Project description:The development and function of stem and progenitor cells that produce blood cells are vital in physiology. GATA2 mutations cause immunodeficiency, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). GATA-2 physiological activities necessitate that it be strictly regulated and cell type-specific enhancers fulfill this role. The +9.5 intronic enhancer harbors multiple conserved cis-elements, and germline mutations of these cis-elements are pathogenic in humans. Since mechanisms underlying how GATA2 enhancer disease mutations impact hematopoiesis and pathology are unclear, we generated mouse models of the enhancer mutations. While a multi-motif mutant was embryonic lethal, a single-nucleotide Ets motif mutant was viable and steady-state hematopoiesis was normal. However, the Ets motif mutation abrogated stem/progenitor cell regeneration following stress. These results reveal a new mechanism in human genetics in which a disease mutation inactivates enhancer regenerative activity, while sparing developmental activity. Mutational sensitization to stress that instigates hematopoietic failure constitutes a paradigm for GATA-2-dependent pathogenesis.
Project description:We have generated a nonconditionall deletion of an E-box - GATA motif composite element from a putative enhancer 9.5 kb downstream of the Gata2 1S promoter. The mutation results in lethality at E13.5 to E14.5 with embryos exhibiting dectects in definitive hematopoiesis and vasculature integrity. Hematopoietic stem and progenitor cells are nearly absent from these mice and Gata2 expression is severely reduced in Pecam-1+ endothelial cells from E12.5-12.5 embryos but is expressed at normal levels in the embryonic brain. We have employed gene expression profiling in Pecam-1+ cells from wild type and Gata 2+9.5 mutant littermates to identify genes involved in maintaining vascular integrity. The Gata2+9.5 mutation was backcrossed into the C57Bl/6J background. Anti-CD31 antibody bound to magnetic beads was used to enrich for PECAM-1+ cells from four Gata2+9.5 E12.5 embryos and four wild type littermates from two litters. A single RNA sample from each embryo was used for array hybridization.
Project description:We have generated a nonconditionall deletion of an E-box - GATA motif composite element from a putative enhancer 9.5 kb downstream of the Gata2 1S promoter. The mutation results in lethality at E13.5 to E14.5 with embryos exhibiting dectects in definitive hematopoiesis and vasculature integrity. Hematopoietic stem and progenitor cells are nearly absent from these mice and Gata2 expression is severely reduced in Pecam-1+ endothelial cells from E12.5-12.5 embryos but is expressed at normal levels in the embryonic brain. We have employed gene expression profiling in Pecam-1+ cells from wild type and Gata 2+9.5 mutant littermates to identify genes involved in maintaining vascular integrity.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
