Project description:The genome is folded into domains that are located in either transcriptionally inert or permissive compartments. Here we used genome-wide strategies to characterize domains during B cell development. Structured Interaction Matrix Analysis revealed that CTCF occupancy was primarily associated with intra-domain interactions, whereas p300, E2A, Pax5 and PU.1 were involved with intra- and inter-domain interactions that are developmentally regulated. We identified a spectrum of genes that switched nuclear location during early B cell development. In progenitors the transcriptionally inactive Ebf1 locus was sequestered at the nuclear lamina, thereby preserving multipotency, however upon development into the pro-B cell stage Ebf1 and other genes switched compartments to establish de novo intra- and inter-domain interactions that were associated with B lineage specific transcription signatures. Performed Hi-C, GRO-seq, and ChIP-seq to pinpoint the underlying molecular mechanisms that link transcriptional regulation to genomic structure and architecture in lymphocyte development
Project description:The genome is folded into domains that are located in either transcriptionally inert or permissive compartments. Here we used genome-wide strategies to characterize domains during B cell development. Structured Interaction Matrix Analysis revealed that CTCF occupancy was primarily associated with intra-domain interactions, whereas p300, E2A, Pax5 and PU.1 were involved with intra- and inter-domain interactions that are developmentally regulated. We identified a spectrum of genes that switched nuclear location during early B cell development. In progenitors the transcriptionally inactive Ebf1 locus was sequestered at the nuclear lamina, thereby preserving multipotency, however upon development into the pro-B cell stage Ebf1 and other genes switched compartments to establish de novo intra- and inter-domain interactions that were associated with B lineage specific transcription signatures.
Project description:Recent studies of genome-wide chromatin interactions have revealed that the human genome is partitioned into many self-associating topological domains. The boundary sequences are enriched for binding sites of CTCF and the cohesin complex, implicating these two factors in the establishment or maintenance of topological domains. To determine the role of cohesin and CTCF in higher order chromatin architecture in human cells, we proteolytically cleaved the cohesin complex from interphase chromatin and examined changes in chromosomal organization as well as transcriptome. We observed a general loss of local chromosomal interactions upon disruption of cohesin complex, but the topological domains remain intact. However, we found that depletion of CTCF by RNA interference in these cells not only reduced intra-domain interactions but also increased inter-domain interactions. Further more, distinct groups of genes become mis-regulated upon depletion of cohesin and CTCF. Taken together, these observations suggest that CTCF and cohesin contribute in different ways to chromatin organization and gene regulation. Hi-C and mRNA-seq experiments in Cohesin and CTCF depleted HEK293 cells
Project description:Proteomic analysis of caeca of gammarids sampled in four different population of Gammarus fossarus (Mandorne, Séran, Ardillat, Baculy). The aim of the project is to analyze the environmental effect of inter- and intra- population proteomic diversity of a key organ involved in organism fitness and tolerance to metal contamination.
