Project description:The mosquito Ae. aegypti is responsible for the transmission of many diseases including yellow fever and Dengue fever. This species exhibits many behaviors that are under diel and circadian control. However, there has been little reporting on gene expression rhythmicity. To study how gene expression is globally regulated by diel and circadian mechanisms, we have undertaken a DNA microarray analysis of Ae. aegypti head and bodies under 12:12 light:dark cycle (LD) and constant dark (DD, free-running) conditions. Zeitgeber Time (ZT) with ZT12 defined as the initiation of the one hour dusk period under the light:dark cycle, and ZT0 defined as beginning of the one hour dawn period. Circadian Time (CT) with CT0 defined as subjective dawn, inferred from ZT0 of the previous light:dark cycle.
2014-08-19 | GSE60496 | GEO
Project description:Investigating circadian influences upon the rhizosphere microbiome under diurnal conditions
Project description:It is well known that host-microbes and immunity interactions are influenced by dietary patterns, as well as daily environmental light-dark (LD) cycles that entrain circadian rhythms in the host. Emerging data has highlighted the importance of diet patterns and timing on the interaction among circadian rhythms, gut microbiome, and immunity, however, their impacts on LD cycles are less reported. Therefore, we aim to study how LD cycles regulate the homeostatic crosstalk between gut microbiome, hypothalamic and hepatic circadian clock oscillations and immunity. We hypothesized that different environmental LD cycles: (1) constant darkness, LD0/24; (2) short light, LD8/16; (3) normal LD cycle, LD12/12; (4) long light, LD16/8; and (5) constant light, LD24/0, may affect immunity and metabolism to varying degrees. Therefore, 240 mice were managed with chow diets (CD) and antibiotics treatments (ABX) under five different LD cycles for 42 days. The colonic (co) and cecum (ce) contents were obtained for studying their impacts on gut microbiome using 16S rRNA sequencing.
Project description:In most organisms biological processes are partitioned, or phased to specific times over the day through interactions between external cycles of temperature (thermocycles) and light (photocycles), and the endogenous circadian clock. This orchestration of biological activities is achieved in part through an underlying transcriptional network. To understand how thermocycles, photocycles and the circadian clock interact to control time of day specific transcript abundance in Arabidopsis thaliana, we conducted four diurnal and three circadian two-day time courses using Affymetrix GeneChips (ATH1). All time courses were carried out with seven-day-old seedlings grown on agar plates under thermocycles (HC, hot/cold) and/or photocycles (LD, light/dark), or continuous conditions (LL, continuous light; DD, continuous dark, HH, continuous hot). Whole seedlings (50-100), including roots, stems and leaves were collected every four hours and frozen in liquid nitrogen. The four time courses interrogating the interaction between thermocycles, photocycles and the circadian clock were carried out as two four-day time courses. Four-day time courses were divided into two days under diurnal conditions, and two days under circadian conditions of continuous light and temperature. Thermocycles of 12 hours at 22C (hot) and 12 hours at 12C (cold) were used in this study. The two time courses interrogating photoperiod were conducted under short days (8 hrs light and 16 hrs dark) or long days (16 hrs light and 8 hrs dark) under constant temperature. In addition, the photoperiod time courses were in the Landsberg erecta (ler) accession, in contrast to the other time courses that are in the Columbia (col) background. The final time course interrogated circadian rhythmicity in seedlings grown completely in the dark (etiolated). Dark grown seedlings were synchronized with thermocycles, and plants were sampled under the circadian conditions of continuous dark and temperature.
Project description:Longitudinal studies associate shiftwork with cardiometabolic disorders but do not establish causation nor elucidate mechanisms of disease. We developed a mouse model based on shiftwork schedules to study circadian misalignment in both sexes, where misaligned mice undergo an 8-hour phase advance every week for 15 weeks. Behavioral and transcriptional rhythmicity were preserved in female mice despite exposure to misalignment. Females were protected against the cardiometabolic impact of circadian disruption seen in males. The liver transcriptome and proteome revealed discordant pathway perturbations between the sexes. Tissue-level changes were accompanied by gut microbiome dysbiosis only in male mice. In the UK biobank, female shiftworkers showed stronger circadian rhythmicity in activity and a lower incidence of metabolic syndrome than males. Thus we show that female mice are resilient to chronic circadian misalignment, and that these differences are conserved in humans.
Project description:Earth tilted rotation and translation around the Sun produce one of the most pervasive rhythms on our planet, giving rise to seasonal variations in diel cycles. Although marine phytoplankton plays a key role on ecosystems, multiomics analysis of its response to these periodic environmental signals remains largely unexplored. The marine picoalga Ostreococcus tauri, which resides at the base of the green lineage, has been chosen as model organism due to its high abundance in marine phytoplankton and its cellular and genomic simplicity, making it the smallest free living eukaryote. Ostreococcus was subjected to different light regimes: summer long days, winter short days, constant light and constant dark conditions, to investigate these responses. Although 80% of the transcriptome presented diel rhythmicity, less than 5% maintained oscillations under constant conditions. A drastic reduction in proteome rhythmicity was observed with 55% of the proteins oscillating. Seasonal specific rhythms were found for key physiological processes such as cell cycle, photosynthesis, carotenoid biosynthesis, starch accumulation and nitrate assimilation. In this study, a global orchestration between transcriptome, proteome and physiological dynamics was characterised identifying specific seasonal temporal offsets between peaks in transcripts, proteins, and physiological responses.
Project description:To gain insights into the mechanisms of TOC1 function in the Arabidopsis circadian clock we performed transcriptional profiling of Wild-Type (WT) and and TOC1 mutant plants (toc1-2) under constant light conditions for two days. Comparisons of WT and toc1-2. Two biological replicates each per array. Two Arabidopsis Oligonucleotide Microarrays (two-color Cy3 and Cy5). synchronized under 12-hour light:12-hour dark (LD) cycles for 10 days followed by two days under constant light conditions. Samples were collected at circadian time 16 (CT16).
Project description:Longitudinal studies associate shiftwork with cardiometabolic disorders but do not establish causation nor elucidate mechanisms of disease. We developed a mouse model based on shiftwork schedules to study circadian misalignment in both sexes, where misaligned mice undergo an 8-hour phase advance every week for 15 weeks. Behavioral and transcriptional rhythmicity were preserved in female mice despite exposure to misalignment. Females were protected against the cardiometabolic impact of circadian disruption seen in males. The liver transcriptome and proteome revealed discordant pathway perturbations between the sexes. Tissue-level changes were accompanied by gut microbiome dysbiosis only in male mice. In the UK biobank, female shiftworkers showed stronger circadian rhythmicity in activity and a lower incidence of metabolic syndrome than males. Thus we show that female mice are resilient to chronic circadian misalignment, and that these differences are conserved in humans.
Project description:It is well known that host-microbes and immunity interactions are influenced by dietary patterns, as well as daily environmental light-dark (LD) cycles that entrain circadian rhythms in the host. Emerging data has highlighted the importance of diet patterns and timing on the interaction among circadian rhythms, gut microbiome, and immunity, however, their impacts on LD cycles are less reported. Therefore, we aim to study how LD cycles regulate the homeostatic crosstalk between gut microbiome, hypothalamic and hepatic circadian clock oscillations and immunity. We hypothesized that different environmental LD cycles: (1) constant darkness, LD0/24; (2) short light, LD8/16; (3) normal LD cycle, LD12/12; (4) long light, LD16/8; and (5) constant light, LD24/0, may affect immunity and metabolism to varying degrees. Therefore, 240 mice were managed with chow diets (CD) and antibiotics treatments (ABX) under five different LD cycles for 42 days. The liver (LIV), hypothalamus (HYP), inguinal white adipose tissue (iWAT), ileum epithelium (ILE), colon epithelium (COL), jejunum epithelium (JEJ), cecum epithelium (CEC), spleen (SPL), mammary gland (MAG), and thymus gland (THY) tissues were obtained for studying their impacts immunity using RNA-Seq data.