Project description:To investigate a Florida manatee (Trichechus manatus latirostris) mortality event following a red tide bloom in Southwest Florida, a RNA-Seq experiment was conducted. Cell processes such as immune response, cell proliferation and differentiation and apoptosis were among the most affected by red tide. These were involved in potential diseases such as neoplasms, inflammation, and wounds and injuries, among others. There were both up-regulated and down-regulated genes, but the highest fold changes relative to controls were for genes that were down-regulated. Piccolo presynaptic cytomatrix protein (PCLO) gene, the one most down-regulated (fold change -9.93; p-value 0.0009) is associated with neurotransmitter release, cognitive functioning, neuronal loss, and neuronal synapse function. Another gene that has a similar function, ankyrin 2, neuronal, transcript variant 1 (ANK2) was also down-regulated (fold change -8.66; p-value 0.0023). ANK2 is associated with the stability of neuron synapses. Two immune genes, interleukin 6 (interferon, beta 2) (IL6) and zinc finger protein 804B (ZNF804B), were down-regulated (fold change -9.31; p-value 0.000003 and fold change -8.90; p-value 0.0164, respectively). Interleukin 6 encodes proteins involved in acute phase response, inflammation, and autoimmune response. ZNF804B is associated with neuronal chemokine and cytokine regulation, autoimmune response, and immune activation. The family with sequence similarity 186, member A (FAM186A) gene was down-regulated (fold change -8.79; p-value 0.0143). FAM186A gene mutation is associated with tumor metastasis in colorectal cancer tumors. Among the most up-regulated genes, CCAAT/enhancer binding protein (C/EBP) is involved in granulocytic differentiation and also involved with the immune system. Determining the differentially expressed genes associated with red tide enhances our understanding of manatee immune response to red tide toxins and aids in the development of red tide biomarkers. This information will better assist clinicians and researchers in diagnosing and treating future illnesses.
Project description:As reef-building corals are increasingly being exposed to persistent threats that operate on both regional and global scales there is a pressing need to better understand the complex processes that diminish coral populations. This study investigated the impacts of the Florida Red Tide dinoflagellate Karenia brevis and associated brevetoxins on selected facets of coral biology using Porites astreoides as a model system. When provided with choice assays, P. astreoides larvae were shown to actively avoid seawater containing red tide or purified brevetoxins. However, forced exposure to similar treatments induced time-dependent physiological and behavioral changes that were captured by PAM fluorometry and settlement and survival assays, respectively. Adult fragments of P. astreoides exposed to red tide or associated brevetoxins displayed signs of proteomic alterations that were characterized by use of an iTRAQ-based quantitative proteomic analysis. The novel use of this technique on P. astreoides demonstrated that protein expression was highly contingent upon biological versus chemical treatment and that several broad pathways associated with cell stress were affected including redox homeostasis, protein folding, energy metabolism, and reactive oxygen species (ROS) production. The results herein provide new insight into the ecology, behavior and sublethal stress of reef-building corals in response to K. brevis exposure and underscore the importance of recognizing the potential of red tide to act as a regional stressor to these important foundation species.
Project description:In 2013, two large-scale Florida manatee (Trichechus manatus latirostris) mortality episodes were reported on separate coasts of Florida. The east coast mortality episode was associated with an unknown etiology in the Indian River Lagoon (IRL). The west coast mortality episode was attributed to a persistent Karenia brevis algal bloom or ‘red tide’ centered in Southwest Florida. To investigate these two mortality episodes, proteomic experiments using two-dimensional difference gel electrophoresis (2D-DIGE) followed by protein identification using liquid chromatography-tandem mass spectrometry (LC-MS/MS) were conducted, along with a separate gel-free analysis using isobaric tags for relative and absolute quantification (iTRAQ) LC-MS/MS. In comparison to the control group, manatees from the IRL, an area associated with an unknown mortality episode, displayed increased levels of several proteins in their serum samples. These increased proteins, which were identified in the iTRAQ experiment, included kininogen-1 isoform 1 (average ratio 1.38), protein AMBP (1.38), histidine-rich glycoprotein (1.34), properdin (1.30), and complement C4-A isoform 1 (1.25). In the red tide group, ceruloplasmin (2.32), pyruvate kinase isozymes M1/M2 isoform 3 (2.29), angiotensinogen (2.08), complement C4-A isoform 1 (1.83), and complement C3 (1.42) were increased. The proteins kininogen-1 isoform 1, histidine-rich glycoprotein, complement C4-A isoform 1, angiotensinogen, and complement C3 were also identified in increased levels in the 2D-DIGE experiment (Table 2b). These proteins are associated with acute-phase response, amyloid formation and accumulation, copper and iron homeostasis, the complement cascade pathway, and other important cellular functions. The increased level of complement C4 protein observed in both the red tide and unknown mortality episode groups was confirmed through the use of Western Blot.
Project description:Light is one of the main environmental cues that affects the physiology and behavior of many organisms. The effect of light on genome-wide transcriptional regulation has been well-studied in green algae and plants, but not in red algae. Cyanidioschyzon merolae is used as a model red algae, and is suitable for studies on transcriptomics because of its compact genome with a relatively small number of genes. In addition, complete genome sequences of the nucleus, mitochondrion, and chloroplast of this organism have been determined. Together, these attributes make C. merolae an ideal model organism to study the response to light stimuli at the transcriptional and the systems biology levels. Previous studies have shown that light significantly affects cell signaling in this organism, but there are no reports on its blue light- and red light-mediated transcriptional responses. We investigated the direct effects of blue and red light at the transcriptional level using RNA-seq. Blue and red light were found to regulate 35% of the total genes in C. merolae. Blue light affected the transcription of genes involved protein synthesis while red light specifically regulated the transcription of genes involved in photosynthesis and DNA repair. Blue or red light regulated genes involved in carbon metabolism and pigment biosynthesis. Overall, our data showed that red and blue light regulate the majority of the cellular, cell division, and repair processes in C. merolae.
Project description:Light is one of the main environmental cues that affects the physiology and behavior of many organisms. The effect of light on genome-wide transcriptional regulation has been well-studied in green algae and plants, but not in red algae. Cyanidioschyzon merolae is used as a model red algae, and is suitable for studies on transcriptomics because of its compact genome with a relatively small number of genes. In addition, complete genome sequences of the nucleus, mitochondrion, and chloroplast of this organism have been determined. Together, these attributes make C. merolae an ideal model organism to study the response to light stimuli at the transcriptional and the systems biology levels. Previous studies have shown that light significantly affects cell signaling in this organism, but there are no reports on its blue light- and red light-mediated transcriptional responses. We investigated the direct effects of blue and red light at the transcriptional level using RNA-seq. Blue and red light were found to regulate 35% of the total genes in C. merolae. Blue light affected the transcription of genes involved protein synthesis while red light specifically regulated the transcription of genes involved in photosynthesis and DNA repair. Blue or red light regulated genes involved in carbon metabolism and pigment biosynthesis. Overall, our data showed that red and blue light regulate the majority of the cellular, cell division, and repair processes in C. merolae.
2016-09-10 | GSE83828 | GEO
Project description:Microbial diversity in red tide
Project description:Light is one of the main environmental cues that affects the physiology and behavior of many organisms. The effect of light on genome-wide transcriptional regulation has been well-studied in green algae and plants, but not in red algae. Cyanidioschyzon merolae is used as a model red algae, and is suitable for studies on transcriptomics because of its compact genome with a relatively small number of genes. In addition, complete genome sequences of the nucleus, mitochondrion, and chloroplast of this organism have been determined. Together, these attributes make C. merolae an ideal model organism to study the response to light stimuli at the transcriptional and the systems biology levels. Previous studies have shown that light significantly affects cell signaling in this organism, but there are no reports on its blue light- and red light-mediated transcriptional responses. We investigated the direct effects of blue and red light at the transcriptional level using RNA-seq. Blue and red light were found to regulate 35% of the total genes in C. merolae. Blue light affected the transcription of genes involved protein synthesis while red light specifically regulated the transcription of genes involved in photosynthesis and DNA repair. Blue or red light regulated genes involved in carbon metabolism and pigment biosynthesis. Overall, our data showed that red and blue light regulate the majority of the cellular, cell division, and repair processes in C. merolae. Identification of blue light and red light regulated genes by deep sequencing in biological duplicates. qRT-PCR was performed to verify the RNA-seq results.
Project description:The variability of the marine intertidal environment poses unique challenges for sessile species. Diurnal, tidal, and seasonal cycles introduce drastic variations in temperature, salinity, availability of nutrients and water. The California ribbed mussel Mytilus californianus is a filter feeder that dominates a middle range of the intertidal of many wave-swept rocky shores. The bivalve attaches to the substrate by several byssal threads. This sessile lifestyle allows us to accurately document the thermal history of an individual. We have profiled gene expression in M. californianus during a natural tidal cycle using a cDNA microarray composed of genes from mussels exposed to various stressors. Over three days, mussels were sampled from two sites differing in emersion exposure and average temperature. At each time point, three mussels were cut open in the field and frozen immediately on dry ice and stored at -80 degrees C until the gill, hepatopancreas, and adductor muscle were excised and processed for RNA extraction, reverse transcription, and hybridization to our microarrays. The resulting expression profile showed that genes involved in the cell cycle were diurnally regulated, heat shock proteins increased with temperature, and expression of several hundred other genes varied across the tidal cycle. Tide series (times and tide height): 26th July, low tide 0052, 0.8 ft; high tide 0705, 3.1 ft; low tide 1113, 2.4 ft; high tide 1810, 5.9ft. 27th July, low tide 0154, 0.1 ft; high tide 0837, 3.3 ft; low tide 1216, 2.7ft; high tide 1903, 6.2 ft. 28th July, low tide 0249, -0.6ft; high tide 0943, 3.5 ft; low tide 1323, 2.8ft; high tide 1903, 6.2ft. 15th Aug, low tide 0530, 0.26 ft; high tide 1200, 4.08 ft, low tide 0432, 2.65 ft; high tide 1036, 5.84 ft.