Heterochromatic position effect variegation (PEV) is the epigenetic disruption of genes expression near the new-formed eu-heterochromatic border. We characterized the inversion In(2)A4, demonstrating cis-acting PEV as well as trans-inactivation of the reporter transgenes on the opposite normal chromosome in combination with the inversion. Euchromatic breakpoint of In(2)A4 inversion was localized at 105 bp region (chr2L:21182214-21182318) of the second exon of the Mcm10 gene, the heterochromatic breakpoint is located at the block of dodecasatellite in 2L pericentromeric heterochromatin. In order to check the effects of heterochromatin on neighbor euchromatic genes and estimate the distance of inactivation spreading, we performed RNA-seq analysis of genes expression in larvae and adults females of genotypes A12/A12 (control) and In(2)A4/In(2)A4. Cis-influence of heterochromatin in the inversion causes not only repression, but also activation of genes, and the effects of heterochromatin are different at different developmental stages. Cis-actions affect only a few genes located near the heterochromatin Overall design: Comparison of genes expression in wild type and demonstrating PEV larvae and adults in two repeats each
Trans-inactivation: Repression in a wrong place.
Sex, Subject
View SamplesPIWI interacting RNAs (piRNAs) provide defense against transposable element (TE) expansion in the germline of metazoans. piRNAs are processed from the transcripts encoded by specialized heterochromatic clusters enriched in damaged copies of transposons. How these regions are recognized as a source of piRNAs is still elusive. The aim of this study is to determine how transgenes that contain a fragment of the LINE-like I transposon lead to an acquired TE resistance in Drosophila. We show that such transgenes, being inserted in unique euchromatic regions which normally do not produce small RNAs, become de novo bidirectional piRNA clusters that silence I-element activity in the germline. Strikingly, small RNAs of both polarities are generated from the entire transgene and flanking genomic sequences — not only from the transposon fragment. Chromatin immunoprecipitation analysis shows that in ovaries the trimethylated histone 3 lysine 9 (H3K9me3) mark associates with transgenes producing piRNAs. We show that transgene-derived hsp70 piRNAs stimulate in trans cleavage of cognate endogenous transcripts with subsequent processing of the non-homologous parts of these transcripts into piRNAs. Overall design: The fractions of small RNAs (19-29 nt) from ovaries of wild type and 11 transgenic lines of Drosophila melanogaster were sequenced using Illumina HiSeq 2000.
De novo piRNA cluster formation in the Drosophila germ line triggered by transgenes containing a transcribed transposon fragment.
Specimen part, Subject
View SamplesGermline-specific RNA helicase Spindle-E (Spn-E) is known to be essential for piRNA silencing in Drosophila that takes place mainly in the perinuclear nuage granules. Loss-of-function spn-E mutations lead to tandem Stellate genes derepression in the testes and retrotransposon mobilization in the ovaries. However, Spn-E functions in the piRNA pathway are still obscure. Analysis of total library of short RNAs from the testes of spn-E heterozygous flies revealed the presence of abundant piRNA ping-pong pairs originating from Su(Ste) transcripts. The abundance of these ping-pong pairs were sharply reduced in the library from the testes of spn-E mutants. Thus we found that ping-pong mechanism contributed to Su(Ste) piRNA generation in the testes. The lack of Spn-E caused a significant drop of protein levels of key ping-pong participants, Aubergine (Aub) and AGO3 proteins of PIWI subfamily, in the germline of both males and females, but did not disrupt of their assembly in nuage granules. We found that observed decline of the protein expression was not caused by suppression of aub and ago3 transcription as well as total transcription, indicating possible contribution of Spn-E to post-transcriptional regulation. Overall design: The fractions of small RNAs (19-29 nt) from testis of Drosophila melanogaster spnE/+ spnE/- strains were sequenced using Illumina HiSeq 2000.
RNA helicase Spn-E is required to maintain Aub and AGO3 protein levels for piRNA silencing in the germline of Drosophila.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
View SamplesEstrogens have been reported to activate several processes via membrane binding to either classic estrogen receptors (ERs) or GPR30. We have used either estradiol or BSA-conjugated estradiol in order to initiate membrane-initiated actions and ICI 172,780 (ICI) or G15 to explore ER- and GPR30-related transcription. Our results show that the majority of G15-inhibited transcription is depending on ERs, as it is also inhibited by ICI. However, a small number of transcripts, related to specific actions/pathways is either exclusively inhibited by G15, providing evidence about a specific GPR30 signature, or not inhibited by ICI or G15 suggesting the existence of another, yet unidentified estrogen receptor.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
View SamplesEstrogens have been reported to activate several processes via membrane binding to either classic estrogen receptors (ERs) or GPR30. We have used either estradiol or BSA-conjugated estradiol in order to initiate membrane-initiated actions and ICI 172,780 (ICI) or G15 to explore ER- and GPR30-related transcription. Our results show that the majority of G15-inhibited transcription is depending on ERs, as it is also inhibited by ICI. However, a small number of transcripts, related to specific actions/pathways is either exclusively inhibited by G15, providing evidence about a specific GPR30 signature, or not inhibited by ICI or G15 suggesting the existence of another, yet unidentified estrogen receptor.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
View SamplesEstrogens have been reported to activate several processes via membrane binding to either classic estrogen receptors (ERs) or GPR30. We have used either estradiol or BSA-conjugated estradiol in order to initiate membrane-initiated actions and ICI 172,780 (ICI) or G15 to explore ER- and GPR30-related transcription. Our results show that the majority of G15-inhibited transcription is depending on ERs, as it is also inhibited by ICI. However, a small number of transcripts, related to specific actions/pathways is either exclusively inhibited by G15, providing evidence about a specific GPR30 signature, or not inhibited by ICI or G15 suggesting the existence of another, yet unidentified estrogen receptor.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
View SamplesEstrogens have been reported to activate several processes via membrane binding to either classic estrogen receptors (ERs) or GPR30. We have used either estradiol or BSA-conjugated estradiol in order to initiate membrane-initiated actions and ICI 172,780 (ICI) or G15 to explore ER- and GPR30-related transcription. Our results show that the majority of G15-inhibited transcription is depending on ERs, as it is also inhibited by ICI. However, a small number of transcripts, related to specific actions/pathways is either exclusively inhibited by G15, providing evidence about a specific GPR30 signature, or not inhibited by ICI or G15 suggesting the existence of another, yet unidentified estrogen receptor.
Early membrane initiated transcriptional effects of estrogens in breast cancer cells: First pharmacological evidence for a novel membrane estrogen receptor element (ERx).
Specimen part, Cell line
View SamplesThe hippocampus is part of a brain network essential for memory function. Paradoxically, the hippocampus is also the brain structure that is most sensitive to hypoxic-ischemic episodes. Here we show that the expression of genes associated with glycolysis and glutamate metabolism in astrocytes and the coverage of excitatory synapses by astrocytic processes undergo significant decreases in the CA1 field of the monkey hippocampus during postnatal development. Given the established role of astrocytes in the regulation of glutamate concentration in the synaptic cleft, our findings indicate that a developmental decrease in astrocytic processes underlies the selective vulnerability of CA1 during hypoxic-ischemic episodes in adulthood, its decreased susceptibility to febrile seizures with age, as well as contribute to the emergence of selective, adult-like memory function.
Developmental regulation of gene expression and astrocytic processes may explain selective hippocampal vulnerability.
Specimen part
View SamplesExtrahepatic bile ducts were isolated from mouse pups at days 0-3 and primary cholangiocytes were isolated. Cholangiocytes were treated with DMSO, bilatresone (TOX4), betavulgarin (TOX2), and isoflavanone (TOX3), as per Lorent et al, Science Translationa Medicine 2015;286:286ra67 (Fig. 1), all in DMSO. Treatment concentrations were 2.0 micrograms/ml, for 6 hours.
Extrahepatic cholangiocyte obstruction is mediated by decreased glutathione, Wnt and Notch signaling pathways in a toxic model of biliary atresia.
Treatment
View Samples