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Perier JD, Kaplan F, Lewis EE, Alborn H, Schliekelman P, Toews MD, Schiller KC, Shapiro-Ilan DI. Enhancing entomopathogenic nematode efficacy with Pheromones: A field study targeting the pecan weevil. J Invertebr Pathol 2024; 203:108070. [PMID: 38311231 DOI: 10.1016/j.jip.2024.108070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/17/2024] [Accepted: 01/19/2024] [Indexed: 02/10/2024]
Abstract
Consistent efficacy is required for entomopathogenic nematodes to gain wider adoption as biocontrol agents. Recently, we demonstrated that when exposed to nematode pheromone blends, entomopathogenic nematodes showed increased dispersal, infectivity, and efficacy under laboratory and greenhouse conditions. Prior to this study, the impact of entomopathogenic nematode-pheromone combinations on field efficacy had yet to be studied. Steinernema feltiae is a commercially available entomopathogenic nematode that has been shown to increase mortality in insect pests such as the pecan weevil Curculio caryae. In this study, the pecan weevil was used as a model system to evaluate changes in S. feltiae efficacy when treated with a partially purified ascaroside pheromone blend. Following exposure to the pheromone blend, the efficacy of S. feltiae significantly increased as measured with decreased C. caryae survival despite unfavorable environmental conditions. The results of this study highlight a potential new avenue for using entomopathogenic nematodes in field conditions. With increased efficacy, using entomopathogenic nematodes will reduce reliance on conventional management methods in pecan production, translating into more environmentally acceptable practices.
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Affiliation(s)
- Jermaine D Perier
- Department of Entomology, University of Georgia, Tifton, GA 31793, United States
| | - Fatma Kaplan
- Pheronym, Inc., Woodland, CA 95695, United States
| | - Edwin E Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, United States
| | - Hans Alborn
- USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32608, United States
| | - Paul Schliekelman
- Department of Statistics, University of Georgia, Athens, GA 30602, United States
| | - Michael D Toews
- Department of Entomology, University of Georgia, Tifton, GA 31793, United States
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Stevens G, Usman M, Gulzar S, Stevens C, Pimentel E, Erdogan H, Schliekelman P, Kaplan F, Alborn H, Wakil W, Shapiro-Ilan D, Lewis EE. Group Movement in Entomopathogenic Nematodes: Aggregation Levels Vary Based on Context. J Nematol 2024; 56:20240002. [PMID: 38495935 PMCID: PMC10940270 DOI: 10.2478/jofnem-2024-0002] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2024] [Indexed: 03/19/2024] Open
Abstract
Maintenance of an aggregated population structure implies within-species communication. In mixed-species environments, species-specific aggregations may reduce interspecific competition and promote coexistence. We studied whether movement and aggregation behavior of three entomopathogenic nematode species changed when isolated, as compared to mixed-species arenas. Movement and aggregation of Steinernema carpocapsae, S. feltiae and S. glaseri were assessed in sand. Each species demonstrated significant aggregation when alone. Mixed-species trials involved adding two species of nematodes, either combined in the center of the arena or at separate corners. While individual species became less aggregated than in single-species conditions when co-applied in the same location, they became more aggregated when applied in separate corners. This increased aggregation in separate-corner trials occurred even though the nematodes moved just as far when mixed together as they did when alone. These findings suggest that maintenance of multiple species within the same habitat is driven, at least in part, by species-specific signals that promote conspecific aggregation, and when the species are mixed (as occurs in some commercial formulations involving multiple EPN species), these signaling mechanisms are muddled.
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Affiliation(s)
- Glen Stevens
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID83844, USA
| | - Muhammad Usman
- Department of Entomology, University of Agriculture Faisalabad38000, Pakistan
| | - Sehrish Gulzar
- Department of Entomology, University of Agriculture Faisalabad38000, Pakistan
| | - Cassandra Stevens
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID83844, USA
| | - Eleanor Pimentel
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID83844, USA
| | - Hilal Erdogan
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID83844, USA
- Faculty of Agriculture, Department of Biosystems Engineering, Bursa Uludağ University, Bursa16059, Turkey
| | - Paul Schliekelman
- University of Georgia, Department of Statistics, Athens, GA30602, USA
| | | | - Hans Alborn
- Center for Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture Agricultural Research Service, 1700SW23rd Drive, Gainesville, FL, USA
| | - Waqas Wakil
- Department of Entomology, University of Agriculture Faisalabad38000, Pakistan
| | | | - Edwin E Lewis
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID83844, USA
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Kaplan F, Erdemir A. Evaluating the effect of different irrigation activation techniques on the dentin tubules penetration of two different root canal sealers by laser scanning confocal microscopy. Microsc Res Tech 2023. [PMID: 37158110 DOI: 10.1002/jemt.24339] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 04/19/2023] [Indexed: 05/10/2023]
Abstract
PURPOSE The aim of this study is to evaluate the effect of different irrigation activation techniques on the dentin tubules penetration of two different sealers by confocal laser scanning microscope (CLSM). METHODS A hundred premolar teeth were used in this study. The root canals were shaped and irrigated with 5% NaOCl and 17% EDTA using the following final irrigation activation techniques in each group; Group1: Conventional Syringe Irrigation (CSI), Group2: Passive Ultrasonic Irrigation (PUI), Group3: Apical Negative Pressure (EndoVac), Group4: Er:YAG laser and Group5: Er,Cr:YSGG laser. Then the teeth were separated two subgroups according to sealers (AH-Plus and Totalfill-BC). Horizontal sections were obtained at 2, 5, 8 mm distance of apex. Images were obtained with CLSM and the penetration areas of sealers were calculated with four different dentin tubule penetration assessment techniques. The data were statistically analyzed with Kruskal Wallis and Mann Whitney U tests. RESULTS No significant difference was observed between the sealers (p > .05). EndoVac, Er:YAG and Er,Cr:YSGG laser activation groups were observed to have a significantly higher mean penetration depth, penetration percentage and penetration area than the Control group. There was a significant difference between all regions in all penetration parameters (p < .05). CONCLUSIONS While the use of resin or bioceramic-based root canal sealers did not affect dentin tubule penetration, the use of activation techniques positively affect the dentin tubule penetration. The average tubule penetration and penetration area assessment techniques are suitable methods for the investigation of dentinal tubule penetration. RESEARCH HIGHLIGHTS It can be stated that the use of resin or bioceramic based root canal sealers does not affect dentin tubule penetration and the use of irrigation activation techniques during removal of the smear layer positively affects dentinal tubule penetration. In addition, it has been determined that the average tubule penetration and penetration area assessment techniques are suitable methods for the investigation of dentinal tubule penetration.
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Affiliation(s)
- Fatma Kaplan
- Department of Endodontics, Faculty of Dentistry, Bezmialem Vakif University, Istanbul, Turkey
| | - Ali Erdemir
- Department of Endodontics, Faculty of Dentistry, Kirikkale University, Kirikkale, Turkey
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Erdogan H, Cruzado-Gutierrez K, Stevens G, Shapiro-Ilan D, Kaplan F, Alborn H, Lewis E. Nematodes Follow a Leader. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.740351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aggregated movement and population structure are known in entomopathogenic nematodes, which are obligate insect parasites. Aggregation behavior in the absence of external stimuli suggests communication among individuals, often in the form of trail-following, which has not been shown by nematodes of any kind. Interactions among individuals are an essential basis of following behaviors and can have significant fitness consequences. We explored intraspecific and interspecific interactions among three Steinernema species (S. glaseri, S. carpocapsae, and S. feltiae) in terms of trail following, and fitness outcomes of following heterospecific individuals. We found that the following behavior is context dependent. Following behavior among conspecifics was significantly increased when the lead nematode had prior contact with host cuticle. However, we did not find a clear association between the following response to heterospecific IJs and their reproductive success in a co-infected host.
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Erdogan H, Stevens G, Stevens A, Shapiro-Ilan D, Kaplan F, Alborn H, Lewis E. Infected host responses across entomopathogenic nematode phylogeny. J Nematol 2021; 53:e2021-105. [PMID: 34957409 PMCID: PMC8672421 DOI: 10.21307/jofnem-2021-105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Indexed: 11/11/2022] Open
Abstract
We used a phylogenetic framework to examine the relationship between entomopathogenic nematode (EPN) vertical dispersal and infectivity when EPNs are exposed to a mixture of compounds found in late-stage EPN-infected insect cadavers. EPNs from five phylogenetically close and distant species (Heterorhabditis bacteriophora, H. georgiana, H. megidis, H. indica and Steinernema feltiae) were exposed to cadaver macerate produced by their own species’ infection and by H. bacteriophora infected hosts. We found that only three of the five species (H. bacteriophora, H. indica and S. feltiae) responded to exposure to their own macerate by increasing rates of dispersal. When we exposed all five species to a H. bacteriophora infected host macerate, we found that only H. bacteriophora responded by increasing dispersal, and that the most distantly related species (S. feltiae) essentially halted dispersal. These findings suggest that (1) responses to cadaver macerate vary, and (2) there may be a relationship between inherent dispersal rates and sensitivity to macerate exposure, as the most rapidly dispersing species (H. megidis) showed no response to macerate exposure.
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Affiliation(s)
- Hilal Erdogan
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID, 83844
- Faculty of Agriculture, Department of Biosystems Engineering, Bursa Uludağ University, Bursa, 16059, Turkey
| | - Glen Stevens
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID, 83844
| | - Asa Stevens
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID, 83844
| | - David Shapiro-Ilan
- USDA-ARS, Southeastern Fruit and Tree Nut Research Laboratory, Byron, GA, 31008
| | | | - Hans Alborn
- Center for Medical, Agricultural, and Veterinary Entomology, U.S. Department of Agriculture Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL
| | - Edwin Lewis
- University of Idaho, Department of Entomology, Plant Pathology and Nematology, Moscow, ID, 83844
- *E-mail:
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Sevim M, Kaplan F. Ketjen Black supported monodisperse nickel–platinum alloy nanoparticles for the efficient catalyst in the hydrolytic dehydrogenation of ammonia borane. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.6095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Melike Sevim
- Department of Chemistry, Faculty of Science Atatürk University Erzurum 25240 Turkey
- Nanoscience and Nanoengineering Department Atatürk University Erzurum 25240 Turkey
| | - Fatma Kaplan
- Department of Chemistry, Faculty of Science Atatürk University Erzurum 25240 Turkey
- Nanoscience and Nanoengineering Department Atatürk University Erzurum 25240 Turkey
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Kaplan F, Shapiro-Ilan D, Schiller KC. Dynamics of entomopathogenic nematode foraging and infectivity in microgravity. NPJ Microgravity 2020; 6:20. [PMID: 32818149 PMCID: PMC7418002 DOI: 10.1038/s41526-020-00110-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 05/21/2020] [Accepted: 07/14/2020] [Indexed: 12/25/2022] Open
Abstract
Microgravity is a unique environment to elucidate host-parasite biology. Entomopathogenic nematodes (EPNs), model parasites, kill host insects with mutualistic bacteria and provide environmentally friendly pest control. It is unknown how microgravity affects a multistep insect invasion by parasites with mutualistic bacteria. EPNs respond directionally to electromagnetic cues and their sinusoidal locomotion is affected by various physical factors. Therefore, we expected microgravity to impact EPN functionality. Microgravity experiments during space flight on the International Space Station (ISS) indicated that EPNs successfully emerged from consumed insect host cadavers, moved through soil, found and infected bait insects in a manner equivalent to Earth controls. However, nematodes that developed entirely in space, from the egg stage, died upon return to Earth, unlike controls in microgravity and on Earth. This agricultural biocontrol experiment in space gives insight to long-term space flight for symbiotic organisms, parasite biology, and the potential for sustainable crop protection in space.
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Affiliation(s)
| | - David Shapiro-Ilan
- US Department of Agriculture, Agricultural Research Service, Byron, GA 31008 USA
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Oliveira-Hofman C, Kaplan F, Stevens G, Lewis E, Wu S, Alborn HT, Perret-Gentil A, Shapiro-Ilan DI. Pheromone extracts act as boosters for entomopathogenic nematodes efficacy. J Invertebr Pathol 2019; 164:38-42. [PMID: 31034842 DOI: 10.1016/j.jip.2019.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [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: 02/22/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 11/17/2022]
Abstract
Inconsistency in entomopathogenic nematode (EPN) efficacy is still one of the biggest challenges for the wider adoption of EPNs as biocontrol agents. Previous studies demonstrated that extracts from EPN-infected hosts enhance dispersal and efficacy, two key factors in success of EPNs. Some active components in the insect host cadavers responsible for dispersal, ascarosides, have been identified as nematode pheromones. We hypothesized that pheromone extracts increase dispersal of EPN infective juveniles (IJs) leading to increased efficacy. First, we determined whether pheromone extracts improved IJ movement/dispersal in soil columns baited with Tenebrio molitor larvae. We found that pheromone extracts induced higher numbers of Steinernema carpocapsae and Steinernema feltiae IJs to move towards T. molitor larvae in the bottom of the column compared to IJs treated with infected cadaver macerate and water, positive and negative controls, respectively. Furthermore, the number of S. carpocapsae IJs that invaded T. molitor larvae was higher for the pheromone extract treatment than the controls. S. feltiae IJs that were pretreated with pheromone extracts and macerate (positive control) infected T. molitor at the same rate but invasion was superior to IJs that were treated with water. Consistent with the soil column tests, both S. carpocapsae and S. feltiae IJs treated with pheromone extracts performed better in killing larvae of two economically important insect larvae, pecan weevil, Curculio caryae, and black soldier fly, Hermetia illucens, in greenhouse tests compared to IJs treated with water. We demonstrated pheromone-mediated behavioral manipulation of a biological control agent to enhance pest control potential. Conceivably, nematodes can be exposed to efficacy-enhancing pheromones prior to field application.
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Affiliation(s)
| | | | - Glen Stevens
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | - Edwin Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | | | - Hans T Alborn
- USDA-ARS Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32608, USA
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Shapiro-Ilan DI, Kaplan F, Oliveira-Hofman C, Schliekelman P, Alborn HT, Lewis EE. Conspecific pheromone extracts enhance entomopathogenic infectivity. J Nematol 2019. [DOI: 10.21307/jofnem-2019-082] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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10
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Wu S, Kaplan F, Lewis E, Alborn HT, Shapiro-Ilan DI. Infected host macerate enhances entomopathogenic nematode movement towards hosts and infectivity in a soil profile. J Invertebr Pathol 2018; 159:141-144. [DOI: 10.1016/j.jip.2018.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/09/2018] [Accepted: 10/15/2018] [Indexed: 11/30/2022]
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11
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Ruan WB, Shapiro-Ilan D, Lewis EE, Kaplan F, Alborn H, Gu XH, Schliekelman P. Movement patterns in Entomopathogenic nematodes: Continuous vs. temporal. J Invertebr Pathol 2017; 151:137-143. [PMID: 29158014 DOI: 10.1016/j.jip.2017.11.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 08/07/2017] [Revised: 11/10/2017] [Accepted: 11/16/2017] [Indexed: 12/18/2022]
Abstract
To exploit resources, animals implement various foraging behaviors to increase their fitness. Entomopathogenic nematodes are obligate parasites of insects in nature. In previous studies, entomopathogenic nematodes were reported to exhibit group movement behavior in the presence and absence of insect hosts. However, it was not determined if group movement is continuous or temporal. For example, nematode movement behavior upon emergence from the host might start out in an independent fashion prior to aggregation, or group movement may be exhibited continuously. In the present study, we explored the propensity for innate group movement behavior of two insect parasitic nematodes in two families and genera: Heterorhabditis indica and Steinernema carpocapsae. We hypothesized the nematode populations would initially move independently from their origin and then come together for group movement. Movement patterns were investigated in sand when nematodes were applied in aqueous suspension (via filter paper) to a specific locus or when the nematodes emerged naturally from infected insect hosts. To compare nematode movement behavior over time and space, nematode dispersal was monitored at three distances (2.5, 4.5 and 8.0 cm) from the center (origin) and at two different time periods, 2 days and 3 days after nematode addition. We discovered that nematode dispersal continuously exhibited an aggregative pattern (independent movement was not observed). Results from both nematode species as well as the host-cadaver and filter paper (aqueous nematode suspension) application methods indicated a continuous aggregative pattern. The discovery of continuous aggregative movement patterns in steinernematid and heterorhabditid nematodes elucidates further the complexity of their foraging behavior and may serve as basis for exploring foraging behavior in other host-parasite systems.
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Affiliation(s)
- Wei-Bin Ruan
- College of Life Sciences, Nankai University, Tianjin 30071, China
| | | | - Edwin E Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | | | - Hans Alborn
- USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32608, USA
| | - Xin-Hui Gu
- Yuxi Tobacco Company, Yuxi 653100, Yunnan, China
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12
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Affiliation(s)
- Fatma Kaplan
- Fatma Kaplan is the co-founder, co-owner, and CEO of Kaplan Schiller Research, LLC in Gainesville, Florida. Send your story to SciCareerEditor@aaas .org
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Affiliation(s)
- F. Kaplan
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Campus North, D-76344 Karlsruhe, Germany
| | - M. E. Harding
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Campus North, D-76344 Karlsruhe, Germany
| | - C. Seiler
- Institute
of Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - F. Weigend
- Institute
of Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
- Institute
of Physical Chemistry, Karlsruhe Institute of Technology, Campus
South, D-76021 Karlsruhe, Germany
| | - F. Evers
- Institute
of Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - M. J. van Setten
- Nanoscopic
Physics, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, 1348 Louvain-la-Neuve, Belgium
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Albertin F, Patera A, Jerjen I, Hartmann S, Peccenini E, Kaplan F, Stampanoni M, Kaufmann R, Margaritondo G. Virtual reading of a large ancient handwritten science book. Microchem J 2016. [DOI: 10.1016/j.microc.2015.11.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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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15
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Kaplan F, Weigend F, Evers F, van Setten MJ. Off-Diagonal Self-Energy Terms and Partially Self-Consistency in GW Calculations for Single Molecules: Efficient Implementation and Quantitative Effects on Ionization Potentials. J Chem Theory Comput 2015; 11:5152-60. [DOI: 10.1021/acs.jctc.5b00394] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- F. Kaplan
- Institute
of Nanotechnology, Karlsruhe Institute of Technology, Campus North, D-76344 Karlsruhe, Germany
| | - F. Weigend
- Institute
of Nanotechnology, Karlsruhe Institute of Technology, Campus North, D-76344 Karlsruhe, Germany
- Institute
of Physical Chemistry, Karlsruhe Institute of Technology, Campus
South, D-76021 Karlsruhe, Germany
| | - F. Evers
- Institute
of Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - M. J. van Setten
- Nanoscopic
Physics, Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Chemin des Étoiles 8, bte
L7.03.01, 1348 Louvain-la-Neuve, Belgium
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Manosalva P, Manohar M, von Reuss SH, Chen S, Koch A, Kaplan F, Choe A, Micikas RJ, Wang X, Kogel KH, Sternberg PW, Williamson VM, Schroeder FC, Klessig DF. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance. Nat Commun 2015; 6:7795. [PMID: 26203561 PMCID: PMC4525156 DOI: 10.1038/ncomms8795] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [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: 11/24/2014] [Accepted: 06/10/2015] [Indexed: 01/27/2023] Open
Abstract
Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture.
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Affiliation(s)
- Patricia Manosalva
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
- Department of Plant Pathology and Microbiology, University of California Riverside, Riverside, California 92521, USA
| | - Murli Manohar
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | | | - Shiyan Chen
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853, USA
| | - Aline Koch
- Research Centre for BioSystems, Land Use, and Nutrition, Justus Liebig University, Giessen D-35392, Germany
| | - Fatma Kaplan
- Kaplan Schiller Research, LLC, Gainesville, Florida 32604, USA
| | - Andrea Choe
- Howard Hughes Medical Institute and Biology Division, California Institute of Technology, Pasadena, California 91125, USA
| | - Robert J. Micikas
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Xiaohong Wang
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853, USA
- Robert W. Holley Center for Agriculture and Health, US Department of Agricultural Research Service, Ithaca, New York 14853, USA
| | - Karl-Heinz Kogel
- Research Centre for BioSystems, Land Use, and Nutrition, Justus Liebig University, Giessen D-35392, Germany
| | - Paul W. Sternberg
- Howard Hughes Medical Institute and Biology Division, California Institute of Technology, Pasadena, California 91125, USA
| | - Valerie M. Williamson
- Department of Plant Pathology, University of California, Davis, California 95616, USA
| | - Frank C. Schroeder
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Daniel F. Klessig
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
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Manosalva P, Manohar M, von Reuss SH, Chen S, Koch A, Kaplan F, Choe A, Micikas RJ, Wang X, Kogel KH, Sternberg PW, Williamson VM, Schroeder FC, Klessig DF. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance. Nat Commun 2015. [PMID: 26203561 DOI: 10.1038/ncomss8795] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture.
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Affiliation(s)
- Patricia Manosalva
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
- Department of Plant Pathology and Microbiology, University of California Riverside, Riverside, California 92521, USA
| | - Murli Manohar
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | | | - Shiyan Chen
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853, USA
| | - Aline Koch
- Research Centre for BioSystems, Land Use, and Nutrition, Justus Liebig University, Giessen D-35392, Germany
| | - Fatma Kaplan
- Kaplan Schiller Research, LLC, Gainesville, Florida 32604, USA
| | - Andrea Choe
- Howard Hughes Medical Institute and Biology Division, California Institute of Technology, Pasadena, California 91125, USA
| | - Robert J Micikas
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Xiaohong Wang
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York 14853, USA
- Robert W. Holley Center for Agriculture and Health, US Department of Agricultural Research Service, Ithaca, New York 14853, USA
| | - Karl-Heinz Kogel
- Research Centre for BioSystems, Land Use, and Nutrition, Justus Liebig University, Giessen D-35392, Germany
| | - Paul W Sternberg
- Howard Hughes Medical Institute and Biology Division, California Institute of Technology, Pasadena, California 91125, USA
| | - Valerie M Williamson
- Department of Plant Pathology, University of California, Davis, California 95616, USA
| | - Frank C Schroeder
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
| | - Daniel F Klessig
- Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA
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18
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Metin K, Kaplan F. Unexpected complication of bee sting; left middle cerebral artery infarction. Eur Geriatr Med 2015. [DOI: 10.1016/j.eurger.2014.11.008] [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: 10/24/2022]
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19
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Albertin F, Astolfo A, Stampanoni M, Peccenini E, Hwu Y, Kaplan F, Margaritondo G. Ancient administrative handwritten documents: X-ray analysis and imaging. J Synchrotron Radiat 2015; 22:446-451. [PMID: 25723946 PMCID: PMC4786057 DOI: 10.1107/s1600577515000314] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 01/07/2015] [Indexed: 06/04/2023]
Abstract
Handwritten characters in administrative antique documents from three centuries have been detected using different synchrotron X-ray imaging techniques. Heavy elements in ancient inks, present even for everyday administrative manuscripts as shown by X-ray fluorescence spectra, produce attenuation contrast. In most cases the image quality is good enough for tomography reconstruction in view of future applications to virtual page-by-page `reading'. When attenuation is too low, differential phase contrast imaging can reveal the characters from refractive index effects. The results are potentially important for new information harvesting strategies, for example from the huge Archivio di Stato collection, objective of the Venice Time Machine project.
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Affiliation(s)
- F. Albertin
- Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - A. Astolfo
- Swiss Light Source, Paul Scherrer Institut (PSI), Villigen, Switzerland
| | - M. Stampanoni
- Swiss Light Source, Paul Scherrer Institut (PSI), Villigen, Switzerland
- Institute for Biomedical Engineering, ETHZ, Zürich, Switzerland
| | - Eva Peccenini
- Department of Physics and Earth Sciences, University of Ferrara, Italy
- Laboratory TekneHub, Technopole of Ferrara, Italy
| | - Y. Hwu
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - F. Kaplan
- Laboratoire d’Humanités Digitales, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - G. Margaritondo
- Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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20
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Wamalwa L, Cheseto X, Ouna E, Kaplan F, Maniania N, Machuka J, Torto B, Ghislain M. Toxic Ipomeamarone accumulation in healthy parts of Sweetpotato (Ipomoea batatas L. Lam) storage roots upon infection by Rhizopus stolonifer. J Agric Food Chem 2015; 63:335-42. [PMID: 25418792 PMCID: PMC4298358 DOI: 10.1021/jf504702z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Furanoterpenoid accumulation in response to microbial attack in rotting sweetpotatoes has long been linked to deaths and lung edema of cattle in the world. However, it is not known whether furanoterpenoid ipomeamarone accumulates in the healthy-looking parts of infected sweetpotato storage roots. This is critical for effective utilization as animal feed and assessment of the potential negative impact on human health. Therefore, we first identified the fungus from infected sweetpotatoes as a Rhizopus stolonifer strain and then used it to infect healthy sweetpotato storage roots for characterization of furanoterpenoid content. Ipomeamarone and its precursor, dehydroipomeamarone, were identified through spectroscopic analyses, and detected in all samples and controls at varying concentrations. Ipomeamarone concentration was at toxic levels in healthy-looking parts of some samples. Our study provides fundamental information on furanoterpenoids in relation to high levels reported that could subsequently affect cattle on consumption and high ipomeamarone levels in healthy-looking parts.
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Affiliation(s)
- Lydia
N. Wamalwa
- International
Potato Centre, P.O. Box 25171-00603, Nairobi, Kenya
- Kenyatta
University, P.O. Box
43844-00100, Nairobi, Kenya
| | - Xavier Cheseto
- International
Centre of Insect Physiology and Ecology (ICIPE)-African Insect Science
for Food and Health, P.O. Box 30772-00100, Nairobi, Kenya
| | - Elizabeth Ouna
- International
Centre of Insect Physiology and Ecology (ICIPE)-African Insect Science
for Food and Health, P.O. Box 30772-00100, Nairobi, Kenya
| | - Fatma Kaplan
- Department
of Biology, University of Florida, Gainesville, Florida 32611, United States
- Kaplan Schiller
Research, LLC., Gainesville, Florida 32604, United
States
| | - Nguya
K. Maniania
- International
Centre of Insect Physiology and Ecology (ICIPE)-African Insect Science
for Food and Health, P.O. Box 30772-00100, Nairobi, Kenya
| | - Jesse Machuka
- Kenyatta
University, P.O. Box
43844-00100, Nairobi, Kenya
| | - Baldwyn Torto
- International
Centre of Insect Physiology and Ecology (ICIPE)-African Insect Science
for Food and Health, P.O. Box 30772-00100, Nairobi, Kenya
| | - Marc Ghislain
- International
Potato Centre, P.O. Box 25171-00603, Nairobi, Kenya
- E-mail: . Phone: 254 (020) 4223641. Fax: 254 (020 4223600)
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21
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Teal PEA, Jones D, Jones G, Torto B, Nyasembe V, Borgemeister C, Alborn HT, Kaplan F, Boucias D, Lietze VU. Identification of methyl farnesoate from the hemolymph of insects. J Nat Prod 2014; 77:402-405. [PMID: 24467367 DOI: 10.1021/np400807v] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Methyl farnesoate, [methyl (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trienoate (1)] has not been thought be present in the hemolymph of insects, although it is the immediate biosynthetic precursor of the circulating insect hormone juvenile hormone III (methyl (2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate) (2). Compound 1 was identified from the hemolymph obtained from five orders of insects. Identification of 1 from the American bird grasshopper was facilitated using both electron impact and chemical-ionization GC-MS, GC-FTIR, and 2D NMR techniques. The identifications from other insects were made using GC-MS, and the amounts of all were quantified using LIM-CI-GC-MS. The ratios of 1 and 2 varied in these insects during different developmental stages. The present results underscore the need for further studies on methyl farnesoate (1) as a circulating hormone in insects.
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Affiliation(s)
- Peter E A Teal
- Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS , 1700 SW 23 Drive, Gainesville, Florida 32604, United States
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Singh D, Jayashekara A, Kaplan F. AB0748 Carbimazole induced ANCA associated renal vasculitis. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.748] [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: 11/04/2022]
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23
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Kaplan F, Zhao W, Richards JT, Wheeler RM, Guy CL, Levine LH. Transcriptional and metabolic insights into the differential physiological responses of arabidopsis to optimal and supraoptimal atmospheric CO2. PLoS One 2012; 7:e43583. [PMID: 22916280 PMCID: PMC3423350 DOI: 10.1371/journal.pone.0043583] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [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: 04/15/2012] [Accepted: 07/23/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In tightly closed human habitats such as space stations, locations near volcano vents and closed culture vessels, atmospheric CO(2) concentration may be 10 to 20 times greater than Earth's current ambient levels. It is known that super-elevated (SE) CO(2) (>1,200 µmol mol(-1)) induces physiological responses different from that of moderately elevated CO(2) (up to 1,200 µmol mol(-1)), but little is known about the molecular responses of plants to supra-optimal [CO(2)]. METHODOLOGY/PRINCIPAL FINDINGS To understand the underlying molecular causes for differential physiological responses, metabolite and transcript profiles were analyzed in aerial tissue of Arabidopsis plants, which were grown under ambient atmospheric CO(2) (400 µmol mol(-1)), elevated CO(2) (1,200 µmol mol(-1)) and SE CO(2) (4,000 µmol mol(-1)), at two developmental stages early and late vegetative stage. Transcript and metabolite profiling revealed very different responses to elevated versus SE [CO(2)]. The transcript profiles of SE CO(2) treated plants were closer to that of the control. Development stage had a clear effect on plant molecular response to elevated and SE [CO(2)]. Photosynthetic acclimation in terms of down-regulation of photosynthetic gene expression was observed in response to elevated [CO(2)], but not that of SE [CO(2)] providing the first molecular evidence that there appears to be a fundamental disparity in the way plants respond to elevated and SE [CO(2)]. Although starch accumulation was induced by both elevated and SE [CO(2)], the increase was less at the late vegetative stage and accompanied by higher soluble sugar content suggesting an increased starch breakdown to meet sink strength resulting from the rapid growth demand. Furthermore, many of the elevated and SE CO(2)-responsive genes found in the present study are also regulated by plant hormone and stress. CONCLUSIONS/SIGNIFICANCE This study provides new insights into plant acclimation to elevated and SE [CO(2)] during development and how this relates to stress, sugar and hormone signaling.
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Affiliation(s)
- Fatma Kaplan
- Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Gainesville, Florida, United States of America
| | - Wei Zhao
- MedImmune LLC, Gaithersburg, Maryland, United States of America
| | - Jeffrey T. Richards
- Enterprise Advisory Services Inc., QinetiQ North America for Engineering Services Contract (ESC), Sustainable Systems Applied Research, Kennedy Space Center, Florida, United States of America
| | - Raymond M. Wheeler
- NASA Engineering Directorate, Kennedy Space Center, Florida, United States of America
| | - Charles L. Guy
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville, Florida, United States of America
| | - Lanfang H. Levine
- Enterprise Advisory Services Inc., QinetiQ North America for Engineering Services Contract (ESC), Sustainable Systems Applied Research, Kennedy Space Center, Florida, United States of America
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24
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Ali JG, Alborn HT, Campos-Herrera R, Kaplan F, Duncan LW, Rodriguez-Saona C, Koppenhöfer AM, Stelinski LL. Subterranean, herbivore-induced plant volatile increases biological control activity of multiple beneficial nematode species in distinct habitats. PLoS One 2012; 7:e38146. [PMID: 22761668 PMCID: PMC3384653 DOI: 10.1371/journal.pone.0038146] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [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: 03/08/2012] [Accepted: 04/30/2012] [Indexed: 11/18/2022] Open
Abstract
While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9-12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.
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Affiliation(s)
- Jared G. Ali
- Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
| | - Hans T. Alborn
- Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, Gainesville, Florida, United States of America
| | - Raquel Campos-Herrera
- Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
- Departamento de Contaminación Ambiental, Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales, Madrid, Spain
| | - Fatma Kaplan
- Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, Gainesville, Florida, United States of America
| | - Larry W. Duncan
- Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
| | - Cesar Rodriguez-Saona
- Department of Entomology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Albrecht M. Koppenhöfer
- Department of Entomology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Lukasz L. Stelinski
- Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America
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25
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Kaplan F, Alborn HT, von Reuss SH, Ajredini R, Ali JG, Akyazi F, Stelinski LL, Edison AS, Schroeder FC, Teal PE. Interspecific nematode signals regulate dispersal behavior. PLoS One 2012; 7:e38735. [PMID: 22701701 PMCID: PMC3368880 DOI: 10.1371/journal.pone.0038735] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 05/09/2012] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective juveniles (IJ)s of entomopathogenic nematodes (EPN), e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs. METHODOLOGY/PRINCIPAL FINDINGS Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9). A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9) and C. elegans (ascr#2) dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers. CONCLUSIONS/SIGNIFICANCE Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes.
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Affiliation(s)
- Fatma Kaplan
- Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Gainesville, Florida, United States of America.
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Lapointe SL, Alessandro RT, Robbins PS, Khrimian A, Svatos A, Dickens JC, Otálora-Luna F, Kaplan F, Alborn HT, Teal PE. Identification and synthesis of a male-produced pheromone for the neotropical root weevil Diaprepes abbreviatus. J Chem Ecol 2012; 38:408-17. [PMID: 22434385 PMCID: PMC3324679 DOI: 10.1007/s10886-012-0096-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/15/2011] [Accepted: 03/02/2012] [Indexed: 11/28/2022]
Abstract
An unsaturated hydroxy-ester pheromone was isolated from the headspace and feces of male Diaprepes abbreviatus, identified, and synthesized. The pheromone, methyl (E)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate, was discovered by gas chromatography-coupled electroantennogram detection (GC-EAD), and identified by gas chromatography–mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). The synthesis yielded an 86:14 mixture of methyl (E)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate (active) and methyl (Z)-3-(2-hydroxyethyl)-4-methyl-2-pentenoate (inactive), along with a lactone breakdown product. The activity of the synthetic E-isomer was confirmed by GC-EAD, GC-MS, NMR, and bioassays. No antennal response was observed to the Z-isomer or the lactone. In a two-choice olfactometer bioassay, female D. abbreviatus moved upwind towards the synthetic pheromone or natural pheromone more often compared with clean air. Males showed no clear preference for the synthetic pheromone. This pheromone, alone or in combination with plant volatiles, may play a role in the location of males by female D. abbreviatus.
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Affiliation(s)
- Stephen L Lapointe
- Agriculture Research Service, United States Department of Agriculture, U. S. Horticultural Research Laboratory, 2001 South Rock Road, Fort Pierce, FL 34945, USA.
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Huffaker A, Kaplan F, Vaughan MM, Dafoe NJ, Ni X, Rocca JR, Alborn HT, Teal PEA, Schmelz EA. Novel acidic sesquiterpenoids constitute a dominant class of pathogen-induced phytoalexins in maize. Plant Physiol 2011; 156:2082-97. [PMID: 21690302 PMCID: PMC3149930 DOI: 10.1104/pp.111.179457] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 06/18/2011] [Indexed: 05/18/2023]
Abstract
Nonvolatile terpenoid phytoalexins occur throughout the plant kingdom, but until recently were not known constituents of chemical defense in maize (Zea mays). We describe a novel family of ubiquitous maize sesquiterpenoid phytoalexins, termed zealexins, which were discovered through characterization of Fusarium graminearum-induced responses. Zealexins accumulate to levels greater than 800 μg g⁻¹ fresh weight in F. graminearum-infected tissue. Their production is also elicited by a wide variety of fungi, Ostrinia nubilalis herbivory, and the synergistic action of jasmonic acid and ethylene. Zealexins exhibit antifungal activity against numerous phytopathogenic fungi at physiologically relevant concentrations. Structural elucidation of four members of this complex family revealed that all are acidic sesquiterpenoids containing a hydrocarbon skeleton that resembles β-macrocarpene. Induced zealexin accumulation is preceded by increased expression of the genes encoding TERPENE SYNTHASE6 (TPS6) and TPS11, which catalyze β-macrocarpene production. Furthermore, zealexin accumulation displays direct positive relationships with the transcript levels of both genes. Microarray analysis of F. graminearum-infected tissue revealed that Tps6/Tps11 were among the most highly up-regulated genes, as was An2, an ent-copalyl diphosphate synthase associated with production of kauralexins. Transcript profiling suggests that zealexins cooccur with a number of antimicrobial proteins, including chitinases and pathogenesis-related proteins. In addition to zealexins, kauralexins and the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-glucose) were produced in fungal-infected tissue. HDMBOA-glucose accumulation occurred in both wild-type and benzoxazine-deficient1 (bx1) mutant lines, indicating that Bx1 gene activity is not required for HDMBOA biosynthesis. Together these results indicate an important cooperative role of terpenoid phytoalexins in maize biochemical defense.
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Affiliation(s)
- Alisa Huffaker
- Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Chemistry Research Unit, Gainesville, Florida 32608, USA.
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Schmelz EA, Kaplan F, Huffaker A, Dafoe NJ, Vaughan MM, Ni X, Rocca JR, Alborn HT, Teal PE. Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize. Proc Natl Acad Sci U S A 2011; 108:5455-60. [PMID: 21402917 PMCID: PMC3069164 DOI: 10.1073/pnas.1014714108] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Phytoalexins constitute a broad category of pathogen- and insect-inducible biochemicals that locally protect plant tissues. Because of their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses, which include insect-inducible monoterpene and sesquiterpene volatiles. Rice also produces a complex array of pathogen-inducible diterpenoid phytoalexins. Despite the demonstration of fungal-induced ent-kaur-15-ene production in maize over 30 y ago, the identity of functionally analogous maize diterpenoid phytoalexins has remained elusive. In response to stem attack by the European corn borer (Ostrinia nubilalis) and fungi, we observed the induced accumulation of six ent-kaurane-related diterpenoids, collectively termed kauralexins. Isolation and identification of the predominant Rhizopus microsporus-induced metabolites revealed ent-kaur-19-al-17-oic acid and the unique analog ent-kaur-15-en-19-al-17-oic acid, assigned as kauralexins A3 and B3, respectively. Encoding an ent-copalyl diphosphate synthase, fungal-induced An2 transcript accumulation precedes highly localized kauralexin production, which can eventually exceed 100 μg · g(-1) fresh weight. Pharmacological applications of jasmonic acid and ethylene also synergize the induced accumulation of kauralexins. Occurring at elevated levels in the scutella of all inbred lines examined, kauralexins appear ubiquitous in maize. At concentrations as low as 10 μg · mL(-1), kauralexin B3 significantly inhibited the growth of the opportunistic necrotroph R. microsporus and the causal agent of anthracnose stalk rot, Colletotrichum graminicola. Kauralexins also exhibited significant O. nubilalis antifeedant activity. Our work establishes the presence of diterpenoid defenses in maize and enables a more detailed analysis of their biosynthetic pathways, regulation, and crop defense function.
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Affiliation(s)
- Eric A Schmelz
- Chemistry Research Unit, Center of Medical, Agricultural, and Veterinary Entomology, US Department of Agriculture, Agricultural Research Service, Gainesville, FL 32608, USA.
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Kaplan F, Srinivasan J, Mahanti P, Ajredini R, Durak O, Nimalendran R, Sternberg PW, Teal PEA, Schroeder FC, Edison AS, Alborn HT. Ascaroside expression in Caenorhabditis elegans is strongly dependent on diet and developmental stage. PLoS One 2011; 6:e17804. [PMID: 21423575 PMCID: PMC3058051 DOI: 10.1371/journal.pone.0017804] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 02/11/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The ascarosides form a family of small molecules that have been isolated from cultures of the nematode Caenorhabditis elegans. They are often referred to as "dauer pheromones" because most of them induce formation of long-lived and highly stress resistant dauer larvae. More recent studies have shown that ascarosides serve additional functions as social signals and mating pheromones. Thus, ascarosides have multiple functions. Until now, it has been generally assumed that ascarosides are constitutively expressed during nematode development. METHODOLOGY/PRINCIPAL FINDINGS Cultures of C. elegans were developmentally synchronized on controlled diets. Ascarosides released into the media, as well as stored internally, were quantified by LC/MS. We found that ascaroside biosynthesis and release were strongly dependent on developmental stage and diet. The male attracting pheromone was verified to be a blend of at least four ascarosides, and peak production of the two most potent mating pheromone components, ascr#3 and asc#8 immediately preceded or coincided with the temporal window for mating. The concentration of ascr#2 increased under starvation conditions and peaked during dauer formation, strongly supporting ascr#2 as the main population density signal (dauer pheromone). After dauer formation, ascaroside production largely ceased and dauer larvae did not release any ascarosides. These findings show that both total ascaroside production and the relative proportions of individual ascarosides strongly correlate with these compounds' stage-specific biological functions. CONCLUSIONS/SIGNIFICANCE Ascaroside expression changes with development and environmental conditions. This is consistent with multiple functions of these signaling molecules. Knowledge of such differential regulation will make it possible to associate ascaroside production to gene expression profiles (transcript, protein or enzyme activity) and help to determine genetic pathways that control ascaroside biosynthesis. In conjunction with findings from previous studies, our results show that the pheromone system of C. elegans mimics that of insects in many ways, suggesting that pheromone signaling in C. elegans may exhibit functional homology also at the sensory level. In addition, our results provide a strong foundation for future behavioral modeling studies.
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Affiliation(s)
- Fatma Kaplan
- Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, Gainesville, Florida, United States of America
| | - Jagan Srinivasan
- Medical Institute and Biology Division, California Institute of Technology, Pasadena, California, United States of America
| | - Parag Mahanti
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Ramadan Ajredini
- Department of Biochemistry and Molecular Biology, High Magnetic Field Laboratory, University of Florida, Gainesville, Florida, United States of America
| | - Omer Durak
- Medical Institute and Biology Division, California Institute of Technology, Pasadena, California, United States of America
| | - Rathika Nimalendran
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Paul W. Sternberg
- Medical Institute and Biology Division, California Institute of Technology, Pasadena, California, United States of America
| | - Peter E. A. Teal
- Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, Gainesville, Florida, United States of America
| | - Frank C. Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Arthur S. Edison
- Department of Biochemistry and Molecular Biology, High Magnetic Field Laboratory, University of Florida, Gainesville, Florida, United States of America
| | - Hans T. Alborn
- Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, Gainesville, Florida, United States of America
- * E-mail:
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Waller S, Thyagarajan S, Kaplan F, Viljoen A. Dramatic resolution of massive retinal hard exudates after correction of extreme dyslipidaemia. Eye (Lond) 2009; 23:738. [DOI: 10.1038/eye.2008.109] [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: 11/09/2022] Open
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Srinivasan J, Kaplan F, Ajredini R, Zachariah C, Alborn HT, Teal PEA, Malik RU, Edison AS, Sternberg PW, Schroeder FC. A blend of small molecules regulates both mating and development in Caenorhabditis elegans. Nature 2008; 454:1115-8. [PMID: 18650807 DOI: 10.1038/nature07168] [Citation(s) in RCA: 266] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 06/13/2008] [Indexed: 11/09/2022]
Abstract
In many organisms, population-density sensing and sexual attraction rely on small-molecule-based signalling systems. In the nematode Caenorhabditis elegans, population density is monitored through specific glycosides of the dideoxysugar ascarylose (the 'ascarosides') that promote entry into an alternative larval stage, the non-feeding and highly persistent dauer stage. In addition, adult C. elegans males are attracted to hermaphrodites by a previously unidentified small-molecule signal. Here we show, by means of combinatorial activity-guided fractionation of the C. elegans metabolome, that the mating signal consists of a synergistic blend of three dauer-inducing ascarosides, which we call ascr#2, ascr#3 and ascr#4. This blend of ascarosides acts as a potent male attractant at very low concentrations, whereas at the higher concentrations required for dauer formation the compounds no longer attract males and instead deter hermaphrodites. The ascarosides ascr#2 and ascr#3 carry different, but overlapping, information, as ascr#3 is more potent as a male attractant than ascr#2, whereas ascr#2 is slightly more potent than ascr#3 in promoting dauer formation. We demonstrate that ascr#2, ascr#3 and ascr#4 are strongly synergistic, and that two types of neuron, the amphid single-ciliated sensory neuron type K (ASK) and the male-specific cephalic companion neuron (CEM), are required for male attraction by ascr#3. On the basis of these results, male attraction and dauer formation in C. elegans appear as alternative behavioural responses to a common set of signalling molecules. The ascaroside signalling system thus connects reproductive and developmental pathways and represents a unique example of structure- and concentration-dependent differential activity of signalling molecules.
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Affiliation(s)
- Jagan Srinivasan
- Howard Hughes Medical Institute and Biology Division, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California 91125, USA
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Abstract
Plants possess inducible tolerance mechanisms that extend the temperature range for survival during acute temperature stress. The inducible mechanisms of cold acclimation and acquired thermotolerance involve highly complex processes. These include perception and signal transduction of non-optimal temperatures or their physical consequences on cellular components that program extensive modification of the transcriptome, proteome, metabolome and composition and physical structure of the cytoplasm, membranes and cell walls. Therefore, a systems biology approach will be necessary to advance the understanding of plant stress responses and tolerance mechanisms. One promise of systems biology is that it will greatly enhance our understanding of individual and collective functions and thereby provide a more holistic view of plant stress responses. Past studies have found that several metabolites that could functionally contribute to induced stress tolerance have been associated with stress responses. Recent metabolite-profiling studies have refocused attention on these and other potentially important components found in the 'temperature-stress metabolome'. These metabolomic studies have demonstrated that active reconfiguration of the metabolome is regulated in part by changes in gene expression initiated by temperature-stress-activated signaling and stress-related transcription factors. One aspect of metabolism that is consistent across all of the temperature-stress metabolomic studies to date is the prominent role of central carbohydrate metabolism, which seems to be a major feature of the reprogramming of the metabolome during temperature stress. Future metabolomic studies of plant temperature-stress responses should reveal additional metabolic pathways that have important functions in temperature-stress tolerance mechanisms.
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Affiliation(s)
- Charles Guy
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville, FL 32611, USA.
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Edner C, Li J, Albrecht T, Mahlow S, Hejazi M, Hussain H, Kaplan F, Guy C, Smith SM, Steup M, Ritte G. Glucan, water dikinase activity stimulates breakdown of starch granules by plastidial beta-amylases. Plant Physiol 2007; 145:17-28. [PMID: 17631522 PMCID: PMC1976587 DOI: 10.1104/pp.107.104224] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them beta-AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized beta-amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants.
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Affiliation(s)
- Christoph Edner
- Plant Physiology, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany
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Kaplan F, Kopka J, Sung DY, Zhao W, Popp M, Porat R, Guy CL. Transcript and metabolite profiling during cold acclimation of Arabidopsis reveals an intricate relationship of cold-regulated gene expression with modifications in metabolite content. Plant J 2007. [PMID: 17461790 DOI: 10.1111/j.1365-313x.2007.03100] [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: 05/02/2023]
Abstract
Exposure of Arabidopsis to low temperatures results in cold acclimation where freezing tolerance is enhanced. To achieve a wider view of the role of transcriptome to biochemical changes that occur during cold acclimation, analyses of concurrent transcript and metabolite changes during cold acclimation was performed revealing the dynamics of selected gene-metabolite relationships. Exposure to low temperature resulted in broad transcriptional and metabolite responses. Principal component analysis revealed sequentially progressive, global changes in both gene expression and metabolite profiles during cold acclimation. Changes in transcript abundance for many metabolic processes, including protein amino acid biosynthetic pathways and soluble carbohydrates, during cold acclimation were observed. For some metabolic processes, changes in transcript abundance temporally correlated with changes in metabolite levels. For other metabolic processes, changes in transcript levels were not correlated with changes in metabolite levels. The present findings demonstrate that regulatory processes independent of transcript abundance represent a key part of the metabolic adjustments that occur during cold acclimation.
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Affiliation(s)
- Fatma Kaplan
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville, FL 32611, USA
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Kaplan F, Kopka J, Sung DY, Zhao W, Popp M, Porat R, Guy CL. Transcript and metabolite profiling during cold acclimation of Arabidopsis reveals an intricate relationship of cold-regulated gene expression with modifications in metabolite content. Plant J 2007; 50:967-81. [PMID: 17461790 DOI: 10.1111/j.1365-313x.2007.03100.x] [Citation(s) in RCA: 265] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Exposure of Arabidopsis to low temperatures results in cold acclimation where freezing tolerance is enhanced. To achieve a wider view of the role of transcriptome to biochemical changes that occur during cold acclimation, analyses of concurrent transcript and metabolite changes during cold acclimation was performed revealing the dynamics of selected gene-metabolite relationships. Exposure to low temperature resulted in broad transcriptional and metabolite responses. Principal component analysis revealed sequentially progressive, global changes in both gene expression and metabolite profiles during cold acclimation. Changes in transcript abundance for many metabolic processes, including protein amino acid biosynthetic pathways and soluble carbohydrates, during cold acclimation were observed. For some metabolic processes, changes in transcript abundance temporally correlated with changes in metabolite levels. For other metabolic processes, changes in transcript levels were not correlated with changes in metabolite levels. The present findings demonstrate that regulatory processes independent of transcript abundance represent a key part of the metabolic adjustments that occur during cold acclimation.
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Affiliation(s)
- Fatma Kaplan
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville, FL 32611, USA
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Whitesides GM, Kaplan F, Nagarajan K, Roberts JD. NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY: ABNORMAL SPLITTING OF ETHYL GROUPS DUE TO MOLECULAR ASYMMETRY, III. Proc Natl Acad Sci U S A 2006; 48:1112-4. [PMID: 16590966 PMCID: PMC220915 DOI: 10.1073/pnas.48.7.1112] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- G M Whitesides
- GATES AND CRELLIN LABORATORIES OF CHEMISTRY, CALIFORNIA INSTITUTE OF TECHNOLOGY
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Kaplan F, Guy CL. RNA interference of Arabidopsis beta-amylase8 prevents maltose accumulation upon cold shock and increases sensitivity of PSII photochemical efficiency to freezing stress. Plant J 2005; 44:730-43. [PMID: 16297066 DOI: 10.1111/j.1365-313x.2005.02565.x] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
It has been suggested that beta-amylase (BMY) induction during temperature stress in Arabidopsis could lead to starch-dependent maltose accumulation, and that maltose may contribute to protection of the electron transport chain and proteins in the chloroplast stroma during acute stress. A time-course transcript profiling analysis for cold shock at 4 degrees C revealed that BMY8 (At4g17090) was induced specifically in response to cold shock, while major induction was not observed for any of the other eight beta-amylases. A parallel metabolite-profiling analysis revealed a robust transient maltose accumulation during cold shock. BMY8 RNAi lines with lower BMY8 expression exhibited a starch-excess phenotype, and a dramatic decrease in maltose accumulation during a 6-h cold shock at 4 degrees C. The decreased maltose content was also accompanied by decreased glucose, fructose and sucrose content in the BMY8 RNAi plants, consistent with the roles of beta-amylase and maltose in transitory starch metabolism. BMY8 RNAi lines with reduced soluble sugar content exhibited diminished chlorophyll fluorescence as F(v)/F(m) ratio compared with wild type, suggesting that PSII photochemical efficiency was more sensitive to freezing stress. Together, carbohydrate analysis and freezing stress results of BMY8 RNAi lines indicate that increased maltose content, by itself or together through a maltose-dependent increase in other soluble sugars, contributes to the protection of the photosynthetic electron transport chain during freezing stress.
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Affiliation(s)
- Fatma Kaplan
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611-0675, USA
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Abstract
MOTIVATION Visualizing and analysing the potential non-linear structure of a dataset is becoming an important task in molecular biology. This is even more challenging when the data have missing values. RESULTS Here, we propose an inverse model that performs non-linear principal component analysis (NLPCA) from incomplete datasets. Missing values are ignored while optimizing the model, but can be estimated afterwards. Results are shown for both artificial and experimental datasets. In contrast to linear methods, non-linear methods were able to give better missing value estimations for non-linear structured data. APPLICATION We applied this technique to a time course of metabolite data from a cold stress experiment on the model plant Arabidopsis thaliana, and could approximate the mapping function from any time point to the metabolite responses. Thus, the inverse NLPCA provides greatly improved information for better understanding the complex response to cold stress. CONTACT scholz@mpimp-golm.mpg.de.
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Affiliation(s)
- Matthias Scholz
- Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany
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Kaplan F, Kopka J, Haskell DW, Zhao W, Schiller KC, Gatzke N, Sung DY, Guy CL. Exploring the temperature-stress metabolome of Arabidopsis. Plant Physiol 2004. [PMID: 15557093 DOI: 10.1104/pp.104.052142.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Metabolic profiling analyses were performed to determine metabolite temporal dynamics associated with the induction of acquired thermotolerance in response to heat shock and acquired freezing tolerance in response to cold shock. Low-M(r) polar metabolite analyses were performed using gas chromatography-mass spectrometry. Eighty-one identified metabolites and 416 unidentified mass spectral tags, characterized by retention time indices and specific mass fragments, were monitored. Cold shock influenced metabolism far more profoundly than heat shock. The steady-state pool sizes of 143 and 311 metabolites or mass spectral tags were altered in response to heat and cold shock, respectively. Comparison of heat- and cold-shock response patterns revealed that the majority of heat-shock responses were shared with cold-shock responses, a previously unknown relationship. Coordinate increases in the pool sizes of amino acids derived from pyruvate and oxaloacetate, polyamine precursors, and compatible solutes were observed during both heat and cold shock. In addition, many of the metabolites that showed increases in response to both heat and cold shock in this study were previously unlinked with temperature stress. This investigation provides new insight into the mechanisms of plant adaptation to thermal stress at the metabolite level, reveals relationships between heat- and cold-shock responses, and highlights the roles of known signaling molecules and protectants.
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Affiliation(s)
- Fatma Kaplan
- Plant Molecular and Cellular Biology Program, Environmental Horticulture , University of Florida, Gainesville, Florida 32611, USA
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Kaplan F, Kopka J, Haskell DW, Zhao W, Schiller KC, Gatzke N, Sung DY, Guy CL. Exploring the temperature-stress metabolome of Arabidopsis. Plant Physiol 2004; 136:4159-68. [PMID: 15557093 PMCID: PMC535846 DOI: 10.1104/pp.104.052142] [Citation(s) in RCA: 581] [Impact Index Per Article: 29.1] [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] [Revised: 10/05/2004] [Accepted: 10/05/2004] [Indexed: 05/17/2023]
Abstract
Metabolic profiling analyses were performed to determine metabolite temporal dynamics associated with the induction of acquired thermotolerance in response to heat shock and acquired freezing tolerance in response to cold shock. Low-M(r) polar metabolite analyses were performed using gas chromatography-mass spectrometry. Eighty-one identified metabolites and 416 unidentified mass spectral tags, characterized by retention time indices and specific mass fragments, were monitored. Cold shock influenced metabolism far more profoundly than heat shock. The steady-state pool sizes of 143 and 311 metabolites or mass spectral tags were altered in response to heat and cold shock, respectively. Comparison of heat- and cold-shock response patterns revealed that the majority of heat-shock responses were shared with cold-shock responses, a previously unknown relationship. Coordinate increases in the pool sizes of amino acids derived from pyruvate and oxaloacetate, polyamine precursors, and compatible solutes were observed during both heat and cold shock. In addition, many of the metabolites that showed increases in response to both heat and cold shock in this study were previously unlinked with temperature stress. This investigation provides new insight into the mechanisms of plant adaptation to thermal stress at the metabolite level, reveals relationships between heat- and cold-shock responses, and highlights the roles of known signaling molecules and protectants.
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Affiliation(s)
- Fatma Kaplan
- Plant Molecular and Cellular Biology Program, Environmental Horticulture , University of Florida, Gainesville, Florida 32611, USA
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Kaplan F, Guy CL. beta-Amylase induction and the protective role of maltose during temperature shock. Plant Physiol 2004; 135:1674-84. [PMID: 15247404 PMCID: PMC519081 DOI: 10.1104/pp.104.040808] [Citation(s) in RCA: 256] [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] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 03/25/2004] [Accepted: 03/25/2004] [Indexed: 05/17/2023]
Abstract
A number of studies have demonstrated beta-amylase induction in response to abiotic stress. In the present work, a temperature response profile in 5 degrees C increments from 45 degrees C to 0 degrees C showed that induction at temperature extremes was specific for two members of the gene family (BMY7 and BMY8). Both members encode proteins that possess apparent transit peptides for chloroplast stromal localization. However, induction was not observed for other key starch degrading enzymes demonstrating a rather specific response to temperature stress for BMY7 and BMY8. Time course experiments for heat shock at 40 degrees C and cold shock at 5 degrees C showed that beta-amylase induction correlated with maltose accumulation. Maltose has the ability, as demonstrated by in vitro assays, to protect proteins, membranes, and the photosynthetic electron transport chain at physiologically relevant concentrations. Therefore, beta-amylase induction and the resultant maltose accumulation may function as a compatible-solute stabilizing factor in the chloroplast stroma in response to acute temperature stress.
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Affiliation(s)
- Fatma Kaplan
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611-0675, USA
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Abstract
Acquired tolerance to temperature stresses is a major protective mechanism. Recent advances have revealed key components of stress signal transduction pathways that trigger enhanced tolerance, and several determinants of acquired tolerance have been identified. Although high and low temperature stresses impose different metabolic and physical challenges, acquired tolerance appears to involve general as well as stress-specific components. Transcriptome studies and other genomic-scale approaches have accelerated the pace of gene discovery, and will be invaluable in efforts to integrate all the different protective and repair mechanisms that function in concert to confer acquired tolerance.
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Affiliation(s)
- Dong-Yul Sung
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville 32611-0670, USA
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Sung DY, Kaplan F, Lee KJ, Guy CL. Acquired tolerance to temperature extremes. Trends Plant Sci 2003. [PMID: 12711230 DOI: 10.1016/s1360-1385(.03)00047-5] [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: 05/10/2023]
Abstract
Acquired tolerance to temperature stresses is a major protective mechanism. Recent advances have revealed key components of stress signal transduction pathways that trigger enhanced tolerance, and several determinants of acquired tolerance have been identified. Although high and low temperature stresses impose different metabolic and physical challenges, acquired tolerance appears to involve general as well as stress-specific components. Transcriptome studies and other genomic-scale approaches have accelerated the pace of gene discovery, and will be invaluable in efforts to integrate all the different protective and repair mechanisms that function in concert to confer acquired tolerance.
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Affiliation(s)
- Dong-Yul Sung
- Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville 32611-0670, USA
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Roje S, Chan SY, Kaplan F, Raymond RK, Horne DW, Appling DR, Hanson AD. Metabolic engineering in yeast demonstrates thatS-adenosylmethionine controls flux through the methylenetetrahydrofolate reductase reaction in vivo. J Biol Chem 2002. [DOI: 10.1016/s0021-9258(18)36677-8] [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: 10/22/2022] Open
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Roje S, Chan SY, Kaplan F, Raymond RK, Horne DW, Appling DR, Hanson AD. Metabolic engineering in yeast demonstrates that S-adenosylmethionine controls flux through the methylenetetrahydrofolate reductase reaction in vivo. J Biol Chem 2002; 277:4056-61. [PMID: 11729203 DOI: 10.1074/jbc.m110651200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [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: 11/06/2022] Open
Abstract
One-carbon flux into methionine and S-adenosylmethionine (AdoMet) is thought to be controlled at the methylenetetrahydrofolate reductase (MTHFR) step. Mammalian MTHFRs are inhibited by AdoMet in vitro, and it has been proposed that methyl group biogenesis is regulated in vivo by this feedback loop. In this work, we used metabolic engineering in the yeast Saccharomyces cerevisiae to test this hypothesis. Like mammalian MTHFRs, the yeast MTHFR encoded by the MET13 gene is NADPH-dependent and is inhibited by AdoMet in vitro. This contrasts with plant MTHFRs, which are NADH-dependent and AdoMet-insensitive. To manipulate flux through the MTHFR reaction in yeast, the chromosomal copy of MET13 was replaced by an Arabidopsis MTHFR cDNA (AtMTHFR-1) or by a chimeric sequence (Chimera-1) comprising the yeast N-terminal domain and the AtMTHFR-1 C-terminal domain. Chimera-1 used both NADH and NADPH and was insensitive to AdoMet, supporting the view that the C-terminal domain is responsible for AdoMet inhibition. Engineered yeast expressing Chimera-1 accumulated 140-fold more AdoMet and 7-fold more methionine than did the wild-type and grew normally. Yeast expressing AtMTHFR-1 accumulated 8-fold more AdoMet. This is the first in vivo evidence that the AdoMet sensitivity and pyridine nucleotide preference of MTHFR control methylneogenesis. (13)C labeling data indicated that glycine cleavage becomes a more prominent source of one-carbon units when Chimera-1 is expressed. Possibly related to this shift in one-carbon fluxes, total folate levels are doubled in yeast cells expressing Chimera-1.
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Affiliation(s)
- Sanja Roje
- Horticultural Sciences Department, University of Florida, Gainesville, Florida 32611, USA
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Abstract
It is clear that the PPAR receptors are exciting targets for therapeutic compounds likely to impact on insulin sensitivity, lipid and glucose homeostasis and vascular disease. The PPARgamma receptor agonists rosiglitazone and pioglitazone are very useful additions to the treatment options for type 2 diabetes. Currently they have limited licences, particularly in Europe, and hopefully as further clinical trial data becomes available these will be extended. Clinical outcome studies are important to ensure that the surrogate effects on glucose and other parameters translate into improved outcomes. There is exciting potential for these agents with the possibility of a combination of effects not only on glucose and lipid homeostasis but also on coagulation and thrombosis, blood pressure and microalbuminuria, which are likely to impact on vascular disease. If the current lack of evidence of serious hepatic toxicity persists they have an advantage over metformin in terms of tolerability and can be used in patients with impaired renal function. In addition to potential effects on diabetic outcome it will be of tremendous interest to determine whether these compounds, which improve insulin sensitivity and beta-cell function, will impact on the natural history of the disease. From what is known of the PPAR receptor systems it is likely that compounds acting as agonists or partial agonists for these receptors will have differing effects and it is possible to envisage the tailoring of compounds to enhance wanted effects and diminish unwanted effects, particularly fluid retention and weight gain. The future certainly looks exciting in this area.
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Affiliation(s)
- F Kaplan
- Department of Medicine, Royal Free and University College Medical School, The Middlesex Hospital, London, UK
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Abstract
The GM2 gangliosidoses are a group of recessive disorders characterized by accumulation of GM2 ganglioside in neuronal cells. The genes responsible for these disorders are HEXA (Tay-Sachs disease and variants), HEXB (Sandhoff disease and variants), and GM2A (AB variant of GM2 gangliosidosis). We report the establishment of three relational locus-specific databases recording allelic variation at the HEXA, HEXB, and GM2A genes and accessed at the GM2 gangliosidoses home page (http://data.mch.mcgill.ca/gm2-gangliosidoses). Submission forms are available for the addition of new mutations to the databases. The databases are available online for users to search and retrieve information about specific alleles by a number of fields describing mutations, phenotypes, or author(s).
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Affiliation(s)
- P Cordeiro
- Department of Biology, McGill University, Montreal, Quebec, Canada
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Affiliation(s)
- F Kaplan
- McGill University-Montreal Children's Hospital Research Institute, McGill University, Montreal, Quebec, H3Z 2Z3, Canada.
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Zhang C, Sweezey NB, Gagnon S, Muskat B, Koehler D, Post M, Kaplan F. A novel karyopherin-beta homolog is developmentally and hormonally regulated in fetal lung. Am J Respir Cell Mol Biol 2000; 22:451-9. [PMID: 10745026 DOI: 10.1165/ajrcmb.22.4.3929] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [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: 12/28/2022] Open
Abstract
To investigate molecular mechanisms of lung organogenesis, we used representational difference analysis to search for glucocorticoid-inducible genes in developing lung in a fetal rat model. Messenger RNA prepared from fetal and adult rat lung was used to prepare "representative amplicons." Adult-lung complementary DNA (cDNA) amplicons were used as "driver" in successive rounds of subtractive hybridization/amplification to isolate target fetal lung-specific cDNAs. A single clone, which was conserved and had near-perfect homology to eight human/rodent expressed sequence tags, was used as template for 5' and 3' rapid amplification of cDNA ends and SPICE (system for polymerase chain reaction amplification of cDNA ends) reactions to obtain the 3.6-kb cDNA, LGL2 (Genbank, AF 110195) encoding a deduced polypeptide (lgl2) of 963 amino acids. Northern analysis confirmed that LGL2 is differentially expressed in fetal lung (maximal during the pseudoglandular stage, gestational Days 14 to 16), induced by glucocorticoid, and enriched in epithelium relative to the mesenchyme. LGL2 was also detected in human fetal lung at gestational Week 16 as well as in human and rat fetal brain, heart, intestine, and kidney. We mapped LGL2 to chromosome 1p33-34.2. Comparison with sequences in the genome database identified lgl2 as a member of the karyopherin-beta family of nuclear import proteins, with greatest homology to transportin SR. Maximal expression of LGL2 in the pseudoglandular stage of development is coordinate with that of key transcription factors that regulate prominent signal transduction pathways in fetal lung organogenesis. We propose a role for lgl2 in nuclear import of transcription factors that regulate signal transduction during fetal lung development.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Cells, Cultured
- Chromosome Mapping
- Chromosomes, Human, Pair 1/genetics
- DNA, Complementary/genetics
- Escherichia coli
- Expressed Sequence Tags
- Fetal Proteins/biosynthesis
- Fetal Proteins/chemistry
- Fetal Proteins/genetics
- Fetal Proteins/isolation & purification
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Gene Expression Regulation, Developmental/drug effects
- Gestational Age
- Humans
- Hydrocortisone/pharmacology
- In Situ Hybridization, Fluorescence
- Lung/embryology
- Lung/metabolism
- Models, Molecular
- Molecular Sequence Data
- Multigene Family
- Nuclear Proteins/biosynthesis
- Nuclear Proteins/chemistry
- Nuclear Proteins/genetics
- Nuclear Proteins/isolation & purification
- Protein Conformation
- RNA, Messenger/genetics
- RNA, Messenger/isolation & purification
- Rats
- Rats, Wistar
- Recombinant Fusion Proteins/biosynthesis
- Sequence Alignment
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Signal Transduction
- Species Specificity
- Subtraction Technique
- beta Karyopherins
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Affiliation(s)
- C Zhang
- Departments of Human Genetics and Pediatrics, and Montreal Children's Hospital Research Institute, McGill University, Montreal, Quebec, Canada
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50
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Abstract
Tay-Sachs disease (TSD) is an autosomal-recessive, progressive, and ultimately fatal neurodegenerative disorder. Within the last 30 years, the discovery of the enzymatic basis of the disease, namely deficiency of the enzyme hexosaminidase A, made possible both enzymatic diagnosis of TSD and heterozygote identification. In the last decade, the cloning of the HEXA gene and the identification of more than 80 associated TSD-causing mutations has permitted molecular diagnosis in many instances. TSD was the first genetic condition for which community-based screening for carrier detection was implemented. As such, the TSD experience can be viewed as a prototypic effort for public education, carrier testing, and reproductive counseling for avoiding fatal childhood disease. More importantly, the outcome of TSD screening over the last 28 years offers convincing evidence that such an effort can dramatically reduce incidence of the disease.
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Affiliation(s)
- F Kaplan
- McGill University-Montreal Children's Hospital Research Institute, Quebec, Canada.
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