Project description:Coral reefs are based on the symbiotic relationship between corals and photosynthetic dinoflagellates of the genus Symbiodinium. We followed gene expression of coral larvae of Acropora palmata and Montastraea faveolata after exposure to Symbiodinium strains that differed in their ability to establish symbioses. We show that the coral host transcriptome remains almost unchanged during infection by competent symbionts, but is massively altered by symbionts that fail to establish symbioses. Our data suggest that successful coral-algal symbioses depend mainly on the symbionts' ability to enter the host in a stealth manner rather than a more active response from the coral host. Acropora palmata Samples: Three biological replicates of pooled larvae from each species and condition (i.e. untreated control, inoculated with competent Symbiodinium strain, inoculated with incompetent Symbiodinium strain) for both time points were hybridized against a pooled reference. Pooled references were constructed by combining equal amounts of aRNA from all control samples from A. palmata. References were labeled with Cy3, samples with Cy5. Montastraea faveolata Samples: Three biological replicates of pooled larvae from each species and condition (i.e. untreated control, inoculated with competent Symbiodinium strain, inoculated with incompetent Symbiodinium strain) for both time points were hybridized against a pooled reference. Pooled references were constructed by combining equal amounts of aRNA from all control samples from M. faveolata. References were labeled with Cy3, samples with Cy5. Symbiodinium sp. CassKB8: competent strain Symbiodinium sp. EL1: incompetent strain Symbiodinium sp. Mf1.05b: competent strain

2010-06-20 | E-GEOD-14923 | biostudies-arrayexpress

Symbiodinium clade content drives host transcriptome more than thermal stress in the coral Montastraea faveolata part 2

Project description:A mutualistic relationship between reef-building corals and endosymbiotic algae (Symbiodinium spp.) forms the basis for the existence of coral reefs. Genotyping tools for Symbiodinium spp. have added a new level of complexity to studies concerning cnidarian growth, nutrient acquisition, and stress. For example, the response of the coral holobiont to thermal stress is connected to the host-Symbiodinium genotypic combination, as different partnerships can have different bleaching susceptibilities. If, and to what extent, differences in algal symbiont clade contents can exert effects on the coral host transcriptome is currently unknown. In this study, we monitored algal physiological parameters and profiled the coral host transcriptional responses in acclimated, thermally stressed, and recovered coral fragments using a custom cDNA gene expression microarray. Combining these analyses with results from algal and host genotyping revealed a striking symbiont effect on both the acclimated coral host transcriptome and the magnitude of the thermal stress response. This is the first study that links coral host transcriptomic patterns to the clade content of their algal symbiont community. Our data provide a critical step to elucidating the molecular basis of the apparent variability seen among different coral-algal partnerships.

2009-05-31 | GSE15253 | GEO

Evidence for a role of viruses in the thermal sensitivity of coral photosymbionts

Project description:Symbiodinium, the dinoflagellate photosymbiont of corals, is posited to become more susceptible to viral infections when heat-stressed. To investigate this hypothesis, we mined transcriptome data of a thermo-sensitive and a thermo-tolerant type C1 Symbiodinium population at ambient (27°C) and elevated (32°C) temperatures. We uncovered hundreds of transcripts from nucleocytoplasmic large double-stranded DNA viruses (NCLDVs) and the genome of a novel positive-sense single-stranded RNA virus (+ssRNAV). In the transcriptome of the thermo-sensitive population only, +ssRNAV transcripts had remarkable expression levels in the top 0.03% of all transcripts at 27°C, but at 32°C, expression levels of +ssRNAV transcripts decreased while expression levels of antiviral transcripts increased. In both transcriptomes, expression of NCLDV transcripts increased at 32°C, but thermal-induction of NCLDV transcripts involved in DNA manipulation was restricted to the thermo-sensitive population. Our findings reveal that viruses infecting Symbiodinium are affected by heat stress and may contribute to Symbiodinium thermal sensitivity.

2016-09-28 | GSE77911 | GEO

Sex, Scavengers, and Chaperones: Transcriptome Secrets of Divergent Symbiodinium Thermal Tolerances

Project description:Using transcriptomics, we show that Symbiodinium acclimation to elevated temperature involves up-regulated expression of meiosis genes followed by up-regulated expression of numerous reactive oxygen species scavenging genes and molecular chaperone genes. Our study connects Symbiodinium transcriptional regulation with physiological heat stress responses as well as known bleaching responses of corals harboring these same Symbiodinium. By uncovering these critical links, we greatly advance understanding of the bleaching susceptibility of corals, which is a key process responsible for global coral reef health.

2016-06-08 | GSE72763 | GEO

The host transcriptome remains unaltered during the establishment of coral-algal symbioses

2009-04-01 | GSE14923 | GEO

Project description:HiC data of Symbiodinium kawagutii

| PRJNA1014126 | ENA