Project description:Genome wide gene expression analysis of mRNA siolated from whole heart tissue from wild type and cardiomyocyte selective MR null mice. The role of mineralocorticoid receptors (MR) in specific cell types of the myocardium in cardiac remodeling remains unknown. We investigated MR in cardiomyocytes in DOC/salt-induced cardiac pathology. Cardiomyocyte MR-null mice (CM-MRKO) and control mice (WT) were given DOC/salt and cardiac responses were examined at 8 days and 8 weeks. Cardiac function in untreated mice wild type and CM-MRKO mice was determined by Langendorf and showed no differences. At 8 days CM-MRKO showed equivalent monocyte/macrophage recruitment to wild type mice in response to DOC/salt treatment. Profibrotic markers were significantly reduced in CM-MRKO hearts at base line and in response to DOC/salt. In contrast, at 8 weeks CM-MRKO mice showed no DOC/salt-induced increase in inflammatory cell infiltrate, fibrosis or systolic blood pressure (SBP). Similarly, DOC/salt-mediated increases in proinflammatory and profibrotic gene expression were not detected in CM-MRKO mice. Although mRNA levels for fibronectin and collagen III were similar for each genotype, this was not translated into protein expression. Interestingly, untreated CM-MRKO mice showed increased mRNA and protein for decorin and a further increase with DOC/salt. Together, these data suggest a direct role for cardiomyocyte MR in DOC/salt-induced tissue remodelling and SBP regulation. Moreover, a specific profibrotic pathway is dysregulated in CM-MRKO mice, suggesting a potential mechanism for the cardioprotective effects of selective MR deletion in cardiomyocytes.
Project description:Genome wide gene expression analysis of mRNA siolated from whole heart tissue from wild type and cardiomyocyte selective MR null mice. The role of mineralocorticoid receptors (MR) in specific cell types of the myocardium in cardiac remodeling remains unknown. We investigated MR in cardiomyocytes in DOC/salt-induced cardiac pathology. Cardiomyocyte MR-null mice (CM-MRKO) and control mice (WT) were given DOC/salt and cardiac responses were examined at 8 days and 8 weeks. Cardiac function in untreated mice wild type and CM-MRKO mice was determined by Langendorf and showed no differences. At 8 days CM-MRKO showed equivalent monocyte/macrophage recruitment to wild type mice in response to DOC/salt treatment. Profibrotic markers were significantly reduced in CM-MRKO hearts at base line and in response to DOC/salt. In contrast, at 8 weeks CM-MRKO mice showed no DOC/salt-induced increase in inflammatory cell infiltrate, fibrosis or systolic blood pressure (SBP). Similarly, DOC/salt-mediated increases in proinflammatory and profibrotic gene expression were not detected in CM-MRKO mice. Although mRNA levels for fibronectin and collagen III were similar for each genotype, this was not translated into protein expression. Interestingly, untreated CM-MRKO mice showed increased mRNA and protein for decorin and a further increase with DOC/salt. Together, these data suggest a direct role for cardiomyocyte MR in DOC/salt-induced tissue remodelling and SBP regulation. Moreover, a specific profibrotic pathway is dysregulated in CM-MRKO mice, suggesting a potential mechanism for the cardioprotective effects of selective MR deletion in cardiomyocytes. Pool mRNA (equal amounts) from whole heart from 8 animals per group.
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:To understand the mechanisms through which JunB regulates Tregs-mediated immune regulation, we examined the global gene expression profiles in the JunB WT and KO Tregs by performing RNA sequencing (RNA-seq) analysis.
Project description:α-myosin heavy chain promoter controlled MerCreMer expression enables conditional, cardiomyocyte specific and tamoxifen dependent gene inactivation of floxed genes. Administration of tamoxifen has been linked to development of acute and transient cardiomyopathy. The mechanism for this is unknown. We used microarrays to sort out factors relevant for adverse effects following tamoxifen dependent gene inactivation, to develop a protocol with minimal adverse effects, and to identify the most proper control animals.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.
Project description:α-myosin heavy chain promoter controlled MerCreMer expression enables conditional, cardiomyocyte specific and tamoxifen dependent gene inactivation of floxed genes. Administration of tamoxifen has been linked to development of acute and transient cardiomyopathy. The mechanism for this is unknown. We used microarrays to sort out factors relevant for adverse effects following tamoxifen dependent gene inactivation, to develop a protocol with minimal adverse effects, and to identify the most proper control animals. Mus musculus Tg(αMHC-MerCreMer) and wild type were sacrificed 4 days after 1 or 4 consecutive days of 40 mg/kg tamoxifen injected intraperitoneally, or after corresponding control injection treatment.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
Project description:BackgroundCopy number variation is an important dimension of genetic diversity and has implications in development and disease. As an important model organism, the mouse is a prime candidate for copy number variant (CNV) characterization, but this has yet to be completed for a large sample size. Here we report CNV analysis of publicly available, high-density microarray data files for 351 mouse tail samples, including 290 mice that had not been characterized for CNVs previously.ResultsWe found 9634 putative autosomal CNVs across the samples affecting 6.87% of the mouse reference genome. We find significant differences in the degree of CNV uniqueness (single sample occurrence) and the nature of CNV-gene overlap between wild-caught mice and classical laboratory strains. CNV-gene overlap was associated with lipid metabolism, pheromone response and olfaction compared to immunity, carbohydrate metabolism and amino-acid metabolism for wild-caught mice and classical laboratory strains, respectively. Using two subspecies of wild-caught Mus musculus, we identified putative CNVs unique to those subspecies and show this diversity is better captured by wild-derived laboratory strains than by the classical laboratory strains. A total of 9 genic copy number variable regions (CNVRs) were selected for experimental confirmation by droplet digital PCR (ddPCR).ConclusionThe analysis we present is a comprehensive, genome-wide analysis of CNVs in Mus musculus, which increases the number of known variants in the species and will accelerate the identification of novel variants in future studies.