Anopheles gambiae mosquitoes play an important role in malaria transmission. In sub-Saharan Africa, the dry season can last several months. The mechanisms for mosquito population to survive through the dry season are poorly understood. One possible mechanism is that adults increase their desiccation tolerance over the dry season. Genetic analyses have shown that inversions 2La, 2Rb, 2Rc, 2Rd and 2Ru are associated with aridity resistance, however little is known about the transcriptional response of genes in response to desiccation.
Genome-wide transcriptional analysis of genes associated with acute desiccation stress in Anopheles gambiae.
Specimen part
View SamplesWith their genome sequenced, Anopheles gambiae mosquitoes now serve as a powerful tool for basic research in comparative, evolutionary and developmental biology. The knowledge generated by these studies is expected to reveal molecular targets for novel vector control and pathogen transmission blocking strategies. Comparisons of gene-expression profiles between adult male and nonblood-fed female Anopheles gambiae mosquitoes revealed that roughly 22% of the genes showed sex-dependent regulation. Blood-fed females switch the majority of their metabolism to blood digestion and egg formation within 3 h after the meal is ingested, in detriment to other activities such as flight and response to environment stimuli. Changes in gene expression are most evident during the first, second and third days after a blood meal, when as many as 50% of all genes showed significant variation in transcript accumulation. After laying the first cluster of eggs (between 72 and 96 h after the blood meal), mosquitoes return to a nongonotrophic stage, similar but not identical to that of 3-dayold nonblood-fed females. Ageing and/or the nutritional state of mosquitoes at 15 days after a blood meal is reflected by the down-regulation of 5% of all genes. A full description of the large number of genes regulated at each analysed time point and each biochemical pathway or biological processes in which they are involved is not possible within the scope of this contribution. Therefore, we present descriptions of groups of genes displaying major differences in transcript accumulation during the adult mosquito life. However, a publicly available searchable database (Anopheles gambiae Gene Expression Database at UC Irvine) has been made available so that detailed analyses of specific groups of genes based on their descriptions, functions or levels of gene expression variation can be performed by interested investigators according to their needs.
Genome-wide analysis of gene expression in adult Anopheles gambiae.
No sample metadata fields
View SamplesSenescence is a biological phenomenon experienced by all living eukaryote organisms. Genome-wide gene expression associated with aging has been explored in model organisms such as Drosophila melanogaster and Caenorhabditis elegans, but this has not been well understood in African malaria vector, Anopheles gambiae. Gene expression profiling using DNA microarray allows for simultaneous study of changes in mRNA levels for thousands of genes. This study examined genome-wide gene expression during aging process in An. gambiae. The influence of blood feeding on gene expression was also examined. The data can be used to further our understanding of mosquito senescence and identify biomarkers for mosquito age grading.
Genome-wide patterns of gene expression during aging in the African malaria vector Anopheles gambiae.
Age, Specimen part
View SamplesThe disrupted genetic mechanisms underlying neural abnormalities in Autism Spectrum Disorder remain mostly unknown and speculative. No biological marker nor genetic signature is currently available to assist with early diagnosis.
Prediction of autism by translation and immune/inflammation coexpressed genes in toddlers from pediatric community practices.
Sex, Specimen part
View SamplesInfection of RAW264.7 cells for 24 hours with 32 Toxoplasma Progeny from a Type II x Type III cross
GRA25 is a novel virulence factor of Toxoplasma gondii and influences the host immune response.
No sample metadata fields
View SamplesPeripherally derived macrophages infiltrate the brain after bone marrow transplantation and during central nervous system (CNS) inflammation. It was initially suggested that these engrafting cells were newly derived microglia and that irradiation was essential for engraftment to occur. However, it remains unclear whether brain-engrafting macrophages (beMfs) acquire a unique phenotype in the brain, whether long-term engraftment may occur without irradiation, and whether brain function is affected by the engrafted cells. In this study, we demonstrate that chronic, partial microglia depletion is sufficient for beMfs to populate the niche and that the presence of beMfs does not alter behavior. Furthermore, beMfs maintain a unique functional and transcriptional identity as compared with microglia. Overall, this study establishes beMfs as a unique CNS cell type and demonstrates that therapeutic engraftment of beMfs may be possible with irradiation-free conditioning regimens. Overall design: Microglia were isolated from the brains of adult male c57BL/6 mice given bone marrow tranplants (BMT) with or without head shield. All mice received PLX5622 for 2 weeks, then placed and normal chow to recoever. Some mice were then challenged with LPS. Cells were isolated by MACS using CD11b magnetic beads.
Peripherally derived macrophages can engraft the brain independent of irradiation and maintain an identity distinct from microglia.
Age, Specimen part, Cell line, Treatment, Subject
View SamplesPeripherally derived macrophages infiltrate the brain after bone marrow transplantation and during central nervous system (CNS) inflammation. It was initially suggested that these engrafting cells were newly derived microglia and that irradiation was essential for engraftment to occur. However, it remains unclear whether brain-engrafting macrophages (beMfs) acquire a unique phenotype in the brain, whether long-term engraftment may occur without irradiation, and whether brain function is affected by the engrafted cells. In this study, we demonstrate that chronic, partial microglia depletion is sufficient for beMfs to populate the niche and that the presence of beMfs does not alter behavior. Furthermore, beMfs maintain a unique functional and transcriptional identity as compared with microglia. Overall, this study establishes beMfs as a unique CNS cell type and demonstrates that therapeutic engraftment of beMfs may be possible with irradiation-free conditioning regimens. Overall design: Mice were given 1000rad whole body irradiation, followed by bone marrow transplant with UBC-GFP bone marrow at 8 weeks of age. Engraftment was allowed to occur for 8 months, then engrafting macrophages and microglia were isolated from whole brains for RNA-Seq.
Peripherally derived macrophages can engraft the brain independent of irradiation and maintain an identity distinct from microglia.
Age, Specimen part, Cell line, Subject
View SamplesGUN1 integrates retrograde signals in the chloroplast but the underlying mechanism is elusive. FUG1, a chloroplast translation initiation factor, and GUN1 are co-expressed at the transcript level, and FUG1 co-immunoprecipitates with GUN1. We used mutants of GUN1 (gun1-103) and FUG1 (fug1-3) to analyse their functional relationship at the physiological and systems-wide level, the latter including transcriptome and proteome analyses. Absence of GUN1 aggravates the effects of decreased FUG1 levels on chloroplast protein translation, resulting in transient additive phenotypes with respect to photosynthesis, leaf coloration, growth and cold acclimation. Variegation of the var2 mutant is enhanced by gun1-103 in terms of increasing the fraction of white sectors, in contrast to fug1-3 that acts as suppressor. The transcriptomes of fug1-3 and gun1-103 are very similar, but absence of GUN1 alone has almost no effects on protein levels, whereas chloroplast protein accumulation is markedly decreased in fug1-3. In gun1 fug1 double mutants, effects on transcriptomes and particularly proteomes are enhanced. Our results show that GUN1 function becomes critical when chloroplast proteostasis is perturbed by decreased translation (fug1) or degradation (var2) of chloroplast proteins. The functions of FUG1 and GUN1 appear to be related, corroborating the view that GUN1 operates in chloroplast proteostasis. Overall design: Examination of differential gene expression in the Arabdidopsis thaliana gun1, fug1 and gun1 fug1 mutants compared to wild type in three replicates
Relationship of GUN1 to FUG1 in chloroplast protein homeostasis.
Subject
View SamplesRNA-seq transcriptome measurements are typically performed by isolating RNA from large numbers of cells in culture or tissues. While highly informative, such experiments mask the variability in gene expression patterns that exists between individual cells. To gain insight into the dynamics of gene expression on the level of single-cells, we have carried out the transcriptomes of single-cells from the GM12878 cell line using RNA-seq. Overall design: Single GM12878 cells were picked and RNA-seq libraries were generated using the SMART-seq protocol. We also carried out RNA-seq experiments on pools of 10, 30 and 100 cells, on 100pg and 10ng of total RNA, and on pools of 10 cells that were subsequently split into 10 separate sample and processed as if they were single cells in order to assess technical variation in our experiments.
From single-cell to cell-pool transcriptomes: stochasticity in gene expression and RNA splicing.
No sample metadata fields
View SamplesOverexpression of the Polycomb group protein Enhancer of Zeste Homolog 2 (EZH2) occurs in diverse malignancies, including prostate cancer, breast cancer, and glioblastoma multiforme (GBM) (1). Based on its ability to modulate transcription of key genes implicated in cell cycle control, DNA repair and cell differentiation, EZH2 is believed to play a crucial role in tissue-specific stem cell maintenance and tumor development. Here we show that targeted pharmacologic disruption of EZH2 by the S-adenosylhomocysteine hydrolase inhibitor 3-Deazaneplanocin A (DZNep), or its specific down-regulation by shRNA, strongly impairs GBM cancer stem cell self-renewal in vitro and tumor-initiating capacity in vivo. Using genome-wide expression analysis of DZNep-treated GBM cancer stem cells, we found the expression of c-myc, recently reported to be essential for GBM cancer stem cells, to be strongly repressed upon EZH2 depletion. Specific shRNA-mediated down-regulation of EZH2 in combination with chromatin immunoprecipitation (ChIP) experiments revealed that c-myc is a direct target of EZH2 in GBM cancer stem cells. Taken together, our observations provide evidence that direct transcriptional regulation of c-myc by EZH2 may constitute a novel mechanism underlying GBM cancer stem cell maintenance and suggest that EZH2 may be a valuable new therapeutic target for GBM management.
EZH2 is essential for glioblastoma cancer stem cell maintenance.
Specimen part, Treatment
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