Project description:The transcription factor Ikaros represses Notch signaling. Since Ikaros and Notch treanscriptional mediator RBPJ both recognize sequences that contain the same core TGGGAA motif, it was hypothesized that Ikaros represses Notch signaling by targeting Notch response elements and competing with RBPJ for their binding. Here we used the mouse T-cell leukemia cell line T29 to compare the genomic binding profiles of Ikaros and RBPJ by ChIP-seq. The T29 cell line is derived from a Ikaros-deficient T-cell leukemia (Dumortier et al, MCB 26, 209-220, 2006) and exhibits strong Notch activation. We performed two chip-seq experiments with an anti-RBPJ antibody to map RBPJ binding sites. To map Ikaros binding sites, we engineered a T29-derived cell line that expresses a fusion protein between Ikaros and the ligand binding domain of the estrogen receptor (Ik1-ER) which is activated by addition of 4-hydroxy-tamoxifen (4OHT). We used an anti-Ikaros antibody to map the sites bound by Ik1-ER after treatment of the cells with 4OHT. Sequencing were performed with the Illumina GAII sequencer as as single end 36 base pair reads.
Project description:The transcription factor Ikaros represses Notch signaling. Since Ikaros and Notch treanscriptional mediator RBPJ both recognize sequences that contain the same core TGGGAA motif, it was hypothesized that Ikaros represses Notch signaling by targeting Notch response elements and competing with RBPJ for their binding. Here we used the mouse T-cell leukemia cell line T29 to compare the genomic binding profiles of Ikaros and RBPJ by ChIP-seq.
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:The mouse Ikaros-deficient thymic lymphoma cell line T29 was transduced with a retrovirus expressing an fusion protein between a dominant-negative form of Mastermind and the ligand binding domain of the estrogen receptor. Cells trreated with Ethanol or 4-hydroxy-tamoxyfen for 24h were profiled. We used expression of an inducible ersion of the dominant negative Mastermind protein in an Ikaros-deficient cell line to identify Notch-regulated genes
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.