molecular Biology, University of South Bohemia, and
| | - Marek Jindra
- Biology Center, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic
- To whom correspondence should be addressed. E-mail:
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Cizmár I, Jindra M, Sedlák P, Drác P, Fialová J. [Wrist arthroscopy]. Cas Lek Cesk 2007; 146:155-8. [PMID: 17373112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
BACKGROUND Pain in the wrist area is quite a frequent lesion. If it is not treated soon enough, it leads to development of degenerative changes which are curable with difficulty. Diagnosing is complicated because it is often difficult to diagnose them by means of radiological methods. Wrist arthroscopy is a method which enables to assess the problem and very often it also helps to solve it with an operation. METHODS AND RESULTS Authors evaluated 93 wrist arthroscopies performed in their departments during 2004-2005. There were 28 arthroscopies performed due to an acute lesion and 65 arthroscopies due to chronic problems. There were 59 arthroscopic curative interventions performed during the operation and 64 open interventions were indicated on the basis of an arthroscopic examination. CONCLUSIONS All wrist lesions where the lesion of connective tissues structures is suspected, accompanied with edema and hematoma, should be indicated for acute wrist arthroscopy, even though there is no finding on radiographs. Another group of patients indicated for the acute wrist arthroscopy are young patients with wrist fractures where there is a frequent ligament lesion associated, and patients with persisting ailments, even after radiologically confirmed healing of the fracture when intra-articular pathology can be expected. All patients with pain in the wrist area are indicated for arthroscopy, including those with not obvious cause of pain and with symptoms of arthrosis, because it is possible to evaluate further procedure of the therapy.
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Affiliation(s)
- I Cizmár
- Traumatologické oddelení FN, Olomouc.
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Asahina M, Valenta T, Silhankova M, Korinek V, Jindra M. Crosstalk between a nuclear receptor and beta-catenin signaling decides cell fates in the C. elegans somatic gonad. Dev Cell 2006; 11:203-11. [PMID: 16890160 DOI: 10.1016/j.devcel.2006.06.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 05/18/2006] [Accepted: 06/06/2006] [Indexed: 01/07/2023]
Abstract
beta-Catenin signaling determines the proximal-distal axis of the C. elegans gonad by promoting distal fate in asymmetrically dividing somatic gonad precursor cells (SGPs). Impaired function of the Wnt effector POP-1/TCF, its coactivator SYS-1/beta-catenin, and of upstream components including beta-catenin WRM-1 causes all SGP daughters to adopt the proximal fate. Consequently, no distal tip cells (DTCs) that would lead differentiation of gonad arms form in the affected hermaphrodites. Here, we show that deficiency of the nuclear receptor NHR-25 has the opposite effect: extra DTCs develop instead of proximal cells. NHR-25 knockdown restores DTC formation and fertility in pop-1 and sys-1 mutants, suggesting that a balance between NHR-25 and beta-catenin pathway activities is required to establish both proximal and distal fates. This balance relies on direct crossregulation between NHR-25 and the distinct beta-catenin proteins WRM-1 and SYS-1. The nuclear receptor-beta-catenin interaction may be an ancient mechanism of cell-fate decision.
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Affiliation(s)
- Masako Asahina
- Biology Center, Czech Academy of Sciences, University of South Bohemia, Budweis 37005, Czech Republic.
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Pavlok A, Cech S, Kubelka M, Lopatárová M, Holý L, Jindra M. Storage of bovine isolated follicles: a new alternative way to improve the recovery rate of viable embryos from ovarian follicles of slaughtered cows. Anim Reprod Sci 2006; 96:186-95. [PMID: 16448792 DOI: 10.1016/j.anireprosci.2005.12.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Revised: 06/20/2005] [Accepted: 12/28/2005] [Indexed: 11/24/2022]
Abstract
The vitality of bovine oocytes stored in isolated follicles was examined. The aim of this work was to prolong the time of in vitro manipulation of oocytes before their maturation and develop a new alternative of oocyte "capacitation" to improve the quality of in vitro produced embryos. Follicles were dissected from the ovaries of slaughtered cows; subsequently, follicles were divided according to their diameter into three categories (2-3, 3-4 and 4-6 mm), and stored at 17-18 degrees C for 24 or 48 h in a modified tissue culture medium-199 (TCM-199) with reduced pH. After that time, the cumulus-oocyte complexes (COCs) were isolated, matured, fertilized, and embryos cultured in vitro for a total of 9 days. The percentage of total blastocysts, and hatched blastocysts developed from oocytes, initially kept ("capacitated") for 24h at 17-18 degrees C, within follicles of 3-6mm size categories, were significantly higher than that oocytes of the control [of control oocytes] (44.9 and 30.3% versus 36.2 and 20.4%, respectively). The oocytes of follicles stored for 48 h at 17-18 degrees C already had decreased developmental capacity. Interesting data were obtained when COCs of the 3-4 and 4-6 categories were additionally divided into two subgroups according to their presumed developmental history (originating from the supposed growing "fit" in contrast to the supposed regressing "unfit" follicles). The higher improvement in the rate of hatched blastocysts from 24h stored oocytes was observed only in the subgroup originated from "fit" COCs (15.3 versus 25.0%, and 20.0 versus 34.4%, in the 3-4 and 4-6mm categories, respectively). The transfer of 26 blastocysts (developed of follicles kept for 24h at 17-18 degrees C) to 26 recipient heifers resulted in 18 pregnancies. Storage of follicles at 17-18 degrees C in vitro resulted not only in recovery of higher numbers of blastocysts of better quality but also facilitated the safe transport of follicles for a long distance. The extended, time of follicle storage before the proper oocyte maturation allowed also the synchronization of an appropriate number of recipient animals according to the number of isolated follicles.
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Affiliation(s)
- A Pavlok
- Czech Academy of Sciences, Institute of Animal Physiology and Genetics, 277 21 Libechov, Czech Republic.
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Silhánková M, Jindra M, Asahina M. Nuclear receptor NHR-25 is required for cell-shape dynamics during epidermal differentiation in Caenorhabditis elegans. J Cell Sci 2005; 118:223-32. [PMID: 15615786 DOI: 10.1242/jcs.01609] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epithelial cell shape changes underlie important events in animal development. During the postembryonic life of the nematode Caenorhabditis elegans, stem epidermal seam cells lose and actively renew mutual adherens junction contacts after each asymmetric division that separates them. The seam cell contacts are important for epidermal differentiation, but what regulates the cell-shape changes that restore them is unknown. Here, we show that NHR-25, a transcription factor of the nuclear receptor family, is expressed in the seam cells and is necessary for these cells to elongate and reach their neighbors after the asymmetric divisions. A failure to do so, caused by nhr-25 RNA interference, compromises the subsequent fate of seam-cell anterior daughters. Unexpectedly, the lack of cell-cell contacts does not prevent a unique seam cell to produce a neuroblast, even though a homeotic gene (mab-5) that normally prevents the neuroblast commitment is ectopically expressed in the absence of nhr-25 function. Seam cells lacking mutual contacts display reduced expression of a Fat-like cadherin marker cdh-3::gfp. Although some seam cells retain the ability to fuse at the final larval stage, the resulting syncytium shows gaps and bifurcations, translating into anomalies in cuticular ridges (alae) produced by the syncytium. nhr-25 RNAi markedly enhances branching of the alae caused by a mutant cuticular collagen gene rol-6. Silencing of nhr-25 also disturbs epidermal ultrastructure, which is probably the cause of compromised cuticle secretion and molting. Cell shape dynamics and molting thus represent distinct roles for NHR-25 in epidermal development.
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Affiliation(s)
- Marie Silhánková
- Department of Molecular Biology, Faculty of Biological Sciences, University of South Bohemia, CZ-370 05, Czech Republic
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Jindra M, Gaziova I, Uhlirova M, Okabe M, Hiromi Y, Hirose S. Coactivator MBF1 preserves the redox-dependent AP-1 activity during oxidative stress in Drosophila. EMBO J 2004; 23:3538-47. [PMID: 15306851 PMCID: PMC516628 DOI: 10.1038/sj.emboj.7600356] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2004] [Accepted: 07/16/2004] [Indexed: 11/09/2022] Open
Abstract
Basic leucine zipper proteins Jun and Fos form the dimeric transcription factor AP-1, essential for cell differentiation and immune and antioxidant defenses. AP-1 activity is controlled, in part, by the redox state of critical cysteine residues within the basic regions of Jun and Fos. Mutation of these cysteines contributes to oncogenic potential of Jun and Fos. How cells maintain the redox-dependent AP-1 activity at favorable levels is not known. We show that the conserved coactivator MBF1 is a positive modulator of AP-1. Via a direct interaction with the basic region of Drosophila Jun (D-Jun), MBF1 prevents an oxidative modification (S-cystenyl cystenylation) of the critical cysteine and stimulates AP-1 binding to DNA. Cytoplasmic MBF1 translocates to the nucleus together with a transfected D-Jun protein, suggesting that MBF1 protects nascent D-Jun also in Drosophila cells. mbf1-null mutants live shorter than mbf1+ controls in the presence of hydrogen peroxide (H2O2). An AP-1-dependent epithelial closure becomes sensitive to H2O2 in flies lacking MBF1. We conclude that by preserving the redox-sensitive AP-1 activity, MBF1 provides an advantage during oxidative stress.
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Affiliation(s)
- Marek Jindra
- Department of Molecular Biology, University of South Bohemia and Institute of Entomology ASCR, Ceske Budejovice, Czech Republic
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Japan
| | - Ivana Gaziova
- Department of Molecular Biology, University of South Bohemia and Institute of Entomology ASCR, Ceske Budejovice, Czech Republic
| | - Mirka Uhlirova
- Department of Molecular Biology, University of South Bohemia and Institute of Entomology ASCR, Ceske Budejovice, Czech Republic
| | - Masataka Okabe
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Japan
| | - Yasushi Hiromi
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Japan
- Department of Genetics, SOKENDAI, Mishima, Japan
| | - Susumu Hirose
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Japan
- Department of Genetics, SOKENDAI, Mishima, Japan
- Department of Developmental Genetics, National Institute of Genetics, 1111, Yata, Mishima, Shizuoka-ken 411-8540, Japan. Tel.: +81 559 816771; Fax: +81 559 816776; E-mail:
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39
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Abstract
Steroid signaling underlies developmental processes in animals. Mutations that impair steroidogenesis in the fruit fly Drosophila melanogaster provide tools to dissect steroid hormone action genetically. The widely used temperature-sensitive mutation ecdysoneless(1) (ecd(1)) disrupts production of the steroid hormone ecdysone, and causes developmental and reproductive defects. These defects cannot be satisfactorily interpreted without analysis of the ecd gene. Here, we show that ecd encodes an as yet functionally undescribed protein that is conserved throughout eukaryotes. The ecd(1) conditional allele contains an amino acid substitution, whereas three non-conditional larval lethal mutations result in truncated Ecd proteins. Consistent with its role in steroid synthesis, Ecd is expressed in the ecdysone-producing larval ring gland. However, development of ecd-null early larval lethal mutants cannot be advanced by Ecd expression targeted to the ring gland or by hormone feeding. Cell-autonomous ecd function, suggested by these experiments, is evidenced by the inability of ecd(-) clones to survive within developing imaginal discs. Ecd is also expressed in the ovary, and is required in both the follicle cells and the germline for oocyte development. These defects, induced by the loss of ecd, provide the first direct evidence for a cell-autonomous function of this evolutionarily conserved protein.
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Affiliation(s)
- Ivana Gaziova
- Department of Molecular Biology, University of South Bohemia, and Institute of Entomology ASCR, Ceske Budejovice 37005, Czech Republic
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40
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Foy BD, Myles KM, Pierro DJ, Sanchez-Vargas I, Uhlírová M, Jindra M, Beaty BJ, Olson KE. Development of a new Sindbis virus transducing system and its characterization in three Culicine mosquitoes and two Lepidopteran species. Insect Mol Biol 2004; 13:89-100. [PMID: 14728670 DOI: 10.1111/j.1365-2583.2004.00464.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Alphavirus transducing systems (ATSs) are alphavirus-based tools for expressing genes in insects. Here we describe an ATS (5'dsMRE16ic) based entirely on Sindbis MRE16 virus. GFP expression was used to characterize alimentary tract infections and dissemination in three Culicine and two Lepidopteran species. Following per os infection, 5'dsMRE16ic-EGFP efficiently infected Aedes aegypti and Culex tritaeniorhynchus, but not Culex pipiens pipiens. Ae. aegypti clearly showed accumulation of green fluorescent protein (GFP) in the posterior midgut and foregut/midgut junction within 2-3 days postinfection. Following parenteral infection of larvae, Bombyx mori had extensive GFP expression in larvae and adults, but Manduca sexta larvae were mostly resistant. 5'dsMRE16ic should be a valuable tool for gene expression in several important insect species that are otherwise difficult to manipulate genetically.
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Affiliation(s)
- B D Foy
- Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
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41
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Uhlirova M, Foy BD, Beaty BJ, Olson KE, Riddiford LM, Jindra M. Use of Sindbis virus-mediated RNA interference to demonstrate a conserved role of Broad-Complex in insect metamorphosis. Proc Natl Acad Sci U S A 2003; 100:15607-12. [PMID: 14668449 PMCID: PMC307615 DOI: 10.1073/pnas.2136837100] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transcription factor Broad-Complex (BR-C) is required for differentiation of adult structures as well as for the programmed death of obsolete larval organs during metamorphosis of the fruit fly Drosophila melanogaster. Whether BR-C has a similar role in other holometabolous insects could not be proven without a loss-of-function genetic test, performed in a non-drosophilid species. Here we use a recombinant Sindbis virus as a tool to silence BR-C expression in the silkmoth Bombyx mori. The virus expressing a BR-C antisense RNA fragment reduced endogenous BR-C mRNA levels in infected tissues (adult wing and leg primordia) via RNA interference (RNAi). The RNAi knock-down of BR-C resulted in the failure of animals to complete the larval-pupal transition or in later morphogenetic defects, including differentiation of adult compound eyes, legs, and wings from their larval progenitors. BR-C RNAi also perturbed the programmed cell death of larval silk glands. These developmental defects correspond to loss-of-function phenotypes of BR-C Drosophila mutants in both the morphogenetic and degenerative aspects, suggesting that the critical role of BR-C in metamorphosis is evolutionarily conserved. We also demonstrate that the Sindbis virus is a useful vehicle for silencing of developmental genes in new insect models.
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Affiliation(s)
- Mirka Uhlirova
- Department of Molecular Biology, University of South Bohemia and Institute of Entomology, the Czech Academy of Sciences, Ceske Budejovice, 37005 Czech Republic
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42
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Liu QX, Jindra M, Ueda H, Hiromi Y, Hirose S. Drosophila MBF1 is a co-activator for Tracheae Defective and contributes to the formation of tracheal and nervous systems. Development 2003; 130:719-28. [PMID: 12506002 DOI: 10.1242/dev.00297] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During gene activation, the effect of binding of transcription factors to cis-acting DNA sequences is transmitted to RNA polymerase by means of co-activators. Although co-activators contribute to the efficiency of transcription, their developmental roles are poorly understood. We used Drosophila to conduct molecular and genetic dissection of an evolutionarily conserved but unique co-activator, Multiprotein Bridging Factor 1 (MBF1), in a multicellular organism. Through immunoprecipitation, MBF1 was found to form a ternary complex including MBF1, TATA-binding protein (TBP) and the bZIP protein Tracheae Defective (TDF)/Apontic. We have isolated a Drosophila mutant that lacks the mbf1 gene in which no stable association between TBP and TDF is detectable, and transcription of a TDF-dependent reporter gene is reduced by 80%. Although the null mutants of mbf1 are viable, tdf becomes haploinsufficient in mbf1-deficient background, causing severe lesions in tracheae and the central nervous system, similar to those resulting from a complete loss of tdf function. These data demonstrate a crucial role of MBF1 in the development of tracheae and central nervous system.
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Affiliation(s)
- Qing-Xin Liu
- Department of Developmental Genetics, National Institute of Genetics, Graduate University for Advanced Studies, Mishima, Shizuoka-ken 411-8540, Japan
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43
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Uhlírová M, Asahina M, Riddiford LM, Jindra M. Heat-inducible transgenic expression in the silkmoth Bombyx mori. Dev Genes Evol 2002; 212:145-51. [PMID: 11976953 DOI: 10.1007/s00427-002-0221-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2001] [Accepted: 01/22/2002] [Indexed: 11/28/2022]
Abstract
Germline transformation with new transposon vectors now enables causal tests of gene function via ectopic protein expression or RNA interference in non-drosophilid insects. The problem remains of how to drive the transgene expression in vivo. We employed germline transformation using the piggyBac 3xP3-EGFP vector to test whether the Drosophila heat shock hsp70 promoter will be active in the live silkworm. We modified the original vector by cloning the coding sequence for Bombyx nuclear receptor Ftz-F1 between the hsp70 promoter and the terminator. Three independent transgenic lines expressing the Pax-6-driven EGFP marker in larval and adult photoreceptors were obtained with efficiencies of up to 1.7% of fertile G0 adults that gave GFP-positive progeny. Chromosomal integration of the transposon was confirmed with inverse PCR. Heat induction of the transgenic BmFtz-F1 was proven at both the mRNA and protein levels. RT-PCR data showed that the Drosophila heat shock promoter was functional in all three transgenic lines. Although basal activity was apparent at 25 degrees C, 1 h at 42 degrees C induced BmFtz-F1 mRNA at different stages of development and in diverse tissues. The relative levels of induction differed among the transgenic lines. Northern blot hybridization detected transgenic BmFtz-F1 only after heat shock and low levels of the mRNA were still present 6 h after the heat treatment. Immunostaining of epidermis using anti-BmFtz-F1 antibody showed a clear increase of nuclear signal 90 min after a heat shock.
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Affiliation(s)
- Mirka Uhlírová
- University of South Bohemia, Branisovká 31, Ceské Budejovice 370 05, Czech Republic
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44
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Abstract
The gene encoding allatostatins (AST) of the FGLamide family from the cricket Gryllus bimaculatus is expressed in the brain. The mRNA, which contains four polyadenylation signals, encodes a hormone precursor that is split into at least 14 putative hormones. Five of them have been previously found in the cricket, six to seven others, or their close homologues, are known from other insects. Hormone AST 2 contains an internal cleavage site and may exist in a shorter version 2b. The hormones AST 3 and 4 are identical. The cDNA sequence revealed that a single point mutation and a single deletion eliminated an additional hormone between AST 12 and 13. The deduced hormone precursor is very similar to that in cockroaches, but is different from a shorter precursor in locusts, indicating that the gene evolved very fast in the latter. Regions conserved between cockroaches and crickets include parts of the acidic spacers that separate clusters of hormones, suggesting that these spacers may have additional functions.
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Affiliation(s)
- M Meyering-Vos
- Lehrstuhl Tierökologie I, Universität Bayreuth, D-95440, Bayreuth, Germany
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45
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Asahina M, Ishihara T, Jindra M, Kohara Y, Katsura I, Hirose S. The conserved nuclear receptor Ftz-F1 is required for embryogenesis, moulting and reproduction in Caenorhabditis elegans. Genes Cells 2000; 5:711-23. [PMID: 10971653 DOI: 10.1046/j.1365-2443.2000.00361.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Nuclear receptors are essential players in the development of all metazoans. The nematode Caenorhabditis elegans possesses more than 200 putative nuclear receptor genes, several times more than the number known in any other organism. Very few of these transcription factors are conserved with components of the steroid response pathways in vertebrates and arthropods. Ftz-F1, one of the evolutionarily oldest nuclear receptor types, is required for steroidogenesis and sexual differentiation in mice and for segmentation and metamorphosis in Drosophila. RESULTS We employed two complementary approaches, direct mutagenesis and RNA interference, to explore the role of nhr-25, a C. elegans ortholog of Ftz-F1. Deletion mutants show that nhr-25 is essential for embryogenesis. RNA interference reveals additional requirements throughout the postembryonic life, namely in moulting and differentiation of the gonad and vulva. All these defects are consistent with the nhr-25 expression pattern, determined by in situ hybridization and GFP reporter activity. CONCLUSIONS Our data link the C. elegans Ftz-F1 ortholog with a number of developmental processes. Significantly, its role in the periodical replacement of cuticle (moulting) appears to be evolutionarily shared with insects and thus supports the monophyletic origin of moulting.
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Affiliation(s)
- M Asahina
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Shizuoka-ken 411-8540, Japan
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46
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Lan Q, Hiruma K, Hu X, Jindra M, Riddiford LM. Activation of a delayed-early gene encoding MHR3 by the ecdysone receptor heterodimer EcR-B1-USP-1 but not by EcR-B1-USP-2. Mol Cell Biol 1999; 19:4897-906. [PMID: 10373539 PMCID: PMC84291 DOI: 10.1128/mcb.19.7.4897] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
MHR3, a homolog of the retinoid orphan receptor (ROR), is a transcription factor in the nuclear hormone receptor family that is induced by 20-hydroxyecdysone (20E) in the epidermis of the tobacco hornworm, Manduca sexta. Its 2.7-kb 5' flanking region was found to contain four putative ecdysone receptor response elements (EcREs) and a monomeric (GGGTCA) nuclear receptor binding site. Activation of this promoter fused to a chloramphenicol acetyltransferase (CAT) reporter by 2 micrograms of 20E per ml in Manduca GV1 cells was similar to that of endogenous MHR3, with detectable CAT by 3 h. When the ecdysone receptor B1 (EcR-B1) and Ultraspiracle 1 (USP-1) were expressed at high levels under the control of a constitutive promoter, CAT levels after a 3-h exposure to 20E increased two- to sixfold. In contrast, high expression of EcR-B1 and USP-2 caused little increase in CAT levels in response to 20E. Moreover, expression of USP-2 prevented activation by EcR-B1-USP-1. Deletion experiments showed that the upstream region, including the three most proximal putative EcREs, was responsible for most of the 20E activation, with the EcRE3 at -671 and the adjacent GGGTCA being most critical. The EcRE1 at -342 was necessary but not sufficient for the activational response but was the only one of the three putative EcREs to bind the EcR-B1-USP-1 complex in gel mobility shift assays and was responsible for the silencing action of EcR-B1-USP-1 in the absence of hormone. EcRE2 and EcRE3 each specifically bound other protein(s) in the cell extract, but not EcR and USP, and so are not EcREs in this cellular context. When cell extracts were used, the EcR-B1-USP-2 heterodimer showed no binding to EcRE1, and the presence of excess USP-2 prevented the binding of EcR-B1-USP-1 to this element. In contrast, in vitro-transcribed-translated USP-1 and USP-2 both formed heterodimeric complexes with EcR-B1 that bound ponasterone A with the same Kd (7 x 10(-10) M) and bound to both EcRE1 and heat shock protein 27 EcRE. Thus, factors present in the cell extract appear to modulate the differential actions of the two USP isoforms.
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Affiliation(s)
- Q Lan
- Department of Zoology, University of Washington, Seattle, Washington 98195-1800, USA
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47
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Zhou B, Hiruma K, Jindra M, Shinoda T, Segraves WA, Malone F, Riddiford LM. Regulation of the transcription factor E75 by 20-hydroxyecdysone and juvenile hormone in the epidermis of the tobacco hornworm, Manduca sexta, during larval molting and metamorphosis. Dev Biol 1998; 193:127-38. [PMID: 9473318 DOI: 10.1006/dbio.1997.8798] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The homolog of the ecdysteroid-induced transcription factor E75A in Drosophila melanogaster was cloned from the tobacco hornworm, Manduca sexta, and its developmental expression and hormonal regulation were analyzed. Both E75A and E75B mRNAs were found in the abdominal epidermis during both the larval and the pupal molts, with E75A appearing before E75B, coincident with the rise of ecdysteroid. Exposure of either fourth or fifth instar epidermis to 20E in vitro caused the rapid, transient induction of E75A RNA with a peak at 6 and 3 h, respectively, followed by maintenance at low levels until 24 h. Epidermis from fourth instar larvae with high endogenous juvenile hormone (JH) showed a 10-fold higher sensitivity to 20E (EC50 = 2 x 10(-8) M for fourth instar and 2 x 10(-7) M for fifth instar epidermis). The presence of the protein synthesis inhibitor anisomycin had no effect on the induction but prevented the decline, indicating that E75A RNA was directly induced by 20E, but its down-regulation depended on protein synthesis. Exposure of day 2 fifth instar epidermis to 20E in the presence of JH I, which prevents the 20E-induced pupal commitment, caused an increased accumulation of E75A RNA throughout the culture period although the temporal pattern was unaffected. These findings show for the first time that JH plays a role in 20E-induced early gene expression and suggest that the higher levels of E75A may be required for maintenance of larval commitment of this epidermis.
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Affiliation(s)
- B Zhou
- Department of Zoology, University of Washington, Seattle 98195-1800, USA
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48
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Jindra M, Huang JY, Malone F, Asahina M, Riddiford LM. Identification and mRNA developmental profiles of two ultraspiracle isoforms in the epidermis and wings of Manduca sexta. Insect Mol Biol 1997; 6:41-53. [PMID: 9013254 DOI: 10.1046/j.1365-2583.1997.00153.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
cDNAs were isolated from Manduca sexta that encode two isoforms of an ultraspiracle (USP) homologue MsUSP-1 and MsUSP-2 with different N-terminal A/B regions. The MsUSP-1 cDNA predicts a protein with 97% and 45% amino acid identities in the DNA- and ligand-binding domains respectively to the Drosophila USP and 89% overall identity with Bombyx mori CF1 (an USP homologue). Northern blot hybridizations with probes specific to MsUSP-1 and MsUSP-2 showed transcripts of an approximately equal size (4.5 kb), but with diverse developmental profiles in Manduca epidermis during the two final larval instars and the onset of the adult moult. The MsUSP-1 mRNA was expressed during the intermoult periods, with higher levels around the time of the larval ecdyses and at the onset of wandering behaviour. In contrast, the MsUSP-2 mRNA was up-regulated at times of high ecdysteroid titre during the larval moults, when the MsUSP-1 mRNA disappeared. Together, these conversely regulated isoform mRNAs contribute to the constitutive expression profile of total MsUSP mRNA.
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Affiliation(s)
- M Jindra
- Department of Zoology, University of Washington, Seattle 98195-1800, USA
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49
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Jindra M, Malone F, Hiruma K, Riddiford LM. Developmental profiles and ecdysteroid regulation of the mRNAs for two ecdysone receptor isoforms in the epidermis and wings of the tobacco hornworm, Manduca sexta. Dev Biol 1996; 180:258-72. [PMID: 8948589 DOI: 10.1006/dbio.1996.0299] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ecdysteroids acting through multiple isoforms of the ecdysone receptor (EcR) initiate molting and metamorphosis of insects. Two isoforms of EcR, A (this paper) and B1 (Fujiwara et al., Insect Biochem. Mol. Biol. 25, 845-856, 1995), were isolated from the tobacco hornworm, Manduca sexta, and shown to be similar to the corresponding Drosophila EcR isoforms. The developmental profiles of both EcR-A and EcR-B1 (determined by both analysis of isoform-specific mRNAs and use of monoclonal antibodies that detect either EcR-B1 or all forms), however, were different in Manduca epidermis, which produces sequentially the larval, the pupal, and the adult cuticles. EcR-B1 predominated through the larval, pupal, and early developing adult stages with an upregulation early in each molt. By contrast, EcR-A was present only at the onset of new cuticle synthesis during the larval molt, but in the pupal and adult molts was upregulated slightly later than EcR-B1 during the commitment period and was present during the predifferentiative phase. Both isoforms appeared in the larval wing discs after pupal commitment and persisted through pupal differentiation. The mRNAs for both isoforms were directly induced in larval epidermis in vitro by 20-hydroxyecdysone, but EcR-B1 mRNA accumulated more rapidly, peaking at 3 hr. In the presence of a protein synthesis inhibitor, the accumulation of EcR-B1 mRNA was slower and its subsequent decline was prevented, but the accumulation of EcR-A mRNA was unaffected. Thus, in this polymorphic epidermis both isoforms appear in every molt, with EcR-B1 present during the commitment and predifferentiative phases and then at the onset of cuticle synthesis EcR-A prevails. Additionally, EcR-A is apparently associated with the switching and predifferentiative events necessary for a new synthetic program.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/pharmacology
- Base Sequence
- Drosophila
- Ecdysteroids
- Ecdysterone/pharmacology
- Epidermis/physiology
- Gene Expression Regulation, Developmental/drug effects
- Genes, Insect
- Larva
- Manduca/growth & development
- Manduca/physiology
- Metamorphosis, Biological
- Molecular Sequence Data
- RNA, Messenger/biosynthesis
- Receptors, Steroid/biosynthesis
- Receptors, Steroid/physiology
- Sequence Homology, Amino Acid
- Steroids/pharmacology
- Transcription, Genetic
- Wings, Animal/physiology
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Affiliation(s)
- M Jindra
- Department of Zoology, University of Washington, Seattle 98195-1800, USA
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50
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Fujiwara H, Jindra M, Newitt R, Palli SR, Hiruma K, Riddiford LM. Cloning of an ecdysone receptor homolog from Manduca sexta and the developmental profile of its mRNA in wings. Insect Biochem Mol Biol 1995; 25:845-856. [PMID: 7633469 DOI: 10.1016/0965-1748(95)00023-o] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Using the Drosophila melanogaster ecdysone receptor (DmEcR) B1 cDNA clone, we isolated three genomic clones for EcR from the tobacco hornworm, Manduca sexta. Subsequent isolation and sequencing of several cDNAs yielded a homolog of the B1 isoform with 50, 95 and 70% amino acid identities with DmEcR in the N-terminal A/B, the DNA binding and the ligand binding domains respectively. Unlike Drosophila, an intron occurs between the exons encoding the two zinc fingers of Manduca EcR (MsEcR). A 6.0 kb mRNA encoding MsEcR was found in both larval wing discs and prothoracic glands and in pupal wings. During the final larval instar, the mRNA was maximal in the wing discs at one day after wandering (W1), whereas in the prothoracic gland EcR mRNA increased rapidly to high levels on day 2 and remained high thereafter. During the onset of adult development, two peaks of EcR mRNA were observed in wings from day 3 to 5 and on day 8 after pupal ecdysis. These two peaks correlated with the time of increasing titers of ecdysone (E) and 20-hydroxyecdysone (20E), respectively. The EcR mRNA peaks always preceded the large ecdysteroid peak, suggesting that the transcription of the EcR gene is induced by a low concentration of ecdysteroid in vivo.
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Affiliation(s)
- H Fujiwara
- Department of Zoology, University of Washington, Seattle 98195, USA
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