C. elegans totalRNA profiles of worms treated with RNAi for different Integrator complex genes or L4440 (Control). Worms were grown at 15ºC and samples were taken six days after silencing Overall design: C. elegans totalRNA profiles of worms treated with RNAi for different Integrator complex genes or L4440 (Control). Three replicates per sample. Deep sequencing in Illumina HiSeq1500.
Disruption of the Caenorhabditis elegans Integrator complex triggers a non-conventional transcriptional mechanism beyond snRNA genes.
Subject
View SamplesThe transcriptomes of model organisms have been defined under specific laboratory growth conditions. The standard protocol for Caenorhabditis elegans growth and maintenance is 20ºC on an Escherichia coli diet. Temperatures ranging from 15ºC to 25ºC or feeding with other species of bacteria are considered physiological lab conditions, but the effect of these conditions on the worm transcriptome have not been well characterized. Here, we compare the global patterns of gene expression for the reference Caenorhabditis elegans strain (N2) grown at 15oC, 20oC, and 25oC on two different diets, Escherichia coli and Bacillus subtilis. When C. elegans were fed E. coli and the growth temperature was increased, we observed an enhancement of defense response pathways and down-regulation of genes associated with metabolic functions. However, when C. elegans were fed B. subtilis and the growth temperature was increased, the nematodes exhibited a decrease in defense response pathways and an enhancement of expression of genes associated with metabolic functions. Our results show that C. elegans undergo significant metabolic and defense response changes when the maintenance temperature fluctuates within the physiologically accepted experimental range and that the degree of pathogenicity of the bacterial diet can further alter the worm transcriptome. Overall design: C. elegans mRNA profiles at different temperatures and feeding in six samples, three replicates per sample. Deep sequencing in Illumina HiSeq2500.
Effect of the diet type and temperature on the <i>C. elegans</i> transcriptome.
Subject
View SamplesAgeing populations pose one of the main public health crises of our time. Reprogramming gene expression by altering the activities of sequence-specific transcription factors (TF) can ameliorate deleterious effects of age. Here we explore how a circuit of TFs coordinates pro-longevity transcriptional outcomes, which reveals a multi-tissue and multi-species role for an entire protein family: the E-twenty-six (ETS) TFs. In Drosophila, reduced insulin/IGF signalling (IIS) extends lifespan by coordinating activation of Aop, an ETS transcriptional repressor, and Foxo, a Forkhead transcriptional activator. Aop and Foxo bind the same genomic loci, and we show that, individually, they effect similar transcriptional programmes in vivo. In combination, Aop can both moderate or synergise with Foxo, dependent on promoter context. Moreover, Foxo and Aop oppose the activities of Pnt, an ETS transcriptional activator, effecting a transcriptomic programme that correlates lifespan outcomes. Directly limiting Pnt extended lifespan, suggesting this is how Aop and Foxo promote longevity. The lifespan-limiting role of Pnt appears to be balanced by a requirement for metabolic regulation in young flies, in which the Aop-Pnt-Foxo circuit determines nutrient storage, and Pnt regulates lipolysis and responses to nutrient stress. Molecular functions are conserved amongst ETS TFs, suggesting others may also affect ageing. We show that Ets21C limits lifespan, functioning in the same genetic network as Foxo and IIS. Other ETS TFs appear to play roles in fly ageing in multiple contexts, since inhibiting the majority of the family in intestine, adipose or neurons extended lifespan. We expand the repertoire of lifespan-limiting ETS TFs in C. elegans, confirming their conserved function in ageing. Altogether this study reveals that roles of ETS TFs in physiology and lifespan are conserved throughout the family, both within and between species. Overall design: foxo, aopACT and pntP1 overexpression in S106 D. melanogaster, polyA RNAseq.
Longevity is determined by ETS transcription factors in multiple tissues and diverse species.
Sex, Specimen part, Cell line, Subject
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