Project description:In this study, we have identified MEF2A-sensitive genes in atrial and ventricular chambers of the adult heart. MEF2A is a member of the myocyte enhancer factor 2 (MEF2) family of transcription factors. MEF2 proteins are expressed in skeletal and cardiac muscle tissues and are conserved across many mammalian species, but the gene programs regulated by MEF2A in adult cardiac chambers are largely unknown. We compared gene expression profiles between WT and Mef2a knockout atria and ventricles from adult mice, and the results identified distinct and overlapping sets of genes sensitive to the loss of MEF2A in the adult heart.
Project description:We identified genes expressed in mouse skeletal muscle, during the process of muscle regeneration after injury, which are dysregulated in the absence of Mef2a expression. MEF2A is a member of the evolutionarily conserved MEF2 transcription factor family which has known roles in cardiac muscle development and function, but is not well studied in skeletal muscle. We performed a comparison of gene expression profiles in wild type and MEF2A knockout tibialis anterior muscle, seven days post-injury with cardiotoxin. The results indicated that a variety of genes expressed during muscle regeneration, predominantly microRNAs in the Gtl2-Dio3 locus, are dysregulated by the loss of MEF2A expression. Skeletal muscle RNA used in the present study included the following two sample groups: (WT) pooled total RNA from tibialis anterior muscle taken from 5 wild type mice at seven days post-injury with 10uM cardiotoxin; (KO) pooled total RNA from tibialis anterior muscle taken from 5 Mef2a knockout mice at seven days post-injury with 10uM cardiotoxin. All mice were between 2-4 months of age. Both male and female mice were used.
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: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 identified genes expressed in mouse skeletal muscle, during the process of muscle regeneration after injury, which are dysregulated in the absence of Mef2a expression. MEF2A is a member of the evolutionarily conserved MEF2 transcription factor family which has known roles in cardiac muscle development and function, but is not well studied in skeletal muscle. We performed a comparison of gene expression profiles in wild type and MEF2A knockout tibialis anterior muscle, seven days post-injury with cardiotoxin. The results indicated that a variety of genes expressed during muscle regeneration, predominantly microRNAs in the Gtl2-Dio3 locus, are dysregulated by the loss of MEF2A expression.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
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.
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.
Project description:Stress-induced cell senescence plays a crucial role in maintaining cardiac function after AMI, but the specific mechanism remains unclear. The objective of this study was to investigate the regulatory role of myocyte enhancer factor 2A (MEF2A) in cardiomyocyte senescence and its impact on cardiac function following AMI. Cardiomyocyte-specific MEF2A knockout mice (MEF2A-MyH6-CreErt2(f/f,+)) were generated, and their anterior descending branches were ligated to establish an AMI model. Ultrasound assessment of cardiac function 30 days post-AMI revealed that the specific knockout of MEF2A in cardiomyocytes worsened cardiac dysfunction and fibrosis, increased biomarkers of myocardial necrosis, and led to senescence in cardiomyocytes. Through high-throughput sequencing analysis of mRNA and protein in myocardial tissue from both MEF2A-MyH6-Creert2 (f/f,+) and wild-type mice, it was discovered that there was a decrease in expression levels for the enzymes of the cyclooxygenase (COX) family after MEF2A knockout. Additionally, KEGG analysis showed that differentially expressed genes were linked to cellular senescence processes . This suggests that MEF2A plays a regulatory role in cellular senescence through its interaction with the cox family. Meanwhile, COX inhibitors were found to weaken the beneficial effects of MEF2A overexpression on cardiomyocyte senescence in H9C2 cells. Our observations showed that knocking out MEF2A led to a decrease in H3K4me3 methylation levels and an increase in H3K4me3 antibody binding to specific cox family promoters when overexpressed. The use of MM102, a methylation inhibitor, nearly eliminated the positive effects of MEF2A overexpression on cell senescence, providing evidence that regulation of methylation is how MEF2A influences COX family expression changes. After screening, it was found that MEF2A can affect the methyltransferase activity partly by regulating the transcription level of SET1A subunit.