The Experts below are selected from a list of 2112 Experts worldwide ranked by ideXlab platform
Takashi Nakamura - One of the best experts on this subject based on the ideXlab platform.
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an aposymbiotic primary Coral polyp counteracts acidification by active ph regulation
Scientific Reports, 2017Co-Authors: Yoshikazu Ohno, Akira Iguchi, Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Takashi Nakamura, Chuya ShinzatoAbstract:Corals build their skeletons using extracellular calcifying fluid located in the tissue–skeleton interface. However, the mechanism by which Corals control the transport of calcium and other ions from seawater and the mechanism of constant alkalization of calcifying fluid are largely unknown. To address these questions, we performed direct pH imaging at calcification sites (subcalicoblastic medium, SCM) to visualize active pH upregulation in live aposymbiotic primary Coral Polyps treated with HCl-acidified seawater. Active alkalization was observed in all individuals using vital staining method while the movement of HPTS and Alexa Fluor to SCM suggests that certain ions such as H+ could diffuse via a paracellular pathway to SCM. Among them, we discovered acid-induced oscillations in the pH of SCM (pHSCM), observed in 24% of Polyps examined. In addition, we discovered acid-induced pH up-regulation waves in 21% of Polyps examined, which propagated among SCMs after exposure to acidified seawater. Our results showed that Corals can regulate pHSCM more dynamically than was previously believed. These observations will have important implications for determining how Corals regulate pHSCM during calcification. We propose that Corals can sense ambient seawater pH via their innate pH-sensitive systems and regulate pHSCM using several unknown pH-regulating ion transporters that coordinate with multicellular signaling occurring in Coral tissue.
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microscopic observation of symbiotic and aposymbiotic juvenile Corals in nutrient enriched seawater
Marine Pollution Bulletin, 2013Co-Authors: Yasuaki Tanaka, Akira Iguchi, Mayuri Inoue, Chiharu Mori, Kazuhiko Sakai, Atsushi Suzuki, Hodaka Kawahata, Takashi NakamuraAbstract:Symbiotic and aposymbiotic juvenile Corals, which were grown in the laboratory from the gametes of the scleractinian Coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic Corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic Corals were in close physical contact with BMA. The areal growth rate of the symbiotic Corals was significantly higher than that of the aposymbiotic Corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic Coral Polyps and enhanced the growth of some of the symbiotic Corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile Corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile Corals to survive in high-nutrient seawater.
Mayuri Inoue - One of the best experts on this subject based on the ideXlab platform.
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an aposymbiotic primary Coral polyp counteracts acidification by active ph regulation
Scientific Reports, 2017Co-Authors: Yoshikazu Ohno, Akira Iguchi, Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Takashi Nakamura, Chuya ShinzatoAbstract:Corals build their skeletons using extracellular calcifying fluid located in the tissue–skeleton interface. However, the mechanism by which Corals control the transport of calcium and other ions from seawater and the mechanism of constant alkalization of calcifying fluid are largely unknown. To address these questions, we performed direct pH imaging at calcification sites (subcalicoblastic medium, SCM) to visualize active pH upregulation in live aposymbiotic primary Coral Polyps treated with HCl-acidified seawater. Active alkalization was observed in all individuals using vital staining method while the movement of HPTS and Alexa Fluor to SCM suggests that certain ions such as H+ could diffuse via a paracellular pathway to SCM. Among them, we discovered acid-induced oscillations in the pH of SCM (pHSCM), observed in 24% of Polyps examined. In addition, we discovered acid-induced pH up-regulation waves in 21% of Polyps examined, which propagated among SCMs after exposure to acidified seawater. Our results showed that Corals can regulate pHSCM more dynamically than was previously believed. These observations will have important implications for determining how Corals regulate pHSCM during calcification. We propose that Corals can sense ambient seawater pH via their innate pH-sensitive systems and regulate pHSCM using several unknown pH-regulating ion transporters that coordinate with multicellular signaling occurring in Coral tissue.
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microscopic observation of symbiotic and aposymbiotic juvenile Corals in nutrient enriched seawater
Marine Pollution Bulletin, 2013Co-Authors: Yasuaki Tanaka, Akira Iguchi, Mayuri Inoue, Chiharu Mori, Kazuhiko Sakai, Atsushi Suzuki, Hodaka Kawahata, Takashi NakamuraAbstract:Symbiotic and aposymbiotic juvenile Corals, which were grown in the laboratory from the gametes of the scleractinian Coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic Corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic Corals were in close physical contact with BMA. The areal growth rate of the symbiotic Corals was significantly higher than that of the aposymbiotic Corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic Coral Polyps and enhanced the growth of some of the symbiotic Corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile Corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile Corals to survive in high-nutrient seawater.
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effects of seawater ph on growth and skeletal u ca ratios of acropora digitifera Coral Polyps
Geophysical Research Letters, 2011Co-Authors: Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Ryota Suwa, Hodaka KawahataAbstract:[1] The impact of ocean acidification caused by the increasing atmospheric CO2 has been studied in marine calcifiers, including hermatypic Corals. However, the effect of elevated pCO2 on the early developmental life-cycle stage of Corals has been little studied. In this study, we reared Polyps of Acropora digitifera in seawater at pHT 6.55, 7.31, 7.64, 7.77, and 8.03, controlled by CO2 bubbling. We measured the dry weights of polyp skeletons after the 40-d experiment to investigate the relationship between the seawater aragonite saturation state and polyp growth. In addition, we measured skeletal U/Ca ratio to estimate their pH dependence. Skeletal weights of Coral Polyps increased with the aragonite saturation state and reached an apparent saturation plateau above pH 7.77. U/Ca ratios had a strong inverse relationship with pH and a negligible relationship with skeletal growth rate (polyp weight), suggesting that skeletal U/Ca could be useful for reconstructing paleo-pH.
Tali Mass - One of the best experts on this subject based on the ideXlab platform.
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combined responses of primary Coral Polyps and their algal endosymbionts to decreasing seawater ph
Proceedings of The Royal Society B: Biological Sciences, 2021Co-Authors: Federica Scucchia, Assaf Malik, Paul Zaslansky, Hollie M Putnam, Tali MassAbstract:With Coral reefs declining globally, resilience of these ecosystems hinges on successful Coral recruitment. However, knowledge of the acclimatory and/or adaptive potential in response to environmen...
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combined responses of primary Coral Polyps and their algal endosymbionts to decreasing seawater ph
bioRxiv, 2021Co-Authors: Federica Scucchia, Assaf Malik, Paul Zaslansky, Hollie M Putnam, Tali MassAbstract:With Coral reefs declining globally, resilience of these ecosystems hinges on successful Coral recruitment. However, knowledge of the acclimatory and/or adaptive potential in response to environmental challenges such as ocean acidification (OA) in earliest life stages is limited. Our combination of physiological measurements, microscopy, computed tomography techniques and gene expression analysis allowed us to thoroughly elucidate the mechanisms underlying the response of early life stages of Corals, together with their algal partners, to the projected decline in oceanic pH. We observed extensive physiological, morphological and transcriptional changes in surviving recruits, and the transition to a less-skeleton/more-tissue phenotype. We found that decreased pH conditions stimulate photosynthesis and endosymbiont growth, and gene expression potentially linked to photosynthates translocation. Our unique holistic study discloses the previously unseen intricate net of interacting mechanisms that regulate the performance of these organisms in response to OA.
Atsushi Suzuki - One of the best experts on this subject based on the ideXlab platform.
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an aposymbiotic primary Coral polyp counteracts acidification by active ph regulation
Scientific Reports, 2017Co-Authors: Yoshikazu Ohno, Akira Iguchi, Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Takashi Nakamura, Chuya ShinzatoAbstract:Corals build their skeletons using extracellular calcifying fluid located in the tissue–skeleton interface. However, the mechanism by which Corals control the transport of calcium and other ions from seawater and the mechanism of constant alkalization of calcifying fluid are largely unknown. To address these questions, we performed direct pH imaging at calcification sites (subcalicoblastic medium, SCM) to visualize active pH upregulation in live aposymbiotic primary Coral Polyps treated with HCl-acidified seawater. Active alkalization was observed in all individuals using vital staining method while the movement of HPTS and Alexa Fluor to SCM suggests that certain ions such as H+ could diffuse via a paracellular pathway to SCM. Among them, we discovered acid-induced oscillations in the pH of SCM (pHSCM), observed in 24% of Polyps examined. In addition, we discovered acid-induced pH up-regulation waves in 21% of Polyps examined, which propagated among SCMs after exposure to acidified seawater. Our results showed that Corals can regulate pHSCM more dynamically than was previously believed. These observations will have important implications for determining how Corals regulate pHSCM during calcification. We propose that Corals can sense ambient seawater pH via their innate pH-sensitive systems and regulate pHSCM using several unknown pH-regulating ion transporters that coordinate with multicellular signaling occurring in Coral tissue.
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microscopic observation of symbiotic and aposymbiotic juvenile Corals in nutrient enriched seawater
Marine Pollution Bulletin, 2013Co-Authors: Yasuaki Tanaka, Akira Iguchi, Mayuri Inoue, Chiharu Mori, Kazuhiko Sakai, Atsushi Suzuki, Hodaka Kawahata, Takashi NakamuraAbstract:Symbiotic and aposymbiotic juvenile Corals, which were grown in the laboratory from the gametes of the scleractinian Coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic Corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic Corals were in close physical contact with BMA. The areal growth rate of the symbiotic Corals was significantly higher than that of the aposymbiotic Corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic Coral Polyps and enhanced the growth of some of the symbiotic Corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile Corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile Corals to survive in high-nutrient seawater.
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effects of seawater ph on growth and skeletal u ca ratios of acropora digitifera Coral Polyps
Geophysical Research Letters, 2011Co-Authors: Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Ryota Suwa, Hodaka KawahataAbstract:[1] The impact of ocean acidification caused by the increasing atmospheric CO2 has been studied in marine calcifiers, including hermatypic Corals. However, the effect of elevated pCO2 on the early developmental life-cycle stage of Corals has been little studied. In this study, we reared Polyps of Acropora digitifera in seawater at pHT 6.55, 7.31, 7.64, 7.77, and 8.03, controlled by CO2 bubbling. We measured the dry weights of polyp skeletons after the 40-d experiment to investigate the relationship between the seawater aragonite saturation state and polyp growth. In addition, we measured skeletal U/Ca ratio to estimate their pH dependence. Skeletal weights of Coral Polyps increased with the aragonite saturation state and reached an apparent saturation plateau above pH 7.77. U/Ca ratios had a strong inverse relationship with pH and a negligible relationship with skeletal growth rate (polyp weight), suggesting that skeletal U/Ca could be useful for reconstructing paleo-pH.
Kazuhiko Sakai - One of the best experts on this subject based on the ideXlab platform.
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an aposymbiotic primary Coral polyp counteracts acidification by active ph regulation
Scientific Reports, 2017Co-Authors: Yoshikazu Ohno, Akira Iguchi, Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Takashi Nakamura, Chuya ShinzatoAbstract:Corals build their skeletons using extracellular calcifying fluid located in the tissue–skeleton interface. However, the mechanism by which Corals control the transport of calcium and other ions from seawater and the mechanism of constant alkalization of calcifying fluid are largely unknown. To address these questions, we performed direct pH imaging at calcification sites (subcalicoblastic medium, SCM) to visualize active pH upregulation in live aposymbiotic primary Coral Polyps treated with HCl-acidified seawater. Active alkalization was observed in all individuals using vital staining method while the movement of HPTS and Alexa Fluor to SCM suggests that certain ions such as H+ could diffuse via a paracellular pathway to SCM. Among them, we discovered acid-induced oscillations in the pH of SCM (pHSCM), observed in 24% of Polyps examined. In addition, we discovered acid-induced pH up-regulation waves in 21% of Polyps examined, which propagated among SCMs after exposure to acidified seawater. Our results showed that Corals can regulate pHSCM more dynamically than was previously believed. These observations will have important implications for determining how Corals regulate pHSCM during calcification. We propose that Corals can sense ambient seawater pH via their innate pH-sensitive systems and regulate pHSCM using several unknown pH-regulating ion transporters that coordinate with multicellular signaling occurring in Coral tissue.
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microscopic observation of symbiotic and aposymbiotic juvenile Corals in nutrient enriched seawater
Marine Pollution Bulletin, 2013Co-Authors: Yasuaki Tanaka, Akira Iguchi, Mayuri Inoue, Chiharu Mori, Kazuhiko Sakai, Atsushi Suzuki, Hodaka Kawahata, Takashi NakamuraAbstract:Symbiotic and aposymbiotic juvenile Corals, which were grown in the laboratory from the gametes of the scleractinian Coral Acropora digitifera and had settled down onto plastic culture plates, were observed with a microscope under different nutrient conditions. The symbiotic Corals successfully removed the surrounding benthic microalgae (BMA), whereas the aposymbiotic Corals were in close physical contact with BMA. The areal growth rate of the symbiotic Corals was significantly higher than that of the aposymbiotic Corals. The addition of nutrients to the culture seawater increased the chlorophyll a content in the symbiotic Coral Polyps and enhanced the growth of some of the symbiotic Corals, however the average growth rate was not significantly affected, most likely because of the competition with BMA. The comparison between the symbiotic and aposymbiotic juvenile Corals showed that the establishment of a symbiotic association could be imperative for post-settlement juvenile Corals to survive in high-nutrient seawater.
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effects of seawater ph on growth and skeletal u ca ratios of acropora digitifera Coral Polyps
Geophysical Research Letters, 2011Co-Authors: Mayuri Inoue, Kazuhiko Sakai, Atsushi Suzuki, Ryota Suwa, Hodaka KawahataAbstract:[1] The impact of ocean acidification caused by the increasing atmospheric CO2 has been studied in marine calcifiers, including hermatypic Corals. However, the effect of elevated pCO2 on the early developmental life-cycle stage of Corals has been little studied. In this study, we reared Polyps of Acropora digitifera in seawater at pHT 6.55, 7.31, 7.64, 7.77, and 8.03, controlled by CO2 bubbling. We measured the dry weights of polyp skeletons after the 40-d experiment to investigate the relationship between the seawater aragonite saturation state and polyp growth. In addition, we measured skeletal U/Ca ratio to estimate their pH dependence. Skeletal weights of Coral Polyps increased with the aragonite saturation state and reached an apparent saturation plateau above pH 7.77. U/Ca ratios had a strong inverse relationship with pH and a negligible relationship with skeletal growth rate (polyp weight), suggesting that skeletal U/Ca could be useful for reconstructing paleo-pH.