Project description:Ataxia-telangiectasia mutated (ATM) kinase plays a central role in maintaining genomic integrity. In both humans and mice, ATM deficiency is associated with an increased incidence of lymphoid cancers that are primarily T cell in origin. We demonstrate here that when T cells are removed as targets for lymphomagenesis and as mediators of immune surveillance, ATM-deficient mice exclusively develop early onset IgM+ B cell lymphomas that by histology and gene expression profiling resemble the activated B cell-like (ABC) subset of human diffuse large B cell lymphomas (DLBCL). These ATM-deficient B cell tumors show considerable chromosomal instability and a recurrent genomic amplification of a 4.48 Mb region on chromosome 18 that contains Malt1 and is orthologous to a region similarly amplified in human ABC-DLBCL. Further, the amplification of Malt1 in these lymphomas correlates with their dependence on NF-kB, MALT1, and BCR signaling for survival, paralleling human ABC-DLBCL. This study reveals that ATM protects against development of B cell lymphomas that model human ABC-DLBCL and identifies a role for T cells in preventing the emergence of these tumors.
Project description:To find genes deregulated in the pathogenisis of T-cells in Atm deficient mice, we performed expression profiling of Atm deficient thymic lymphomas, wildtype thymi and Atm deficient thymi without macroscopic enlargement, representing an intermediate stage in the process of tumorigenisis. Keywords: genetic modification, disease state analysis
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:Ataxia-telangiectasia mutated (ATM) kinase plays a central role in maintaining genomic integrity. In both humans and mice, ATM deficiency is associated with an increased incidence of lymphoid cancers that are primarily T cell in origin. We demonstrate here that when T cells are removed as targets for lymphomagenesis and as mediators of immune surveillance, ATM-deficient mice exclusively develop early onset IgM+ B cell lymphomas that by histology and gene expression profiling resemble the activated B cell-like (ABC) subset of human diffuse large B cell lymphomas (DLBCL). These ATM-deficient B cell tumors show considerable chromosomal instability and a recurrent genomic amplification of a 4.48 Mb region on chromosome 18 that contains Malt1 and is orthologous to a region similarly amplified in human ABC-DLBCL. Further, the amplification of Malt1 in these lymphomas correlates with their dependence on NF-kB, MALT1, and BCR signaling for survival, paralleling human ABC-DLBCL. This study reveals that ATM protects against development of B cell lymphomas that model human ABC-DLBCL and identifies a role for T cells in preventing the emergence of these tumors. We performed gene expression profiling on nine ATMKO.CD3epsilonKO lymphoma cell lines (n=12, 3 technical repeats). We analyzed gene expression of anti-IgM stimulated primary B cells from both ATMKO.CD3epsilonKO (n=7, 5 technical repeats) and ATMWT.CD3epsilonKO mice (n=2), and GC B cells isolated from SRBC-immunized ATMWT mice (n=3, 1 biological repeat and 2 technical repeats). We analyzed gene expression following treatment of two ATMKO.CD3epsilonKO lymphoma cell lines with the BTK inhibitor, PCI-32765, at time points (1, 3, 6, and 24 hours) as compared to time points with vehicle (DMSO) (n=8).
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: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.