Whole-Exome Sequencing Identifies Loci Associated with Blood Cell Traits and Reveals a Role for Alternative GFI1B Splice Variants in Human Hematopoiesis

(The American Journal of Human Genetics 99, 481–488; August 4, 2016

Insight into GATA1 transcriptional activity through interrogation of cis

Whole-exome sequencing has been incredibly successful in identifying causal genetic variants and has revealed a number of novel genes associated with blood and other diseases. One limitation of this approach is that it overlooks mutations in noncoding regulatory elements. Furthermore, the mechanisms by which mutations in transcriptional cis-regulatory elements result in disease remain poorly understood. Here we used CRISPR/Cas9 genome editing to interrogate three such elements harboring mutations in human erythroid disorders, which in all cases are predicted to disrupt a canonical binding motif for the hematopoietic transcription factor GATA1. Deletions of as few as two to four nucleotides resulted in a substantial decrease (>80%) in target gene expression. Isolated deletions of the canonical GATA1 binding motif completely abrogated binding of the cofactor TAL1, which binds to a separate motif. Having verified the functionality of these three GATA1 motifs, we demonstrate strong evolutionary conservation of GATA1 motifs in regulatory elements proximal to other genes implicated in erythroid disorders, and show that targeted disruption of such elements results in altered gene expression. By modeling transcription factor binding patterns, we show that multiple transcription factors are associated with erythroid gene expression, and have created predictive maps modeling putative disruptions of their binding sites at key regulatory elements. Our study provides insight into GATA1 transcriptional activity and may prove a useful resource for investigating the pathogenicity of noncoding variants in human erythroid disorders

Study of 249Cf by Coulomb Excitation Gamma-ray Spectroscopy

Californium 249 (Z=98, N=151) is a deformed nucleus in the N=152, Z=100 nuclear region. The energy gaps of nuclei in this region arise in the deformed single-particle spectrum. Some excited states in these nuclei are predicted to be built on the same orbits which become spherical in the long-lived Super-Heavy-Element region near N =184, Z = 114 [1,2] (the so-called “Island of Stability”). Studies of excited states in the N=152, Z=100 region, and specifically in this research of 249Cf, provide a connection to the study of shell structure in the Island of Stability.The experiment has been performed at JAEA – Tokai Tandem Laboratory using 4 HPGe detectors and 4 LaBr3 scintillators for gamma detection and 2 S3-type [3] silicon detectors for particle detection. The silicon detectors were placed backward and forward to the target. 18O beam with energy 70 MeV and 58Ni beam with energy 245 MeV have been used for the experiment.A Coulomb excitation with beam energy well below the Coulomb barrier of 249Cf was achieved for the first time. The gamma rays in coincidence with scattered particles give the spectrum of gamma rays emitted from excited states of 249Cf and thus give the intensity of E2 transition. The intensity of E2 transitions, combined with the scattering angle of incoming particle, detector geometry, beam intensity, etc. were used as input for the GOSIA [4] code to deduce the B(E2) value to determine the deformation of 249Cf. The extracted data could help to complete the 249Cf level scheme.日本物理学会2020年秋季大

Yrast spectroscopy in Ti49-51 via fusion-evaporation reaction induced by a radioactive beam

International audienceIn-beam $\gamma$ -ray spectroscopy of high-spin states in 49-51Ti was performed via the fusion-evaporation reaction using a radioactive beam. By excitation function and $\gamma$ -$\gamma$ coincidence analysis, yrast high-spin levels up to I = (21/2-),(11+),(17/2-) in 49-51Ti were determined. The levels were compared with full-pf -shell model calculation. The level structure indicates the persistency of the N = 28 shell gap at yrast states in 49-51Ti

ZMYND8-regulated IRF8 transcription axis is an acute myeloid leukemia dependency

The transformed state in acute leukemia requires gene regulatory programs involving transcription factors and chromatin modulators. Here, we uncover an IRF8-MEF2D transcriptional circuit as an acute myeloid leukemia (AML)-biased dependency. We discover and characterize the mechanism by which the chromatin "reader" ZMYND8 directly activates IRF8 in parallel with the MYC proto-oncogene through their lineage-specific enhancers. ZMYND8 is essential for AML proliferation in vitro and in vivo and associates with MYC and IRF8 enhancer elements that we define in cell lines and in patient samples. ZMYND8 occupancy at IRF8 and MYC enhancers requires BRD4, a transcription coactivator also necessary for AML proliferation. We show that ZMYND8 binds to the ET domain of BRD4 via its chromatin reader cassette, which in turn is required for proper chromatin occupancy and maintenance of leukemic growth in vivo. Our results rationalize ZMYND8 as a potential therapeutic target for modulating essential transcriptional programs in AML

Targeted Application of Human Genetic Variation Can Improve Red Blood Cell Production from Stem Cells

Multipotent and pluripotent stem cells are potential sources for cell and tissue replacement therapies. For example, stem cell-derived red blood cells (RBCs) are a potential alternative to donated blood, but yield and quality remain a challenge. Here, we show that application of insight from human population genetic studies can enhance RBC production from stem cells. The SH2B3 gene encodes a negative regulator of cytokine signaling and naturally occurring loss-of-function variants in this gene increase RBC counts in vivo. Targeted suppression of SH2B3 in primary human hematopoietic stem and progenitor cells enhanced the maturation and overall yield of in vitro-derived RBCs. Moreover, inactivation of SH2B3 by CRISPR/Cas9 genome editing in human pluripotent stem cells allowed for enhanced erythroid cell expansion with preserved differentiation. Our findings therefore highlight the potential for combining human genome variation studies with genome editing approaches to improve cell and tissue production for regenerative medicine