Project description:Purkinje cells (PC) of the cerebellum degenerate in adult mice with mutations in the Niemann-Pick type C (NPC) disease 1 (Npc1) gene. We subjected BALB/c Npc1+/+ and Npc1-/- mouse cerebella from an early and a later time point of PC degeneration to a genome-wide microarray gene expression analysis. We found general underrepresentation of PC-specific transcripts, consistent with PC loss, and elevated markers of microglia activation at the later time point. Keywords: Niemann-Pick type C, Purkinje cell degeneration
Project description:Purkinje cells (PC) of the cerebellum degenerate in adult mice with mutations in the Niemann-Pick type C (NPC) disease 1 (Npc1) gene. We subjected BALB/c Npc1+/+ and Npc1-/- mouse cerebella from an early and a later time point of PC degeneration to a genome-wide microarray gene expression analysis. We found general underrepresentation of PC-specific transcripts, consistent with PC loss, and elevated markers of microglia activation at the later time point. Experiment Overall Design: 12 BALB/c Npc1 mice of the two ages P21 and P49 and the two genotypes Npc1+/+ and Npc1-/- were used, 3 replicates for each age and genotype. The animals were of the same breed and lived under identical housing conditions. All except one animal were female. The animals were not further treated, but only sacrificed at P21 or P49.
Project description:Niemann-Pick Type C disease is an autosomal recessive neurodegenerative disorder with abnormal lipid storage as the major cellular pathologic hallmark. Genetic analyses have identified mutations in NPC1 gene in the great majority of cases, while mutations in NPC2 account for the remainders. Yet, little is known regarding the cellular mechanisms responsible for NPC pathogenesis, especially for neurodegeneration, which is the usual cause of death. To identify critical steps that could account for the pathological manifestations of the disease in one of the most affected brain structures, we performed global gene expression analysis in the cerebellum from three-week old Npc1+/+ and Npc1-/- mice with two different microarray platforms (Agilent and Illumina). Our results provide novel molecular insight regarding the mechanisms of pathogenesis in NPC disease and reveal potential new therapeutic targets. We performed global gene expression analysis in the cerebellum from three-week old Npc1+/+ and Npc1-/- mice with two different microarray platforms (Agilent and Illumina). Differentially-expressed genes identified by both microarray platforms were then subjected to KEGG pathway analysis. Expression of genes in six pathways was significantly altered in Npc1-/- mice; functionally, these signaling pathways belong to the following three categories: 1) steroid and terpenoid biosynthesis, 2) immune response, and 3) cell adhesion/motility. In addition, the expression of several proteins involved in lipid transport was significantly altered in Npc1-/- mice.
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: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: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:Macrophage inflammatory protein 1alpha/CCL3 protein is a known pro-inflammatory cytokine that can mediate chemotaxis of monocytes and promote cell degranulation. Ccl3 gene expression is elevated in the CNS and visceral tissue of many lysosomal storage disorders. The deletion of Ccl3 in a mouse model of Sandhoff disease was reported to result in reduced monocyte-associated pathology in the brain, delayed neurodegeneration, and prolonged health. However, deletion of Ccl3 in a mouse model of Niemann-Pick C disease was dentrimental or neutral instead of beneficial. Prevention of neuronal loss was instead mediated by providing NPC1 to neurons. We used microarrays to detail the global change in gene expression of the cerebellum in Niemann-Pick C disease animals, Niemann-Pick C disease animals with Ccl3 gene deletion, and Niemann-Pick C disease animals with Purkinje neuron-specific NPC1-YFP rescue. To identify the top ~50 genes elevated in NPC disease Npc1-/- (NPC) and Npc1+/- (WT) mice were compared at age P50; To profile changes in gene expression as a result of Ccl3 gene deletion Ccl3-/-;Npc1-/- mice were compared against Npc1-/- mice across various ages; To profile changes in gene expression as a result of Purkinje neuron-sepcific NPC1 rescue P;N;Npc1-/- mice were compared against Npc1-/- mice across various ages.
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.