Project description:Mouse cuprizone (CPZ ) model of experimental de- and remyelination was applied to mimic demyelination pathology of multiple sclerosis. The aim of the study was to profile whole genome expression to identify differentially expressed genes during the demyelinisation and after discontinuation of cuprizon treatment, during rapid remyelinisation in affected areas of mouse corpus callosum. Control mice were kept on a normal diet. The following groups representing de- and remyelinisation pathology in corpus callosum of CPZ-treated mice were compared: Partial demyelination: 2weeks CPZ (dem_2w); Complete demyelination: 4weeks CPZ (dem_4w); Remyelination: 4weeks CPZ + UNTREATED (rem); and UNTREATED control (C). The experiments were performed using 3-4 animals per groups.
Project description:Mouse cuprizone (CPZ ) model of experimental de- and remyelination was applied to mimic demyelination pathology of multiple sclerosis. In order to identify differentially expressed microRNAs involved in de- and remyelination, the affected areas of corpus callosum were isolated from mice exposed to CPZ and conducted an Agilent microarray analysis. To induce demyelination, CPZ was administrated for four weeks. Spontaneous remyelination occurs as mice returned to the regular diet after four weeks feeding with CPZ (DEM_4w). Remyelination was examined at two time points: acute remyelination induced by four weeks CPZ feeding followed by two days of regular diet (two days remyelination: REM_2d), and full remyelination induced by four weeks CPZ feeding followed by two weeks of regular diet (two weeks remyelination: REM_2w). Control mice (C) were kept on a normal diet. The following groups representing de- and remyelinisation pathology in corpus callosum of CPZ-treated mice were compared: Demyelination: 4weeks CPZ: DEM_4w; Acute remyelination: 4 weeks CPZ +2 days UNTREATED: REM_2d; Full remyelination: 4 weeks CPZ +2 weeks UNTREATED: REM_2w; and UNTREATED control (C). The experiments were performed using 2-4 animals per groups.
Project description:NestinCreERT2:RosaYFP mice were fed with cuprizone for 4 weeks to induce brain demyelination. Corpus callosum was then dissected, dissociated and YFP+ subventricular zone-derived cells were isolated by FACS. 1931 cells were then processed for single-cell RNA-seq analysis. Single Cell RNA sequencing library were generated using the 10x Genomics Chromium Platform and sequenced on the Illumina Nextseq 500.
Project description:Formation of cortical connections requires the precise coordination of several discrete stages. This is particularly significant with regard to the corpus callosum, the largest white matter structure bridging both cerebral hemispheres, whose development undergoes several dynamic stages including the crossing of axon projections, the elimination of exuberant projections, and the myelination of established tracts. To comprehensively characterize the molecular events in this dynamic process, we set to determine the distinct temporal expression of proteins regulating the formation of the corpus callosum and their respective developmental functions. Mass spectrometry-based proteomic profiling was performed on early postnatal mouse corpus callosi, for which limited evidence has been obtained previously, using stable isotope of labeled amino acids in mammals (SILAM). The analyzed corpus callosi had distinct proteomic profiles depending on age, indicating rapid progression of specific molecular events during this period. The proteomic expression profiles were then segregated into five separate protein clusters, each with distinct trajectories relevant to their intended developmental functions. Our analysis both confirms many previously-identified proteins in aspects of corpus callosum development, and identifies new candidates in understudied areas of development including callosal axon refinement. We present a valuable resource for identifying new proteins integral to corpus callosum development that will provide new insights into the development and diseases afflicting this structure.
Project description:Remyelination failure contributes to axonal dysfunction in neurodegenerative disorders. But whether astrocytes, the most abundant glial cell type in demyelinated lesions, support or impede remyelination is controversial. Following focal demyelinated lesions of the mouse corpus callosum induced with the myelin toxin lysolecithin, we used TRAP (translational ribosome affinity purification) sequencing to isolate and sequence ribosome-associated mRNAs which are being actively translated in astrocytes, and studied how the responses and molecular mechanisms in astrocytes are linked to remyelination.
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.