Project description:Light is a source of energy and an environmental cue that is available in excess in most surface environments. In prokaryotic systems, conversion of light to energy by photoautotrophs and photoheterotrophs is well understood, but the conversion of light to information and the cellular response to that information has been characterized in only a few species. Our goal was to explore the response of freshwater Actinobacteria, which are ubiquitous in illuminated aquatic environments, to light. We found that Actinobacteria without functional photosystems grow faster in the light, likely because sugar transport and metabolism are upregulated in the light, while protein synthesis is upregulated in the dark. Based on the action spectrum of the growth effect, and comparisons of the genomes of three Actinobacteria with this growth rate phenotype, we propose that the photosensor in these strains is a putative CryB-type cryptochrome. The ability to sense light and upregulate carbohydrate transport during the day could allow these cells to coordinate their time of maximum organic carbon uptake with the time of maximum organic carbon release by primary producers.
Project description:Two genome sequences of the phylum Armatimonadetes, derived from terrestrial environments, have been previously described. Here, two additional Armatimonadetes genome sequences were obtained via single-molecule real-time (SMRT) sequencing of an enrichment culture of the bloom-forming cyanobacterium Microcystis sp. isolated from a eutrophic lake (Brandenburg, Germany). The genomes are most closely affiliated with the class Fimbriimonadales, although they are smaller than the 5.6-Mbp type strain genome.
Project description:we obtained a HL tolerant (Tol) strain Synechocystis sp. PCC 6803 by adaptive evolution experiment that the cells were repeatedly subcultured for prolonged periods of time (52 days) under high light stress condition (7000 to 9000 μmol m-2 s-1). Although the growth of the parental strain almost stopped under 9000 μmol m-2 s-1, no growth inhibition was observed in the Tol strain. Furthermore, the growth rate was identical to that of parental strain under low light condition (40 μmol m-2 s-1). To further investigate the high light tolerant mechanisms in the Tol strain, the transcriptome was performed. The transcriptome data suggests the increase of isiA expression in the Tol strain under HL condition. The overexpression of isiA successfully enhanced the HL stress tolerance in the parental strain. The HL tolerant mechanism was different from previous reported mechanisms, such as a reduction of the light-harvesting antenna size. The tolerant strain would be an attractive host for bio-production under high light conditions.
Project description:Background: Epigenetic remodeling is emerging as a critical process for both onset and progression of Alzheimer's disease (AD), the most common form of neurodegenerative dementia. However, it is not clear to what extent the distribution of histone modifications is involved in AD Methods: To investigate histone H3 modifications in AD, we compared the genome-wide distributions of H3K4me3 and H3K27me3 in entorhinal cortices from severe sporadic AD patients and from age-matched healthy individuals of both sexes. Conclusions: The signature of H3K4me3 and H3K27me3 identified in AD patients validates the role of epigenetic chromatin remodeling in neurodegenerative disease and sheds light on genomic adaptive mechanisms involved in AD.
Project description:We report three metagenome-assembled genomes (MAGs) of Planktomarina strains from coastal seawater (Portugal) to help illuminate the functions of understudied Rhodobacteraceae bacteria in marine environments. The MAGs encode proteins involved in aerobic anoxygenic photosynthesis and a versatile carbohydrate metabolism, strengthening the role of Planktomarina species in oceanic carbon cycling.
Project description:Meningeal lymphatic vessels (mLVs) have been shown to be involved in amyloid beta (Aβ) clearance, which is considered as a potential therapeutic target for Alzheimer’s disease (AD). In this study, based on the superficial spatial distribution of mLVs, a near-infrared light is employed to modulate lymphatic drainage, significantly improving cognition of both aged and AD (5xFAD and APP/PS1) mice, and alleviating AD-associated pathology by reducing Aβ deposition, neuroinflammation and neuronal damage. Furthermore, transmission electron microscopy imaging and RNA sequencing data indicate amelioration of mitochondrial metabolism and cellular junction of meningeal lymphatic endothelial cells (mLECs) by light modulation. These studies collectively suggest that near-infrared light treatment can improve cognitive function by strengthening scavenging ability of mLVs through restoring mLEC function. In conclusion, lymphatic drainage potentiation by light promotes pathological remission and cognitive enhancement in aging and AD mouse models, which offers a potential amelioration strategy for neurodegenerative diseases.
