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Series GSE98981 Query DataSets for GSE98981
Status Public on Jul 12, 2018
Title Key role of piRNAs in telomeric chromatin maintenance and telomere nuclear positioning in Drosophila germline
Organism Drosophila melanogaster
Experiment type Non-coding RNA profiling by high throughput sequencing
Summary Background.
Telomeric small RNAs related to PIWI-interacting RNAs (piRNAs) have been described in various eukaryotes; however, their role in germline-specific telomere function remains poorly understood. Using a Drosophila model, we performed an in-depth study of the biogenesis of telomeric piRNAs and their function in telomere homeostasis in the germline.

Results
To fully characterize telomeric piRNA clusters, we integrated the data obtained from analysis of endogenous telomeric repeats, as well as transgenes inserted into different telomeric and subtelomeric regions. The small RNA-seq data from strains carrying telomeric transgenes demonstrated that all transgenes belong to a class of dual-strand piRNA clusters; however, their capacity to produce piRNAs varies significantly. Rhino, a paralog of heterochromatic protein 1 (HP1) expressed exclusively in the germline, is associated with all telomeric transgenes, but its enrichment correlates with the abundance of transgenic piRNAs. It is likely that this heterogeneity is determined by the sequence peculiarities of telomeric retrotransposons. In contrast to the heterochromatic non-telomeric germline piRNA clusters, piRNA loss leads to a dramatic decrease in HP1, Rhino, and trimethylated histone H3 lysine 9 in telomeric regions. Therefore, the presence of piRNAs is required for the maintenance of telomere chromatin in the germline. Moreover, piRNA loss causes telomere translocation from the nuclear periphery toward the nuclear interior but does not affect telomere end capping. Analysis of the telomere-associated sequences (TASs) chromatin revealed strong tissue specificity. In the germline, TASs are enriched with HP1 and Rhino, in contrast to somatic tissues, where they are repressed by Polycomb group proteins.

Conclusions
piRNAs play an essential role in the assembly of telomeric chromatin, as well as in nuclear telomere positioning in the germline. Telomeric arrays and TASs belong to a unique type of Rhino-dependent piRNA clusters with transcripts that serve simultaneously as piRNA precursors and as their only targets. Telomeric chromatin is highly sensitive to piRNA loss, implying the existence of a novel developmental checkpoint that depends on telomere integrity in the germline.
 
Overall design The fractions of small RNAs (19-29 nt) from ovaries of four transgenic strains of Drosophila melanogaster were sequenced using Illumina HiSeq 2000.
 
Contributor(s) Radion E, Morgunova V, Ryazansky S, Akulenko N, Lavrov S, Abramov Y, Komarov P, Glukhov S, Olovnikov I, Kalmykova A
Citation(s) 30001204
Submission date May 16, 2017
Last update date Jul 25, 2021
Contact name Sergei Ryazansky
E-mail(s) s.ryazansky@gmail.com
Phone +7-499-196-81-73
Organization name Institute of Molecular Genetics
Department Department of Molecular Genetics of Cell
Street address Kurchatov sq., 2
City Moscow
ZIP/Postal code 123182
Country Russia
 
Platforms (2)
GPL13304 Illumina HiSeq 2000 (Drosophila melanogaster)
GPL17275 Illumina HiSeq 2500 (Drosophila melanogaster)
Samples (9)
GSM2629593 Small RNAs from ovaries of EY00453 transgenic strain
GSM2629594 Small RNAs from ovaries of EY00802 transgenic strain
GSM2629595 Small RNAs from ovaries of EY08176 transgenic strain
Relations
BioProject PRJNA386922
SRA SRP107233

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Supplementary file Size Download File type/resource
GSE98981_RAW.tar 112.5 Mb (http)(custom) TAR (of TXT)
SRA Run SelectorHelp
Raw data are available in SRA
Processed data provided as supplementary file

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