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Jundi D, Coutanceau JP, Bullier E, Imarraine S, Fajloun Z, Hong E. Expression of olfactory receptor genes in non-olfactory tissues in the developing and adult zebrafish. Sci Rep 2023; 13:4651. [PMID: 36944644 PMCID: PMC10030859 DOI: 10.1038/s41598-023-30895-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/02/2023] [Indexed: 03/23/2023] Open
Abstract
Since the discovery of olfactory receptor (OR) genes, their expression in non-olfactory tissues have been reported in rodents and humans. For example, mouse OR23 (mOR23) is expressed in sperm and muscle cells and has been proposed to play a role in chemotaxis and muscle migration, respectively. In addition, mouse mesencephalic dopaminergic neurons express various ORs, which respond to corresponding ligands. As the OR genes comprise the largest multigene family of G protein-coupled receptors in vertebrates (over 400 genes in human and 1000 in rodents), it has been difficult to categorize the extent of their diverse expression in non-olfactory tissues making it challenging to ascertain their function. The zebrafish genome contains significantly fewer OR genes at around 140 genes, and their expression pattern can be easily analyzed by carrying out whole mount in situ hybridization (ISH) assay in larvae. In this study, we found that 31 out of 36 OR genes, including or104-2, or108-1, or111-1, or125-4, or128-1, or128-5, 133-4, or133-7, or137-3 are expressed in various tissues, including the trunk, pharynx, pancreas and brain in the larvae. In addition, some OR genes are expressed in distinct brain regions such as the hypothalamus and the habenula in a dynamic temporal pattern between larvae, juvenile and adult zebrafish. We further confirmed that OR genes are expressed in non-olfactory tissues by RT-PCR in larvae and adults. These results indicate tight regulation of OR gene expression in the brain in a spatial and temporal manner and that the expression of OR genes in non-olfactory tissues are conserved in vertebrates. This study provides a framework to start investigating the function of ORs in the zebrafish brain.
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Affiliation(s)
- Dania Jundi
- INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Sorbonne Université, 75005, Paris, France
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, EDST, Lebanese University, Tripoli, 1300, Lebanon
| | - Jean-Pierre Coutanceau
- INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Sorbonne Université, 75005, Paris, France
| | - Erika Bullier
- INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Sorbonne Université, 75005, Paris, France
| | - Soumaiya Imarraine
- INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Sorbonne Université, 75005, Paris, France
- CNRS, Laboratoire Jean Perrin-Institut de Biologie Paris Seine (LJP-IBPS), Sorbonne Université, 75005, Paris, France
| | - Ziad Fajloun
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, EDST, Lebanese University, Tripoli, 1300, Lebanon
- Department of Biology, Faculty of Sciences 3, Campus Michel Slayman, Lebanese University, Tripoli, 1352, Lebanon
| | - Elim Hong
- INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine (NPS-IBPS), Sorbonne Université, 75005, Paris, France.
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Zaupa M, Naini SMA, Younes MA, Bullier E, Duboué ER, Le Corronc H, Soula H, Wolf S, Candelier R, Legendre P, Halpern ME, Mangin JM, Hong E. Trans-inhibition of axon terminals underlies competition in the habenulo-interpeduncular pathway. Curr Biol 2021; 31:4762-4772.e5. [PMID: 34529937 DOI: 10.1016/j.cub.2021.08.051] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/12/2021] [Accepted: 08/18/2021] [Indexed: 11/19/2022]
Abstract
Survival of animals is dependent on the correct selection of an appropriate behavioral response to competing external stimuli. Theoretical models have been proposed and underlying mechanisms are emerging to explain how one circuit is selected among competing neural circuits. The evolutionarily conserved forebrain to midbrain habenulo-interpeduncular nucleus (Hb-IPN) pathway consists of cholinergic and non-cholinergic neurons, which mediate different aversive behaviors. Simultaneous calcium imaging of neuronal cell bodies and of the population dynamics of their axon terminals reveals that signals in the cell bodies are not reflective of terminal activity. We find that axon terminals of cholinergic and non-cholinergic habenular neurons exhibit stereotypic patterns of spontaneous activity that are negatively correlated and localize to discrete subregions of the target IPN. Patch-clamp recordings show that calcium bursts in cholinergic terminals at the ventral IPN trigger excitatory currents in IPN neurons, which precede inhibition of non-cholinergic terminals at the adjacent dorsal IPN. Inhibition is mediated through presynaptic GABAB receptors activated in non-cholinergic habenular neurons upon GABA release from the target IPN. Together, the results reveal a hardwired mode of competition at the terminals of two excitatory neuronal populations, providing a physiological framework to explore the relationship between different aversive responses.
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Affiliation(s)
- Margherita Zaupa
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Seyedeh Maryam Alavi Naini
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Maroun Abi Younes
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Erika Bullier
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Erik R Duboué
- Jupiter Life Science Initiative, Wilkes Honors College and Charles E. Schmidt College of Science, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Hervé Le Corronc
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Hédi Soula
- INSERM, Sorbonne Université, Nutriomics, La Pitié Salpétrière, 75013 Paris, France
| | - Sebastien Wolf
- Laboratoire Jean Perrin, CNRS, Sorbonne Université, 75005 Paris, France
| | - Raphaël Candelier
- Laboratoire Jean Perrin, CNRS, Sorbonne Université, 75005 Paris, France
| | - Pascal Legendre
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Marnie E Halpern
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Jean-Marie Mangin
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France
| | - Elim Hong
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005 Paris, France.
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Arulkandarajah KH, Osterstock G, Lafont A, Le Corronc H, Escalas N, Corsini S, Le Bras B, Chenane L, Boeri J, Czarnecki A, Mouffle C, Bullier E, Hong E, Soula C, Legendre P, Mangin JM. Neuroepithelial progenitors generate and propagate non-neuronal action potentials across the spinal cord. Curr Biol 2021; 31:4584-4595.e4. [PMID: 34478646 DOI: 10.1016/j.cub.2021.08.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 12/22/2020] [Revised: 06/29/2021] [Accepted: 08/05/2021] [Indexed: 11/30/2022]
Abstract
In the developing central nervous system, electrical signaling is thought to rely exclusively on differentiating neurons as they acquire the ability to generate and propagate action potentials. Accordingly, neuroepithelial progenitors (NEPs), which give rise to all neurons and glial cells during development, have been reported to remain electrically passive. Here, we investigated the physiological properties of NEPs at the onset of spontaneous neural activity (SNA) initiating motor behavior in mouse embryonic spinal cord. Using patch-clamp recordings, we discovered that spinal NEPs exhibit spontaneous membrane depolarizations during episodes of SNA. These rhythmic depolarizations exhibited a ventral-to-dorsal gradient with the highest amplitude located in the floor plate, the ventral-most part of the neuroepithelium. Paired recordings revealed that NEPs are coupled via gap junctions and form an electrical syncytium. Although other NEPs were electrically passive, we discovered that floor-plate NEPs generated large Na+/Ca2+ action potentials. Unlike in neurons, floor-plate action potentials relied primarily on the activation of voltage-gated T-type calcium channels (TTCCs). In situ hybridization showed that all 3 known subtypes of TTCCs are predominantly expressed in the floor plate. During SNA, we found that acetylcholine released by motoneurons rhythmically triggers floor-plate action potentials by acting through nicotinic acetylcholine receptors. Finally, by expressing the genetically encoded calcium indicator GCaMP6f in the floor plate, we demonstrated that neuroepithelial action potentials are associated with calcium waves and propagate along the entire length of the spinal cord. Our work reveals a novel physiological mechanism to generate and propagate electrical signals across a neural structure independently from neurons.
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Affiliation(s)
- Kalaimakan Hervé Arulkandarajah
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Guillaume Osterstock
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Agathe Lafont
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Hervé Le Corronc
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France; Université d'Angers, 49000 Angers, France
| | - Nathalie Escalas
- Centre de Biologie du Développement (CBD) CNRS/UPS, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31000 Toulouse, France
| | - Silvia Corsini
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Barbara Le Bras
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Linda Chenane
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Juliette Boeri
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Antonny Czarnecki
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Christine Mouffle
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Erika Bullier
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Elim Hong
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Cathy Soula
- Centre de Biologie du Développement (CBD) CNRS/UPS, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31000 Toulouse, France
| | - Pascal Legendre
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France
| | - Jean-Marie Mangin
- Sorbonne Université, INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), 75005 Paris, France.
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Rima M, Lattouf Y, Abi Younes M, Bullier E, Legendre P, Mangin JM, Hong E. Author Correction: Dynamic regulation of the cholinergic system in the spinal central nervous system. Sci Rep 2021; 11:20036. [PMID: 34608247 PMCID: PMC8490346 DOI: 10.1038/s41598-021-99492-6] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Mohamad Rima
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM, CNRS, Université de Strasbourg, 67400, Illkirch, France
| | - Yara Lattouf
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France
| | - Maroun Abi Younes
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France
| | - Erika Bullier
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France
| | - Pascal Legendre
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France
| | - Jean-Marie Mangin
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France
| | - Elim Hong
- INSERM, CNRS, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Sorbonne Université, 75005, Paris, France.
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Osterstock G, Le Bras B, Arulkandarajah KH, Le Corronc H, Czarnecki A, Mouffle C, Bullier E, Legendre P, Mangin JM. Axoglial synapses are formed onto pioneer oligodendrocyte precursor cells at the onset of spinal cord gliogenesis. Glia 2018; 66:1678-1694. [PMID: 29603384 DOI: 10.1002/glia.23331] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 03/05/2018] [Accepted: 03/05/2018] [Indexed: 12/12/2022]
Abstract
Virtually all oligodendrocyte precursors cells (OPCs) receive glutamatergic and/or GABAergic synapses that are lost upon their differentiation into oligodendrocytes in the postnatal and adult brain. Although OPCs are generated at mid-embryonic stages, several weeks before the onset of myelination, it remains unknown when and where OPCs receive their first synapses and become susceptible to the influence of neuronal activity. In the embryonic spinal cord, neuro-epithelial precursors in the pMN domain cease generating cholinergic motor neurons (MNs) to produce OPCs when the first synapses are formed in the ventral-lateral marginal zone. We discovered that when the first synapses form onto MNs, axoglial synapses also form onto the processes of neuro-epithelial precursors located in the marginal zone as they differentiate into OPCs. After leaving the neuro-epithelium, these pioneer OPCs preferentially accumulate in the marginal zone where they are contacted by functional glutamatergic and GABAergic synapses. Spontaneous activity of these axoglial synapses was significantly potentiated by cholinergic signaling acting through presynaptic nicotinic acetylcholine receptors. Moreover, we discovered that chronic nicotine treatment significantly increases early OPC proliferation and density in the marginal zone. Our results demonstrate that OPCs are contacted by functional synapses as soon as they emerge from their precursor domain and that embryonic spinal cord colonization by OPCs can be regulated by cholinergic signaling acting onto these axoglial synapses.
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Affiliation(s)
- Guillaume Osterstock
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Barbara Le Bras
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Kalaimakan Hervé Arulkandarajah
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Hervé Le Corronc
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France.,Université d'Angers, Angers, 49000, France
| | - Antonny Czarnecki
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Christine Mouffle
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Erika Bullier
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Pascal Legendre
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
| | - Jean-Marie Mangin
- Sorbonne Université, UM119, Neuroscience Paris Seine, Paris F-75005, France Centre National de la Recherche Scientifique (CNRS), UMR 8246, Paris F-75005, France Institut National de la Santé et de la Recherche Médicale (INSERM), U1130, Paris, F-75005, France
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Gerbaud E, Cochet H, Bullier E, Ragot C, Gilbert SH, Douard H, Pucheu Y, Laurent F, Coste P, Bordenave L, Montaudon M. Peri-infarct ischaemia assessed by cardiovascular MRI: comparison with quantitative perfusion single photon emission CT imaging. Br J Radiol 2014; 87:20130774. [DOI: 10.1259/bjr.20130774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Duflocq A, Le Bras B, Bullier E, Couraud F, Davenne M. Nav1.1 is predominantly expressed in nodes of Ranvier and axon initial segments. Mol Cell Neurosci 2008; 39:180-92. [DOI: 10.1016/j.mcn.2008.06.008] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 06/11/2008] [Accepted: 06/13/2008] [Indexed: 12/19/2022] Open
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Lafay B, Bullier E, Burdon JJ. Bradyrhizobia isolated from root nodules of Parasponia (Ulmaceae) do not constitute a separate coherent lineage. Int J Syst Evol Microbiol 2006; 56:1013-1018. [PMID: 16627647 DOI: 10.1099/ijs.0.63897-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rhizobial bacteria almost exclusively nodulate members of the families Fabaceae, Mimosaceae and Caesalpiniaceae, but are found on a single non-legume taxon, Parasponia (Ulmaceae). Based on their host-range, their nitrogen-fixing ability and strain competition experiments, bacterial strains isolated from Parasponia were thought to constitute a separate lineage that would account for their exceptional host affinity. This hypothesis was investigated by focusing on four isolates that are representative of the morphological and cultural types of Parasponia-nodulating bradyrhizobia. Their evolutionary relationships with other rhizobia were analysed using 16S rRNA gene sequences and their nodulation properties were explored using the nodA gene as a proxy for host-range specificity. Phylogenetic analyses of the 16S rRNA and nodA gene sequences revealed that bacterial isolates from Parasponia species are embedded among other bradyrhizobia. They did not cluster together in topologies based on the 16S rRNA or nodA gene sequences, but were scattered among other bradyrhizobia belonging to either the Bradyrhizobium japonicum or the Bradyrhizobium elkanii lineages. These data suggest that the ability of some bradyrhizobia to nodulate species of the genus Parasponia does not represent a historical relationship that predates the relationship between rhizobia and legumes, but is probably a more recent host switch for some rhizobia.
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Affiliation(s)
- Bénédicte Lafay
- CSIRO Plant Industry, PO Box 1600, Canberra, ACT 2601, Australia
| | - Erika Bullier
- UMR CNRS-IRD 2724, Centre IRD, 911, Avenue Agropolis - BP 64501, 34394 Montpellier Cedex 5, France
| | - Jeremy J Burdon
- CSIRO Plant Industry, PO Box 1600, Canberra, ACT 2601, Australia
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Foo E, Bullier E, Goussot M, Foucher F, Rameau C, Beveridge CA. The branching gene RAMOSUS1 mediates interactions among two novel signals and auxin in pea. Plant Cell 2005; 17:464-74. [PMID: 15659639 PMCID: PMC548819 DOI: 10.1105/tpc.104.026716] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 11/12/2004] [Indexed: 05/18/2023]
Abstract
In Pisum sativum, the RAMOSUS genes RMS1, RMS2, and RMS5 regulate shoot branching via physiologically defined mobile signals. RMS1 is most likely a carotenoid cleavage enzyme and acts with RMS5 to control levels of an as yet unidentified mobile branching inhibitor required for auxin inhibition of branching. Our work provides molecular, genetic, and physiological evidence that RMS1 plays a central role in a shoot-to-root-to-shoot feedback system that regulates shoot branching in pea. Indole-3-acetic acid (IAA) positively regulates RMS1 transcript level, a potentially important mechanism for regulation of shoot branching by IAA. In addition, RMS1 transcript levels are dramatically elevated in rms3, rms4, and rms5 plants, which do not contain elevated IAA levels. This degree of upregulation of RMS1 expression cannot be achieved in wild-type plants by exogenous IAA application. Grafting studies indicate that an IAA-independent mobile feedback signal contributes to the elevated RMS1 transcript levels in rms4 plants. Therefore, the long-distance signaling network controlling branching in pea involves IAA, the RMS1 inhibitor, and an IAA-independent feedback signal. Consistent with physiological studies that predict an interaction between RMS2 and RMS1, rms2 mutations appear to disrupt this IAA-independent regulation of RMS1 expression.
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Affiliation(s)
- Eloise Foo
- Australian Research Council Centre of Excellence for Integrative Legume Research, University of Queensland, St. Lucia, Queensland, 4072, Australia
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10
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Mercier R, Vezon D, Bullier E, Motamayor JC, Sellier A, Lefèvre F, Pelletier G, Horlow C. SWITCH1 (SWI1): a novel protein required for the establishment of sister chromatid cohesion and for bivalent formation at meiosis. Genes Dev 2001; 15:1859-71. [PMID: 11459834 PMCID: PMC312743 DOI: 10.1101/gad.203201] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2001] [Accepted: 05/18/2001] [Indexed: 11/25/2022]
Abstract
We have characterized a new gene, SWI1, involved in sister chromatid cohesion during both male and female meiosis in Arabidopsis thaliana. A first allele, swi1.1, was obtained as a T-DNA tagged mutant and was described previously as abnormal exclusively in female meiosis. We have isolated a new allele, swi1.2, which is defective for both male and female meiosis. In swi1.2 male meiosis, the classical steps of prophase were not observed, especially because homologs do not synapse. Chromatid arms and centromeres lost their cohesion in a stepwise manner before metaphase I, and 20 chromatids instead of five bivalents were seen at the metaphase plate, which was followed by an aberrant segregation. In contrast, swi1.2 female meiocytes performed a mitotic-like division instead of meiosis, indicating a distinct role for SWI1 or a different effect of the loss of SWI1 function in both processes. The SWI1 gene was cloned; the putative SWI1 protein did not show strong similarity to any known protein. Plants transformed with a SWI1-GFP fusion indicated that SWI1 protein is present in meiocyte nuclei, before meiosis and at a very early stage of prophase. Thus, SWI1 appears to be a novel protein involved in chromatid cohesion establishment and in chromosome structure during meiosis, but with clear differences between male and female meiosis.
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Affiliation(s)
- R Mercier
- Station de Génétique et d'Amélioration des Plantes, Institut National de la Recherche Agronomique, Route de Saint-Cyr, 78026 Versailles cedex, France.
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