Project description:Sarcophyton soft coral samples collected in Palau 2019 (Dataset includes 83 crude extracts, with two technical replicates and two injections of each, plus 10 reference samples of cembrane diterpenes isolated from soft corals from Palau or Okinawa)
Project description:Purpose: There is a dearth of knowledge regarding the molecular pathology of growth anomaly in corals. We investigated the gene expression profile of Montipora capitata metatranscriptomes from healthy and diseased (growth anomaly) coral colonies to elucidate differentially expressed genes. Methods: mRNA profiles of coral tissue (including symbionts) were generated from three different tissue states: healthy, affected and unaffected. Healthy tissue was collected from coral colonies not affected by growth anomaly. Affected tissue was collected from coral growth anomaly lesions. Unaffected tissue was collected from coral colonies affected by growth anomaly.
Project description:The emergence of genomic tools for reef-building corals and symbiotic anemones comes at a time when alarming losses in coral cover are being observed worldwide. These tools hold great promise in elucidating novel and unforeseen cellular processes underlying the successful mutualism between corals and their algal endosymbionts (Symbiodinium spp.). Since thermal stress triggers a breakdown in the symbiosis (coral bleaching), measuring the transcriptomic response to thermal stress-induced bleaching offers an extraordinary view of the cellular processes specific to coral-algal symbioses. In the present study, we utilized a cDNA microarray containing 2,059 genes of the Caribbean Elkhorn coral Acropora palmata to identify genes differentially expressed upon thermal stress. Fragments from four separate colonies were exposed to elevated temperature (3˚C increase) for two days, and samples were frozen for microarray analysis after 24 and 48 hours. Fragments experienced a 60% reduction in algal cell density after two days. 204 genes were differentially expressed in samples collected one day after thermal stress; in samples collected after two days, 104 genes. Annotations of the differentially expressed genes indicate a conserved cellular stress response in A. palmata involving: 1) growth arrest; 2) chaperone activity; 3) nucleic acid stabilization and repair; and 4) the removal of damaged macromolecules. Other differentially expressed processes include sensory perception, metabolite transfer between host and symbiont, nitric oxide signaling, and modifications to the actin cytoskeleton and extracellular matrix. The results are also compared to those from a previous coral microarray study of thermal stress in Montastraea faveolata.
Project description:Despite the fact that taro, colocasia esculenta, is an important staple food for millions of people around the world, its genome and transcriptome sequence has not yet been investigated. The objective of this study was to generate transcriptome sequence information from taro cultivars Niue, Palau 10, and Sam-07. Niue and Sam-07 are highly susceptible to the taro leaf blight (TLB) disease caused by Phytophthora colocasiae, to which Palau 10 is resistant. The analysis of the taro transcriptome will facilitate gene discovery, including genes that are responsible for TLB-resistance. Moreover, microsatellites (SSRs) developped from these data will be useful for marker-assisted breeding of improved taro cultivars, QTL mapping, and characterization of the genetic diversity in taro.
Project description:Short title: Coral Meta-Transcriptomics Reveal Pollutant Stress Background: Corals represent symbiotic meta-organisms that require harmonization among the coral animal, photosynthetic zooxanthellae and associated microbes to survive environmental stresses. We investigated integrated-responses among coral and zooxanthellae in the scleractinian coral Acropora formosa in response to an emerging marine pollutant, the munitions constituent, 1,3,5-trinitro-1,3,5 triazine (RDX; 5 day exposures to 0 (control), 0.5, 0.9, 1.8, 3.7, and 7.2 mg/L, measured in seawater). Results: RDX accumulated readily in coral soft tissues with bioconcentration factors ranging from 1.1 to 1.5). Next-generation sequencing of a normalized meta-transcriptomic library developed for the eukaryotic components of the A. formosa coral holobiont was leveraged to conduct microarray-based global transcript expression analysis of integrated coral / zooxanthellae responses to the RDX exposure. Total differentially expressed transcripts (DET) increased with increasing RDX exposure concentrations as did the proportion of zooxanthellae DET relative to the coral animal. Transcriptional responses in the coral demonstrated higher sensitivity to RDX compared to zooxanthellae where increased expression of gene transcripts coding xenobiotic detoxification mechanisms (ie. cytochrome P450 and UDP glucuronosyltransferase 2) were initiated at the lowest exposure concentration. Increased expression of these detoxification mechanisms was sustained at higher RDX concentrations as well as production of a physical barrier to exposure through a 40% increase in mucocyte density at the maximum RDX exposure. At and above the 1.8 mg/L exposure concentration, DET coding for genes involved in central energy metabolism, including photosynthesis, glycolysis and electron-transport functions, were decreased in zooxanthellae although preliminary data indicated that zooxanthellae densities were not affected. In contrast, significantly increased transcript expression for genes involved in cellular energy production including glycolysis and electron-transport pathways was observed in the coral animal. Conclusions: Transcriptional network analysis for central energy metabolism demonstrated highly correlated responses to RDX among the coral animal and zooxanthellae indicative of potential compensatory responses to lost photosynthetic potential within the holobiont. These observations underscore the potential for complex integrated responses to RDX exposure among species comprising the coral holobiont and highlight the need to understand holobiont-species interactions to accurately assess pollutant impacts.
Project description:Non-targeted LC-MS/MS of PPL extracts from experimental and environmental seawater samples from coral reefs from Mo'orea (French Polynesia), collected in May 2019.