Project description:Functional liability conferred by gene expression profile can be a possible basis for diseases phenotype. By comparing gene expression profiles in splenic T cells from NOD, C57BL/6 mice and their congenic strains with altered MHCs (NOD.H2^h4 , B6.NOD/Idd1,5/), we identified that the NOD splenic T cells have a strain dependent, tissue specific unique gene expression profile that can be but not necessarily be modulated by alternation of MHC. The NOD splenic T cells gene expression profile indicated a deregulated stress response system, especially heat shock protein family. We demonstrated that NOD splenic T cells have apoptosis defect in vivo and in vitro. Therefore, the gene expression profile may confer liability upon NOD splenic T cells to make them more susceptible to apoptosis, which can be a critical factor to lead to NOD lymphopenia. As recently described, compensatory homeostatic proliferation, driven by lymphopenia, generates autoimmunity in the NOD mouse. Keywords: other
Project description:Functional liability conferred by gene expression profile can be a possible basis for diseases phenotype. By comparing gene expression profiles in splenic T cells from NOD, C57BL/6 mice and their congenic strains with altered MHCs (NOD.H2^h4 , B6.NOD/Idd1,5/), we identified that the NOD splenic T cells have a strain dependent, tissue specific unique gene expression profile that can be but not necessarily be modulated by alternation of MHC. The NOD splenic T cells gene expression profile indicated a deregulated stress response system, especially heat shock protein family. We demonstrated that NOD splenic T cells have apoptosis defect in vivo and in vitro. Therefore, the gene expression profile may confer liability upon NOD splenic T cells to make them more susceptible to apoptosis, which can be a critical factor to lead to NOD lymphopenia. As recently described, compensatory homeostatic proliferation, driven by lymphopenia, generates autoimmunity in the NOD mouse.
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
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.