Project description:Among epigenetic modifiers, telomeres, represent attractive modulators of the genome in part through position effects. Telomere Position Effect – Over Long Distances (TPE-OLD) modulates genes expression by changes in telomeric-dependent long-distance loops, with a reach of 10Mb from the telomeres. However, TPE-OLD remain poorly defined. We used cells with controlled telomere length combined to a genome wide approach revealing its transcriptome and methylome. We identified a common cis element that behaved as an insulator/ enhancer. By using reporter assays integrating this element, we disclosed additional trans partners further validated by in silico data. Exploiting our cellular model we observed the depletion of one candidate (RBPJ) at TPE-OLD associated loci concomitant to telomere shortening. Therefore, we conclude that TPE-OLD is orchestrated by Alu-like elements acting as enhancers in association with RBPJ. We propose that TPE-OLD functions by the coordinated action of newly evolved enhancers; an associated protein RBPJ and telomere length to produce an adapted response to external stimuli (i.e., Aging)
Project description:Among epigenetic modifiers, telomeres, represent attractive modulators of the genome in part through position effects. Telomere Position Effect – Over Long Distances (TPE-OLD) modulates genes expression by changes in telomeric-dependent long-distance loops, with a reach of 10Mb from the telomeres. However, TPE-OLD remain poorly defined. We used cells with controlled telomere length combined to a genome wide approach revealing its transcriptome and methylome. We identified a common cis element that behaved as an insulator/ enhancer. By using reporter assays integrating this element, we disclosed additional trans partners further validated by in silico data. Exploiting our cellular model we observed the depletion of one candidate (RBPJ) at TPE-OLD associated loci concomitant to telomere shortening. Therefore, we conclude that TPE-OLD is orchestrated by Alu-like elements acting as enhancers in association with RBPJ. We propose that TPE-OLD functions by the coordinated action of newly evolved enhancers; an associated protein RBPJ and telomere length to produce an adapted response to external stimuli (i.e., Aging)
Project description:Lipids play an important role in energy storage, membrane structure stabilization and signaling. Parasitoids are excellent models to study lipidomics because a majority of them do not accumulate during their free-living life-stage. Studies on parasitoids have mostly focused on the changes in the lipids and gene transcripts in hosts and little attention has been devoted to lipidomics and transcriptomics changes in parasitoids. In this study, a relative quantitative analysis of lipids and their gene transcripts in 3-days-old Lysiphlebia japonica larva (3 days after spawning) and pupae were performed using liquid chromatography, mass spectrometry and RNA-seq. Thirty-three glycerolipids and 250 glycerophospholipids were identified in this study; all triglycerides and the vast majority of phospholipids accumulated in the pupal stage. This was accompanied by differentially regulated lipid uptake and remolding. Furthermore, our data showed that gene transcription was up-regulated in key nutrient metabolic pathways involved in lipid synthesis in 3-days-old larvae. Finally, our data suggests that larva and pupa of L. japonica may lack the ability for fatty acids synthesis. A comprehensive, quantitative, and expandable resource was provided for further studies of metabolic regulation and molecular mechanisms underlying parasitic response to hosts defense.