Jeju National University
Marine Life Sciences
Interferon-related developmental regulator 1 (IFRD1) is a viral responsive gene associated with interferon gamma. Herein, we identified the IFRD1 gene (EaIFRD1) from red-spotted grouper (Epinephelus akaara), eval uated its transcriptional... more
Interferon-related developmental regulator 1 (IFRD1) is a viral responsive gene associated with interferon gamma. Herein, we identified the IFRD1 gene (EaIFRD1) from red-spotted grouper (Epinephelus akaara), eval uated its transcriptional responses, and investigated its functional features using various biological assays. EaIFRD1 encodes a protein comprising 428 amino acids with a molecular mass of 48.22 kDa. It features a substantial domain belonging to the interferon-related developmental regulator superfamily. Spatial mRNA expression of EaIFRD1 demonstrated the highest expression levels in the brain and the lowest in the skin. Furthermore, EaIFRD1 mRNA expression in grouper tissues exhibited significant modulation in response to immune stimulants, including poly (I:C), LPS, and nervous necrosis virus (NNV) infection. We analyzed down stream gene regulation by examining type I interferon pathway genes following EaIFRD1 overexpression. The results demonstrated a significant upregulation in cells overexpressing EaIFRD1 compared to the control after infection with viral hemorrhagic septicemia virus (VHSV). A subcellular localization assay confirmed the nuclear location of the EaIFRD1 protein, consistent with its role as a transcriptional coactivator. Cells overexpressing EaIFRD1 exhibited increased migratory activity, enhancing wound-healing capabilities compared to the control. Additionally, under H2O2 exposure, EaIFRD1 overexpression protected cells against oxidative stress. Over expression of EaIFRD1 also reduced poly (I:C)-mediated NO production in RAW267.4 macrophage cells. In FHM cells, EaIFRD1 overexpression significantly reduced VHSV virion replication. Collectively, these findings suggest that EaIFRD1 plays a crucial role in the antiviral immune response and immunological regulation in E. akaara.
- by Vileka Jayamali
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Membrane-associated Ring-CH 5 (MARCH5) is a mitochondrial E3 ubiquitin ligase playing a key role in the regulation of mitochondrial dynamics. In mammals, MARCH5 negatively regulates mitochondrial antiviral signaling (MAVS) protein... more
Membrane-associated Ring-CH 5 (MARCH5) is a mitochondrial E3 ubiquitin ligase playing a key role in the regulation of mitochondrial dynamics. In mammals, MARCH5 negatively regulates mitochondrial antiviral signaling (MAVS) protein aggregation during viral infection and hampers downstream type I interferon signaling to prevent excessive immune activation. However, its precise functional role in the teleost immune system re mains unclear. This study investigated the molecular characteristics and immune response of the MARCH5 ortholog in Amphiprion clarkii (A. clarkii; AcMARCH5). The predicted AcMARCH5 protein sequence consists of 287 amino acids with a molecular weight of 32.02 kDa and a theoretical isoelectric point of 9.11. It contains four C-terminal transmembrane (TM) domains and an N-terminal RING cysteine-histidine (CH) domain, which directly regulates ubiquitin transfer. Multiple sequence alignment revealed a high level of conservation between AcMARCH5 and its orthologs in other vertebrate species. Under normal physiological conditions, AcMARCH5 showed the highest mRNA expression in the muscle, brain, and kidney tissues of A. clarkii. Upon stimulation with polyinosinic:polycytidylic acid (Poly I:C), lipopolysaccharide (LPS), and Vibrio harveyi, AcMARCH5 expression was drastically modulated. Functional assays showed that overexpression of AcMARCH5 in fathead minnow (FHM) cells downregulated antiviral gene expression, accompanied by enhanced viral hemorrhagic septicemia virus (VHSV) replication. In murine macrophages, AcMARCH5 overexpression markedly reduced the production of pro-inflammatory cytokines in response to poly I:C treatment. Additionally, AcMARCH5 exhibited an anti apoptotic effect in H2O2-treated FHM cells. Collectively, these results suggest that AcMARCH5 may play a role in maintaining cellular homeostasis under disease and stress conditions in A. clarkii.
- by Vileka Jayamali
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Coral reefs are declining worldwide due to increased incidence of climate-induced coral bleaching, which will have widespread biodiversity and economic impacts. A simple method to measure the sub-bleaching level of heat-light stress... more
Coral reefs are declining worldwide due to increased incidence of climate-induced coral bleaching, which will have widespread biodiversity and economic impacts. A simple method to measure the sub-bleaching level of heat-light stress experienced by corals would greatly inform reef management practices by making it possible to assess the distribution of bleaching risks among individual reef sites. Gene expression analysis based on quantitative PCR (qPCR) can be used as a diagnostic tool to determine coral condition in situ. We evaluated the expression of 13 candidate genes during heat-light stress in a common Caribbean coral Porites astreoides, and observed strong and consistent changes in gene expression in two independent experiments. Furthermore, we found that the apparent return to baseline expression levels during a recovery phase was rapid, despite visible signs of colony bleaching. We show that the response to acute heat-light stress in P. astreoides can be monitored by measuring the difference in expression of only two genes: Hsp16 and actin. We demonstrate that this assay discriminates between corals sampled from two field sites experiencing different temperatures. We also show that the assay is applicable to an Indo-Pacific congener, P. lobata, and therefore could potentially be used to diagnose acute heat-light stress on coral reefs worldwide.
- by Carly Kenkel and +6
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- Coral Reefs, Multidisciplinary, Light, PLoS one
1. The Chagos Archipelago was designated a no-take marine protected area (MPA) in 2010; it covers 550 000 km 2 , with more than 60 000 km 2 shallow limestone platform and reefs. This has doubled the global cover of such MPAs.
A new shallow-water species, Polycyathus chaishanensis sp. nov. (Scleractinia: Caryophylliidae), from Chaishan, Kaohsiung, Taiwan. Zoological Studies 51(2): 213-221. A small population of a new species of zooxanthellate scleractinian... more
A new shallow-water species, Polycyathus chaishanensis sp. nov. (Scleractinia: Caryophylliidae), from Chaishan, Kaohsiung, Taiwan. Zoological Studies 51(2): 213-221. A small population of a new species of zooxanthellate scleractinian coral, Polycyathus chaishanensis sp. nov., is described from shallow water (< 3 m) off Chiashan, Kaohsiung, an uplifted Pleistocene reef located on the southwest coast of Taiwan. Polycyathus chaishanensis sp. nov. is a zooxanthellate coral associated with Symbiodinium C1 and forms small encrusting colonies. Polycyathus chaishanensis sp. nov. differs from other Polycyathus by having (1) the smallest corallites (2.0-3.7 mm in calicular diameter) reported in the genus Polycyathus; (2) septa hexamerally arranged in 4 incomplete cycles displaying dentate or laciniate axial edges; (3) crispate and well-developed pali before the secondary septa; and (4) light brown pigmented pali/columellar elements. When expanded, vivid-red to brown polyps rise considerably above the calice, and long and slender tentacles are covered with white nematocyst batteries. Polycyathus chaishanensis is the only species of Polycyathus known from Taiwanese waters and appears to be endemic to a small region at Chaishan. The small population of this new species raises concerns as to its vulnerability to natural and anthropogenic threats.
The scale and intensity of marine cage culture have increased in the Asian-Pacific region, particularly in oligotrophic waters where coral reef organisms flourish. In this study, the influence of marine cage culture on subtropical coral... more
The scale and intensity of marine cage culture have increased in the Asian-Pacific region, particularly in oligotrophic waters where coral reef organisms flourish. In this study, the influence of marine cage culture on subtropical coral communities in turbid waters was evaluated by measuring environmental parameters and benthic community compositions at Magongwan in the Penghu Islands, Taiwan. A canonical discriminant analysis of environmental parameters revealed that elevated levels of ammonium, nitrite, and chlorophyll a (chl a) released from the cages were the main pollution indicators that, in addition to sedimentation and turbidity, distinguished Impact Zone 1 (cage-culture zone) from the other 2 zones -Impact Zone 2 (800 m away from the cages) and the reference zone -in these turbid waters. Results of the canonical correlation analysis indicated that the coverage extents of macroalgae, sponges, and zoanthids were strongly correlated with levels of ammonium, nitrite, phosphate, chl a, and dissolved oxygen. Coral communities in Impact Zone 1 were mostly composed of stress-tolerant massive and submassive corals, but were lacking branching Acropora corals. In contrast, coral communities in the other zones, with high habitat complexity and species richness, were dominated by coral species with diverse morphologies, including branching Acropora coral communities. These results suggest that marine cage culture has been causing chronic nutrient enrichment in the surrounding waters at Magongwan, which may have resulted in a deterioration of suitable habitats for coral reef organisms. Nevertheless, intermediate levels of nutrients and particulate organic matter relative to the other zones might have been caused by the adjacent cage culture, resulting in the high coral coverage and diversity in the Impact Zone 2 in particular.
- by Pei-jie Meng and +1
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- Zoology, Ecology
Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter 'Gulf') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms... more
Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter 'Gulf') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms of scientific importance (i.e., filled a knowledge gap and was a research priority) and efficiency in resource use (i.e., was highly feasible and ecologically broad). Ten research questions, in six major research areas, were highly important for both understanding Gulf coral reef ecosystems and also an efficient use of limited research resources. These questions mirrored global evaluations of the importance of understanding and evaluating biodiversity, determining the potential impacts 0025-326X/$ -see front matter Ó of climate change, the role of anthropogenic impacts in structuring coral reef communities, and economically evaluating coral reef communities. These questions provide guidance for future research on coral reef ecosystems within the Gulf, and enhance the potential for assessment and management of future changes in this globally significant region.
A novel symbiosis between scleractinians and hydroids (Zanclea spp.) was recently discovered using taxonomic approaches for hydroid species identification. In this study, we address the question whether this is a species-specific... more
A novel symbiosis between scleractinians and hydroids (Zanclea spp.) was recently discovered using taxonomic approaches for hydroid species identification. In this study, we address the question whether this is a species-specific symbiosis or a cosmopolitan association between Zanclea and its coral hosts. Three molecular markers, including mitochondrial 16S and nuclear 28S ribosomal genes, and internal transcribed spacer (ITS), were utilized to examine the existence of Zanclea species from 14 Acropora species and 4 other Acroporidae genera including 142 coral samples collected from reefs in Kenting and the Penghu Islands, Taiwan, Togian Island, Indonesia, and Osprey Reef and Orpheus Island on the Great Barrier Reef, Australia. Molecular phylogenetic analyses of the 16S and 28S genes showed that Acropora-associated Zanclea was monophyletic, but the genus Zanclea was not. Analysis of the ITS, and 16S and 28S genes showed either identical or extremely low genetic diversity (with mean pairwise distances of 0.009 and 0.006 base substitutions per site for the 16S and 28S genes, respectively) among Zanclea spp. collected from diverse Acropora hosts in different geographic locations, suggesting that a cosmopolitan and probably genus-specific association occurs between Zanclea hydroids and their coral hosts.
- by Shashank Keshavmurthy and +1
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- Geography, RNA, Australia, Symbiosis
Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter 'Gulf') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms... more
Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter 'Gulf') coral reefs. Thirty-one participants submitted 71 research questions that were peer-assessed in terms of scientific importance (i.e., filled a knowledge gap and was a research priority) and efficiency in resource use (i.e., was highly feasible and ecologically broad). Ten research questions, in six major research areas, were highly important for both understanding Gulf coral reef ecosystems and also an efficient use of limited research resources. These questions mirrored global evaluations of the importance of understanding and evaluating biodiversity, determining the potential impacts 0025-326X/$ -see front matter Ó of climate change, the role of anthropogenic impacts in structuring coral reef communities, and economically evaluating coral reef communities. These questions provide guidance for future research on coral reef ecosystems within the Gulf, and enhance the potential for assessment and management of future changes in this globally significant region.
- by Shashank Keshavmurthy and +2
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Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well... more
Most reviews concerning the impact of climate change on coral reefs discuss independent effects of warming or ocean acidification. However, the interactions between these, and between these and direct local stressors are less well addressed. This review underlines that coral bleaching, acidification, and diseases are expected to interact synergistically, and will negatively influence survival, growth, reproduction, larval development, settlement, and post-settlement development of corals. Interactions with local stress factors such as pollution, sedimentation, and overfishing are further expected to compound effects of climate change.
Determination of the genetic diversity and structure of coral populations across their biogeographic range must include the investigation of the coral host and its associated Symbiodinium. We examined the genetic similarity of the... more
Determination of the genetic diversity and structure of coral populations across their biogeographic range must include the investigation of the coral host and its associated Symbiodinium. We examined the genetic similarity of the stress-tolerant coral Oulastrea crispata and the diversity of Symbiodinium D across part of their geographic distribution, which ranges across 5800 km in the West Pacific from tropical Thailand (~7°N) to the outlying regions of temperate Japan (36°N). F ST -statistics and AMOVA of directly sequenced coral ribosomal internal transcribed spacer (ITS) DNA sequences showed a high genetic homogeneity between temperate and subtropical populations, but showed a significant difference between temperate and subtropical populations and their tropical counterparts. Denaturing gradient gel electrophoresis (DGGE) of ITS DNA sequences identified 4 major O. crispata-associated Symbiodinium D types: D8, D8−12, D12−13, and D15; these were found in the regions extending from tropical Thailand towards the high latitude regions of Japan. F ST -statistics and AMOVA of Symbiodinium ITS showed significant differences between tropical, subtropical, and temperate regions, with the D8 and D8−12 dominant in the tropical and subtropical regions, the D12−13 endemic in the subtropical northern South China Sea, and D15 restricted to the high-latitudinal outlying coral communities. Consistent variation in environmental factors, such as temperature and light, may have driven the regionalspecific divergence of the Symbiodinium D types, suggesting that habitat-specific Symbiodinium types can assist O. crispata in acclimating to the environmental fluctuations found in the marginal range of coral distribution.
In this work, we investigate the mechanisms of ciliate infection in the coral Acropora formosa. The results of laboratory experiments showed that healthy corals kept at 24 º C in aquaria and inoculated with cultured ciliates (3-5... more
In this work, we investigate the mechanisms of ciliate infection in the coral Acropora formosa. The results of laboratory experiments showed that healthy corals kept at 24 º C in aquaria and inoculated with cultured ciliates (3-5 cells/ml) remained healthy throughout the experimental period of 120 hours. However, corals kept at 29 º C began to experience tissue loss within three hours of the start of the experiment. There was 40% 5% tissue loss within 24 hours of the start of the experiment. The ciliates engulfed the zooxanthellae cells and eventually degraded them. The infection spreaded and killed coral pieces of 5cm in length in approximately 48 hours. Microscopic observations showed destruction of polyps, coenosarc, and the surface of the coenosteum. As the infection spread and the ciliate abundance increased in the aquaria, all coral fragments were killed. Our results show that ciliates act as opportunists feeding on zooxanthellae from physiologically compromised A. formosa. Our results suggest that temperature stress plays a role in this coral becoming susceptible to ciliate infection.
Over the period of BIOT’s existence, there have been a dozen scientific visits to its atolls by more than 50 scientists, and double this number have become engaged in work on materi- als sent back. It is clear, during this period when... more
Over the period of BIOT’s existence, there have been a dozen scientific visits to its atolls by more than 50 scientists, and double this number have become engaged in work on materi- als sent back. It is clear, during this period when coral reefs in most of the Indian Ocean have become seriously degraded, that the reefs of Chagos persist in an exceptionally good state. The results of these research expeditions led increas- ingly to calls to extend conservation in the area, and data to support this concept has come from over 200 papers arising from the research. This summarises current understanding of the reefs, but starts with an account of their condition through the major bleaching event of 1998.
We used an integrative genetics approach using sequences of (1) nuclear ribosomal rDNA (internal transcribed spacers and partial large subunit rDNA), (2) single-copy microsatellite nuclear DNA, (3) chloroplast-encoded 23S rDNA, (4)... more
We used an integrative genetics approach using sequences of (1) nuclear ribosomal rDNA (internal transcribed spacers and partial large subunit rDNA), (2) single-copy microsatellite nuclear DNA, (3) chloroplast-encoded 23S rDNA, (4) mitochondrial cytochrome b, and (5) repeat variation at eight microsatellite markers, to test the hypothesis that the stress-tolerant, ‘morphologically cryptic' Clade D Symbiodinium (Dinophyceae) was composed of more than one species. Concordant phylogenetic and population genetic evidence clearly differentiate separately evolving, reproductively isolated lineages. We describe Symbiodinium boreum sp. nov. and S. eurythalpos sp. nov., two symbionts known to occur in colonies of the zebra coral, Oulastrea crispata (Scleractinia), which lives in turbid, marginal habitats extending from equatorial Southeast Asia to the main islands of Japan in the temperate northwest Pacific Ocean. Symbiodinium boreum was associated with O. crispata in temperate latitudes...
Temporal and spatial variations in symbiont communities of the catch bowl coral Isopora palifera (Scleractinia: Acroporidae) on reefs in Kenting National Park, Taiwan. Zoological Studies 51(8): 1343-1353. Acclimatization through... more
Temporal and spatial variations in symbiont communities of the catch bowl coral Isopora palifera (Scleractinia: Acroporidae) on reefs in Kenting National Park, Taiwan. Zoological Studies 51(8): 1343-1353. Acclimatization through Symbiodinium shuffling is one of potential mechanisms in reef- building corals to survive environmental stress. In our previous study, the catch bowl coral Isopora palifera in Tantzei Bay (TZB), Nanwan, Kenting National Park (KNP), southern Taiwan was demonstrated to shuffle thermal-tolerant Symbiodinium D1a and thermal-sensitive Symbiodinium C3 in response to seasonal variations in sea surface temperatures (SSTs) in 2000 and 2001. In this study, we reexamined the temporal dynamics of the Symbiodinium community of I. palifera in TZB in 2006-2009. In addition, spatial variations in Symbiodinium communities in I. palifera were also examined at 6 other sites of Nanwan, KNP in 2009, including a site located at a nuclear power plant outlet (NPP-OL) in southern Ta...
- by Pei-jie Meng and +1
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- Zoology
Acropora species distribution patterns at Larak, Farur, and Khark Islands along the Iranian coast were investigated from October 2008 to November 2009 based on a previous study conducted on the taxonomy of Acropora by examining 1,169... more
Acropora species distribution patterns at Larak, Farur, and Khark Islands along the Iranian coast were investigated from October 2008 to November 2009 based on a previous study conducted on the taxonomy of Acropora by examining 1,169 colonies. The analysis showed that the species diversity and evenness were low at the three islands, but the total percentage cover of Acropora was relatively high at Larak (38.52%) with lower cover at Khark (24.01%). The Acropora community at Larak Island was significantly dissimilar to those at Farur and Khark Islands, whereas the latter two possessed similar community structures. Chlorophyll a differences of Larak with Farur and Khark Islands coincided with Acropora community differences among these islands. Relatively high coral coverage found at the islands off the Iranian coast suggests important implications for coral reef resilience and mitigation (e.g., assisted migration) in response to changing environmental conditions, not only for the Persi...