Project description:In the present study, we performed HITS-CLIP analysis for FUS using mouse brain to extensively characterize tits RNA-binding sites and functional roles in RNA metabolisms. We identified preferential binding of FUS to stem-and-loop structures but without any discernible consensus motifs. FUS was preferentially bound to introns and 3' untranslated regions, but the exon/intron boundaries were mostly devoid of FUS-tags. Analysis of position-dependence of FUS-binding sites in regulating inclusion and skipping of exons disclosed that FUS is bound broadly around the alternatively spliced exons. Among them, however, noticeable CLIP-tags were observed in the downstream introns. We also noticed that FUS occasionally binds to the antisense strands in the promoter regions. Global analysis of CLIP-tags and expression profiles revealed that binding of FUS to the promoter antisense regions downgregulates transcription of the sense strand. HITS-CLIP (High Throughput Sequencing after Crosslinking and Immunoprecipitation) experiments targeting FUS in mouse cerebrums derived from 12-week-old C57BL/6 mice
Project description:In the present study, we performed HITS-CLIP analysis for FUS using mouse brain to extensively characterize tits RNA-binding sites and functional roles in RNA metabolisms. We identified preferential binding of FUS to stem-and-loop structures but without any discernible consensus motifs. FUS was preferentially bound to introns and 3' untranslated regions, but the exon/intron boundaries were mostly devoid of FUS-tags. Analysis of position-dependence of FUS-binding sites in regulating inclusion and skipping of exons disclosed that FUS is bound broadly around the alternatively spliced exons. Among them, however, noticeable CLIP-tags were observed in the downstream introns. We also noticed that FUS occasionally binds to the antisense strands in the promoter regions. Global analysis of CLIP-tags and expression profiles revealed that binding of FUS to the promoter antisense regions downgregulates transcription of the sense strand.
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: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.