Project description:Purpose: The goal of this study was to characterize the transcript levels of genes in Drosophila photoreceptor neurons in response to blue light. Using transcriptome profiling of isolated photoreceptor nuclei, we analyzed the changes in gene expression that occur in response to 3h of blue light exposure at 1 or 6 days post-eclosion. We identified sets of genes with both up-regulated and down-regulated expression in response to blue light at either age.
Project description:Purpose: The goal of this study was to identify the differential expressed genes in Drosophila photoreceptors with age or upon blue lgiht exposure.
Project description:We investigated light dependent gene expression changes in the marine ochrophyte Nannochloropsis oceanica CCMP1779. These algae have several putative blue light photoreceptors but appear to lack red light photoreceptors. To study early light signaling in N. oceanica and avoid as much as possible secondary downstream events, we quantified gene expression changes in dark-adapted cells after a short blue or red light pulse. More genes were differentially expressed under blue than under red light. In addition, fold change in expression was smaller for the red light-treated samples. For example, the median fold change of induced genes was 3 for blue light and 2.5 for red light. Moreover, hierarchical cluster analysis showed that gene expression after red light treatment was more similar to the dark control than after blue light treatment.
Project description:Aureochromes represent a unique type of blue-light photoreceptors that possess a blue-light sensing flavin-binding LOV-domain and a DNA-binding bZIP domain. Therefore, in contrast to other photoreceptors, aureochromes are considered as light-driven transcription factors. As a member of the essential group of marine primary producers, the pennate diatom Phaeodactylum tricornutum possesses four aureochromes (PtAUREO1a, 1b, 1c, 2). We here show a dramatic change in the global gene expression pattern of P. tricornutum cells after a shift from red to blue light. About 75% of the genes show significantly changed transcript levels already after 10 and 60 min of blue light exposure, which includes genes of major transcription factors as well as other photoreceptors. Very surprisingly, in two independent PtAureo1a knockout lines, this light induced regulation of gene expression is almost completely abolished. Such a massive and fast transcriptional change depending on only one single photoreceptor is so far unprecedented. We hence conclude that PtAUREO1a plays a key role in light regulation.
Project description:Sun-loving plants have the ability to detect and avoid shading through sensing of both blue and red light wavelengths. Higher plant cryptochromes (CRYs) control how plants modulate growth in response to changes in blue light. For growth under a canopy, where blue light is diminished, CRY1 and CRY2 perceive this change and respond by directly contacting two bHLH transcription factors, PIF4 and PIF5. These factors are also known to be controlled by phytochromes, the red/far-red photoreceptors; however, transcriptome analyses indicate that the gene regulatory programs induced by the different light wavelengths are distinct. Our results indicate that CRYs signal by modulating PIF activity genome-wide, and that these factors integrate binding of different plant photoreceptors to facilitate growth changes under different light conditions.
Project description:Sun-loving plants have the ability to detect and avoid shading through sensing of both blue and red light wavelengths. Higher plant cryptochromes (CRYs) control how plants modulate growth in response to changes in blue light. For growth under a canopy, where blue light is diminished, CRY1 and CRY2 perceive this change and respond by directly contacting two bHLH transcription factors, PIF4 and PIF5. These factors are also known to be controlled by phytochromes, the red/far-red photoreceptors; however, transcriptome analyses indicate that the gene regulatory programs induced by the different light wavelengths are distinct. Our results indicate that CRYs signal by modulating PIF activity genome-wide, and that these factors integrate binding of different plant photoreceptors to facilitate growth changes under different light conditions.
Project description:Sun-loving plants have the ability to detect and avoid shading through sensing of both blue and red light wavelengths. Higher plant cryptochromes (CRYs) control how plants modulate growth in response to changes in blue light. For growth under a canopy, where blue light is diminished, CRY1 and CRY2 perceive this change and respond by directly contacting two bHLH transcription factors, PIF4 and PIF5. These factors are also known to be controlled by phytochromes, the red/far-red photoreceptors; however, transcriptome analyses indicate that the gene regulatory programs induced by the different light wavelengths are distinct. Our results indicate that CRYs signal by modulating PIF activity genome-wide, and that these factors integrate binding of different plant photoreceptors to facilitate growth changes under different light conditions. We performed whole-genome chromatin immunoprecipitation with sequencing (ChIP-Seq) analysis on 5 day old Flash-CRY2, PIF4-Flash and PIF5-Flash treated in low blue-light for 16h.
Project description:Sun-loving plants have the ability to detect and avoid shading through sensing of both blue and red light wavelengths. Higher plant cryptochromes (CRYs) control how plants modulate growth in response to changes in blue light. For growth under a canopy, where blue light is diminished, CRY1 and CRY2 perceive this change and respond by directly contacting two bHLH transcription factors, PIF4 and PIF5. These factors are also known to be controlled by phytochromes, the red/far-red photoreceptors; however, transcriptome analyses indicate that the gene regulatory programs induced by the different light wavelengths are distinct. Our results indicate that CRYs signal by modulating PIF activity genome-wide, and that these factors integrate binding of different plant photoreceptors to facilitate growth changes under different light conditions. We performed whole-genome transcriptome (mRNA-seq) analysis on 5-day-old Arabidopsis thaliana Columbia wild-type (WT) and pif4pif5 seedlings exposed to low blue-light (LBL) or mock-treated for 1, 6 and 24 hours. In addition we performed mRNA-seq on WT, 35S::PIF4-9xMyc-6x-His-3xFlag(Flash) and 35S::PIF5-9xMyc-6x-His-3xFlag (Flash) seedlings treated with LBL or mock-treated for 16 hours.
Project description:In this study the global transcriptional response of L. monocytogenes to blue light was elucidated using an RNAseq-based approach. A transcriptomic analysis of the response to sub-lethal levels of blue light found that the changes in transcription were almost entirely SigB-dependent. A mutant where the light sensing mechanism of RsbL was inactivated through an amino acid substitution (Cys56Ala) was found to have an attenuated response to blue light, but residual activation of SigB-dependent genes suggested that alternative routes for activation of SigB by light are likely to exist.