Project description:By their impact on nuclear organisation, enhancers are master regulators of cell fate. We thus developed double Emu-RAG-deficient, 3’RR-RAG-deficient mice and KOKI-RAG-deficient mice to investigate a potential transcriptional cross-talk between Emu and 3'RR enhancers at the pro-B cell stage.
Project description:Investigation of B cell lymphomas (IgM+ IgD+) located in various places (lung, mesenteric lymph nodes,…) of three different c-myc Igh transgenic mice. Insertion of c-myc in 5' to Emu (cr), in 5' to Cmu with Emu deletion (hv), and in Calpha (co).
Project description:Histones were isolated from brown adipose tissue and liver from mice housed at 28, 22, or 8 C. Quantitative top- or middle-down approaches were used to quantitate histone H4 and H3.2 proteoforms. See published article for complimentary RNA-seq and RRBS datasets.
Project description:The IgH 3â?? regulatory region (3â??RR) controls class switch recombination (CSR) and somatic hypermutation (SHM) in B cells. The mouse 3â??RR contains four enhancer elements with hs1,2 flanked by inverted repeated sequences and the center of a 25-kb palindrome bounded by two hs3 enhancer inverted copies (hs3a and hs3b). hs4 lies downstream of the palindrome. Evolution maintained in mammals this unique palindromic arrangement suggesting that it is functionally significant. We report that deconstructing the palindromic IgH 3â??RR strongly impacts its function even when enhancers are preserved. CSR and IgH transcription appear poorly dependent from the 3â??RR architecture and are more or less preserved provided 3â??RR enhancers are present. By contrast, an â??architectural effectâ?? significantly lowers VH germline transcription, AID recruitment and SHM. In conclusion, this work indicates that the IgH 3â??RR does not simply pile up enhancer units but also optimally expose them into a functional architecture of crucial importance. RNAseq analysis of B-cell splenocytes with (S=stimulated) or without (R=resting) LPS activation from wt, delta2leftPAL, and deltaIRIS mice.
Project description:Numerous B-cell lymphomas feature translocations linking oncogenes with the IgH locus and epigenetic drugs such as histone deacetylase inhibitors (HDACi) have been approved to treat some of them. In this study we investigated IgH locus transcription in B-cell splenocytes stimulated with LPS and the HDACi SAHA. B-cell development is spatially and temporally regulated with the 3'RR enhancer of the IgH locus as a conductor. 3'RR is composed of 4 enhancer elements with a palindromic structure of great significance. We investigated the role of this palindrome with KOKI mice where the 30Kb structure of the 3'RR has been deleted of its palindromic structure.
