Project description:Crustose coralline algae (CCA) are calcifying red macroalgae that play important ecological roles including stabilisation of reef frameworks and provision of settlement cues for a range of marine invertebrates. Previous research into the responses of CCA to ocean warming (OW) and ocean acidification (OA) have found magnitude of effect to be species-specific. Response to OW and OA could be linked to divergent underlying molecular processes across species. Here we show Sporolithon durum, a species that exhibits low sensitivity to climate stressors, had little change in metabolic performance and did not significantly alter the expression of any genes when exposed to temperature and pH perturbations. In contrast, Porolithon onkodes, a major coral reef builder, reduced photosynthetic rates and had a labile transcriptomic response with over 400 significantly differentially expressed genes, with differential regulation of genes relating to physiological processes such as carbon acquisition and metabolism. The differential gene expression detected in P. onkodes implicates possible key metabolic pathways, including the pentose phosphate pathway, in the stress response of this species. We suggest S. durum is more resistant to OW and OA than P. onkodes, which demonstrated a high sensitivity to climate stressors and may have limited ability for acclimatisation. Understanding changes in gene expression in relation to physiological processes of CCA could help us understand and predict how different species will respond to, and persist in, future ocean conditions predicted for 2100.

2022-08-26 | GSE211882 | GEO

algae metagenome

Project description:Crustose coralline algae associated bacteria Raw sequence reads

| PRJNA315461 | ENA

Molecular response of the coral Acropora millepora to three settlement and/or metamorphosis induced stimuli

Project description:Two known settlement/metamorphosis inducing stimuli (crustose coralline algae, and ethanolic extract of crustose coralline algae) and one stimulus which just induces metamorphosis (LWamide) were used to stimulate competent planula larvae of the coral Acropora millepora. Samples were taken 0.5h, 4h and 12h post induction isolate the genes controlling settlement and metamorphosis in this coral.

2009-12-07 | GSE11709 | GEO

Arctic Coralline Algae Elevate Surface pH and Carbonate in the Dark.

Project description:Red coralline algae are projected to be sensitive to ocean acidification, particularly in polar oceans. As important ecosystem engineers, their potential sensitivity has broad implications, and understanding their carbon acquisition mechanisms is necessary for making reliable predictions. Therefore, we investigated the localized carbonate chemistry at the surface of Arctic coralline algae using microsensors. We report for the first time carbonate ion concentration and pH measurements ([CO3 2-]) at and above the algal surface in the microenvironment. We show that surface pH and [CO3 2-] are higher than the bulk seawater in the light, and even after hours of darkness. We further show that three species of Arctic coralline algae have efficient carbon concentrating mechanisms including direct bicarbonate uptake and indirect bicarbonate use via a carbonic anhydrase enzyme. Our results suggest that Arctic corallines have strong biological control over their surface chemistry, where active calcification occurs, and that net dissolution in the dark does not occur. We suggest that the elevated pH and [CO3 2-] in the dark could be explained by a high rate of light independent carbon fixation that reduces respiratory CO2 release. This mechanism could provide a potential adaptation to ocean acidification in Arctic coralline algae, which has important implications for future Arctic marine ecosystems.

| S-EPMC6167962 | biostudies-literature

Transcriptomes of individual Amphimedon queenslandica larvae and settled post-larvae that were presented with one of three different settlement cues at different times (hours) post emergence from the adult sponge

Project description:To assess how larvae of different ages vary in their responses to different settlement cues, we induced individual Amphimedon queenslandica larvae with one of three different settlement cues at 1.5, 3, 5, and 8 hours post emergence (hpe) from the adult sponge. The settlement cues were (1) the articulated coralline algae Amphiroa fragilissima, (2) the crustose coralline algae Mesophyllum sp., and (3) the filtered seawater (FSW) negative control. We used CEL-Seq2, an RNA-Sequencing approach (Hashimshony et al., 2016), to generate transcriptome data for a total of 144 individuals (larvae and settled post-larvae) at 2 hours post induction (hpi) to the different settlement cues.

2024-06-11 | GSE134077 | GEO

Effects of nutrient enrichment on surface microbial community gene expression in the oligotrophic North Pacific Subtropical Gyre

Project description:Marine microbial communities are critical for biogeochemical cycles and the productivity of ocean ecosystems. Primary productivity, at the base of marine food webs, is constrained by nutrient availability in the surface ocean, and nutrient advection from deeper waters can fuel photosynthesis. In this study, we compared the transcriptional responses by surface microbial communities after experimental deep water mixing to the transcriptional patterns of in situ microbial communities collected with high-resolution automated sampling during a bloom in the North Pacific Subtropical Gyre. Transcriptional responses were assayed with the MicroTOOLs (Microbiological Targets for Ocean Observing Laboratories) marine environmental microarray, which targets all three domains of life and viruses. The experiments showed that mixing of deep and surface waters substantially affects the transcription of photosystem and nutrient response genes among photosynthetic taxa within 24 hours, and that there are specific responses associated with the addition of deep water containing particles (organisms and detritus) compared to filtered deep water. In situ gene transcription was most similar to that in surface water experiments with deep water additions, showing that in situ populations were affected by mixing of nutrients at the six sampling sites. Together, these results show the value of targeted metatranscriptomes for assessing the physiological status of complex microbial communities.

2018-09-03 | GSE109218 | GEO

Project description:Coralline algae microbiota

| PRJNA643495 | ENA