305 research outputs found

    Warm seawater temperature promotes substrate colonization by the blue coral, Heliopora coerulea

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    Background: Heliopora coerulea, the blue coral, is a reef building octocoral that is reported to have a higher optimum temperature for growth compared to most scleractinian corals. This octocoral has been observed to grow over both live and dead scleractinians and to dominate certain reefs in the Indo-Pacific region. The molecular mechanisms underlying the ability of H. coerulea to tolerate warmer seawater temperatures and to effectively compete for space on the substrate remain to be elucidated. Methods: In this study, we subjected H. coerulea colonies to various temperatures for up to 3 weeks. The growth and photosynthetic efficiency rates of the coral colonies were measured. We then conducted pairwise comparisons of gene expression among the different coral tissue regions to identify genes and pathways that are expressed under different temperature conditions. Results: A horizontal growth rate of 1.13 +/- 0.25 mm per week was observed for corals subjected to 28 or 31 degrees C. This growth rate was significantly higher compared to corals exposed at 26 degrees C. This new growth was characterized by the extension of whitish tissue at the edges of the colony and was enriched for a matrix metallopeptidase, a calcium and integrin binding protein, and other transcripts with unknown function. Tissues at the growth margin and the adjacent calcified encrusting region were enriched for transcripts related to proline and riboflavin metabolism, nitrogen utilization, and organic cation transport. The calcified digitate regions, on the other hand, were enriched for transcripts encoding proteins involved in cell-matrix adhesion, translation, receptor-mediated endocytosis, photosynthesis, and ion transport. Functions related to lipid biosynthesis, extracellular matrix formation, cell migration, and oxidation-reduction processes were enriched at the growth margin in corals subjected for 3 weeks to 28 or 31 degrees C relative to corals at 26 degrees C. In the digitate region of the coral, transcripts encoding proteins that protect against oxidative stress, modify cell membrane composition, and mediate intercellular signaling pathways were enriched after just 24 h of exposure to 31 degrees C compared to corals at 28 degrees C. The overall downregulation of gene expression observed after 3 weeks of sustained exposure to 31 degrees C is likely compensated by symbiont metabolism. Discussion: These findings reveal that the different regions of H. coerulea have variable gene expression profiles and responses to temperature variation. Under warmer conditions, the blue coral invests cellular resources toward extracellular matrix formation and cellular migration at the colony margins, which may promote rapid tissue growth and extension. This mechanism enables the coral to colonize adjacent reef substrates and successfully overgrow slower growing scleractinian corals that may already be more vulnerable to warming ocean waters

    Influence of the Blue Coral Heliopora coerulea on Scleractinian Coral Larval Recruitment

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    The octocoral Heliopora coerulea has emerged as one of the most dominant reef-building corals in the Bolinao Reef Complex, northern Philippines. One of the possible mechanisms that may contribute to the success of H. coerulea over scleractinian corals is its ability to compete effectively for space on the reef by inhibiting the settlement of coral larvae in its immediate vicinity. To determine whether H. coerulea can indeed inhibit larval recruitment, settlement tiles were deployed inside H. coerulea aggregations or on hard substrate at a distance of about 2 to 3 meters away. After three months of deployment, only a single H. coerulea recruit was observed on tiles placed within aggregations whereas many different coral recruits were observed on tiles placed on substrate away from the blue coral. These results suggest that adult H. coerulea can inhibit the settlement of scleractinian larvae. This effect may be mediated by various mechanisms, such as the production of allelopathic compounds, deployment of mesenterial filaments, and sweeper tentacles. However, further studies are needed to determine the modes of competition that are used by the coral

    Influence of the Blue Coral Heliopora coerulea

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    The octocoral Heliopora coerulea has emerged as one of the most dominant reef-building corals in the Bolinao Reef Complex, northern Philippines. One of the possible mechanisms that may contribute to the success of H. coerulea over scleractinian corals is its ability to compete effectively for space on the reef by inhibiting the settlement of coral larvae in its immediate vicinity. To determine whether H. coerulea can indeed inhibit larval recruitment, settlement tiles were deployed inside H. coerulea aggregations or on hard substrate at a distance of about 2 to 3 meters away. After three months of deployment, only a single H. coerulea recruit was observed on tiles placed within aggregations whereas many different coral recruits were observed on tiles placed on substrate away from the blue coral. These results suggest that adult H. coerulea can inhibit the settlement of scleractinian larvae. This effect may be mediated by various mechanisms, such as the production of allelopathic compounds, deployment of mesenterial filaments, and sweeper tentacles. However, further studies are needed to determine the modes of competition that are used by the coral

    Transcriptome analysis of the reef-building octocoral, Heliopora coerulea

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    The blue coral, Heliopora coerulea, is a reef-building octocoral that prefers shallow water and exhibits optimal growth at a temperature close to that which causes bleaching in scleractinian corals. To better understand the molecular mechanisms underlying its biology and ecology, we generated a reference transcriptome for H. coerulea using next-generation sequencing. Metatranscriptome assembly yielded 90,817 sequences of which 71% (64,610) could be annotated by comparison to public databases. The assembly included transcript sequences from both the coral host and its symbionts, which are related to the thermotolerant C3-Gulf ITS2 type Symbiodinium. Analysis of the blue coral transcriptome revealed enrichment of genes involved in stress response, including heat-shock proteins and antioxidants, as well as genes participating in signal transduction and stimulus response. Furthermore, the blue coral possesses homologs of biomineralization genes found in other corals and may use a biomineralization strategy similar to that of scleractinians to build its massive aragonite skeleton. These findings thus offer insights into the ecology of H. coerulea and suggest gene networks that may govern its interactions with its environment

    Beliefs and practices about reproductive tract infections: Findings from a series of Philippine FGDs

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    The past decade has been characterized by increasing concern about the medical, social, and economic problems associated with reproductive tract infections (RTIs). The goal of preventing and curing RTIs is now being prioritized by public health agencies in the developing world. Very little research has been conducted on the problem of RTIs in the local context, and it would be helpful for program managers if the knowledge and beliefs now being held about RTIs were more clearly delineated. Knowing more about the way in which these illnesses are viewed by the community, about traditional practices for preventing and curing RTIs, and about the results of ongoing public health initiatives designed to deal with these conditions is also needed. The present study, as this report states, utilizes a qualitative research technique known as focus group discussions as a means of stimulating people to speak up on this subject. While the study won’t provide precise statistical profiles of study respondents, it should allow a first-hand glimpse of the ways in which RTIs are perceived and responded to by a group of typical Filipinos

    Perceiving societal pressure to be happy is linked to poor well-being, especially in happy nations

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    Happiness is a valuable experience, and societies want their citizens to be happy. Although this societal commitment seems laudable, overly emphasizing positivity (versus negativity) may create an unattainable emotion norm that ironically compromises individual well-being. In this multi-national study (40 countries; 7443 participants), we investigate how societal pressure to be happy and not sad predicts emotional, cognitive and clinical indicators of well-being around the world, and examine how these relations differ as a function of countries’ national happiness levels (collected from the World Happiness Report). Although detrimental well-being associations manifest for an average country, the strength of these relations varies across countries. People’s felt societal pressure to be happy and not sad is particularly linked to poor well-being in countries with a higher World Happiness Index. Although the cross-sectional nature of our work prohibits causal conclusions, our findings highlight the correlational link between social emotion valuation and individual well-being, and suggest that high national happiness levels may have downsides for some.info:eu-repo/semantics/publishedVersio

    The REST remodeling complex protects genomic integrity during embryonic neurogenesis

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    The timely transition from neural progenitor to post-mitotic neuron requires down-regulation and loss of the neuronal transcriptional repressor, REST. Here, we have used mice containing a gene trap in the Rest gene, eliminating transcription from all coding exons, to remove REST prematurely from neural progenitors. We find that catastrophic DNA damage occurs during S-phase of the cell cycle, with long-term consequences including abnormal chromosome separation, apoptosis, and smaller brains. Persistent effects are evident by latent appearance of proneural glioblastoma in adult mice deleted additionally for the tumor suppressor p53 protein (p53). A previous line of mice deleted for REST in progenitors by conventional gene targeting does not exhibit these phenotypes, likely due to a remaining C-terminal peptide that still binds chromatin and recruits co-repressors. Our results suggest that REST-mediated chromatin remodeling is required in neural progenitors for proper S-phase dynamics, as part of its well-established role in repressing neuronal genes until terminal differentiation
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