The sequence of gene regulatory events that drive neonatal germ cell development in the mammalian testis is not yet clear. We assessed changes in mRNA utilization in the neonatal testis at 1 and 4 dpp, times when the testis contains quiescent gonocytes (1 dpp) and proliferating spermatogonia (4 dpp). There are not thought to be major changes in the nature or number of somatic cells over that interval.
Translational activation of developmental messenger RNAs during neonatal mouse testis development.
Age, Specimen part
View SamplesInsulators delimit independent transcriptional domains within genomes by constraining enhancer and silencer action. These transcriptional effects depend upon DNA recognition by insulator binding proteins that recruit partners that protect against inappropriate long range modulation of non-target promoters. Insulator binding proteins are broadly expressed during development, with largely constitutive binding to thousands of genomic sites. Yet, tissue-specific transcriptional changes result from the loss of individual insulator binding proteins. To understand the molecular basis for such effects, we are studying the classic Drosophila insulator protein Suppressor of Hairy-wing [Su(Hw)]. Genetic studies show that loss of this broadly expressed insulator protein prevents oocyte development. To determine the basis for the block in oogenesis, we coupled transcriptional analyses in su(Hw) mutant ovaries with genome-wide definition of Su(Hw) binding in this tissue. These studies identified 71 direct targets of Su(Hw) regulation, with nearly 70% of these genes showing increased RNA accumulation when Su(Hw) is lost. Surprisingly, derepressed Su(Hw) target genes correspond to genes normally highly expressed in neural tissues, suggesting that Su(Hw) has a critical role in silencing neural genes in the ovary. Support for this postulate was obtained by genetic studies. We found that oocyte production was restored in su(Hw) mutant females that carry a deletion of one allele of the elav family RNA binding protein 9 (Rbp9) gene. These su(Hw) null oocytes can be fertilized, with evidence that embryos lacking Su(Hw) show compromised development. Our studies extend the known transcriptional activities of Su(Hw), indicating that Su(Hw) can function as an insulator, activator and repressor, the latter function being essential for oogenesis. These findings highlight that insulator proteins are versatile transcriptional regulatory proteins, suggesting that tissue specific contributions to transcription result from direct regulation of individual genes.
The insulator protein Suppressor of Hairy-wing is an essential transcriptional repressor in the Drosophila ovary.
Specimen part
View SamplesSuppressor of Hairy-wing [Su(Hw)] is a multi-zinc finger DNA binding factor required for gypsy insulator function and female germline development in Drosophila. The enhancer-blocking and barrier functions of the gypsy retrotransposon involve Su(Hw) binding to twelve clustered Su(Hw) binding sites (SBSs) and recruitment of the Centrosomal Protein of 190 kD (CP190) and Modifier of mdg4 67.2 kD isoform (Mod67.2) insulator proteins. In contrast, the Su(Hw) germline function involves binding to non-clustered genomic SBSs and does not require CP190 or Mod67.2. Here, we use genome-wide expression analyses in the ovary to identify the first Su(Hw) regulated target genes.
The insulator protein Suppressor of Hairy-wing is an essential transcriptional repressor in the Drosophila ovary.
Specimen part
View SamplesLEM Domain proteins are key components of the nuclear lamina. Mutations in LEM-D proteins cause dystrophic diseases associated with compromised adult stem cells, yet it remains unclear how LEM-D proteins support stem cell function. Studies described here use the homologue of the LEM-D protein emerin in Drosophila, Otefin (Ote) as a model to understand LEM-D protein function in adult stem cells. Loss of Ote causes female sterility due to a complex germline stem cell (GSC) phenotype that includes both an early block in germline differentiation followed by GSC death. In vivo cell cycle analysis revealed that ote mutant GSCs display a lengthened S phase.We find that loss of the DNA Damage Response (DDR) Chk2 is able to not only rescue the lengthened S phase, but also GSC death and the block in germline differentiation. Activation of detrimental checkpoint in absence of Ote is conserved in both male and female GSCs and surprisingly occurs independent of detectable canonical DDR triggers, including transposon de-repression and DNA damage. Two defects were found to occur upstream of Chk2 activation: nuclear lamina morphological defects and altered heterochromatin organization. Together, our data identify the primary cause for a compromised adult stem cell population in the absence of a LEM-D protein.
Nuclear lamina dysfunction triggers a germline stem cell checkpoint.
Specimen part
View SamplesThe MYC transcription factor is an unstable protein and its turnover is controlled by the ubiquitin system. Ubiquitination enhances MYC-dependent transactivation, but the underlying mechanism remains unresolved. Here we show that proteasomal turnover of MYC is dispensable for recruitment of RNA polymerase II (RNAPII), but is required to promote transcriptional elongation at MYC target genes. Degradation of MYC stimulates histone acetylation and recruitment of BRD4 and P-TEFb to target promoters, leading to phosphorylation of RNAPII CTD and the release of elongating RNAPII. In the absence of degradation, the RNA polymerase II-associated factor (PAF) complex associates with MYC via interaction of its CDC73 subunit with a conserved domain in the amino-terminus of MYC ("MYC box I"), suggesting that a MYC/PAF complex is an intermediate in transcriptional activation. Since histone acetylation depends on a second highly conserved domain in MYCs amino-terminus ("MYC box II"), we propose that both domains co-operate to transfer elongation factors onto paused RNAPII. Overall design: RNA-Seq Experiments were performed in a primary breast epithelial cell line (IMEC).The cell line expressed doxycycline-inducible versions of MYC (WT;Kless,Swap=WTN-KC). Where indicated cells were transfected with siRNAs (siCtrl;siSKP2). Where indicated cells were treaed with the proteasome inhibitor MG132 or EtOH as solvent control. DGE was performed by comparing Dox-treated populations expressing either Dox-inducible MYC or a vector control or comparing Dox-induced cells with EtOH (solvent control) treated cells.
Ubiquitin-Dependent Turnover of MYC Antagonizes MYC/PAF1C Complex Accumulation to Drive Transcriptional Elongation.
No sample metadata fields
View SamplesAnalysis of the transcriptomes of nearly ripe siliques (18-19 DAP) of the rdo2-1, rdo3 and hub1-2 (rdo4) mutants in comparison with wild-type Ler, using Affymetrix GeneChip Arabidopsis ATH1 Genome Array.
Identification of the Arabidopsis REDUCED DORMANCY 2 gene uncovers a role for the polymerase associated factor 1 complex in seed dormancy.
No sample metadata fields
View SamplesIn this study we analyzed the myeloma cell contact-mediated changes on the transcriptome of skeletal precursor cells. Therefore, human mesenchymal stem cells (MSC) and osteogenic precursor cells (OPC) were co-cultured with the representative myeloma cell line INA-6 for 24 h. Afterwards, MSC and OPC were separated from INA-6 cells by fluorescence activated cell sorting. Total RNA of MSC and OPC fractions was used for whole genome array analysis.
Contact of myeloma cells induces a characteristic transcriptome signature in skeletal precursor cells -Implications for myeloma bone disease.
Sex, Age, Specimen part, Disease stage
View SamplesType II testicular germ cell cancers (GCC) are the most frequently diagnosed tumors in young men (20 - 40 years) and are classified as seminoma or non-seminoma. GCCs are commonly treated by orchiectomy and chemo- or radiotherapy. However, a subset of metastatic non-seminomas display only incomplete remission or relapse and require novel treatment options. Recent studies have shown effective application of the small-molecule inhibitor JQ1 in tumor therapy, which interferes with the function of bromodomain and extra-terminal (BET)-proteins. Here, we demonstrate that upon JQ1 doses 250 nM GCC cell lines and Sertoli cells display compromised survival and induction of cell cycle arrest. JQ1 treated GCC cell lines display upregulation of genes indicative for DNA damage and a cellular stress response. Additionally, downregulation of pluripotency factors and induction of mesodermal differentiation was detected. GCCs xenografted in vivo showed a reduction in tumor size, proliferation and angiogenesis when subjected to JQ1 treatment. The combination of JQ1 and the histone deacetylase inhibitor romidepsin further enhanced the apoptotic effect in vitro and in vivo. Thus, we propose that JQ1 alone, or in combination with romidepsin may serve as a novel therapeutic option for GCCs.
The bromodomain inhibitor JQ1 triggers growth arrest and apoptosis in testicular germ cell tumours in vitro and in vivo.
Specimen part, Cell line, Time
View SamplesP6 ID4-EGFP+ undifferentiated spermatogonia, including those stained robustly (high) or weakly (low) for TSPAN8 were isolated by FACS. Overall design: Three replicate preparations of each population were used for independent RNA-seq using SMART-seq v4, Nextera XT libraries, Hiseq2500 sequencing, and TopHat/Bowtie/Cufflinks analyses.
TSPAN8 Expression Distinguishes Spermatogonial Stem Cells in the Prepubertal Mouse Testis.
Cell line, Subject
View SamplesPurpose: More than 90% of children with diffuse intrinsic pontine glioma (DIPG) die within 2 years of diagnosis. There is a dire need to identify therapeutic targets, however lack of patient material for research has limited progress. We evaluated a large cohort of diffuse intrinsic pontine gliomas (DIPGs) to identify recurrent genomic abnormalities and gene expression signatures underlying DIPG.
Genome-wide analyses identify recurrent amplifications of receptor tyrosine kinases and cell-cycle regulatory genes in diffuse intrinsic pontine glioma.
Age, Specimen part, Disease
View Samples