BACKGROUND: The transcript levels of many genes exhibit significant variation in tissue samples from inbred laboratory mice. A microarray experiment was designed to separate transcript abundance variation across samples from adipose, heart, kidney, and liver tissues of C57BL/6J mice into within-mouse and between-mouse components. Within-mouse variance captures variation due to heterogeneity of gene expression within tissues, RNA-extraction, and array processing. Between-mouse variance reflects differences in transcript levels between these genetically identical mice. Many biological sources can contribute to heterogeneous transcript levels within a tissue sample including inherent stochasticity of biochemical processes such as intrinsic and extrinsic noise within cells and differences in cell-type composition which can result from heterogeneity of stem and progenitor cell populations. Differences in global signaling patterns between individuals and micro-environmental influences such as interactions with pathogens and cage mates can also contribute to variation, but are likely to contribute more to the between-mouse variance component.
Stochastic variation of transcript abundance in C57BL/6J mice.
Sex, Age, Specimen part
View SamplesWe have reported previously that when chromosome Y (chrY) from the mouse strain C57BL/6J (abbreviated as B) was substituted for that of A/J mice (ChrY<A>), cardiomyocytes from the resulting 'chromosome substitution' C57BL/6J-chrY<A> strain (abbreviated as B.Y) were smaller than that of their C57BL/6J counterparts. In reverse, when chrY<A> from A/J mice was substituted for that of chrY<B>, cardiomyocytes from the resulting A/J-chrY<C57> strain were larger than in their A/J counterparts. We further used these strains (B and the consomic B.Y) to test whether the origin of chrY could also be linked to differences in the profile of gene expression in their cardiac left ventricles in adult mice where either sham surgery (intact animals) or castration has been performed at 3-4 weeks of age..
Chromosome Y variants from different inbred mouse strains are linked to differences in the morphologic and molecular responses of cardiac cells to postpubertal testosterone.
Sex
View SamplesGenetic variation governs protein expression through both transcriptional and post-transcriptional processes. To investigate this relationship, we combined a multiplexed, mass spectrometry-based method for protein quantification with an emerging mouse model harboring extensive genetic variation from 8 founder strains. We collected genome-wide mRNA and protein profiling measurements to link genetic variation to protein expression differences in livers from 192 Diversity Outcross mice. Overall design: Illumina 100bp single-end liver RNA-seq from 192 male and female Diversity Outbred 26-week old mice raised on standard chow or high fat diet. Each sample was sequenced in 2x technical replicates across multiple flowcells. Samples were randomly assigned lanes and multiplexed at 12-24x.
Epistatic Networks Jointly Influence Phenotypes Related to Metabolic Disease and Gene Expression in Diversity Outbred Mice.
Sex, Specimen part, Cell line, Subject
View SamplesIdentifying the genes underlying quantitative trait loci (QTL) for disease has proven difficult, mainly due to the low resolution of the approach and the complex genetics involved. However, recent advances in bioinformatics and the availability of genetic resources now make it possible to narrow the genetic intervals and test candidate genes. In addition to identifying the causative genes, defining the pathways that are affected by these QTL is of major importance as it can give us insight into the disease process and provide evidence to support candidate genes. In this study we mapped three significant and one suggestive QTL on Chromosomes (Chrs) 1, 4, 15, and 17, respectively, for increased albumin excretion (measured as albumin-to-creatinine ratio) in a cross between the MRL/MpJ and SM/J mouse inbred strains. By combining data from several sources and by utilizing gene expression data, we identified Tlr12 as a likely candidate for the Chr 4 QTL. Through the mapping of 33,881 transcripts measured by microarray on kidney RNA from each of the 173 male F2 animals, we identified several downstream pathways associated with these QTL. Among these were the glycan degradation, leukocyte migration, and antigen presenting pathways. We demonstrate that by combining data from multiple sources, we can identify not only genes that are likely to be causal candidates for QTL, but also the pathways through which these genes act to alter phenotypes. This combined approach provides valuable insights into the causes and consequences of renal disease.
Uncovering genes and regulatory pathways related to urinary albumin excretion.
Sex, Age
View SamplesAnalysis of tissues of DBA/2 mice fed a standard breeding diet (SBD) and high fat diet (HFD) revealed tissue specific roles in inflammation and disease, and altered communication between tissues. The tissues surveyed incuded adipose tissues (brown, inguinal, mesenteric, retro-peritoneal, subcutaneious and gonadal), muscle and liver.
High-fat diet leads to tissue-specific changes reflecting risk factors for diseases in DBA/2J mice.
Specimen part, Treatment
View SamplesRosiglitazone (Rosi), a member of the thiazolidinedione class of drugs used to treat type 2 diabetes, activates the adipocyte-specific transcription factor peroxisome proliferator-activated receptor gamma (PPARg). This activation causes bone loss in animals and humans, at least in part due to suppression of osteoblast differentiation from marrow mesenchymal stem cells (MSC). In order to identify mechanisms by which PPARg2 suppresses osteoblastogenesis and promotes adipogenesis in MSC, we have analyzed the PPARg2 transcriptome in response to Rosi. A total of 4,252 transcriptional changes resulted when Rosi (1 uM) was applied to the U-33 marrow stromal cell line, stably transfected with PPARg2 (U-33/g2), as compared to non-induced U-33/g2 cells. Differences between U-33/g2 and U-33 cells stably transfected with empty vector (U-33/c) comprised 7,928 transcriptional changes, independent of Rosi. Cell type-, time- and treatment-specific gene clustering uncovered distinct patterns of PPARg2 transcriptional control of MSC lineage commitment. The earliest changes accompanying Rosi activation of PPARg2 included adjustments in morphogenesis, Wnt signaling, and immune responses, as well as sustained induction of lipid metabolism. Expression signatures influenced by longer exposure to Rosi provided evidence for distinct mechanisms governing the repression of osteogenesis and stimulation of adipogenesis. Our results suggest interactions that could lead to the identification of a master regulatory scheme controlling osteoblast differentiation.
PPARgamma2 nuclear receptor controls multiple regulatory pathways of osteoblast differentiation from marrow mesenchymal stem cells.
Compound, Time
View SamplesDomesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation.
Brain transcriptome variation among behaviorally distinct strains of zebrafish (Danio rerio).
Sex, Specimen part
View SamplesAim:Transcriptional analysis of NKX2.2 knockdown versus control in human pancreatic islets Methods:Pancreatic islets from 3 human donors were transduced with an adenovirus encoding an shRNA directed against human NKX2.2 or a scrambled shRNA control. Total RNA was extracted.Libraries were prepared from total RNA (RIN>8) with the TruSeq RNA prep kit (Illumina) and sequenced using the HiSeq2000 (Illumina) instrument. More than 20 million reads were mapped to the human genome (Human: NCBI/build37.2)) using Tophat (version 2.0.4) with 4 mismatches and 10 maximum multiple hits. Significantly differentially expressed genes were calculated using DEseq. Results: Among the dysregulated genes with a p-value=0.05 are important genes for the maintenance of beta cell function and idenity. Conclusion: Nkx2.2 is a critical regulator of beta cell function and identity Overall design: mRNA profiles of the pancreatic islets from 3 human donors transduced with Ad.sh-NKX2.2 or scramble sh-RNA control vector were generated by deep sequencing , using Illumina HiSeq2000.
Genetic evidence that Nkx2.2 acts primarily downstream of Neurog3 in pancreatic endocrine lineage development.
Specimen part, Subject
View SamplesAim:Transcriptional analysis of the pancreatic islets of adult Nkx2.2 flox/flox; RipCre mice versus control Methods:Pancreatic islets from 4week old Nkx2.2 mutant mice and controls were isolated and total RNA was extracted.Libraries were prepared from total RNA (RIN>8) with the TruSeq RNA prep kit (Illumina) and sequenced using the HiSeq2000 (Illumina) instrument. More than 20 million reads were mapped to the mouse genome (UCSC/mm9) using Tophat (version 2.0.4) with 4 mismatches and 10 maximum multiple hits. Significantly differentially expressed genes were calculated using DEseq. Results: Among the downregulated genes with a p-value=0.05 are important genes for beta cell function and idenity.Among the upregulated genes with a p-value=0.05 are non beta endocrine hormones. Conclusion: Nkx2.2 activates important beta cell genes and actively represses non beta cell genes Overall design: mRNA profiles of the pancreatic islets of 4 week old control and Nkx2.2 mutant mice were generated by deep sequencing , in triplicate, using Illumina HiSeq2000.
Genetic evidence that Nkx2.2 acts primarily downstream of Neurog3 in pancreatic endocrine lineage development.
Specimen part, Subject
View SamplesA QTL analysis between inbred mouse strains MRL/MpJ and SM/J was performed to identify genetic loci influencing high-density lipoprotein (HDL) cholesterol and triglycerides (TG) at eight weeks of age in F2 mice fed a chow diet. In order to narrow down lists of candidate genes, expression levels from liver tissue were used to test for differential expression among parental and F1 strains and to scan for eQTL in F2 animals. We provide evidence for Mppe1 (Chr 18) as an HDL QTL candidate gene and Cyp2d26 (Chr 15) as a TG QTL candidate gene.
Integration of QTL and bioinformatic tools to identify candidate genes for triglycerides in mice.
Sex, Age, Specimen part
View Samples