Project description:It is known that CBFB-MYH11, the fusion gene generated by inversion of chromosome 16 in human acute myeloid leukemia, is causative for oncogenic transformation. However, the mechanism by which CBFB-MYH11 initiates leukemogenesis is not clear. Previously published reports showed that CBFB-MYH11 dominantly inhibits RUNX1 and CBFB, and such inhibition has been suggested as the mechanism for leukemogenesis. However, knockin mice expressing Cbfb-MYH11 (Cbfb+/MYH11) showed defects in primitive hematopoiesis not seen in Cbfb null (Cbfb-/-) embryos indicating that Cbfb-MYH11 has repression independent activities as well. To identify gene expression changes associated with this novel activity, we compared the gene expression profile in the blood cells of Cbfb+/MYH11 and Cbfb-/- embryonic day 12.5 (E12.5) embryos with that of their wildtype littermates. Cbfb-MYH11 chimeras were mated to C57/Bl6 females to generate Cbfb+/MYH11 (Cbfb+/MYH11) and Cbfb+/+ (WT) embryos. Cbfb+/- x Cbfb+/- matings were used to generate Cbfb+/+ (Cbfb+/+) and Cbfb-/- (Cbfb-/-) embryos. Blood from 8-10 E12.5 embryos of the same genotype was pooled, and RNA was isolated, labeled, and hybridized to Affymetrix Genechip mouse microarray (430 2.0) chips. 4 chips were used for both the Cbfb+/MYH11 and littermate control samples. 3 chips were used for the Cbfb-/- samples and littermate control samples.
Project description:It is known that CBFB-MYH11, the fusion gene generated by inversion of chromosome 16 in human acute myeloid leukemia, is causative for oncogenic transformation. However, the mechanism by which CBFB-MYH11 initiates leukemogenesis is not clear. Previously published reports showed that CBFB-MYH11 dominantly inhibits RUNX1 and CBFB, and such inhibition has been suggested as the mechanism for leukemogenesis. However, knockin mice expressing Cbfb-MYH11 (Cbfb+/MYH11) showed defects in primitive hematopoiesis not seen in Cbfb null (Cbfb-/-) embryos indicating that Cbfb-MYH11 has repression independent activities as well. To identify gene expression changes associated with this novel activity, we compared the gene expression profile in the blood cells of Cbfb+/MYH11 and Cbfb-/- embryonic day 12.5 (E12.5) embryos with that of their wildtype littermates.
Project description:Ptf1a is a lineage-specific basic-helix-loop-helix transcription factor critical in the development of both the pancreas and nervous system. How one transcription factor controls diverse programs of gene expression is a fundamental question in developmental biology. To uncover molecular strategies for the program-specific functions of Ptf1a, we identified bound genomic regions in vivo during development of both tissues. A majority of regions bound by Ptf1a are tissue-specific, lie near genes needed for proper formation and maturation of each tissue, and reflect regions of open chromatin.M-BM- M-BM- Information for the specificity of Ptf1a binding and function is encoded in the DNA surrounding the Ptf1a-bound sites, since Ptf1a-bound regions are sufficient to direct tissue-restricted reporter expression when tested in transgenic mice. Fox and Sox factors were identified as lineage specific modifiers ofM-BM- Ptf1a binding, sinceM-BM- binding motifs for these factors are enriched in Ptf1a-bound regions in pancreas and neural tube, respectively. Although Ptf1a and Foxa2 co-localize to sites in embryonic pancreas and can act synergistically in cell transfection assays, biochemical experiments detected no physical interaction between the two factors. These findingsM-BM- indicateM-BM- that lineage-specific chromatin landscapes likely constrain the functions of Ptf1a, and identify Fox and Sox gene families as part of this process. RNA-Seq: Examination of gene expression in Ptf1a expressing cells (NT E.12.5, Pancreas E15.5) ChIP-Seq: Examination of chromatin occupancy in 2 tissue types (E12.5 NT and 17.5 Pancreas). Faire-Seq: Examination of open chromatin in 2 tissue types (E12.5 NT and 17.5 Pancreas).
Project description:The C-terminus of CBFß-SMMHC, the fusion protein produced by a chromosome 16 inversion in acute myeloid leukemia subtype M4Eo, contains domains for self-mulimerization and transcriptional repression, both of which have been proposed to be important for leukemogenesis by CBFß-SMMHC. To test the role of the fusion protein's C-terminus in vivo, we generated knock-in mice expressing a C-terminally truncated CBFß-SMMHC (CBFß-SMMHCΔC95). Embryos with a single copy of CBFß-SMMHCDC95 were viable and showed no defects in hematopoiesis, while embryos homozygous for the CBFß-SMMHCΔC95 allele had hematopoietic defects and died in mid-gestation, similar to embryos with a single-copy of the full-length CBFß-SMMHCΔC95. To identify gene expression changes induced by CBFß-SMMHCDC95, we compared the gene expression profile in the blood cells of Cbfb+/+, Cbfb+/ΔC95, and CbfbΔC95/ΔC95 embryonic day 12.5 (E12.5) mice. Cbfb+/ΔC95 were mated together to generate Cbfb+/+, Cbfb+/ΔC95, and CbfbΔC95/ΔC95 embryos. Blood from 8-10 E12.5 embryos of the same genotype was pooled, and RNA was isolated, labeled, and hybridized to Affymetrix Genechip mouse microarray (430 2.0) chips. 3 chips were used for each genotype.
Project description:Themis1, a recently described T-lineage specific protein, is essential for thymic positive and negative selection. Although Themis1 has been clearly identified as a component of the T cell antigen receptor (TCR) signalosome, its precise role in TCR signaling remains unclear. Here, we used quantitative proteomic and TCR signaling reporter mice to gain insight into Themis1 signaling function. Mass spectrometry analysis of the Themis1 interactome identified Grb2, SHP1 and Vav1 as the principal interacting partners of Themis1 in thymocytes. The dataset contains mass spectrometry results from the analysis of 6 different kind of AP-MS purifications (based on immunoprecipitation using a Themis1 antibody) starting from the following samples: - thymocytes from WT mice, non stimulated (noted WT NS) - thymocytes from WT mice, stimulated with pervanadate (noted WT P) - thymocytes from GRB2 +/- mice (with decreased expression of GRB2), non stimulated (noted GRB2 NS) - thymocytes from GRB2 +/- mice (with decreased expression of GRB2), stimulated with pervanadate (noted GRB2 P) - thymocytes from Themis1 -/- mice (knock-out for Themis1), non stimulated (noted KO NS) - thymocytes from Themis1 -/- mice (knock-out for Themis1), stimulated with pervanadate (noted KO P) Three biological replicates were prepared for these 6 different conditions (noted, 1,2,3), yielding 18 analyzed samples. Three technical nanoLC-MS runs were acquired for each sample (noted R1, R2, R3), leading to the 54 nanoLC-MS raw files contained in the dataset.
Project description:Lineage negative, CD44 negative, CD25 positive thymocytes were isolated from wt mice or Miz1 POZ-domain knockout mice to analyze the effect of loss of Miz1 in the DN3 population of T-cells We used the mouse Affymetrix MOE430-2 microarray to characterize global gene expression changes of DN3 thymocytes from Miz1 knockout mice.
Project description:Programming T lymphocytes to distinguish self from non-self is a vital, multi-step process arising in the thymus. Signalling through the pre-T cell receptor (preTCR), a CD3-associated heterodimer comprising an invariant pTα chain and a clone-specific β chain, constitutes a critical early checkpoint in thymocyte development within the αβ T-cell lineage. Recent work demonstrates that preTCRs arrayed on double negative (DN) thymocytes, like αβ TCRs appearing on double positive (DP) thymocytes, ligate peptides bound to MHC molecules (pMHC) on thymic stroma but via a different molecular docking strategy. Here we show the consequences of those distinctive interactions for thymocyte progression, using synchronized fetal thymic progenitor cultures differing in the presence or absence of pMHC on support stroma, determining single cell transcriptomes at key thymocyte developmental transitions. Although MHC negative stroma fosters αβ T lymphocyte differentiation, the absence of pMHC-preTCR interplay leads to deviant thymocyte transcriptional programming associated with de-differentiation. Highly proliferative DN and DP subsets with antecedent characteristics of T cell lymphoblastic and myeloid malignancies emerge. Thus, in addition to fostering β chain repertoire broadening for subsequent αβ TCR utilization, preTCR-pMHC interaction limits cellular plasticity to facilitate normal thymocyte differentiation and proliferation that, if absent, introduces significant developmental vulnerabilities.
Project description:ChIP-Sequencing on Shox2-HA E12.5 and E13.5 Limb and Palate, as well as Pbx on E12.5 limb . Abstract: Vertebrate appendage patterning is programmed by Hox-TALE factors-bound regulatory elements. However, it remains enigmatic which cell lineages are commissioned by Hox-TALE factors to generate regional specific pattern and whether other Hox-TALE co-factors exist. In this study, we investigated the transcriptional mechanisms controlled by the Shox2 transcriptional regulator in limb patterning. Harnessing an osteogenic lineage-specific Shox2 inactivation approach we show that despite widespread Shox2 expression in multiple cell lineages, lack of the stylopod observed upon Shox2 deficiency is a specific result of Shox2 loss of function in the osteogenic lineage. ChIP-Seq revealed robust interaction of Shox2 with cis-regulatory enhancers clustering around skeletogenic genes that are also bound by Hox-TALE factors, supporting a lineage autonomous function of Shox2 in osteogenic lineage fate determination and skeleton patterning. Pbx ChIP-Seq further allowed the genome-wide identification of cis-regulatory modules exhibiting co-occupancy of Pbx, Meis, and Shox2 transcriptional regulators. Integrative analysis of ChIP-Seq and RNA-Seq data and transgenic enhancer assays indicate that Shox2 patterns the stylopod as a repressor via interaction with enhancers active in the proximal limb mesenchyme and antagonizes the repressive function of TALE factors in osteogenesis. Shox2/TALE For ChIP-Seq, the list of libraries below, including controls, were generated [listed in the format of (antibody)-target-tissue-stage]: (α-HA)-Shox2-Limb-E12.5, (α-HA)-Shox2-Limb-E13.5, (α-HA)-Shox2-Palate-E12.5, (α-HA)-Shox2-Limb/Palate-E12.5, (α-Pbx)-Pbx-Limb-E12.5, Input (control), (α-HA)-Mixed Limb/Palate from Shox2+/+ mice-E12.5 (control). *The attached signal tracks(*.bigwig) were generated by âbdgcmp (MACS2) to filter out background signal(by filtering against the signal track obtained from (α-HA)-Mixed Limb/Palate from Shox2+/+ mice-E12.5 (control)) and subsequently convert to bigwig for analysis and visualization.