Diurnal Variation of Melatonin Receptors in Danio rerio (Zebrafish)
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ABSTRACT: To gain a better understanding of the diurnal variation in gene expression, we analyzed the changes in gene expression in the eye of zebrafish. Dual color oligonucleotide microarrays were used to compare total RNA harvested from eyes of adult zebrafish at midday and midnight. Statistical analyses identified 44 genes which showed significant, 2-fold or more change; 26 genes showed decreased expression at midnight (D/L ≤ 0.5) and 18 genes showed increased expression at midnight (D/L ≥ 2). Seven genes were further analyzed using qPCR. The results of qPCR identified AANAT, Mel1a1, Mel1a3, Mel1b1, Mel1b2 and Melc as genes that showed significant change in expression at dawn, dusk, midday and midnight. These results suggest that expression of melatonin receptors is subject to diurnal regulation. Wild-type ZDR zebrafish (Danio rerio) were obtained from Animal Wonders, San Marcos, TX, and Aquatica Tropicals, Plant City, FL. Fish were conditioned on a 12 hour light/dark cycle for a minimum of 14 days before use. The design of this analysis compared the experimental to the control: midnight samples were used as experimental and midday as control. Samples were collected in triplicate per time point with each replicate representing total RNA pooled from 9 fish. Dual-color microarray was used to compare the midnight and midday samples. A statistically significant (p-value ≤ 0.05) and 2-fold or more change in an experimental sample as compared to a control indicated an up- or down-regulation in gene expression. Supplementary files: In Complete processed data file, "x" marked spots show intensities of less than 1000. In Intensity trimmed data file, all genes with signal intensities of less than 1000 in all triplicate time points were removed from the analysis.
Project description:To gain a better understanding of the diurnal variation in gene expression, we analyzed the changes in gene expression in the eye of zebrafish. Dual color oligonucleotide microarrays were used to compare total RNA harvested from eyes of adult zebrafish at midday and midnight. Statistical analyses identified 44 genes which showed significant, 2-fold or more change; 26 genes showed decreased expression at midnight (D/L ≤ 0.5) and 18 genes showed increased expression at midnight (D/L ≥ 2). Seven genes were further analyzed using qPCR. The results of qPCR identified AANAT, Mel1a1, Mel1a3, Mel1b1, Mel1b2 and Melc as genes that showed significant change in expression at dawn, dusk, midday and midnight. These results suggest that expression of melatonin receptors is subject to diurnal regulation.
Project description:Under natural conditions, plants experience episodes of drought for periods of days or longer. Plants respond to drought stress by reconfiguring their transcriptome activity. Transcriptome changes in response to drought are dynamic, and are likely to be shaped by mitigating factors such as diel signals. To gain insights into the dynamics of transcriptome reconfiguration in response to gradual soil drying, the drought-induced transcriptomes of Arabidopsis thaliana were examined at four time points over a single diel period â midday, late day, midnight, and pre-dawn. A core set of genes was identified that was responsive to drought, independent of the time of day at which they were measured. Strikingly, the magnitude of the drought-induced changes for these genes varied in a time-of-day-dependent manner. An additional set of time-of-day-specific drought-responsive genes were also identified. The diurnal patterns of transcript accumulation for these genes was strongly influenced by drought stress. This study indicates that analysis of a single time point would miss suites of drought-responsive genes that are revealed through assessment of the dynamics of diurnal changes, emphasizing the value of characterizing multiple time-of-day-specific drought transcriptomes. 24 arrays total. 4 time points (midday, late day, midnight, pre-dawn). 2 water regimes (well-watered, water-limited). 3 biological replicates per treatment.
Project description:Under natural conditions, plants experience episodes of drought for periods of days or longer. Plants respond to drought stress by reconfiguring their transcriptome activity. Transcriptome changes in response to drought are dynamic, and are likely to be shaped by mitigating factors such as diel signals. To gain insights into the dynamics of transcriptome reconfiguration in response to gradual soil drying, the drought-induced transcriptomes of Arabidopsis thaliana were examined at four time points over a single diel period – midday, late day, midnight, and pre-dawn. A core set of genes was identified that was responsive to drought, independent of the time of day at which they were measured. Strikingly, the magnitude of the drought-induced changes for these genes varied in a time-of-day-dependent manner. An additional set of time-of-day-specific drought-responsive genes were also identified. The diurnal patterns of transcript accumulation for these genes was strongly influenced by drought stress. This study indicates that analysis of a single time point would miss suites of drought-responsive genes that are revealed through assessment of the dynamics of diurnal changes, emphasizing the value of characterizing multiple time-of-day-specific drought transcriptomes.
Project description:Transcriptional reprogramming and stimulation of leaf respiration by elevated CO2 concentration is diminished, but not eliminated, under limiting nitrogen supply. Arabidopsis plants were grown in either ambient (370 ppm) or elevated (750 ppm) CO2 with either ample N supply or limiting N supply. Leaf tissue was harvested from youngest most fully expanded leaves 35 days after plant germination at either midday or midnight.
Project description:To study the diurnal transcriptome (RNA-seq) expressed by the monocot model plant B. distachyon under submergence stress, we analyzed two different ecotypes (Bd21, submergence sensitive; Bd21-3, submergence tolerant) at 5 different time points (dawn, ZT0; midday, ZT8; dusk, ZT16; middnight ZT20, end of night, ZT24).
Project description:Artificial light at night (ALAN) disrupts natural light-dark cycles, posing ecological challenges for wildli in urban areas. Here we investigated the efcts of ALAN on gene expression in the brain, liver, skin, and gonads of green anole lizards (Anolis carolinensis) whose urban populations are increasingly exposed to light pollution. To identify genetic pathways impacted by ALAN exposure we analysed expression of genes associated with circadian and metabolic regulation at midday, midnight and at midnight with artificial light. Difrential expression analysis revealed that clock-related genes (PER1, NR1D1, CRY2) were significantly altered in the brain, liver, and skin following ALAN treatment and genes involved in glucagon regulation (GCG) and lipid metabolism (NOCT) were difrentially expressed in the liver, indicating metabolic disruptions. Skin exhibited unique responses to ALAN suggesting that repair responses may be altered as genes related to cellular processes, such as wound healing, were upregulated under normal light and dark conditions. Our findings also show that ALAN disrupts core circadian genes, impacting physiological processes including hormone regulation, glucose homeostasis, and potentially reproductive cycles. This study provides the first transcriptomic evidence of the efcts of light pollution on green anoles, highlighting the need to preserve natural light cycles in urban habitats. An interactive online database developed for this study allows further exploration of gene expression changes, to promote research on artificial light-polluted environments.
Project description:The metabolic bases of the interaction between the coral Acropora millepora and its dinoflagellate symbiont were investigated by comparing gene expression levels under light and dark conditions at the whole transcriptome level. Among the differentially expressed genes identified, a suite of genes involved in cholesterol transport was found to be up-regulated under light conditions, confirming the significance of this compound in the coral symbiosis. Although ion transporters likely to have roles in calcification were not differentially expressed in this study, expression levels of many genes associated with skeletal organic matrix composition and organization were higher in light conditions. This implies that the rate of organic matrix synthesis is one factor limiting calcification at night. Thus, LEC during the day is likely to be a consequence of increases in both matrix synthesis and the supply of precursor molecules as a result of photosynthetic activity. Branch tips from three adult colonies of Acropora millepora were sampled at midday and midnight
Project description:The fusion oncoprotein EWS-FLI1 arises from a t(11;22)(q24;q12) chromosomal translocation and causes Ewing's Sarcoma, a malignant bone tumor. The mechanism whereby EWS-FLI1 transforms cells is unknown. We made germline transgenic zebrafish expressing human EWS-FLI1 under the control of the heat shock promoter. Induction of EWS-FLI1 expression causes multiple defects in embryonic development. We compared gene expression in control and transgenic EWS-FLI1 zebrafish. The results identify a conserved set of EWS-FLI1-regulated genes, and provide insight into the pathogenesis of Ewing's Sarcoma tumors. We performed heat shock and isolated total RNA for microarray studies comparing wildtype AB strain zebrafish with transgenic zebrafish expressing human EWS-FLI1 [Tg(HSP:EWS-FLI1)]. RNA was biotin-lableled and hybridized to zebrafish-specific Affymetrix arrays.
Project description:The fusion oncoprotein EWS-FLI1 arises from a t(11;22)(q24;q12) chromosomal translocation and causes Ewing's Sarcoma, a malignant bone tumor. The mechanism whereby EWS-FLI1 transforms cells is unknown. Somatic, mosaic expression of human EWS-FLI1 in zebrafish from the heat shock promoter [Tg(HSP:EWS-FLI1)] caused small round blue cell tumors (SRBCTs) similar to human Ewing's sarcoma. We performed microarray studies comparing zebrafish SRBCTs to another tumor type, zebrafish malignant peripheral nerve sheath tumors (MPNSTs). The results identify a conserved set of EWS-FLI1-regulated genes,and provide insight into the pathogenesis of Ewing's Sarcoma tumors. Zebrafish SRBCTs arising from somatic insertions of the EWS-FLI1 transgene were collected. MPNSTs from non-transgenic fish of the same genetic background were collected in parallel. RNA was prepared from all samples and hybridized to zebrafish-specific Affymetrix arrays.