94 research outputs found

    Search for particles with unexpected mass and charge in Z decays

    Get PDF

    Update of electroweak parameters from Z decays

    Get PDF

    Zebrafish globin switching occurs in two developmental stages and is controlled by the LCR

    Get PDF
    AbstractGlobin gene switching is a complex, highly regulated process allowing expression of distinct globin genes at specific developmental stages. Here, for the first time, we have characterized all of the zebrafish globins based on the completed genomic sequence. Two distinct chromosomal loci, termed major (chromosome 3) and minor (chromosome 12), harbor the globin genes containing α/β pairs in a 5′–3′ to 3′–5′ orientation. Both these loci share synteny with the mammalian α-globin locus. Zebrafish globin expression was assayed during development and demonstrated two globin switches, similar to human development. A conserved regulatory element, the locus control region (LCR), was revealed by analyzing DNase I hypersensitive sites, H3K4 trimethylation marks and GATA1 binding sites. Surprisingly, the position of these sites with relation to the globin genes is evolutionarily conserved, despite a lack of overall sequence conservation. Motifs within the zebrafish LCR include CACCC, GATA, and NFE2 sites, suggesting functional interactions with known transcription factors but not the same LCR architecture. Functional homology to the mammalian α-LCR MCS-R2 region was confirmed by robust and specific reporter expression in erythrocytes of transgenic zebrafish. Our studies provide a comprehensive characterization of the zebrafish globin loci and clarify the regulation of globin switching

    Constitutively active AKT depletes hematopoietic stem cells and induces leukemia in mice

    No full text
    Human cancers, including acute myeloid leukemia (AML), commonly display constitutive phosphoinositide 3-kinase (PI3K) AKT signaling. However, the exact role of AKT activation in leukemia and its effects on hematopoietic stem cells (HSCs) are poorly understood. Several members of the PI3K pathway, phosphatase and tensin homolog (Pten), the forkhead box, subgroup O (FOXO) transcription factors, and TSC1, have demonstrated functions in normal and leukemic stem cells but are rarely mutated in leukemia. We developed an activated allele of AKT1 that models increased signaling in normal and leukemic stem cells. In our murine bone marrow transplantation model using a myristoylated AKT1 (myr-AKT), recipients develop myeloproliferative disease, T-cell lymphoma, or AML. Analysis of the HSCs in myr-AKT mice reveals transient expansion and increased cycling, associated with impaired engraftment. myr-AKT–expressing bone marrow cells are unable to form cobblestones in long-term cocultures. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR) rescues cobblestone formation in myr-AKT–expressing bone marrow cells and increases the survival of myr-AKT mice. This study demonstrates that enhanced AKT activation is an important mechanism of transformation in AML and that HSCs are highly sensitive to excess AKT/mTOR signaling

    Measurement of the Mass of the Z-Boson and the Energy Calibration of Lep

    Get PDF
    Contains fulltext : 26847___.PDF (publisher's version ) (Open Access

    Electroweak parameters of the z0 resonance and the standard model

    Get PDF
    Contains fulltext : 124399.pdf (publisher's version ) (Open Access
    • …
    corecore