62 results on '"H, Kumagai"'
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2. Photosynthesis and growth of Ulva ohnoi and Ulva pertusa (Ulvophyceae) under high light and high temperature conditions, and implications for green tide in Japan
- Author
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Masanori Tamaoki, Tohru Yabe, Nobuyoshi Nakajima, Naoki H. Kumagai, Masaya Nakamura, Yuichi Ishii, and Koichi Arita
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biology ,Ulvophyceae ,Ulva ohnoi ,Relative growth rate ,Botany ,Plant Science ,Ulva pertusa ,Aquatic Science ,biology.organism_classification ,Photosynthesis ,Agricultural and Biological Sciences (miscellaneous) ,Algal bloom - Published
- 2019
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3. Comprehensive management program of crown-of-thorns starfish outbreaks in Okinawa
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Koichi Kinjo, Eiji Yamakawa, Ryota Nakajima, Naoki H. Kumagai, Shuichi Yamamoto, Ken Okaji, Makoto Kitamura, Nina Yasuda, Nobuyuki Nakatomi, Kei Ogasawara, and Masako Nakamura
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Fishery ,Thesaurus (information retrieval) ,Geography ,Crown-of-thorns starfish ,biology ,Outbreak ,biology.organism_classification - Published
- 2019
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4. Effects of temperature and red tides on sea urchin abundance and species richness over 45 years in southern Japan
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Shun-Ichi Ohgaki, Yoichi Yusa, Yoko Wada, Tetsuya Kato, Hidetomo Tanase, Naoki H. Kumagai, Tomoyuki Nakano, So Ishida, and Naomasa Kobayashi
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0106 biological sciences ,Echinometra ,education.field_of_study ,Ecology ,biology ,Population ,General Decision Sciences ,Intertidal zone ,010501 environmental sciences ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Abundance (ecology) ,biology.animal ,Species richness ,Quadrat ,education ,Sea urchin ,Relative species abundance ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
Continuous long-term monitoring is important for detecting ecological changes and understanding their causes, including anthropogenic impacts such as climate changes and eutrophication. Nonetheless, such long-term population studies have been rare, especially for sea urchins, which can affect community dynamics owing to their extensive herbivory and large population fluctuations. Here we present a long-term (from 1963 to 2014) dynamics of sea urchins in a fixed quadrat on a lower intertidal rocky flat in Hatakejima Island, southern Japan. We also conducted a complementary survey over the entire island approximately every five years from 1975 to 2013, and a 41-year assay for developmental abnormality of the sea urchin Heliocidaris crassispina using water adjacent to the island. The abundance of three commonest species in this area (H. crassispina, Echinostrephus molaris, and Echinometra spp.) and the richness of urchin species showed large variations, with high numbers in the 1960s and 1970s, followed by an abrupt decline in the late 1970s or early 1980s, and a gradual recovery subsequently. The species abundance and richness in the entire island survey showed good correlations with those in the quadrat census. Statistical analyses indicated that increasing water temperature and red tides were the major factors influencing the dynamics of abundance and species richness. Our studies reveal that anthropogenic environmental changes influence the long-term dynamics in abundance and richness of sea urchins.
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- 2019
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5. Induction of bud breaking and flowering during paradormancy in apple trees
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R. Kagi, H. Kumagai, Y. Inoda, S. Komori, M. Murakami, S. Kogawa, and M. Watanabe
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chemistry.chemical_compound ,Horticulture ,chemistry ,Shoot ,Fluridone ,Biology - Published
- 2018
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6. Intraspecific variations in responses to ocean acidification in two branching coral species
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Hikaru Uechi, Atsushi Suzuki, Akira Iguchi, Ayami Sekizawa, Naoki H. Kumagai, Takashi Nakamura, Kazuhiko Sakai, and Yukihiro Nojiri
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0106 biological sciences ,Oceans and Seas ,Coral ,Population ,Aquatic Science ,Oceanography ,010603 evolutionary biology ,01 natural sciences ,Montipora digitata ,Intraspecific competition ,Animals ,Seawater ,Photosynthesis ,education ,education.field_of_study ,Phenotypic plasticity ,biology ,Coral Reefs ,Ecology ,010604 marine biology & hydrobiology ,fungi ,Ocean acidification ,Interspecific competition ,Carbon Dioxide ,Hydrogen-Ion Concentration ,Anthozoa ,biology.organism_classification ,Adaptation, Physiological ,Pollution ,Porites cylindrica - Abstract
Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO2, respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration.
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- 2017
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7. Distribution gradient of fucoid algae (Sargassaceae, Phaeophyta) along the coastline of Okinawa Island, southern Japan: Relationship to environmental factors
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Haruka Suzuki, Hiroya Yamano, Hiroya Abe, and Naoki H. Kumagai
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,Ecology ,biology ,010604 marine biology & hydrobiology ,Hermatypic coral ,Subtropics ,Aquatic Science ,biology.organism_classification ,01 natural sciences ,Ecosystem services ,Oceanography ,Canonical correspondence analysis ,Threatened species ,Environmental science ,Sargassaceae ,Animal Science and Zoology ,Ecosystem ,Water quality ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences - Abstract
Coastal ecosystems can provide significantly high ecosystem services via various processes. Tropical and/or subtropical coastal ecosystems are constituted by reef-building corals, macroalgae, and seagrasses. The study was conducted in a subtropical coastal area, Okinawa Island, Japan, where macroalgal beds are distributed. Since few studies have focused on the macroalgal community compared to corals in the study area, the relationship between macroalgal (especially Sargassaceae species) distribution and environmental factors were evaluated. Environmental parameters used in the analysis were obtained by field observation, geographic analysis, satellite observation of water quality, and numerical simulation of wave height. Sampling was conducted mainly between May and August in 2018 and 2019, and 31 sampling stations were established along the coastline of Okinawa Island. Though hermatypic corals occurred in most of the stations, the distribution of Sargassaceae was spatially skewed from the southern and central part of the east coast. Canonical correspondence analysis (CCA) was applied to obtained environmental variables and presence–absence data on macroalgae (Sargassaceae), corals, and seagrasses. CCA results indicated that the geographical setting (openness) and wave exposure in winter are the primary factors determining the macroalgal distribution, whereas nutrient (dissolved inorganic nitrogen, phosphorous, and silicon) concentrations at each sampling occasion were not significant factors. Since coastal ecosystems are threatened by both local and global impacts, elucidation of the major mechanism limiting Sargassaceae distribution is significant for coastal ecosystem management, here we use Okinawa Island as an example.
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- 2020
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8. Author Correction: Declaration of local chemical eradication of the Argentine ant: Bayesian estimation with a multinomial-mixture model
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Naoki H. Kumagai, Yoshiko Sakamoto, and Koichi Goka
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0106 biological sciences ,Insecticides ,Computer science ,Declaration ,lcsh:Medicine ,010603 evolutionary biology ,01 natural sciences ,Insect Control ,Argentine ant ,Econometrics ,Animals ,lcsh:Science ,Author Correction ,Bayes estimator ,Multidisciplinary ,Models, Statistical ,biology ,Ants ,lcsh:R ,Bayes Theorem ,biology.organism_classification ,Mixture model ,010602 entomology ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,lcsh:Q ,Multinomial distribution ,Introduced Species ,Entomology - Abstract
Determining the success of eradication of an invasive species requires a way to decide when its risk of reoccurrence has become acceptably low. In Japan, the area populated by the Argentine ant, Linepithema humile (Mayr), is expanding, and eradication via chemical treatment is ongoing at various locations. One such program in Tokyo was apparently successful, because the ant population decreased to undetectable levels within a short time. However, construction of a population model for management purposes was difficult because the probability of detecting ants decreases rapidly as the population collapses. To predict the time when the ant was eradicated, we developed a multinomial-mixture model for chemical eradication based on monthly trapping data and the history of pesticide applications. We decided when to declare that eradication had been successful by considering both 'eradication' times, which we associated with eradication probabilities of 95% and 99%, and an optimal stopping time based on a 'minimum expected economic cost' that considered the possibility that surveys were stopped too soon. By applying these criteria, we retroactively declared that Argentine ants had been eradicated 38-42 months after the start of treatments (16-17 months after the last sighting).
- Published
- 2018
9. Spatial variability in recruitment of acroporid corals and predatory starfish along the Onna coast, Okinawa, Japan
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Masako Nakamura, Naoki H. Kumagai, Ken Okaji, Kei Ogasawara, Satoshi Mitarai, and Kazuhiko Sakai
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geography ,education.field_of_study ,geography.geographical_feature_category ,Ecology ,Population ,Acanthaster ,Metapopulation ,Coral reef ,Aquatic Science ,Biology ,biology.organism_classification ,Predation ,Oceanography ,Spatial ecology ,Spatial variability ,Quadrat ,education ,Ecology, Evolution, Behavior and Systematics - Abstract
We compared spatial variability in re- cruitment patterns between acroporid corals and the predatory crown-of-thorns starfish Acanthaster planci along the Onna village coast of Okinawa Island, Japan. Our objective was to understand population dynamics of both predator and prey. To quantify re- cruitment, we established artificial recruitment plates for acroporid corals and conducted quadrat surveys for juvenile A. planci at 7 sites. We also examined dis- tributional patterns of adult populations of both spe- cies and observed surface currents during larval dis- persal periods using GPS-equipped surface drifters. Acroporid recruits typically arrived in greater num- bers at more northern sites. Despite high variability, A. planci recruits displayed similar spatial patterns. Drifter trajectories suggest that these spatial recruit- ment patterns are probably driven by near-shore currents in the summer. Moreover, current data imply a complicated metapopulation relationship in this region, especially for A. planci, new recruits of which may mainly originate outside of the Onna area. Meta - population dynamics within the study area and among surrounding regions must be explained by the com- plex surface current circulation, because simpler ex- planations involving only the Kuroshio Current do not adequately describe the relationship between these populations.
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- 2015
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10. Projecting the impacts of rising seawater temperatures on the distribution of seaweeds around Japan under multiple climate change scenarios
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Hiroya Yamano, Masahiko Fujii, Shintaro Takao, Naoki H. Kumagai, and Yasuhiro Yamanaka
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Coupled model intercomparison project ,Ecology ,Global warming ,Biodiversity ,Climate change ,future projection ,Representative Concentration Pathways ,Biology ,global warming ,herbivores ,Sea surface temperature ,Oceanography ,climate change ,seaweed ,Grazing ,Temperate climate ,Ecology, Evolution, Behavior and Systematics ,Barren ground ,Nature and Landscape Conservation ,Original Research - Abstract
Seaweed beds play a key role in providing essential habitats and energy to coastal areas, with enhancements in productivity and biodiversity and benefits to human societies. However, the spatial extent of seaweed beds around Japan has decreased due to coastal reclamation, water quality changes, rising water temperatures, and heavy grazing by herbivores. Using monthly mean sea surface temperature (SST) data from 1960 to 2099 and SST-based indices, we quantitatively evaluated the effects of warming seawater on the spatial extent of suitable versus unsuitable habitats for temperate seaweed Ecklonia cava, which is predominantly found in southern Japanese waters. SST data were generated using the most recent multiple climate projection models and emission scenarios (the Representative Concentration Pathways or RCPs) used in the Coupled Model Intercomparison Project phase 5 (CMIP5). In addition, grazing by Siganus fuscescens, an herbivorous fish, was evaluated under the four RCP simulations. Our results suggest that continued warming may drive a poleward shift in the distribution of E. cava, with large differences depending on the climate scenario. For the lowest emission scenario (RCP2.6), most existing E. cava populations would not be impacted by seawater warming directly but would be adversely affected by intensified year-round grazing. For the highest emission scenario (RCP8.5), previously suitable habitats throughout coastal Japan would become untenable for E. cava by the 2090s, due to both high-temperature stress and intensified grazing. Our projections highlight the importance of not only mitigating regional warming due to climate change, but also protecting E. cava from herbivores to conserve suitable habitats on the Japanese coast.
- Published
- 2015
11. Identification of important marine areas around the Japanese Archipelago: Establishment of a protocol for evaluating a broad area using ecologically and biologically significant areas selection criteria
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Shigeho Kakehi, Hiroyuki Yamamoto, Haruyuki Morimoto, Katsuhiko Tanaka, Ryota Nakajima, Yuichi Hirota, Yumiko Yara, Hiroomi Miyamoto, Kazushi Miyashita, Katsunori Fujikura, Norishige Yotsukura, Kazuaki Tadokoro, Shingo Sakamoto, Takehisa Yamakita, Yoshihisa Shirayama, Tadafumi Ichikawa, Kou Nishiuchi, Masayoshi Sano, Hiromi Watanabe, Shuhei Nishida, Naoki H. Kumagai, Teruhisa Komatsu, Satoshi Kitajima, Hiroya Sugisaki, Kiyotaka Hidaka, Takahiko Kameda, Yoshie Jintsu-Uchifune, Kazuhiro Kogure, Masahiro Nakaoka, Kenji Sudo, Hiroya Yamano, and Kentaro Watanabe
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Economics and Econometrics ,geography ,geography.geographical_feature_category ,biology ,business.industry ,Environmental resource management ,Biodiversity ,Coral reef ,Management, Monitoring, Policy and Law ,Aquatic Science ,biology.organism_classification ,Kelp forest ,Fishery ,Seagrass ,Environmental Science(all) ,Archipelago ,Ecosystem management ,Marine ecosystem ,business ,Strategic environmental assessment ,Law ,General Environmental Science - Abstract
After the adoption of the Aichi Target, data accumulation and evaluation regarding biodiversity have progressed rapidly. The use of ecologically and biologically significant areas (EBSAs) criteria to evaluate important areas enables the identification of effective and prioritized areas for ecosystem management. This includes strategic environmental assessment and discussions aimed at establishing protected marine areas based on scientific data. This paper reviews previous and current ideas as well as the methods used, for the identification of EBSAs. In particular, the following issues are addressed: problems associated with different types of marine ecosystems in the Japanese Archipelago, such as seagrass and seaweed beds, coral reefs, offshore pelagic plankton, and deep-sea benthic ecosystems; and problems associated with the integration of multiple criteria that are not totally exclusive. Several candidate variables accounting for each of the 7 criteria used to identify ecologically important areas are presented. Data availability is the most important criterion that allowed for the comprehensive evaluation of different types of ecosystems in the same localities. In particular, for coastal ecosystems such as seagrass, seaweed beds, and coral reefs, it is possible to carry out broad spatial comparisons using variables representing most of these 7 criteria. Regarding methods for the quantitative evaluation of each criterion and their integration, application of these methods to kelp forest ecosystems in Hokkaido, Northern Japan is presented as a case study.
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- 2015
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12. Declaration of local chemical eradication of the Argentine ant: Bayesian estimation with a multinomial-mixture model
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Naoki H. Kumagai, Koichi Goka, and Yoshiko Sakamoto
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0106 biological sciences ,Science ,Population ,Declaration ,macromolecular substances ,010603 evolutionary biology ,01 natural sciences ,Article ,Bayes' theorem ,Economic cost ,Argentine ant ,education ,education.field_of_study ,Multidisciplinary ,biology ,Ecology ,biology.organism_classification ,Mixture model ,010602 entomology ,Geography ,Population model ,Medicine ,Linepithema ,Demography - Abstract
Determining the success of eradication of an invasive species requires a way to decide when its risk of reoccurrence has become acceptably low. In Japan, the area populated by the Argentine ant, Linepithema humile (Mayr), is expanding, and eradication via chemical treatment is ongoing at various locations. One such program in Tokyo was apparently successful, because the ant population decreased to undetectable levels within a short time. However, construction of a population model for management purposes was difficult because the probability of detecting ants decreases rapidly as the population collapses. To predict the time when the ant was eradicated, we developed a multinomial-mixture model for chemical eradication based on monthly trapping data and the history of pesticide applications. We decided when to declare that eradication had been successful by considering both ‘eradication’ times, which we associated with eradication probabilities of 95% and 99%, and an optimal stopping time based on a ‘minimum expected economic cost’ that considered the possibility that surveys were stopped too soon. By applying these criteria, we retroactively declared that Argentine ants had been eradicated 38–42 months after the start of treatments (16–17 months after the last sighting).
- Published
- 2017
- Full Text
- View/download PDF
13. Negative effects of ocean acidification on two crustose coralline species using genetically homogeneous samples
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Kazuhiko Sakai, Naoki H. Kumagai, Yukihiro Nojiri, Atsushi Suzuki, Mana Hikami, and Aki Kato
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Aquatic Science ,Oceanography ,Calcification, Physiologic ,Algae ,Botany ,medicine ,Animals ,Seawater ,geography ,Pacific Ocean ,geography.geographical_feature_category ,biology ,Coral Reefs ,fungi ,Coralline algae ,Corallinaceae ,Ocean acidification ,General Medicine ,Coral reef ,Carbon Dioxide ,Hydrogen-Ion Concentration ,medicine.disease ,biology.organism_classification ,Pollution ,Thallus ,Rhodophyta ,Microscopy, Electron, Scanning ,Crustose ,Calcification - Abstract
We evaluated acidification effects on two crustose coralline algal species common to Pacific coral reefs, Lithophyllum kotschyanum and Hydrolithon samoense. We used genetically homogeneous samples of both species to eliminate misidentification of species. The growth rates and percent calcification of the walls of the epithallial cells (thallus surface cells) of both species decreased with increasing pCO2. However, elevated pCO2 more strongly inhibited the growth of L. kotschyanum versus H. samoense. The trend of decreasing percent calcification of the cell wall did not differ between these species, although intercellular calcification of the epithallial cells in L. kotschyanum was apparently reduced at elevated pCO2, a result that might indicate that there are differences in the solubility or density of the calcite skeletons of these two species. These results can provide knowledge fundamental to future studies of the physiological and genetic mechanisms that underlie the response of crustose coralline algae to environmental stresses.
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- 2014
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14. Maternal inheritance of F1 hybrid morphology and colony shape in the coral genus Acropora
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Naoko Isomura, Masaya Morita, Hironobu Fukami, Naoki H. Kumagai, and Kenji Iwao
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0106 biological sciences ,Non-Mendelian inheritance ,Evolution ,lcsh:Medicine ,Scleractinia ,Zoology ,Marine Biology ,010603 evolutionary biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Genus ,Acropora ,Clade ,Hybrid ,Ecology ,biology ,Phylogenetic tree ,010604 marine biology & hydrobiology ,General Neuroscience ,lcsh:R ,Biodiversity ,Intermediate morphology ,General Medicine ,biology.organism_classification ,Evolutionary Studies ,Morphological analysis ,Coral ,General Agricultural and Biological Sciences - Abstract
Background The coral genus Acropora contains more than 150 species with very high morphological diversity. This high diversity may have been caused by repeated hybridization via mass spawning. However, we have little information whether hybrids are formed in these corals. Identifying morphological differences between hybrids and their parental species would provide an opportunity to find wild hybrids in the field and to understand how colony shapes of Acropora have become highly diversified throughout evolutionary history. In the two morphologically distinctive coral species Acropora florida and A. intermedia in the Indo-Pacific, their gametes show high rates of bi-directional intercrossing in vitro, and thus these two species are ideal species to investigate the morphological traits of the hybrids. Methods We examined morphological characters of F1 hybrids from A. florida to A. intermedia, which were produced from in vitro crossing experiments. To compare morphological differences, we grew juveniles and mature colonies of reciprocal F1 hybrids (FLOint: A. florida eggs × A. intermedia sperm, and INTflo: A. intermedia eggs × A. florida sperm) and of the parental species (purebreds of A. intermedia and A. florida). We analyzed skeletal morphology such as colony size, branch length, and branching number, and compared them with those of a putative F1 hybrid between A. florida and A. intermedia found in the field. We also confirmed the molecular phylogenetic position of F1 hybrids, parental species, and a putative F1 hybrid using the mitochondrial non-coding region. Results Our morphological analysis revealed that branching number of the F1 hybrids was intermediate relative to the parental species. Moreover, the FLOint hybrids were morphologically more closely related to the maternal species A. florida, and the INTflo hybrids were to A. intermedia. Molecular data showed that A. florida and A. intermedia were clearly divided into two clades, and that F1 hybrids grouped in the clade based on their maternal parent. A very similar pattern to the INTflo hybrids was obtained for the putative F1 hybrid in nature. Discussion Our results revealed that F1 hybrids between two Indo-Pacific species A. florida and A. intermedia had intermediate morphology relative to their parent species but reflected the maternal parent more. Similarity to maternal species in hybrids is opposite to the Caribbean Acropora species that had more paternal morphological characters in hybrids. These results further suggest that some genetic factor in eggs is likely to affect determination of colony shape in the Indo-Pacific. At present, we have considered colonies with intermediate morphs between different species to be intra-specific morphological variation, but they may be real F1 hybrids. Indeed, a putative F1 hybrid represented similar morphological and molecular features to the F1 hybrids, and thus it is plausible to be attributed as a “real” F1 hybrid in nature.
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- 2019
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15. Identification of small molecules that promote human embryonic stem cell self-renewal
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H. Kumagai, Motonari Uesugi, Eihachiro Kawase, Hirofumi Suemori, and Norio Nakatsuji
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Pluripotent Stem Cells ,Green Fluorescent Proteins ,Basic fibroblast growth factor ,Cell Culture Techniques ,Biophysics ,Mice, SCID ,Germ layer ,Biology ,Self renewal ,Promethazine ,Biochemistry ,Regenerative medicine ,Cell Line ,Small Molecule Libraries ,Mice ,chemistry.chemical_compound ,Phenothiazines ,Methotrimeprazine ,Animals ,Humans ,Organic Chemicals ,Induced pluripotent stem cell ,Molecular Biology ,Embryonic Stem Cells ,reproductive and urinary physiology ,Cell Proliferation ,Molecular Structure ,Cell Differentiation ,Trimipramine ,Cell Biology ,Trimeprazine ,Flow Cytometry ,equipment and supplies ,Immunohistochemistry ,Small molecule ,Embryonic stem cell ,Cell biology ,chemistry ,High-content screening ,embryonic structures ,biological phenomena, cell phenomena, and immunity ,Octamer Transcription Factor-3 - Abstract
Human embryonic stem cells (hESCs) and induced pluripotent cells have the potential to provide an unlimited source of tissues for regenerative medicine. For this purpose, development of defined/xeno-free culture systems under feeder-free conditions is essential for the expansion of hESCs. Most defined/xeno-free media for the culture of hESCs contain basic fibroblast growth factor (bFGF). Therefore, bFGF is thought to have an almost essential role for the expansion of hESCs in an undifferentiated state. Here, we report identification of small molecules, some of which were neurotransmitter antagonists (trimipramine and ethopropazine), which promote long-term hESC self-renewal without bFGF in the medium. The hESCs maintained high expression levels of pluripotency markers, had a normal karyotype after 20 passages, and could differentiate into all three germ layers.
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- 2013
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16. Importance of seagrass vegetation for habitat partitioning between closely related species, mobile macrofauna Neomysis (Misidacea)
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Katsumasa Yamada and Naoki H. Kumagai
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Neomysis ,Seagrass ,biology ,Habitat ,Ecology ,Range (biology) ,Abundance (ecology) ,Epiphyte ,Aquatic Science ,biology.organism_classification ,Intraspecific competition ,Invertebrate - Abstract
Seagrass meadows provide both habitats and a range of food sources for macrofaunal communities. These functions facilitate the coexistence of less mobile invertebrates (in comparison with mysids, such as amphipods) that are associated with seagrass leaves, and may also enhance the coexistence of highly mobile invertebrates such as mysid. We investigated the function of seagrass in supporting the coexistence of two mysid species, Neomysis awatschensis and N. mirabilis. These taxa are dominant in seagrass ecosystems of temperate coastal areas. We compared patterns of habitat use between the two species at mesoscales (among seagrass patches) and microscales (among seagrass leaves) by performing field surveys and laboratory experiments. The field survey results showed positive correlations in the abundance of the two mysid species, indicating that both species select similar habitats at the mesoscale level. In the laboratory experiments, the pattern of microhabitat selection (fundamental habitat) was similar for both species, even at increased densities and with the presence of an immobile habitat-competitor (the gastropod Barleeia angustata) on the leaves. However, this pattern changed significantly when a food source (epiphytic microalgae) was present on the leaves. This result indicates that (i) inter- and intraspecific interference competition does not affect microhabitat selection in these two mysids and (ii) both Neomysis species use similar habitats at the feeding stage. Although these two closely related mysids species may have similar requirements for microhabitat and food, the evidence that they did not act as competitors is attributable to unrestricted microhabitat and food (e.g., epiphytic algae) in the presence of seagrass vegetation.
- Published
- 2011
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17. Characterization of Prolyl Oligopeptidase Genes Differentially Expressed Between Two Cultivars of Coffea arabica L
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Beth Irikura, Henrik Albert, Chifumi Nagai, Ratnesh Singh, Robert E. Paull, Monto H. Kumagai, Paul H. Moore, and Ming-Li Wang
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Genetics ,biology ,Coffea arabica ,Wild type ,food and beverages ,Oligopeptidase ,Promoter ,Plant Science ,biology.organism_classification ,Transcription (biology) ,Arabidopsis ,Ectopic expression ,Gene - Abstract
Two closely related, Coffea arabica cultivars Tall Mokka and Typica, yield coffee with excellent flavor, but they differ distinctively in the size of aerial organs including the fruit and in the degree of branching. Using potato cross-species microarray hybridization, we identified prolyl oligopeptidase (CaPOP) gene(s) as differentially expressed between the shoot tips of ‘Tall Mokka’ and ‘Typica’. Isolation and sequencing of these POP genes identified three paralogs, CaPOP1, CaPOP2 and CaPOP3. All three genes were present in both cultivars, which suggest that differences in the expression of CaPOP are caused by factor(s) regulating their transcription. CaPOP1 differs in sequence from CaPOP2 primarily in having two large deletions in the promoter region. CaPOP3 is probably a recombination product of CaPOP1 and CaPOP2 and encodes a protein identical to CaPOP2. Coffee’s POP (CaPOP) genes are homologous to the arabidopsis gene At1g20380, encoding a post-proline cleaving enzyme that acts on substrates shorter than 30 amino acids. Ectopic expression of CaPOP1 under its native promoter in transgenic arabidopsis resulted in more secondary branches than in the wild type. This is the first study to successfully isolate CaPOP genes and characterize their expression in the developing tissues of coffee. This study also reports a novel role for prolyl oligopeptidase in control of lateral shoot branching.
- Published
- 2011
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18. Mechanisms of host use by small crustaceans in marine systems: comparison with terrestrial herbivorous insects
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Naoki H. Kumagai
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Amphipoda ,biology ,Ecology ,Host (biology) ,Chemical defense ,biology.organism_classification ,Crustacean - Published
- 2007
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19. Comparative studies on dry matter intake, digestibility and nitrogen metabolism between Thai native (TN) and Anglo Nubian×TN bucks
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W. Ngampongsai and H. Kumagai
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business.industry ,Biology ,biology.organism_classification ,Biotechnology ,Excretion ,chemistry.chemical_compound ,Animal science ,Nutrient ,Food Animals ,Fodder ,chemistry ,Hay ,Urea ,Animal Science and Zoology ,Dry matter ,Anglo-Nubian ,business ,Paspalum plicatulum - Abstract
Metabolic experiments were conducted for each Thai native (TN) and Anglo Nubian–TN 50% (AN × TN) bucks, 26.5–38 kg BW and 35–52 months of age, by assigning the following concentrate diets, which had four levels of CP concentrations, T1: 14%, T2: 21%, T3: 28% and T4: 35%, on a DM basis. The animals were fed the concentrates at a rate of 1% of their BW and had ad libitum access to Paspalum plicatulum hay. As the CP level increased, digestibility of CP, N excretion in urine and N retention increased ( P P 0.75 day) versus 36.0 g/(kg BW 0.75 day)), thus N intake of AN × TN was higher than that of TN ( P 0.75 day) versus 0.90 g/(kg BW 0.75 day)). Digestibility of CP and blood urea N concentrations of TN were higher than those of AN × TN ( P 0.75 day) versus 0.11 g/(kg BW 0.75 day)) and T4 (0.25 g/(kg BW 0.75 day) versus 0.17 g/(kg BW 0.75 day)). Digestibility of NDF and ADF, and TDN of TN were higher than those of AN × TN ( P 0.75 day), and no significant difference of DE among CP levels nor breeds of bucks was observed. Thai native was superior to AN × TN in digestibility of N and fiber fractions at the maintenance level of DE, which might have overcome inferiority of TN to AN × TN in amount of N and energy intake caused by the lower DMI. It is likely that TN goats are well adapted to fodder shortage condition due to their efficient utilization of nutrients.
- Published
- 2006
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20. Distance effects on patterns and processes of dispersal in an octocoral-associated amphipod
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Naoki H. Kumagai
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education.field_of_study ,Amphipoda ,Ecology ,biology ,Population ,Pelagic zone ,Aquatic Science ,biology.organism_classification ,Gorgonian ,Habitat ,Benthic zone ,Biological dispersal ,education ,Coelenterata ,Ecology, Evolution, Behavior and Systematics - Abstract
Similar to pelagic larval dispersal, it has been suggested that dispersal of post-larval benthic organisms and species with direct development plays an important role in population persis- tence. However, effective dispersal distances required for the maintenance of local populations have been poorly characterized. This study elucidated distance effects on patterns and processes in disper- sal of the amphipod Incisocalliope symbioticus, which is associated exclusively with the gorgonian octocoral Melithaea flabellifera. Dispersal patterns over an annual cycle were examined by the place- ment of defaunated gorgonians at 3 distance levels (
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- 2006
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21. Development of Electronic Barcodes for use in Plant Pathology and Functional Genomics
- Author
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Philip Miller and Monto H. Kumagai
- Subjects
Radio Waves ,Genomic data ,Arabidopsis ,Plant Science ,Biology ,Barcode ,Bioinformatics ,law.invention ,GTP-Binding Proteins ,law ,Human–computer interaction ,Tobacco ,Genetics ,Radio-frequency identification ,Gene Library ,Electronic Data Processing ,Arabidopsis Proteins ,Computers ,business.industry ,Tobamovirus ,Genomics ,General Medicine ,Plants ,Plants, Genetically Modified ,Plant development ,Phenotype ,ComputingMethodologies_PATTERNRECOGNITION ,Computers, Handheld ,business ,Agronomy and Crop Science ,Mobile device ,Functional genomics ,Cell Phone - Abstract
We have developed a novel 'electronic barcode' system that uses radio frequency identification (RFID) tags, cell phones, and portable computers to link phenotypic, environmental, and genomic data. We describe a secure, inexpensive system to record and retrieve data from plant samples. It utilizes RFID tags, computers, PDAs, and cell phones to link, record, and retrieve positional, and functional genomic data. Our results suggest that RFID tags can be used in functional genomic screens to record information that is involved in plant development or disease.
- Published
- 2006
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22. Transplantation of Gorgonian Octocorals for in situ Experimental Manipulations
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Masakazu N. Aoki, Toshihiko Sato, Hideo Shinagawa, Yasutaka Tsuchiya, and Naoki H. Kumagai
- Subjects
Transplantation ,In situ ,Economics and Econometrics ,Gorgonian ,Oceanography ,biology ,Ecology ,Materials Chemistry ,Media Technology ,Forestry ,biology.organism_classification - Published
- 2004
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23. Lipomatous primitive neuroectodermal tumor with a glioblastoma component: a case report
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H. Kumagai, Takanori Hirose, Takashi Komori, Keisuke Ishizawa, and S. Kan-nuki
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Adult ,Pathology ,medicine.medical_specialty ,Autopsy ,Biology ,Pathology and Forensic Medicine ,Rosette (botany) ,Lesion ,Central nervous system disease ,Cellular and Molecular Neuroscience ,Fatal Outcome ,medicine ,Humans ,Lipomatosis ,Neuroectodermal Tumors, Primitive ,Neuroectodermal tumor ,Brain Neoplasms ,Lipoma ,medicine.disease ,Radiography ,Primitive neuroectodermal tumor ,Immunohistochemistry ,Female ,Neurology (clinical) ,medicine.symptom ,Glioblastoma - Abstract
A case of extracerebellar lipomatous primitive neuroectodermal tumor (PNET) with glioblastoma multiforme (GBM) areas is reported. A 44-year-old woman who had been on antipsychotic agents for schizophrenia complained of hemiparesis and drowsiness. She deteriorated progressively and died 3 months later. The autopsy revealed a huge, ill-defined tumor located from right basal ganglia to brain stem. Microscopically, the tumor consisted of three distinct components: clusters of small primitive cells consistent with PNET, mature lipoma-like islands, and a GBM-like component. Neuronal differentiation in PNET areas was confirmed by the presence of Homer Wright rosette, synaptophysin-positive fibrillary background, and ultrastructural demonstration of neuritic processes. Lipoma-like areas composed of lipidized cells containing large lipid droplets were intimately intermingled and closely related with PNET areas. Furthermore, GBM areas were, although predominantly located in the brain stem, often blended with the previous two components. This component was characterized by glial fibrillary acid protein immunoreactivity of atypical tumor cells and the presence of necrosis and endothelial proliferation. PNET areas with lipomatous differentiation in the present tumor may suggest the morphological and histogenetic similarity to liponeurocytoma, although the neuronal element in the former was anaplastic. The association with a GBM component makes the present tumor a unique, and, to our knowledge, previously unrecognized lesion.
- Published
- 2002
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24. Identification of neoxanthin synthase as a carotenoid cyclase paralog
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Bilal Camara, Alain d'Harlingue, Monto H. Kumagai, Florence Bouvier, and Ralph A. Backhaus
- Subjects
chemistry.chemical_classification ,ATP synthase ,biology ,fungi ,virus diseases ,food and beverages ,Neoxanthin synthase ,biochemical phenomena, metabolism, and nutrition ,Biochemistry ,Cyclase ,chemistry.chemical_compound ,chemistry ,Neoxanthin ,immune system diseases ,Complementary DNA ,Xanthophyll ,biology.protein ,Abscisic acid ,Violaxanthin - Abstract
Neoxanthin, a precursor of the plant hormone abscisic acid, is an allenic xanthophyll recognized as the last product of carotenoid synthesis in green plants. A cDNA for neoxanthin synthase (NSY) was isolated from tomato using a molecular approach based on the mechanistic and structural similarities of NSY to two other closely related carotenogenic enzymes, lycopene cyclase (LCY) and capsanthin-capsorubin synthase (CCS). The identified tomato NSY cDNA (T.NSY) encodes a 56-kDa plastid-targeted protein that when expressed in Escherichia coli, catalyzes the conversion of violaxanthin to neoxanthin. In tobacco leaves that transiently express T.NSY, an increase in neoxanthin content with a concomitant decrease in violaxanthin is observed. NSY is structurally similar to LCY and CCS. However, in Cyanobacteria, the generally accepted progenitor of plastids, both CCS and NSY are absent while LCY is present. LCY catalyzes a simplified version of the reaction catalyzed by NSY and CCS suggesting that these two enzymes were remodeled from LCY during higher plant evolution to create new forms of oxidized carotenoids.
- Published
- 2000
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25. Rapid production of specific vaccines for lymphoma by expression of the tumor-derived single-chain Fv epitopes in tobacco plants
- Author
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Kathleen M. Hanley, Thomas H. Turpen, Laurence K. Grill, Ronald Levy, Alison A. McCormick, Monto H. Kumagai, Itzhak Hakim, Shoshana Levy, and Daniel Tuse
- Subjects
Glycosylation ,Lymphoma ,medicine.medical_treatment ,Genetic Vectors ,Molecular Sequence Data ,Nicotiana benthamiana ,chemical and pharmacologic phenomena ,Biology ,Epitope ,Epitopes ,Mice ,Affinity chromatography ,Gene Expression Regulation, Plant ,Conjugate vaccine ,Tobacco ,Tumor Cells, Cultured ,medicine ,Animals ,Amino Acid Sequence ,Cloning, Molecular ,B-cell lymphoma ,Immunoglobulin Fragments ,Plant Proteins ,B-Lymphocytes ,Vaccines ,Multidisciplinary ,Base Sequence ,Tobamovirus ,Vaccination ,Hemocyanin ,Neoplasms, Experimental ,Biological Sciences ,medicine.disease ,biology.organism_classification ,Virology ,Molecular biology ,Blot ,Plants, Toxic ,biology.protein ,Antibody - Abstract
Rapid production of protein-based tumor-specific vaccines for the treatment of malignancies is possible with the plant-based transient expression system described here. We created a modified tobamoviral vector that encodes the idiotype-specific single-chain Fv fragment (scFv) of the immunoglobulin from the 38C13 mouse B cell lymphoma. InfectedNicotiana benthamianaplants contain high levels of secreted scFv protein in the extracellular compartment. This material reacts with an anti-idiotype antibody by Western blotting, ELISA, and affinity chromatography, suggesting that the plant-produced 38C13 scFv protein is properly folded in solution. Mice vaccinated with the affinity-purified 38C13 scFv generate >10 μg/ml anti-idiotype immunoglobulins. These mice were protected from challenge by a lethal dose of the syngeneic 38C13 tumor, similar to mice immunized with the native 38C13 IgM-keyhole limpet hemocyanin conjugate vaccine. This rapid production system for generating tumor-specific protein vaccines may provide a viable strategy for the treatment of non-Hodgkin’s lymphoma.
- Published
- 1999
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26. Effects of nutritional level on digestive enzyme activities in the pancreas and small intestine of calves slaughtered at same body weight
- Author
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H. Uike, K. Mitani, H. Kumagai, T. Ogawa, K. Taniguchi, X. B. Wang, and S. Suda
- Subjects
medicine.medical_specialty ,medicine.anatomical_structure ,Endocrinology ,biology ,Internal medicine ,Digestive enzyme ,medicine ,biology.protein ,Animal Science and Zoology ,Pancreas ,Body weight ,Small intestine ,Food Science - Published
- 1998
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27. Functional integration of non‐native carotenoids into chloroplasts by viral‐derived expression of capsanthin–capsorubin synthase inNicotiana benthamiana
- Author
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Bilal Camara, Monto H. Kumagai, Dave Clary, Yves Keller, and Florence Bouvier
- Subjects
Chloroplasts ,DNA, Complementary ,Photosystem II ,Genetic Vectors ,Molecular Sequence Data ,Nicotiana benthamiana ,macromolecular substances ,Plant Science ,Xanthophylls ,Tobacco ,Chromoplast ,Genetics ,RNA Viruses ,Amino Acid Sequence ,Photosynthesis ,Carotenoid ,Plant Proteins ,chemistry.chemical_classification ,Base Sequence ,ATP synthase ,biology ,fungi ,food and beverages ,Cell Biology ,biology.organism_classification ,Carotenoids ,Plant Leaves ,Chloroplast ,Microscopy, Electron ,Plants, Toxic ,Phenotype ,chemistry ,Biochemistry ,Thylakoid ,Xanthophyll ,biology.protein ,Oxidoreductases - Abstract
The biosynthesis of leaf carotenoids in Nicotiana benthamiana was altered by forced re-routing of the pathway to the synthesis of capsanthin, a non-native chromoplast-specific xanthophyll, using an RNA viral vector containing capsanthin-capsorubin synthase (Ccs) cDNA. The cDNA encoding Ccs was placed under the transcriptional control of a tobamovirus subgenomic promoter. Leaves from transfected plants expressing Ccs developed an orange phenotype and accumulated high levels of capsanthin (up to 36% of total carotenoids). This phenomenon was associated with thylakoid membrane distortion and reduction of grana stacking. In contrast to the situation prevailing in chromoplasts, capsanthin was not esterified and its increased level was balanced by a concomitant decrease of the major leaf xanthophylls, suggesting an autoregulatory control of chloroplast carotenoid composition. Capsanthin was exclusively recruited into the trimeric and monomeric light-harvesting complexes of photosystem II (PSII) and shown to significantly contribute to the light-harvesting capacity. On a chlorophyll basis, the concentrations of PSI and PSII reaction centres were not modified. This demonstration that higher plant antenna complexes can accommodate non-native carotenoids provides compelling evidence for functional remodelling of photosynthetic membranes toward a better photoreactivity by rational design of the incorporated carotenoid structures.
- Published
- 1998
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28. Characteristics of a chimeric enzyme engineered from two rice α-amylase isozymes
- Author
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Masaaki Terashima, Shigeo Katoh, Monto H. Kumagai, Raymond L. Rodriguez, and M. Kawai
- Subjects
chemistry.chemical_classification ,food and beverages ,General Medicine ,Biology ,Oligosaccharide ,Applied Microbiology and Biotechnology ,Isozyme ,law.invention ,Hydrolysis ,Enzyme ,chemistry ,Biochemistry ,law ,Gene expression ,biology.protein ,Recombinant DNA ,Amylase ,Biotechnology ,Thermostability - Abstract
A chimeric enzyme, engineered from two rice α-amylase isozymes, Amy1A and Amy3D, showed unique characteristics in soluble-starch and maltoheptaose hydrolysis. Effects of pH on soluble-starch hydrolysis and the thermostability of the chimeric enzyme were similar to those of the isozyme Amy3D. The previous study revealed that Amy1A shows high activity in soluble-starch hydrolysis and low activity in oligosaccharide degradation, while Amy3D shows low activity in soluble-starch hydrolysis and high activity in oligosaccharide degradation. The chimeric enzyme showed high activities in both soluble-starch hydrolysis and oligosaccharide degradation. These results suggest that protein modules of highly homologous enzymes are interchangeable, and that a novel enzyme with unique characteristics can be obtained by creating a chimeric enzyme.
- Published
- 1996
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29. Habitat-forming seaweeds in Japan (fucoids and temperate kelps)
- Author
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Yasuhiro Yamanaka, Naoki H. Kumagai, Hiroya Yamano, and Masahiko Fujii
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0106 biological sciences ,Flora ,biology ,Ecology ,010604 marine biology & hydrobiology ,Biogeography ,AlgaeBase ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Algae ,Habitat ,Temperate climate ,Nomenclature ,Ecology, Evolution, Behavior and Systematics - Abstract
This paper describes the flora of habitat-forming seaweeds (fucoids and temperate kelps) at 7673 sites of the Japanese coast encompassing its warm to cold temperate zone, recorded from 1887 to 2014. The data set includes 86 species (21,168 presence and 20,845 absence records), compiled from 355 literature sources, most of which were written in Japanese and published as grey literature in local journals or individual reports. Scientific names were consolidated under currently-accepted nomenclature based on Algaebase ( http://www.algaebase.org ). The data set compiled the seaweed flora at each study site each year, the geographical location and the scientific names. Additionally, three supporting data sets were created respectively including name of each site, synonyms of the seaweeds, and the corresponding literature list. This rich collection of data can be used to study the biogeography and long-term changes of particular species and the diversity of habitat-forming seaweeds of the Japanese coast.
- Published
- 2016
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30. Cytoplasmic inhibition of carotenoid biosynthesis with virus-derived RNA
- Author
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Laurence K. Grill, Damon A. Harvey, Monto H. Kumagai, J Donson, Kathleen M. Hanley, and Guy Della-Cioppa
- Subjects
Phytoene desaturase ,viruses ,Molecular Sequence Data ,Nicotiana benthamiana ,Genes, Plant ,Structure-Activity Relationship ,chemistry.chemical_compound ,Phytoene ,Gene Expression Regulation, Plant ,Sequence Homology, Nucleic Acid ,Complementary DNA ,Gene expression ,Amino Acid Sequence ,RNA, Messenger ,Multidisciplinary ,Phytoene synthase ,Base Sequence ,biology ,Tobamovirus ,fungi ,food and beverages ,RNA ,Oligonucleotides, Antisense ,Plants, Genetically Modified ,biology.organism_classification ,Carotenoids ,Molecular biology ,Antisense RNA ,chemistry ,Mutagenesis, Site-Directed ,biology.protein ,RNA, Viral ,Oxidoreductases ,Sequence Alignment ,Research Article - Abstract
The carotenoid biosynthetic pathway in higher plants was manipulated by using an RNA viral vector. A cDNA encoding phytoene synthase and a partial cDNA encoding phytoene desaturase (PDS) were placed under the transcriptional control of a tobamovirus subgenomic promoter. One to two weeks after inoculation, systemically infected Nicotiana benthamiana plants were analyzed for phytoene. Leaves from transfected plants expressing phytoene synthase developed a bright orange phenotype and accumulated high levels of phytoene. Cytoplasmic inhibition of plant gene expression by viral RNA was demonstrated with an antisense RNA transcript to a partial PDS cDNA derived from tomato. The leaves of the plants transfected with the antisense PDS sequence developed a white phenotype and also accumulated high levels of phytoene. A partial cDNA to the corresponding N. benthamiana PDS gene was isolated and found to share significant homology with the tomato antisense PDS transcript. This work demonstrates that an episomal RNA viral vector can be used to deliberately manipulate a major, eukaryotic biosynthetic pathway. In addition, our results indicate that an antisense transcript generated in the cytoplasm of a plant cell can turn off endogenous gene expression.
- Published
- 1995
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31. Increased expression of angiotensin peptides in the brain of transgenic hypertensive rats
- Author
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Carlos M. Ferrario, H. Kumagai, K B Brosnihan, Atsushi Moriguchi, Detlev Ganten, and P D Senanayake
- Subjects
medicine.medical_specialty ,Physiology ,Central nervous system ,Hypothalamus ,Biology ,Biochemistry ,Animals, Genetically Modified ,Rats, Sprague-Dawley ,Cellular and Molecular Neuroscience ,Endocrinology ,Internal medicine ,Renin ,Renin–angiotensin system ,medicine ,Animals ,Endocrine system ,Cerebral Cortex ,Medulla Oblongata ,Angiotensin II ,Radioimmunoassay ,Peptide Fragments ,Rats ,medicine.anatomical_structure ,Blood pressure ,Hypertension ,cardiovascular system ,Medulla oblongata ,Female ,Angiotensin I ,hormones, hormone substitutes, and hormone antagonists - Abstract
We determined the levels of angiotensin I (ANG I), angiotensin II (ANG II), and the heptapeptide angiotensin(1-7) [ANG(1-7)] in the blood and brain of female Hannover Sprague-Dawley (SD) and transgenic hypertensive rats [mRen-2]27 by radioimmunoassay and high performance liquid chromatography. Hypertension was accompanied by higher plasma concentrations of ANG II, no statistical changes in ANG(1-7), and no differences in plasma ANG I levels. In the hypothalamus of transgenic rats, concentrations of ANG II and ANG(1-7) averaged 827% and 168% above values in SD rats (p < 0.005) whereas both ANG I and ANG II increased in the medulla oblongata. The data showed that the established phase of hypertension in rats harboring the mouse Ren-2 gene is associated with overexpression of the renin-angiotensin system in brain regions participating in the endocrine regulation of blood pressure.
- Published
- 1994
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32. Transfection of whole plants from wounds inoculated with Agrobacterium tumefaciens containing cDNA of tobacco mosaic virus
- Author
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Nicole Weinzettl, William O. Dawson, Ann Myers Turpen, Monto H. Kumagai, and Thomas H. Turpen
- Subjects
Virulence Factors ,Agrobacterium ,viruses ,Nicotiana tabacum ,Genetic Vectors ,Molecular Sequence Data ,Biology ,Transfection ,Defective virus ,Ti plasmid ,Bacterial Proteins ,Virology ,Tobacco ,Tobacco mosaic virus ,RNA, Catalytic ,Base Sequence ,fungi ,Tobamovirus ,Agrobacterium tumefaciens ,biology.organism_classification ,Molecular biology ,Tobacco Mosaic Virus ,Plants, Toxic ,RNA, Viral ,Plasmids - Abstract
We engineered cDNA of tobacco mosaic tobamovirus (TMV) into Agrobacterium tumefaciens for inoculation of plant cells. The resulting bacterial strains were used to transfect tobacco (Nicotiana tabacum cv. Xanthi and Xanthi/nc) with wild type and a defective virus. Lesion formation on Xanthi/nc tobacco was used to measure the timing and efficiency of transfection. Infections mediated by Agrobacterium produced lesions an average of two days later than infections produced by inoculation with virions. The addition of approximately 80 bp of non-viral sequences to the 5'-end of TMV transcripts abolished transfection. Transcripts with non-viral sequences at the 3'-end initiated infections, while precise transcript termination with a synthetic ribozyme sequence increased transfection frequencies two-fold. Culture conditions reported to induce genes of the vir region of the Agrobacterium Ti plasmid also increased the transfection frequency approximately two-fold. Therefore, in addition to the pararetroviruses and geminiviruses previously described, 'agroinoculation' may be used to infect plants with plus-sense RNA viruses.
- Published
- 1993
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33. Conversion of Starch to Ethanol in a Recombinant Saccharomyces cerevisiae Strain Expressing Rice α-Amylase from a Novel Pichia pastoris Alcohol Oxidase Promoter
- Author
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Genadie G. Sverlow, Guy Della-Cioppa, Laurence K. Grill, and Monto H. Kumagai
- Subjects
Starch ,Genes, Fungal ,Molecular Sequence Data ,Saccharomyces cerevisiae ,Biomedical Engineering ,Gene Expression ,Bioengineering ,Applied Microbiology and Biotechnology ,Saccharomyces ,Pichia ,Pichia pastoris ,chemistry.chemical_compound ,Escherichia coli ,Amino Acid Sequence ,Cloning, Molecular ,DNA, Fungal ,Promoter Regions, Genetic ,Conserved Sequence ,Ethanol ,Base Sequence ,biology ,food and beverages ,Oryza ,biology.organism_classification ,Molecular biology ,Yeast ,Alcohol oxidase ,Alcohol Oxidoreductases ,Biochemistry ,chemistry ,biology.protein ,Molecular Medicine ,Transformation, Bacterial ,alpha-Amylases ,Alpha-amylase ,Biotechnology - Abstract
A recombinant Saccharomyces cerevisiae, expressing and secreting rice alpha-amylase, converts starch to ethanol. The rice alpha-amylase gene (OS103) was placed under the transcriptional control of the promoter from a newly described Pichia pastoris alcohol oxidase genomic clone. The nucleotide sequences of ZZA1 and other methanol-regulated promoters were analyzed. A highly conserved sequence (TTG-N3-GCTTCCAA-N5-TGGT) was found in the 5' flanking regions of alcohol oxidase, methanol oxidase, and dihydroxyacetone synthase genes in Pichia pastoris, Hansenula polymorpha, and Candida boidinii S2. The yeast strain containing the ZZA1-OS103 fusion secreted biologically active enzyme into the culture media while fermenting soluble starch.
- Published
- 1993
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34. Nicotiana benthamiana: Tobamoviral Vectors Redirect Carotenogenesis
- Author
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Monto H. Kumagai and Jennifer Lee Busto
- Subjects
Nicotiana benthamiana ,Biology ,biology.organism_classification ,Virology - Published
- 2010
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35. Renal nerve activity in rats with spontaneous hypertension: effect of converting enzyme inhibitor
- Author
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Carlos M. Ferrario, David B. Averill, and H. Kumagai
- Subjects
medicine.medical_specialty ,Mean arterial pressure ,Sympathetic Nervous System ,Baroreceptor ,Physiology ,Angiotensin-Converting Enzyme Inhibitors ,Blood Pressure ,Pressoreceptors ,Baroreflex ,Kidney ,Rats, Inbred WKY ,Heart Rate ,Lisinopril ,Rats, Inbred SHR ,Physiology (medical) ,Internal medicine ,Reflex ,Heart rate ,medicine ,Animals ,cardiovascular diseases ,Phenylephrine ,biology ,business.industry ,Angiotensin-converting enzyme ,Dipeptides ,Rats ,Endocrinology ,Blood pressure ,Hypertension ,cardiovascular system ,biology.protein ,business ,circulatory and respiratory physiology ,medicine.drug - Abstract
We studied the effects of chronic oral inhibition of angiotensin-converting enzyme on the baroreflex control of renal sympathetic nerve activity (RSNA) and heart rate (HR) in 14-wk-old conscious spontaneously hypertensive rats (SHR; n = 12) and age-matched Wistar-Kyoto rats (WKY; n = 11). Rats were treated with lisinopril (10 mg.kg-1.day-1 in tap water) or vehicle for 7 days. We evaluated the baroreflex control of efferent RSNA and HR in awake rats 2 days after implantation of electrodes around the renal sympathetic nerves. The relation between mean arterial pressure (MAP) and either RSNA or HR was analyzed by a logistic function curve during intravenous infusions of phenylephrine and nitroglycerin. The maximum gain of the curve was considered as the sensitivity of the baroreflex. MAP in lisinopril-treated SHR averaged 93 +/- 3 mmHg, a value lower than that obtained in vehicle-treated SHR (147 +/- 5 mmHg) but not in WKY (96 +/- 4 mmHg). In vehicle-treated SHR baroreflex sensitivity (-4.3 +/- 0.5% change nerve activity/mmHg) was significantly (P less than 0.005) smaller than that of WKY (-15.8 +/- 1.5%/mmHg). Seven days of oral treatment of lisinopril caused significant improvement of the baroreflex sensitivity in SHR (-10.5 +/- 0.7%/mmHg, P less than 0.01). The maximum gain of MAP and HR relation of lisinopril-treated SHR was also larger (P less than 0.05) than that of vehicle-treated SHR.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1992
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36. The α-amylase genes in Oryza sativa: Characterization of cDNA clones and mRNA expression during seed germination
- Author
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Monto H. Kumagai, Ning Huang, Thomas D. Sutliff, Sharman D. O'Neill, Raymond L. Rodriguez, and Arindam Majumdar
- Subjects
Signal peptide ,Oryza sativa ,Base Sequence ,Protein Conformation ,Sequence analysis ,Molecular Sequence Data ,Restriction Mapping ,food and beverages ,Oryza ,DNA ,Biology ,Isozyme ,Molecular biology ,Sequence Homology, Nucleic Acid ,Complementary DNA ,Seeds ,Gene expression ,Genetics ,Amino Acid Sequence ,RNA, Messenger ,alpha-Amylases ,Molecular Biology ,Gene ,Peptide sequence - Abstract
Two cDNA clones, pOS103 and pOS137, were isolated which code for distinct alpha-amylase isozymes in germinating rice seeds. Sequence analysis indicated that the clones encode polypeptides of approximately 48 kDa, both of which possess a signal peptide involved in directing secretion of the protein. Comparison of the two rice alpha-amylase amino acid sequence showed that they are 76% similar to each other, while showing 85% to 90% similarity with other cereal alpha-amylases. A comparison of eleven cereal alpha-amylases also revealed three new conserved regions (I', II', and IV') not previously identified in the animal, bacterial, and fungal alpha-amylases. Regions I' and IV' are sites for intron splicing while region II' is probably involved in calcium binding. One of the rice alpha-amylase cDNAs, pOS103, encodes a protein that has two potential N-glycosylation sites, one in the signal peptide and the other in the mature portion of the protein. The cDNA clone, pOS137, encodes an alpha-amylase with a single glycosylation site in the signal peptide, suggesting that the mature OS137 isozyme is not glycosylated. Analysis of the expression of these genes in germinating rice seeds indicated that mRNA corresponding to pOS103 and pOS137 could be detected throughout a 48 h period of seed imbibition. RNA levels, however, were dramatically stimulated by treatment of embryoless half-seeds with exogenous GA3. Our results demonstrate that at least two forms of alpha-amylase are expressed in germinating rice seeds and that the expression of these genes is regulated by the phytohormone GA3.
- Published
- 1990
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37. Angiotensins and the failing heart. Enhanced positive inotropic response to angiotensin I in cardiomyopathic hamster heart in the presence of captopril
- Author
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B Healy, Fetnat M. Fouad-Tarazi, Ahsan Husain, H Kumagai, Mahesh C. Khosla, F M Bumpus, H Hirakata, and Hidenori Urata
- Subjects
Male ,Inotrope ,medicine.medical_specialty ,Angiotensins ,Captopril ,Physiology ,Cardiac Output, Low ,Hamster ,Propranolol ,Angiotensin Receptor Antagonists ,Cricetinae ,Internal medicine ,Renin–angiotensin system ,medicine ,Animals ,Receptors, Angiotensin ,Mesocricetus ,biology ,Chemistry ,Angiotensin II ,Myocardium ,Drug Synergism ,Heart ,Angiotensin-converting enzyme ,medicine.disease ,Myocardial Contraction ,Endocrinology ,Heart failure ,cardiovascular system ,biology.protein ,Angiotensin I ,Cardiomyopathies ,Cardiology and Cardiovascular Medicine ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
We examined the hypothesis that the positive inotropic effect of angiotensin I (Ang I) may be retained in the presence of angiotensin converting enzyme inhibitors so that it may have a direct beneficial effect on the heart. Accordingly, isolated perfused hearts (Langendorff preparation) of 300-day-old cardiomyopathic hamsters (a model of spontaneous cardiomyopathy) and age-matched normal hamsters (controls) were infused with Ang I in the presence of captopril; propranolol was added to the perfusing medium to block catecholamine-mediated effects of angiotensins on the heart. Left ventricular developed pressure and the rate of increase in left ventricular developed pressure increased significantly (p less than 0.001) in both the cardiomyopathic and the normal hamster heart despite concomitant reduction in myocardial flow rate favoring a direct inotropic effect of Ang I in both normal and myopathic hearts; these changes were significantly higher by almost threefold in the cardiomyopathic than in the normal hamsters (p less than 0.01) and were blocked by the angiotensin II (Ang II) antagonist [Sar1,Thr8]Ang II. Comparing dose-left ventricular contractility response curves for Ang I and Ang II, ED50 for responses was identical in both normal and myopathic hearts, whereas peak responses to Ang II were double those to Ang I in normal hearts but were almost identical in the myopathic hearts. Binding of [125I]Ang II in six cardiomyopathic and four normal hamster hearts was of high affinity, but there was no evidence for Ang I-saturable high-affinity binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1990
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38. A study on nutritional status of trace minerals of cattle in Java in Indonesia
- Author
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J. Jachja, Hideo Yano, R. Kawashima, H. Katsumata, H. Kumagai, and N. Ishida
- Subjects
Java ,business.industry ,Metallurgy ,Animal Science and Zoology ,Nutritional status ,Macro ,Biology ,business ,computer ,Food Science ,computer.programming_language ,Biotechnology - Published
- 1990
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39. Expression and secretion of rice α-amylase by Saccharomyces cerevisiae
- Author
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Zeljko Vrkljan, Monto H. Kumagai, Mena J. Shah, John R. Whitaker, Masaaki Terashima, and Raymond L. Rodriguez
- Subjects
Signal peptide ,Glycosylation ,Transcription, Genetic ,Blotting, Western ,Genetic Vectors ,Molecular Sequence Data ,Restriction Mapping ,Saccharomyces cerevisiae ,Biology ,Chromatography, Affinity ,chemistry.chemical_compound ,Affinity chromatography ,Gene Expression Regulation, Fungal ,Sequence Homology, Nucleic Acid ,Gene expression ,Genetics ,Amino Acid Sequence ,Amylase ,Promoter Regions, Genetic ,chemistry.chemical_classification ,Base Sequence ,food and beverages ,Oryza ,DNA ,General Medicine ,biology.organism_classification ,Molecular biology ,Recombinant Proteins ,Yeast ,Blotting, Southern ,Enzyme ,chemistry ,Biochemistry ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,alpha-Amylases - Abstract
We report the high level expression and secretion of rice α-amylase isozyme by Saccharomyces cerevisiae . Transcription of this gene was under control of the yeast enolase promoter. The synthesized protein had an approximate molecular size of 45 kDa and a pI of approx 4.7 to 5.0. The rice α-amylase signal peptide was recognized and efficiently processed by yeast and the active, glycosylated enzyme was secreted into the culture media. This enzyme was purified to homogeneity by affinity chromotography and its enzymatic properties were characterized. The K m and V max were found to be similar to those of α-amylase from other organisms. The high level of secretion observed in these studies may be due to the unique features of the rice signal peptide and/or to the glycosylation of the recombinant enzyme.
- Published
- 1990
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40. Role of food source and predator avoidance in habitat specialization by an octocoral-associated amphipod
- Author
-
Naoki H. Kumagai
- Subjects
Amphipoda ,Detritus ,biology ,Ecology ,Fishes ,Marine invertebrates ,biology.organism_classification ,Anthozoa ,Predation ,Diet ,Food Preferences ,Habitat ,Escape Reaction ,Animals ,Chemical defense ,Flabellifera ,Ecology, Evolution, Behavior and Systematics ,Ecosystem ,Invertebrate ,Demography - Abstract
Small marine invertebrates often use sessile organisms as microhabitats, which can provide food sources and/or serve as refugees from predators. Because of the availability of external food items such as epibionts and detritus in the marine environment, these invertebrates may not depend on the sessile organisms as sole food sources. In this study, I hypothesized that habitat specialization by a marine invertebrate is determined by factors other than food. Results of field surveys off the coast of the Izu Peninsula, on the eastern coast of Japan, showed that, with few exceptions, the distribution of the amphipod Incisocalliope symbioticus was restricted to the octocoral Melithaea flabellifera. When presented with several habitat options, I. symbioticus selected M. flabellifera most frequently, although some individuals chose the octocoral Acabaria japonica. The selection was proximately determined by water-borne cues from M. flabellifera that appear to be unrelated to the octocoral as a food source, since the amphipod preferred detritus to the octocoral. As a chemical refuge, M. flabellifera had an allelopathic effect that deterred fish predation on the exposed epifauna. With regard to octocoral habitat in the study area, I. symbioticus may be restricted to M. flabellifera because this was the only abundant octocoral consistently occurring in shallow water (or =10 m), where predation is intensive. The relationship between I. symbioticus and M. flabellifera was commensal and was ultimately driven by the value of M. flabellifera as a chemical refuge from predation, rather than its food value. This study supports the idea that protection from predators, rather than food utilization, can promote ecological specialization.
- Published
- 2006
41. Tobamoviral Vectors: Developing a Production System for Pharmaceuticals in Transfected Plants
- Author
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Jennifer Lee Busto and Monto H. Kumagai
- Subjects
Transfection ,Biology ,Cell biology ,Production system - Published
- 2004
- Full Text
- View/download PDF
42. Rapid, high-level expression of glycosylated rice alpha-amylase in transfected plants by an RNA viral vector
- Author
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Jonathan Donson, Guy Della-Cioppa, Monto H. Kumagai, and Laurence K. Grill
- Subjects
Glycosylation ,viruses ,Recombinant Fusion Proteins ,Blotting, Western ,Genetic Vectors ,Molecular Sequence Data ,Nicotiana benthamiana ,Biology ,Transfection ,Gene Expression Regulation, Enzymologic ,Pichia pastoris ,Gene expression ,Genetics ,Amino Acid Sequence ,Subgenomic mRNA ,chemistry.chemical_classification ,Base Sequence ,fungi ,Tobamovirus ,food and beverages ,RNA ,Oryza ,General Medicine ,biology.organism_classification ,Molecular biology ,chemistry ,Heterologous expression ,alpha-Amylases ,Glycoprotein - Abstract
Tobamoviral vectors have been developed for the heterologous expression of glycoproteins in plants. The rice alpha-amylase gene (OS103) was placed under the transcriptional control of a tobamovirus subgenomic promoter in a RNA viral vector. One to two weeks after inoculation, transfected Nicotiana benthamiana plants accumulated glycosylated alpha-amylase to levels of at least 5% total soluble protein. The 46kDa recombinant enzyme was purified, and its structural and biological properties were analyzed. Post-translational modifications of the secreted protein were compared to rice alpha-amylase expressed in amylolytic strains of Pichia pastoris and Saccharomyces cerevisiae. Endo-H analysis revealed that the alpha-amylase was moderately glycosylated in transfected plants and hyperglycosylated in yeast.
- Published
- 2000
43. Comparative and Functional Study on Rhodobacter capsulatus rnf Gene Products and Their Homologs
- Author
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K. Saeki and H. Kumagai
- Subjects
chemistry.chemical_classification ,Enzyme ,Rhodobacter ,chemistry ,biology ,Membrane protein complex ,Homologous chromosome ,Nitrogenase ,Quinone oxidoreductase ,biology.organism_classification ,Gene ,Function (biology) ,Cell biology - Abstract
The rnfABCDE genes in Rhodobacter capsulatus are essential for diazotrophic growth under illuminated conditions. They locate near fdxN gene whose product is a major electron donor to nitrogenase. Since disruption of rnf genes conferred metronidazole resistance under pseudo-diazotrophic conditions and two of the rnf products, RnfB and RnfC, are supposed to hold iron-sulfur clusters, the genes are expected to encode some ferredoxin reductase. Because most of rnf products are highly hydrophobic it is hypothesized that rnf products constitute a membrane protein complex. In this study, we have 1) experimentally investigated their presence at chromatophore membranes, 2) made a prediction of enzymatic function and 3) collected data that the rnf products also serve for nitrogen fixation in darkness and that their homologs present in non-diazotrophs.
- Published
- 1998
- Full Text
- View/download PDF
44. Escherichia coli K-12 copper-containing monoamine oxidase: investigation of the copper binding ligands by site-directed mutagenesis, elemental analysis and topa quinone formation
- Author
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Yasuhiro Takenaka, Hideyuki Suzuki, Kazuhiro Yamamoto, Jung Hyeob Roh, and H. Kumagai
- Subjects
DNA, Bacterial ,Amine oxidase ,Monoamine oxidase ,Molecular Sequence Data ,Biophysics ,chemistry.chemical_element ,medicine.disease_cause ,Ligands ,Biochemistry ,Cofactor ,medicine ,Escherichia coli ,Histidine ,Amino Acid Sequence ,Cloning, Molecular ,Site-directed mutagenesis ,Molecular Biology ,Monoamine Oxidase ,DNA Primers ,Binding Sites ,biology ,Base Sequence ,Sequence Homology, Amino Acid ,Cell Biology ,Periplasmic space ,Elements ,Copper ,Dihydroxyphenylalanine ,chemistry ,Spectrophotometry ,biology.protein ,Mutagenesis, Site-Directed - Abstract
Copper-containing monoamine oxidase (EC 1.4.3.6) from Escherichia coli is a periplasmic enzyme containing topa quinone in addition to divalent copper as a cofactor. The amino acid sequence of E. coli monoamine oxidase was compared to several cloned amine oxidase genes and five well-conserved histidine residues were found. Site-directed mutagenesis studies were performed to determine which histidine residue serves as the binding Ligand to the copper. Enzyme activity, absorption spectrum, and atomic absorption spectrophotometry of the mutant enzymes indicated that histidines 470, 554, and 556 are the copper binding ligands. The absorption spectra of phenylhydrazine derivatives suggested that copper is necessary for topa quinone formation.
- Published
- 1995
45. Seasonal changes in the epifaunal community on the shallow-water gorgonian Melithaea flabellifera
- Author
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Masakazu N. Aoki and Naoki H. Kumagai
- Subjects
geography ,geography.geographical_feature_category ,biology ,Incisocalliope ,Ecology ,Melithaea ,Aquatic Science ,biology.organism_classification ,Waves and shallow water ,Oceanography ,Gorgonian ,Peninsula ,Period (geology) ,Flabellifera - Abstract
Periodic surveys of the subtidal epifaunal community on the gorgonian Melithaea flabellifera were conducted over a five year period at the Izu Peninsula, southern Japan. The occurrence patterns of epifaunal species on M. flabellifera were examined. The epifauna consisted of 16 species representing five phyla. The amphipod Incisocalliope symbioticus dominated (usually >80%) and occurred throughout the study.
- Published
- 2003
- Full Text
- View/download PDF
46. Laminin E8 fragments support efficient adhesion and expansion of dissociated human pluripotent stem cells
- Author
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Masashi Yamada, Miwa Kawasaki, Hirofumi Suemori, Maria Hayashi, Yukimasa Taniguchi, Eihachiro Kawase, H. Kumagai, Sugiko Futaki, Norio Nakatsuji, Takamichi Miyazaki, and Kiyotoshi Sekiguchi
- Subjects
Pluripotent Stem Cells ,Cell biology ,General Physics and Astronomy ,Embryoid body ,Germ layer ,Biology ,Bioinformatics ,Regenerative medicine ,General Biochemistry, Genetics and Molecular Biology ,Article ,Cell Adhesion ,Humans ,Protein Isoforms ,Induced pluripotent stem cell ,reproductive and urinary physiology ,Cell Proliferation ,Matrigel ,Multidisciplinary ,General Chemistry ,equipment and supplies ,Flow Cytometry ,Embryonic stem cell ,humanities ,Recombinant Proteins ,Culture Media ,Chemically defined medium ,Biological sciences ,Karyotyping ,embryonic structures ,Laminin ,Stem cell ,biological phenomena, cell phenomena, and immunity ,Biotechnology - Abstract
Miyazaki, T. et al.. Laminin E8 fragments support efficient adhesion and expansion of dissociated human pluripotent stem cells. Nat. Commun. 3:1236 doi: 10.1038/ncomms2231 (2012)., Human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) have the potential to provide an infinite source of tissues for regenerative medicine. Although defined xeno-free media have been developed, culture conditions for reliable propagation of hESCs still require considerable improvement. Here we show that recombinant E8 fragments of laminin isoforms (LM-E8s), which are the minimum fragments conferring integrin-binding activity, promote greater adhesion of hESCs and hiPSCs than do Matrigel and intact laminin isoforms. Furthermore, LM-E8s sustain long-term self-renewal of hESCs and hiPSCs in defined xeno-free media with dissociated cell passaging. We successfully maintained three hESC and two hiPSC lines on LM-E8s in three defined media for 10 passages. hESCs maintained high level expression of pluripotency markers, had a normal karyotype after 30 passages and could differentiate into all three germ layers. This culture system allows robust proliferation of hESCs and hiPSCs for therapeutic applications.
- Published
- 2012
47. Rapid, high-level expression of biologically active alpha-trichosanthin in transfected plants by an RNA viral vector
- Author
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N Weinzettl, Thomas H. Turpen, Monto H. Kumagai, M.E. Hilf, J Donson, George L. Grantham, Guy Della-Cioppa, William O. Dawson, T P Chow, and A M Turpen
- Subjects
Trichosanthin ,viruses ,Genetic Vectors ,Molecular Sequence Data ,Nicotiana benthamiana ,Protein Sorting Signals ,Transfection ,Antiviral Agents ,Gene expression ,Amino Acid Sequence ,Gene ,Protein Synthesis Inhibitors ,Multidisciplinary ,biology ,Base Sequence ,Dose-Response Relationship, Drug ,fungi ,RNA ,food and beverages ,RNA virus ,Tobamovirus ,biology.organism_classification ,Virology ,Molecular biology ,Tobacco Mosaic Virus ,Protein Processing, Post-Translational ,Research Article - Abstract
alpha-Trichosanthin, a eukaryotic ribosome-inactivating protein from Trichosanthes kirilowii, inhibits the replication of the human immunodeficiency virus (HIV) in vitro. The alpha-trichosanthin gene was placed under the transcriptional control of a tobamovirus subgenomic promoter in a plant RNA viral vector. Two weeks after inoculation, transfected Nicotiana benthamiana plants accumulated alpha-trichosanthin to levels of at least 2% of total soluble protein. The recombinant alpha-trichosanthin was purified and its structural and biological properties were analyzed. The 23-amino acid signal peptide was recognized by N. benthamiana and the processed enzyme caused a concentration-dependent inhibition of protein synthesis in vitro. The high level of heterologous gene expression observed in these studies is due to the unique features of the RNA viral-based transfection system.
- Published
- 1993
48. The sulfur and selenium status of pregnant ewes grazing Mediterranean pastures
- Author
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C. L. White, H. Kumagai, and M. J. Barnes
- Subjects
Vitamin ,geography ,geography.geographical_feature_category ,Domestic sheep reproduction ,chemistry.chemical_element ,Biology ,Sulfur ,Pasture ,chemistry.chemical_compound ,Animal science ,chemistry ,Botany ,Weaning ,Animal nutrition ,General Agricultural and Biological Sciences ,Plant nutrition ,Selenium - Abstract
Sheep require both sulfur and selenium for normal wool growth and to protect against diseases caused by free radical damage. This work describes the seasonal changes in the concentrations of sulfur, both as glutathione and inorganic sulfur, and selenium, in pregnant ewes, and the effects thereon of a multi-element supplement containing sulfate, selenium, and vitamins A and E. Merino ewes (420) were divided into 4 equal treatment groups, control (C), vitamins (V), minerals (M), and vitamins plus minerals (V+M), in a 22 factorial design. The control group was offered a loose salt lick NaCl at 175 g/head· day and the mineral group an equivalent amount of a multi-element mineral mix (Siromin). The vitamin groups were offered either salt or the mineral mix with added vitamins E and A. Treatments started 3 weeks prior to mating in November and lasted until 1 week prior to lambing in May. Sheep were sampled until weaning in September. Regardless of treatment, the concentrations of glutathione in blood and liver declined by 60% and 40%, respectively, when sheep were grazing dry pasture during summer. Sulfate-sulfur concentration in plasma of ewes in the C and V groups declined by 80% in the same period to
- Published
- 1997
- Full Text
- View/download PDF
49. The effect of supplementary minerals, retinol and α -tocopherol on the vitamin status and productivity of pregnant Merino ewes
- Author
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CL White and H Kumagai
- Subjects
Vitamin ,medicine.medical_specialty ,Animal breeding ,Domestic sheep reproduction ,Retinol ,Weanling ,Biology ,chemistry.chemical_compound ,Endocrinology ,Animal science ,chemistry ,Internal medicine ,medicine ,Weaning ,Tocopherol ,Animal nutrition ,General Agricultural and Biological Sciences - Abstract
Four hundred and twenty Merino ewes were divided into four treatment groups: control (NaCl at 175 g head-1 week-1 ), vitamins (salt containing 0.24 g/kg retinol plus 12 g/kg �-tocopherol), minerals (a multi-element mineral mix (Siromin ) at 175 g head-1 week-1) and vitamins plus minerals (mineral mix plus vitamins) in a two by two factorial design. Treatments started in November prior to mating and finished in May 1 week prior to lambing. Measurements of vitamin status and animal productivity were made on ewes and foetal and weanling lambs. Compared with salt, the mineral mix increased ewe body weight by up to 3% ( P < 0.05), annual wool growth by 4.4% ( P < 0.001) and birth and weaning weights of single lambs by 7.3% ( P < 0.01) and 3.7% (P < 0.05) respectively. Since ewes had been given selenium and cobalt bullets at weaning, the results suggest either that the bullets do not offer protection for the lifetime of the ewe and that additional bulleting is warranted, or that other minerals are limiting production. As pastures dried off, the concentrations of �-tocopherol and G-carotene fell and this was reflected in a decline in the concentrations of �-tocopherol and retinol in liver. However, the liver stores at the beginning of summer were sufficient to prevent the appearance of clinical signs of vitamin deficiency. Vitamin supplementation significantly increased the concentration of vitamins in the plasma and liver of ewes ( P < 0.001)) but it had no significant effect on ewe reproductive performance or on ewe or lamb body weights or wool growth. Vitamin supplements increased the concentrations of retinol and �-tocopherol in the liver of foetal lambs, but even with supplements the levels remained well below normal adult reference values.
- Published
- 1995
- Full Text
- View/download PDF
50. Studies on tyrosine phenol lyase. Modification of essential histidyl residues by diethylpyrocarbonate
- Author
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T Utagawa, Hideaki Yamada, and H Kumagai
- Subjects
biology ,Stereochemistry ,Active site ,Tyrosine phenol-lyase ,Cell Biology ,Biochemistry ,Cofactor ,chemistry.chemical_compound ,Hydroxylamine ,chemistry ,biology.protein ,Aromatic amino acids ,Pyridoxal phosphate ,Tyrosine ,Molecular Biology ,Histidine - Abstract
Tyrosine phenol-lyase of Escherichia intermedia is inactivated by treatment with diethylpyrocarbonate at pH 6.0 AND 4 degrees. Spectrophotometric studies show that the inactivation is stoichiometric, with a modification of 2 histidyl residues per molecule of the enzyme. Finding that this inactivation is largely reversed by treatment with hydroxylamine indicates that the inactivation is mainly due to modification of the histidyl residues. No changes in the sulfhydryl content or in the aromatic amino acids are observed as a result of this modification. The modified tyrosine phenol-lyase retains most of its ability to form a nearly normal complex with its coenzyme, pyridoxal phosphate. This has been shown by studies of its absorption, by the determination of pyridoxal phosphate, and by reduction of the holoenzyme with tritiated sodium borohydride. The modified enzyme also appears to form a Schiff base intermediate with L-alanine. The modified holoenzyme fails to catalyze the exchange of the alpha-hydrogen of L-alanine with tritium from tritiated water. This is consistent with a catalytic role for modified histidyl residues at the active site of the enzyme; this role is the removal of the alpha-hydrogen of substrates.
- Published
- 1975
- Full Text
- View/download PDF
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