Vertebrates are colonized at birth by complex microbial communities (microbiota) that influence diverse aspects of host biology. We have used a functional genomics approach to identify zebrafish genes that are differentially expressed in response to the microbiota. We assessed RNA expression profiles from zebrafish larvae at 6 days post-fertilization (dpf) that were either raised continuously in the absence of any microorganism (germ-free or GF), or raised GF through 3dpf then colonized with a normal zebrafish microbiota (conventionalized or CONVD).
Microbial colonization induces dynamic temporal and spatial patterns of NF-κB activation in the zebrafish digestive tract.
Age, Specimen part
View SamplesThe undifferentiated state of pluripotent stem cells depends heavily on the culture conditions. We show that a unique combination of small molecules, SMC4, added to culture conditions converts primed pluripotent stem cells to a more nave state. By conducting Affymetix analysis we show of majority of lineage markers are repressed in SMC4 culture.
A novel platform to enable the high-throughput derivation and characterization of feeder-free human iPSCs.
Specimen part, Cell line
View SamplesLong-term maintenance of spermatogenesis in mammals is supported by GDNF, an essential growth factor required for spermatogonial stem cell (SSC) self-renewal. Exploiting a transgenic GDNF overexpression model, which expands and normalizes the pool of undifferentiated spermatogonia between Plzf +/+ and Plzf lu/lu mice, we used RNAseq to identify a rare subpopulation of cells that express EOMES, a T-box transcription factor. Lineage tracing, conditional ablation, and busulfan challenge show that these are long-term SSCs that contribute to steady state spermatogenesis as well as regeneration following chemical injury. EOMES+ SSCs have a lower proliferation index than EOMES- GFRA1+ spermatogonia in wild-type but not in Plzf lu/lu mice. This comparison demonstrates that PLZF regulates their proliferative activity and suggests that EOMES+ SSCs are lost through proliferative exhaustion in Plzf lu/lu mice. Single cell RNA sequencing of EOMES+ cells from Plzf +/+ and Plzf lu/lu mice support a hierarchical model of a slow-cycling long-term SSC population supporting more rapid-cycling short-term SSCs. Overall design: 384-well plate-based 3'-end scRNA-seq was performed on two groups, Plzf +/+ and Plzf lu/lu, of cells across 4 plates. Plzf +/+ cells were spread across 2 plates and Plzf lu/lu cells were spread over 1 plate. The 4th plate contains both Plzf lu/lu (up to well C15) and Plzf +/+ (well C15 onward). Each sample in this record represents one plate.
Identification of EOMES-expressing spermatogonial stem cells and their regulation by PLZF.
Specimen part, Cell line, Subject
View SamplesIGHV mutation status is a well-established prognostic factor in chronic lymphocytic leukemia, and also provides crucial insights into tumor cell biology and function. Currently, determination of IGHV transcript sequence, from which mutation status is calculated, requires a specialized laboratory procedure. RNA sequencing is a method that provides high resolution, high dynamic range transcriptome data that can be used for differential expression, isoform discovery, and variant determination. In this paper, we demonstrate that unselected next-generation RNA sequencing can accurately determine the IGH@ sequence, including the complete sequence of the complementarity-determining region 3 (CDR3), and mutation status of CLL cells, potentially replacing the current method which is a specialized, single-purpose Sanger-sequencing based test. Overall design: CLL cells were sequenced by mRNA-seq on the Illumina platform then subjected to the costom bioinformatic pipeline Ig-ID which yields IGH data
Immunoglobulin transcript sequence and somatic hypermutation computation from unselected RNA-seq reads in chronic lymphocytic leukemia.
No sample metadata fields
View SamplesHIV-associated dementia (HAD) is a syndrome occurring in HIV-infected patients with advanced disease that likely develops as a result of macrophage and microglial activation as well as other immune events triggered by virus in the central nervous system. The most relevant experimental model of HAD, rhesus macaques exhibiting SIV encephalitis (SIVE), closely reproduces the human disease and has been successfully used to advance our understanding of mechanisms underlying HAD. In this study we integrate gene expression data from uninfected and SIV-infected hippocampus with a human protein interaction network and discover modules of genes whose expression patterns distinguish these two states, to facilitate identification of neuronal genes that may contribute to SIVE/HIV cognitive deficits. Using this approach we identify several downregulated candidate genes and select one, EGR1, a key molecule in hippocampus-related learning and memory, for further study. We show that EGR1 is downregulated in SIV-infected hippocampus and that it can be downregulated in differentiated human neuroblastoma cells by treatment with CCL8, a product of activated microglia. Integration of expression data with protein interaction data to discover discriminatory modules of interacting proteins can be usefully employed to prioritize differentially expressed genes for further study. Investigation of EGR1, selected in this manner, indicates that its downregulation in SIVE may occur as a consequence of the host response to infection, leading to deficits in cognition.
An integrated systems analysis implicates EGR1 downregulation in simian immunodeficiency virus encephalitis-induced neural dysfunction.
Sex
View SamplesLong intervening noncoding RNAs (lincRNAs) are prevalent genes with poorly understood functions. Here we discover a pathway of lincRNA-regulated proteolysis. The enhancer-like lincRNA HOTTIP extends the half-life of its binding protein WDR5, a subunit of the MLL H3K4 methylase complex, resulting in increased chromatin occupancy and gene activation. LincRNA-mediated stabilization requires direct RNA-protein interaction in a long RNA context, and blocks turnover at a step after target protein poly-ubiquitination. We elucidate the lincRNA binding interface on WDR5. A WDR5 mutant that selectively abrogates lincRNA binding becomes unstable, and is defective in gene activation, maintenance of histone H3 lysine 4 trimethylation, and embryonic stem cell self renewal. The ability to modulate protein turnover may allow lincRNAs to control the lifespan of molecular interactions at chromatin and elsewhere, broadening their scope in epigenetics and cell fate control.
Essential role of lncRNA binding for WDR5 maintenance of active chromatin and embryonic stem cell pluripotency.
Specimen part, Treatment
View SamplesThe global gene expression profiles of human umbilical cord blood and adult bone marrow CD34+CD33-CD38-Rho(lo)c-kit+ cells, enriched for hematopoietic stem/progenitor cells (HSC) with CD34+CD33-CD38-Rho(hi) cells, enriched in committed hematopoietic progenitor cells (HPC), were compared to identify candidate regulators of HSC self-renewal versus differentiation fate decisions.
Functional analysis of human hematopoietic stem cell gene expression using zebrafish.
No sample metadata fields
View SamplesGenome-wide gene expression analysis of MyoD-infected DMD-specific iPSCs (GM05112-M5.1) on days 0 (untreated), day 3 and day 8 post Dox treatment, human primary myoblasts (undifferentiated and as differentiated myotubes), and undifferentiated iPSCs from healthy donors (iPSCs-1 and iPSCs-2).
Myogenic differentiation of muscular dystrophy-specific induced pluripotent stem cells for use in drug discovery.
Specimen part
View SamplesThe Alternative Lengthening of Telomeres (ALT) pathway stimulates telomere elongation and prevents cellular senescence in approximately 60% of osteosarcoma. While the precise mechanisms underlying the ALT pathway are unclear, mutations in the chromatin remodeling protein ATRX, histone chaperone DAXX, and the histone variant H3.3, correlate with ALT status. ATRX and DAXX facilitate deposition of the histone variant H3.3 within heterochromatic regions including the telomere suggesting that loss of ATRX, DAXX, and/or H3.3 lead to defects in heterochromatin maintenance at telomeres, ultimately contributing to ALT activity. Previous studies have detected genetic mutations in ATRX, DAXX, and H3.3 in ALT cell lines and tumor samples. However, a subset of ALT samples show loss of ATRX or DAXX protein expression or localization without evidence of genetic alterations, indicating a role for other defects in ATRX/DAXX/H3.3 function. Here, using Next Generation Sequencing, we identified a novel gene fusion event between DAXX and the kinesin motor protein, KIFC3, which leads to the translation of a chimeric DAXX-KIFC3 fusion protein. Here, we demonstrate that the fusion of KIFC3 to DAXX leads to defects in DAXX function and likely perpetuates ALT activity. These data highlight a previously unrecognized mechanism of DAXX inactivation in ALT positive osteosarcoma and provide rationale for thorough and comprehensive analyses of ATRX/DAXX/H3.3 proteins in ALT positive cancers. Overall design: 13 cell lines sequenced in triplicate, totaling 39 sequencing samples
Identification of a novel gene fusion in ALT positive osteosarcoma.
Cell line, Subject
View SamplesHuman pluripotent stem cells in culture are often associated with the prime state which represents a more developed state relative to the nave state which is often associated with the inner cell mass and thought to have the potential to give rise to all cell types. We have developed a small molecule-driven cocktail FMM that maintains human pluripotent stem cells in a state similar to the naive state as defined by several properties including gene expression profile.
Platform for induction and maintenance of transgene-free hiPSCs resembling ground state pluripotent stem cells.
Specimen part
View Samples