Project description:Over the past several decades, corals worldwide have been affected by global warming, experiencing severe bleaching events that have often lead to coral death. The symbiotic Red Sea coral Stylophora pistillata is considered an opportunistic ‘r’ strategist, thriving in relatively unstable and unpredictable environments, and it is considered a stress-tolerant species. This study aimed to examine S. pistillata gene expression and to clarify the cellular pathways that are active during short-term heat stress caused by an increase from 24°C to 34°C over a 10-day period. Total RNA was extracted from heat-stressed coral fragments, labeled and hybridized against a designated S. pistillata custom microarray containing approximately 12,000 genes. Our results show that the heat stress reaction was sighted from 32°C and intensified significantly after 34°C treatment. Protein interaction networks of up- and down-regulated genes were constructed. The main clustering groups of up-regulated genes were ER stress and ER protein folding, cell cycle, ubiquitin-mediated proteolysis, cell death and cell death regulation and cellular stress response genes. These genes were enriched in cellular pathways related to the unfolded protein response (UPR) in the ER, ER-associated degradation (ERAD) and ubiquitin-mediated proteolysis. An analysis of the down-regulated genes yielded different clusters of genes related to extracellular matrix and actin organization, collagen, negative regulation of cell death and the Notch and Wnt signaling pathways. Genes encoding redox regulation proteins and molecular chaperones may be considered accurate “early warning genes”, while genes related to sensing and repairing DNA damage are severe heat-related genes. Here, we suggest that during short-term heat stress, S. pistillata might divert cellular energy into mechanisms such as UPR and ERAD at the expense of growth and biomineralization processes in an effort to recover from the stress.
Project description:We performed transcriptime analysis (RNA-seq) in the stony coral Stylophora pistillata treated with different nucleotide messengers produced by cGLRs.
Project description:Increasing seawater’s calcium concentration has shown to increase reef building (scleractinian) coral’s calcification rates. In this way the expression of the genes that are associated with the calcification process also altered and, thus can be identified. Needless to say that the overall gene repertoire that participate in the coral calcification process and its molecular mechanisms have not yet been revealed, although sporadic genes that are related to the process have been discovered and investigated. In this study, nubbins of the Red Sea scleractinian coral, Stylophora pistillata were treated with increased calcium concentrations seawater (addition of 100 gm/L) and the genes that have been up-regulated were compared to the genes expression profile of corals with natural seawater calcium concentration. Measurements of AT were taken at mid-day (11:00) and in nighttime (23:00), to record the calcification rates of coral individuals under normal and increased calcium seawater concentrations. In order to reveal the gene involved in the calcification process, S. pistillata fragments of normal and of increased calcium concentrations were sampled for microarray RNA transcriptional profiling at two time-points (mid-day and nighttime).Results of this study have revealed that Smad genes may play a role in the coral skeletal growth apparatus. This study show that the calcification molecular mechanism is conserved Among identified genes are large group of genes that are characterized in the TGF-b/BMP signal transduction pathways which have been revealed in other organisms to participate in bone and cartilage tissue development molecular processes.
Project description:Aging is a multifactorial process that results in progressive loss of regenerative capacity and tissue function while simultaneously favoring the development of a large array of age-related diseases. Evidence suggests that the accumulation of senescent cells in tissue promotes both normal and pathological aging. Oxic stress is a key driver of cellular senescence. Because symbiotic long-lived reef corals experience daily hyperoxic and hypoxic transitions, we hypothesized that these long-lived animals have developed specific longevity strategies in response to light. We analyzed transcriptome variation in the reef coral Stylophora pistillata during the day–night cycle and revealed a signature of the FoxO longevity pathway. We confirmed this pathway by immunofluorescence using antibodies against coral FoxO to demonstrate its nuclear translocation. Among genes that were specifically up- or downregulated on exposure to light, human orthologs of two “light-up” genes (HEY1 and LONF3) exhibited anti-senescence properties in primary human fibroblasts. Therefore, these genes are interesting candidates for counteracting skin aging. We propose a large screen for other light-up genes and an investigation of the biological response of reef corals to light (e.g., metabolic switching) to elucidate these processes and identify effective interventions for promoting healthy aging in humans.
Project description:Coral Stylophora pistillata was exposed to octocrylene at 300 and 1000 microg/L in sea water. Blank analyses are present, along with extract profiles of control and exposed corals.
Project description:Stony corals generate their calcium carbonate exoskeleton in a highly controlled biomineralization process mediated by a variety of macromolecules including proteins. Fully identifying and classifying these proteins is crucial to understanding their role in exoskeleton formation, yet no optimal method to extract and isolate and characterize coral skeletal proteins has been established and their complete composition remains obscure. Here, we tested four skeletal protein extraction protocols using acetone precipitation and ultrafiltration dialysis filters to present a comprehensive scleractinian coral skeletal proteome. We identified a total of 60 proteins in the coral skeleton, 44 of which were not present in previously published stony coral skeletal proteomes. Extracted protein treatment protocols carried out in this study revealed that there is no “one optimal method” and each protocol revealed a unique set of method-exclusive proteins. To better understand the general mechanism of skeletal protein transportation, we further examined the proteins’ gene ontology, transmembrane domains, and signal peptides. We found that transmembrane domain proteins and signal peptide secretion pathways, by themselves, could not explain the transportation of proteins to the skeleton . We therefore propose that proteins are transported to the skeletal via vesicles and possibly non-traditional secretion pathways.