Significance Control of transposable elements (TEs) by RNAi has a large impact on genome evolution in higher eucaryotes. In this paper, we study detail Piwi-interacting RNA (piRNA)-producing locus Drosophila melanogaster , flamenco ( flam ), known to be responsible for the control at least three retrotransposons RNAi. We demonstrate high structural dynamics resulting loss and gain TEs establish link between such variations its ability silence retrotransposons. show that is trap coming...

PIWI-interacting RNAs (piRNAs) provide defence against transposable element (TE) expansion in the germ line of metazoans. piRNAs are processed from transcripts encoded by specialized heterochromatic clusters enriched damaged copies transposons. How these regions recognized as a source is still elusive. The aim this study to determine how transgenes that contain fragment Long Interspersed Nuclear Elements (LINE)-like I transposon lead an acquired TE resistance Drosophila . We show such...

For species survival, the germline must faithfully transmit genetic information to progeny. Transposable elements (TEs) constitute a significant threat genome stability due their mobility. In metazoan germline, mobilization is limited by class of small RNAs called PIWI-interacting (piRNAs) produced dedicated genomic loci piRNA clusters. Although pathway an adaptive immunity system, it remains unclear how gains protection from new transposon invasion. To address this question, we analyze...

Specific genomic loci, termed Piwi-interacting RNA (piRNA) clusters, manufacture piRNAs that serve as guides for the inactivation of complementary transposable elements (TEs). The piRNA pathway has been accurately detailed in Drosophila melanogaster, while it remains poorly examined other insects. This is increasingly recognized critical germline development and reproduction. Understanding functions mosquitoes could offer an opportunity disease vector control by reduction their reproductive...

Abstract We have previously shown that the activity of functional I elements introduced into Drosophila devoid such can be repressed by transgenes containing an internal nontranslatable part element itself and this repressing effect presents features characteristic homology-dependent gene silencing or cosuppression. Here we show a fragment in antisense orientation induce I-element with same as corresponding sense construct: namely, repression takes several generations to fully established,...

The piRNA pathway protects genomes by silencing mobile elements. Despite advances in understanding the processing events that generate piRNAs for silencing, little is known about how primary transcripts are transported from their genomic clusters to centers. Using a model of Drosophila COM/flamenco locus ovarian somatic cells, we identified prominent nuclear structure called Dot COM, which enriched long but located far transcription sites. Remarkably, multiple accumulate at often juxtaposed...

The field of small RNA is one the most investigated research areas since they were shown to regulate transposable elements and gene expression play essential roles in fundamental biological processes. Small deep sequencing (sRNA-seq) now routinely used for large-scale analyses RNA. Such high-throughput typically produces several millions reads. Here we present a computational pipeline (sRNAPipe: pipeline) based on Galaxy framework that takes as input fastq file RNA-seq reads performs...

Expression of transposable elements in the germline is controlled by Piwi-interacting (pi) RNAs produced genomic loci termed piRNA clusters and associated with Rhino, a heterochromatin protein 1 (HP1) homolog. Previously, we have shown that transgenes containing fragment I retrotransposon form de novo Drosophila providing suppression I-element activity. We noted identical located different sites vary considerably production classified them as "strong" "weak" clusters. Here, investigated what...

Most Drosophila transposable elements are LTR retrotransposons, some of which belong to the genus Errantivirus and share structural functional characteristics with vertebrate endogenous retroviruses. Like retroviruses, it is unclear whether errantiviruses retain infectivity transposition capacity. We created conditions where control ZAM errantivirus through piRNA pathway was abolished leading its de novo reactivation in somatic gonadal cells. After reactivation, invaded oocytes severe...

By transfection experiments, we previously identified a 72-bp enhancer sequence within the Drosophila copia retrotransposon which is involved in control of transcription level this mobile element cells culture. Gel shift assays with nuclear extracts from hydei-derived DH-33 further demonstrated specific interactions at least two factors sequence. Using as probe for screening an expression cDNA library that constructed RNA, have isolated clone encoding 110-kDa protein features common to those...

PIWI-interacting RNAs (piRNAs) target transcripts by sequence complementarity serving as guides for RNA slicing in animal germ cells. The piRNA pathway is increasingly recognized critical essential cellular functions such germline development and reproduction. In the Anopheles gambiae ovary, much 11% of piRNAs map to protein-coding genes. Here, we show that ovarian mRNAs long non-coding (lncRNAs) are processed into can direct other biogenesis pathway. Targeting fuel either ping-pong cycle...

Abstract We have previously shown that the activity of functional I retrotransposons (I factors) introduced into Drosophila devoid such elements can be repressed by transgenes containing an internal fragment factor itself and this repressing effect presents characteristic features homology-dependent gene silencing or cosuppression. Here we show same induce a nonhomologous reporter as sole I-factor sequence its 100-bp promoter fragment. Silencing shows strong similarities to cosuppression: It...

Transposable elements are major components of most eukaryotic genomes. Such sequences generally defective for transposition and have little or no coding capacity. Because can be highly mutagenic, mobile that remain functional tightly repressed in all living species. Drosophila pericentromeric heterochromatin naturally contains transposition-defective, non-coding derivatives a LINE retrotransposon related to the I-factor. The I-factor is good model study regulation vivo because, under...

Transgenes containing a fragment of the I retrotransposon represent powerful model piRNA cluster de novo formation in Drosophila germline. We revealed that same transgenes located at different genomic loci form clusters with various capacity small RNA production. Transgenic are not established pathway mutants. However, wild-type context, endogenous ancestral I-related piRNAs heterochromatinize and convert I-containing into piRNA-producing loci. Here, we address how quantitative level...

We have marked a Drosophila transposable element— the LINE-like I element-with an intron-contalnlng indicator gene inserted in place of large deletion element second ORF encompassing reverse transcriptase domain, and this was placed downstream to potent actin promoter. An expression vector for ORFs also constructed, under same heterologous The contains lacZ reporter which is conditioned by retrotransposition element, thus allowing detection transposition events testing either...

ABSTRACT PIWI-interacting RNAs (piRNAs) target transcripts by sequence complementarity serving as guides for RNA slicing in animal germ cells. The piRNA pathway is increasingly recognized critical essential cellular functions such germline development and reproduction. In the Anopheles gambiae ovary, much 11% of piRNAs map to protein-coding genes. Here we show that ovarian mRNAs long non-coding (lncRNAs) are processed into can direct other biogenesis pathway. Targeting fuel either ping-pong...

Summary Most Drosophila transposable elements (TEs) are LTR retrotransposons, some of which belong to the genus Errantivirus and share structural functional characteristics with vertebrate endogenous retroviruses (ERVs). These virus-derived occupy a large part genome, but it is unclear whether how they can be reactivated if retain their replication capacity. We created conditions where control ZAM errantivirus through piRNA pathway was abolished leading its reactivation in real time somatic...