X chromosome inactivation (XCI) compensates for differences in X-chromosome number between male and female mammals. XCI is orchestrated by Xist RNA, whose expression in early development leads to transcriptional silencing of one X-chromosome in the female. Knockout studies have established a requirement for Xist, with inviability of female embryos that inherit an Xist deletion from the father. Here, we report that female mice lacking Xist RNA can, surprisingly, develop and survive to term. Xist-null females are born at lower frequency and are smaller at birth, but organogenesis is mostly normal. Transcriptomic analysis indicates significant overexpression of hundreds of X-linked genes across multiple tissues. Therefore, Xist-null mice can develop to term in spite of a deficiency of dosage compensation. However, the degree of X-autosomal dosage imbalance was less than anticipated (1.14- to 1.36-fold). Thus, partial dosage compensation can be achieved without Xist, supporting the idea of inherent genome balance. Nevertheless, to date, none of the mutant mice has survived beyond weaning stage. Sudden death is associated with failure of postnatal organ maturation. Our data suggest Xist-independent mechanisms of dosage compensation and demonstrate that small deviations from X-autosomal balance can have profound effects on overall fitness. Overall design: RNA-sequencing of tail-tip fibroblasts (TTFs), spleen, liver and heart tissue from Xist-null and control female mice. Sequencing performed with 50nt read length on Illumina HiSeq2000 or 2500. Data consists of 3 biological replicates for TTFs (6 datasets) and 2 biological replicates for tissues (12 datasets).
Female mice lacking Xist RNA show partial dosage compensation and survive to term.
Sex, Specimen part, Subject
View SamplesDose-dependent duodenal gene expression was examined following repeated exposure (every 4 days for 28 days) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These data were used to examine the effect of repeated TCDD exposure on gene expression in the intestinal epithelium of C57BL/6 male mice. Overall design: Three biological replicates for each dose (0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30) of TCDD and sesame oil vehicle
Convergence of hepcidin deficiency, systemic iron overloading, heme accumulation, and REV-ERBα/β activation in aryl hydrocarbon receptor-elicited hepatotoxicity.
Sex, Specimen part, Cell line, Treatment, Subject
View SamplesDose-dependent hepatic gene expression was examined following repeated exposure (every 4 days for 28 days) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). These data were used to examine the effect of repeated TCDD exposure on gene expression in the liver of C57BL/6 male mice. Overall design: Three biological replicates for each dose (0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30) of TCDD and sesame oil vehicle
Convergence of hepcidin deficiency, systemic iron overloading, heme accumulation, and REV-ERBα/β activation in aryl hydrocarbon receptor-elicited hepatotoxicity.
Sex, Specimen part, Cell line, Treatment, Subject
View SamplesZnO nanoparticles can elicit a range of perturbed cell responses in vitro. Exposure to topically applied sunscreens containing ZnO particles may or may not elicit a biological effect in mice.
Dermal absorption and short-term biological impact in hairless mice from sunscreens containing zinc oxide nano- or larger particles.
Specimen part
View SamplesMicroarray analysis has been applied to the study of ALS in order to investigate gene expression in whole spinal cord homogenates of SOD1 G93A mice and human ALS cases, although the massive presence of glial cells and inflammatory factors has made it difficult to define which gene expression changes were motor neuron specific. Recently, laser capture microdissection (LCM), combined with microarray analysis, has allowed the identification of motor neuron specific changes in gene expression in human ALS cases.
Microarray analysis of the cellular pathways involved in the adaptation to and progression of motor neuron injury in the SOD1 G93A mouse model of familial ALS.
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View SamplesTranscriptome analysis of skeletal muscle during hypertrophic growth in aged mice
Blunted hypertrophic response in aged skeletal muscle is associated with decreased ribosome biogenesis.
Sex, Age, Specimen part, Time
View SamplesX-chromosome aneuploidies have long been associated with human cancers, but causality has not been established. In mammals, X-chromosome inactivation (XCI) is triggered by Xist RNA to equalize gene expression between the sexes. Here we delete Xist in the blood compartment of mice and demonstrate that mutant females develop a highly aggressive myeloproliferative neoplasm and myelodysplastic syndrome (mixed MPN/MDS) with 100% penetrance. Significant disease components include primary myelofibrosis, leukemia, histiocytic sarcoma, and vasculitis. Xist-deficient hematopoietic stem cells (HSC) show aberrant maturation and age-dependent loss. Reconstitution experiments indicate that MPN/MDS and myelofibrosis are of hematopoietic rather than stromal origin. We propose that Xist loss results in X-reactivation and consequent genome-wide changes that lead to cancer, thereby causally linking the X-chromosome to cancer in mice. Thus, Xist RNA is not only required to maintain XCI but also suppresses cancer in vivo.
Xist RNA is a potent suppressor of hematologic cancer in mice.
Sex, Age, Specimen part
View SamplesIt is known that CBFB-MYH11, the fusion gene generated by inversion of chromosome 16 in human acute myeloid leukemia, is causative for oncogenic transformation. However, the mechanism by which CBFB-MYH11 initiates leukemogenesis is not clear. Previously published reports showed that CBFB-MYH11 dominantly inhibits RUNX1 and CBFB, and such inhibition has been suggested as the mechanism for leukemogenesis. However, knockin mice expressing Cbfb-MYH11 (Cbfb+/MYH11) showed defects in primitive hematopoiesis not seen in Cbfb null (Cbfb-/-) embryos indicating that Cbfb-MYH11 has repression independent activities as well.
Cbfb/Runx1 repression-independent blockage of differentiation and accumulation of Csf2rb-expressing cells by Cbfb-MYH11.
Specimen part
View SamplesZnO and TiO2 nanoparticles can elicit a range of perturbed cell responses in vitro. Exposure to topically applied sunscreens containing ZnO or TiO2 particles may or may not elicit a biological effect in mice. We aimed to compare the biological responses of immune-competent hairless mice receiving topical applications of commercially available sunscreens with or without metal oxide nanoparticles, with the responses of mice receiving no sunscreen.
Long-term exposure to commercially available sunscreens containing nanoparticles of TiO2 and ZnO revealed no biological impact in a hairless mouse model.
Specimen part, Time
View SamplesUremic media calcification is not only driven by systemic factors such as hyperphosphatemia, but also crticially dependent on vascular smooth muscle cells per se. We hypothesized that the different developmental origins of vscular smooth muscle cells might lead to a heterogeneous susceptibility to develop media calcification.
Heterogeneous susceptibility for uraemic media calcification and concomitant inflammation within the arterial tree.
Specimen part
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