Project description:Ecotropic viral integration site 1 (EVI1/MECOM) overexpression is common in myeloid malignancies. We present a new Evi1 transgenic mouse model with inducible expression in hematopoietic stem cells (HSCs) and progenitor cells (HPCs) at lower levels. Upon exogenous Evi1 induction, mice displayed anemia, thrombocytopenia, lymphopenia, and dysplasia in erythroid and megakaryocyte cells with a significant expansion of committed myeloid progenitor cells, resembling human Myelodysplastic syndrome/Myeloproliferative neoplasm (MDS/MPN)-like disease. Methods: Lin-C-Kit+ cells were isolated from 3 pairs of WT and Evi1 overexpressing mice. Around 1X106 Lin-C-Kit+ cells were harvested from each mouse. Then the cells were lysated by Trizol and total RNA was extracted by phenol-chloroform. Results: Molecular pathways altered in Lin-C-Kit+ cells from Evi1-OE mice. Conclusions: Multiple molecular pathways changed in Evi1 overexpressing hematopoietic stem and progenitor cells.
Project description:Ecotropic viral integration site 1 (EVI1/MECOM) overexpression is common in myeloid malignancies. We present a new Evi1 transgenic mouse model with inducible expression in hematopoietic stem cells (HSCs) and progenitor cells (HPCs) at lower levels. Upon exogenous Evi1 induction, mice displayed anemia, thrombocytopenia, lymphopenia, and dysplasia in erythroid and megakaryocyte cells with a significant expansion of committed myeloid progenitor cells, resembling human Myelodysplastic syndrome/Myeloproliferative neoplasm (MDS/MPN)-like disease. Methods: Lin-C-Kit+ cells were isolated from 2 Evi1 overexpressing mice for CUT&RUN assay using flag antibody and IgG. Lin-C-Kit+ cells were isolated from 2 pair of WT mice and Evi1 overexpressing mice for CUT&RUN assay using H3K27me3 antibody.Around 5X105 Lin-C-Kit+ cells for each group were used in CUT&RUN assay. About 10 ng of the purified CUT&RUN DNA was used for preparation of multiplexed libraries with the NEB Ultra II DNA Library Prep Kit per manufacturer's instruction (NEB #E7103). Sequencing was conducted using an Illumina NextSeq 500 Sequencing System. Results: Molecular pathways altered in Lin-C-Kit+ cells from Evi1-OE mice. Conclusions: Evi1 has a special binding profiling in Lin-C-Kit+ cells. The modification profile of H3K27me3 was altered in Evi1-OE hematopoietic stem and progenitor cells.
Project description:The transcription factor Evi1 is essential for the formation and maintenance of hematopoietic stem cells, and induces clonal dominance with malignant progression upon constitutive activation by chromosomal rearrangements or transgene integration events. To understand the immediate and adaptive response of primary murine hematopoietic cells to the transcriptional upregulation of Evi1, we developed an inducible lentiviral vector system with a robust expression switch. We found that Evi1 delays differentiation and promotes survival in myeloid culture conditions, orchestrating a battery of genes involved in stemness (Aldh1a1, Ly6a [Sca1], Abca1, Epcam, among others). Importantly, Evi1 suppresses Cyclins and Cyclin-dependent kinases (Cdk), while it upregulates Cdk inhibitors, inducing quiescence in various proliferation-inducing cytokine conditions and operating in a strictly dose-dependent manner. Hematopoietic cells with persisting Evi1-induction tend to adopt a relatively low expression level. We thus classify Evi1 as a dormancy-inducing oncogene, likely requiring epigenetic and genetic compensation for cell expansion and malignant progression. Lin- Rosa26rtTA cells were isolated, transduced in S3F11 cytokines, induced the next day with DOX [1 μg/ml] and 20 hours later sorted for negative/low or highly EGFP expressing cells, from which total RNA was extraced and subjected to Microarray Analysis
Project description:The transcription factor Evi1 is essential for the formation and maintenance of hematopoietic stem cells, and induces clonal dominance with malignant progression upon constitutive activation by chromosomal rearrangements or transgene integration events. To understand the immediate and adaptive response of primary murine hematopoietic cells to the transcriptional upregulation of Evi1, we developed an inducible lentiviral vector system with a robust expression switch. We found that Evi1 delays differentiation and promotes survival in myeloid culture conditions, orchestrating a battery of genes involved in stemness (Aldh1a1, Ly6a [Sca1], Abca1, Epcam, among others). Importantly, Evi1 suppresses Cyclins and Cyclin-dependent kinases (Cdk), while it upregulates Cdk inhibitors, inducing quiescence in various proliferation-inducing cytokine conditions and operating in a strictly dose-dependent manner. Hematopoietic cells with persisting Evi1-induction tend to adopt a relatively low expression level. We thus classify Evi1 as a dormancy-inducing oncogene, likely requiring epigenetic and genetic compensation for cell expansion and malignant progression. Lin- Rosa26rtTA cells were isolated, transduced either with pRRL.PPT.Tet.Evi1.IRES.EGFP.pre or with the pRRL.PPT.Tet.EGFP.pre control vector in S3F11 cytokines, induced the next day with DOX [1 μg/ml] and 20 hours later sorted for EGFP expressing cells, from which total RNA was extraced and subjected to Microarray Analysis.
Project description:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.