Project description:We created mice, which are deficient for Myc specifically in cardiac myocytes by crossing crossed Myc-floxed mice (Mycfl/fl) and MLC-2VCre/+ mice. Serial analysis of earlier stages of gestation revealed that Myc-deficient mice died prematurely at E13.5-14.5. Morphological analyses of E13.5 Myc-null embryos showed normal ventricular size and structure; however, decreased cardiac myocyte proliferation and increased apoptosis was observed. BrdU incorporation rates were also decreased significantly in Myc-null myocardium. Myc-null mice displayed a 3.67-fold increase in apoptotic cardiomyocytes by TUNEL assay. We examined global gene expression using oligonucleotide microarrays. Numerous genes involved in mitochondrial death pathways were dysregulated including Bnip3L and Birc2. Hearts were taken from wide type and Myc-null Mouse embryos at E13.5 under the dissecting scope. Cardiac myocyte RNA was isolated using TRIZOL®Reagent Total RNA (100 ng) was hybridized to the Sentrix® MouseRef-8 Expression BeadChip that contains probes for ~24,000 transcripts. GeneChips were scanned using the Hewlett-Packard GeneArray Scanner G2500A. The data were analyzed with Illumina Inc. BeadStudio version 1.5.0.34 and normalized by rank invariant method.
Project description:We created mice, which are deficient for Myc specifically in cardiac myocytes by crossing crossed Myc-floxed mice (Mycfl/fl) and MLC-2VCre/+ mice. Serial analysis of earlier stages of gestation revealed that Myc-deficient mice died prematurely at E13.5-14.5. Morphological analyses of E13.5 Myc-null embryos showed normal ventricular size and structure; however, decreased cardiac myocyte proliferation and increased apoptosis was observed. BrdU incorporation rates were also decreased significantly in Myc-null myocardium. Myc-null mice displayed a 3.67-fold increase in apoptotic cardiomyocytes by TUNEL assay. We examined global gene expression using oligonucleotide microarrays. Numerous genes involved in mitochondrial death pathways were dysregulated including Bnip3L and Birc2. Keywords: wildtype vs Myc-null
Project description:Mutations in methyl-CpG-binding protein 2 (MeCP2), a major epigenetic regulator, are the predominant cause of Rett syndrome, an X-linked neurodevelopmental disorder. We previously found that Mecp2-null microglia are functionally impaired, and that engraftment of wild-type monocytes into the brain of Mecp2-deficient mice attenuates pathology. In this study we show that Mecp2 is expressed in macrophage and monocyte populations throughout the body, and is indispensable for their transcriptional regulation in multiple contexts. We demonstrate that Mecp2-null mice progressively lose or are chronically deficient in several macrophage populations and resident monocytes. Postnatal re-expression of Mecp2 driven by a tamoxifen-inducible CX3CR1 promoter significantly increased the lifespan of otherwise Mecp2-null mice, suggesting that epigenetic regulation of macrophage function by Mecp2 significantly contributes to pathology. RNA-Seq of acutely isolated microglia and peritoneal macrophages (to our knowledge, the first cell-specific RNA-Seq analysis comparing Mecp2-null and wild type cells of any kind) revealed significantly increased transcription of glucocorticoid- and hypoxia-signaling genes in Mecp2-null cells compared to that in their wild-type counterparts, suggesting that Mecp2 functions as a repressor of these pathways. Furthermore, in-vitro and in vivo validation studies demonstrated that the absence of Mecp2 is associated with cell-intrinsic dysfunction of signaling underlying inflammatory activation, suggesting that Mecp2 is important for regulation of specific macrophage gene-expression programs in response to stimuli and stressors. Our findings demonstrate a fundamental role for Mecp2 in the regulation of macrophage functions, which may provide a link to pathologies in Rett syndrome across multiple organs.
Project description:Mutations in methyl-CpG-binding protein 2 (MeCP2), a major epigenetic regulator, are the predominant cause of Rett syndrome, an X-linked neurodevelopmental disorder. We previously found that Mecp2-null microglia are functionally impaired, and that engraftment of wild-type monocytes into the brain of Mecp2-deficient mice attenuates pathology. In this study we show that Mecp2 is expressed in macrophage and monocyte populations throughout the body, and is indispensable for their transcriptional regulation in multiple contexts. We demonstrate that Mecp2-null mice progressively lose or are chronically deficient in several macrophage populations and resident monocytes. Postnatal re-expression of Mecp2 driven by a tamoxifen-inducible CX3CR1 promoter significantly increased the lifespan of otherwise Mecp2-null mice, suggesting that epigenetic regulation of macrophage function by Mecp2 significantly contributes to pathology. RNA-Seq of acutely isolated microglia and peritoneal macrophages (to our knowledge, the first cell-specific RNA-Seq analysis comparing Mecp2-null and wild type cells of any kind) revealed significantly increased transcription of glucocorticoid- and hypoxia-signaling genes in Mecp2-null cells compared to that in their wild-type counterparts, suggesting that Mecp2 functions as a repressor of these pathways. Furthermore, in-vitro and in vivo validation studies demonstrated that the absence of Mecp2 is associated with cell-intrinsic dysfunction of signaling underlying inflammatory activation, suggesting that Mecp2 is important for regulation of specific macrophage gene-expression programs in response to stimuli and stressors. Our findings demonstrate a fundamental role for Mecp2 in the regulation of macrophage functions, which may provide a link to pathologies in Rett syndrome across multiple organs. Mecp2-null microglia and resident peritoneal macrophages from 10-12 week old mice were acutely isolated via AutoMACS, total RNA collected, and analyzed via RNA-Seq to compare for transcriptional differences in microglia and macrophages in the absence of Mecp2.
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.