Background
Expression quantitative trait loci mapping identifies new genetic models of glutathione S-transferase variation.
No sample metadata fields
View SamplesBoth the mechanism of action and the factors determining the behavioral response to antidepressants are unknown. It has been shown that antidepressant treatment promotes the proliferation and survival of hippocampal neurons via enhanced serotonergic signaling, but it is still unclear whether hippocampal neurogenesis is responsible for the behavioral response to antidepressants. Furthermore, a large subpopulation of patients fails to respond to antidepressant treatment due to presumed underlying genetic factors. In the present study, we have used the phenotypic and genotypic variability of inbred mouse strains to show that there is a genetic component to both the behavioral and neurogenic effects of chronic fluoxetine treatment, and that this antidepressant induces an increase in hippocampal cell proliferation only in the strains that also show a positive behavioral response to treatment. The behavioral and neurogenic responses are associated with an upregulation of genes known to promote neuronal proliferation and survival. These results suggest that inherent genetic predisposition to increased serotonin-induced neurogenesis is a determinant of antidepressant efficacy.
Genetic regulation of behavioral and neuronal responses to fluoxetine.
Sex, Treatment
View SamplesAustism spectrum disorder (ASD) is a heterogeneous behavioral disease most commonly characterized by severe impairment of social engagement and the presence of repetitive activities. The molecular etiology of ASD is still largely unknown despite a strong genetic component. Part of the difficulty in turning genetics into disease mechanisms and potentially new therapeutics is the sheer number and diversity of the genes that have been associated with ASD and ASD symptoms. The goal of this work is to use shRNA-generated models of genetic defects proposed as causative for ASD to identify the common pathways that might explain how they produce a common clinical outcome. Transcript levels of Mecp2, Mef2a, Mef2d, Fmr1, Nlgn1, Nlgn3, Pten, and Shank3 were knocked-down in mouse primary neuron cultures using shRNA/lentivirus constructs. Whole genome expression analysis was conducted for each of the knock-down cultures as well as a mock-transduced culture and a culture exposed to a lentivirus expressing luciferase. Gene set enrichment and a causal reasoning engine were employed to indentify pathway level perturbations generated by the transcript knock-down. Quantitation of the shRNA targets confirmed the successful knock-down at the transcript and protein levels of at least 75% for each of the genes. After subtracting out potential artifacts caused by transfection and viral infection, gene set enrichment and causal reasoning engine analysis showed that a significant number of gene expression changes mapped to pathways associated with neurogenesis, long-term potentiation, and synaptic activity. This work demonstrates that despite the complex genetic nature of ASD, there are common molecular mechanisms that connect many of the best established autism candidate genes. By identifying the key regulatory checkpoints in the interlinking transcriptional networks underlying autism, we are better able to discover the ideal points of intervention that provide the broadest efficacy across the diverse population of autism patients.
Transcriptomic analysis of genetically defined autism candidate genes reveals common mechanisms of action.
Specimen part, Treatment
View SamplesIn order to establish a list of candidate direct COUP-TFI gene targets in the inner ear, we analyzed the differential gene expression profiles of the wild-type and the COUP-TFI/ P0 inner ears.
Genome-wide analysis of binding sites and direct target genes of the orphan nuclear receptor NR2F1/COUP-TFI.
Specimen part
View SamplesWe explored the transcriptional response to parasitoid attack in Drosophila larvae at nine time points following parasitism, hybridizing five biologic replicates per time point to whole-genome microarrays for both parasitized and control larvae. We found significantly different expression profiles for 159 probe sets (representing genes), and we classified them into 16 clusters based on patterns of co-expression. A series of functional annotations were nonrandomly associated with different clusters, including several involving immunity and related functions. We also identified nonrandom associations of transcription factor binding sites for three main regulators of innate immune responses (GATA/srp-like, NF-kappaB/Rel-like and Stat), as well as a novel putative binding site for an unknown transcription factor. The appearance or absence of candidate genes previously associated with insect immunity in our differentially expressed gene set was surveyed
Genome-wide gene expression in response to parasitoid attack in Drosophila.
Time
View SamplesIn order to understand how biochemical and genetic differences correlate with treatment response, we measured depressive-like behavior, gene expression and the levels of thirty-six neurobiochemical analytes across a panel of genetically-diverse mouse inbred lines after chronic treatment with vehicle or fluoxetine. Neurobiochemical markers were chosen based on their putative molecular function within pathways proposed to underlie depression, which include neuronal transmission, HPA-axis regulation, and neuroimmune processes. The goal of this study is to establish genetic and biochemical biomarkers that can predict treatment response and to propose a molecular pathway that is critical in mediating anti-depressant response.
Evaluating genetic markers and neurobiochemical analytes for fluoxetine response using a panel of mouse inbred strains.
Sex, Specimen part
View SamplesIsoniazid induced varying degrees of hepatic steatosis in an inbred strain Mouse Diversity Panel (MDP) study. RNA was isolated from all animals for analysis of gene expression changes in the liver. The objective of this study was to identify gene expression changes that drive isoniazid-induced steatosis.
A systems biology approach utilizing a mouse diversity panel identifies genetic differences influencing isoniazid-induced microvesicular steatosis.
Sex, Specimen part, Treatment
View SamplesWe demonstrate the feasibility of performing single cell RNA sequencing on cells isolated from whole blood using a novel flow cytometry-based platform Overall design: Whole transcriptome sequencing of single and pooled cells from a mouse pancreatic cancer cell line to validate rare cell pre-enrichment and isolation approach
An integrated flow cytometry-based platform for isolation and molecular characterization of circulating tumor single cells and clusters.
Specimen part, Cell line, Subject
View SamplesWe have combined large-scale mRNA expression and gene mapping methods to identify genes and loci that control hematopoietic stem cell (HSC) functioning. mRNA expression levels were measured in purified HSC isolated from a panel of densely genotyped recombinant inbred mouse strains. Quantitative trait loci (QTLs) associated with variation in expression of thousands of transcripts were mapped. Comparison of the physical transcript position with the location of the controlling QTL identified polymorphic cis-acting stem cell genes. In addition, multiple trans-acting control loci were highlighted that modify expression of large numbers of genes. These groups of co-regulated transcripts identify pathways that specify variation in stem cells. We illustrate this concept with the identification of strong candidate genes involved with HSC turnover. We compared expression QTLs in HSC and brain from the same animals, and document both shared and tissue-specific QTLs. Our data are accessible through WebQTL, a web-based interface that allows custom genetic linkage analysis and identification of co-regulated transcripts.
Uncovering regulatory pathways that affect hematopoietic stem cell function using 'genetical genomics'.
No sample metadata fields
View SamplesTrichomes are specialised epidermal cells that generally play a role in reducing transpiration and act as a deterrent to herbivory. In a screen of activation tagged Populus tremula x P. alba 717-1B4 trees, we identified a mutant line, fuzzy, with increased foliar trichome density. This mutant also had a 35% increase in growth rate and a 200% increase in the rate of photosynthesis as compared to wild-type poplar. The fuzzy mutant had significant resistance to feeding by larvae of the white spotted tussock moth (Orgyia leucostigma), a generalist insect pest of poplar trees. The fuzzy phenotype is attributable to activation tagging and increased expression of the gene encoding PtaMYB186, which is related to Arabidopsis thaliana MYB106, a known regulator of trichome initiation. The fuzzy phenotype can be recapitulated by overexpressing PtaMYB186 in poplar. PtaMYB186 overexpression results in reconfiguration of the poplar transcriptome, with changes in the transcript abundance of suites of genes that are related to trichome differentiation. It is notable that this gene responsible for trichome development also altered traits related to growth rate and pest resistance, suggesting that non-intuitive facets of plant development might be useful targets for plant improvement.
Endogenous overexpression of Populus MYB186 increases trichome density, improves insect pest resistance, and impacts plant growth.
Specimen part
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