Drosophila melanogaster
Ontology highlight
ABSTRACT:
REPOSITORIES: ENA
Similar Datasets
Project description:Transposons evolve rapidly and can mobilize and trigger genetic instability. piRNAs silence these genome pathogens, but it is unclear how the piRNA pathway adapts to new transposons. In Drosophila piRNAs, encoded by heterochromatic clusters are maternally deposited in the embryo. Paternally inherited P-element transposons thus escape silencing and trigger a genetic instability and sterility. We show that this syndrome, termed P-M hybrid dysgenesis, also disrupts the piRNA biogenesis machinery and activates resident transposons. As dysgenic hybrids age, however, fertility is restored, P-elements are silenced, and P-element piRNAs are produced de novo. In addition, the piRNA biogenesis machinery is restored and resident elements are silenced. Significantly, new resident transposons insertions accumulate in piRNA clusters, and these new insertions are transmitted to progeny with high fidelity, produce novel piRNAs, and are associated with reduced transposition. P-M hybrid dysgenesis thus leads to heritable changes in chromosome structure that appear to enhance transposon silencing.
2011-12-23 | GSE31813 | GEO
Project description:Transposons evolve rapidly and can mobilize and trigger genetic instability. piRNAs silence these genome pathogens, but it is unclear how the piRNA pathway adapts to new transposons. In Drosophila piRNAs, encoded by heterochromatic clusters are maternally deposited in the embryo. Paternally inherited P-element transposons thus escape silencing and trigger a genetic instability and sterility. We show that this syndrome, termed P-M hybrid dysgenesis, also disrupts the piRNA biogenesis machinery and activates resident transposons. As dysgenic hybrids age, however, fertility is restored, P-elements are silenced, and P-element piRNAs are produced de novo. In addition, the piRNA biogenesis machinery is restored and resident elements are silenced. Significantly, new resident transposons insertions accumulate in piRNA clusters, and these new insertions are transmitted to progeny with high fidelity, produce novel piRNAs, and are associated with reduced transposition. P-M hybrid dysgenesis thus leads to heritable changes in chromosome structure that appear to enhance transposon silencing. 3 replicates of each sample (Har 2-4 days, w1 x Har 2-4 days, w1 x Har 21 days), total RNA samples hybridized to tiling array.
2011-12-23 | E-GEOD-31813 | biostudies-arrayexpress
Project description:Species of the genus Drosophila have served as favorite models in speciation studies, however genetic factors of the interspecific hybrid sterility are underinvestigated to date. Here we performed the analysis of reproductive incompatibilities of hybrid females in crossing Drosophila melanogaster females and Drosophila simulans males. Using transcriptomic data analysis, molecular, cellular and genetic approaches we analyzed differential gene expression, transposable element (TE) activity, piRNA biogenesis and functional defects of oogenesis in hybrids. A premature GSC loss was a most prominent defect of oogenesis in hybrid ovaries. Owing differential expression of genes encoding components of the piRNA pathway rhino and deadlock, functional RDCmel complex in hybrid ovaries was not assembled. At the same time the activity of RDCsim complex was maintained in hybrids, independently from the genomic origin of piRNA clusters. Despite identification of a cohort of overexpressed TEs in hybrid ovaries we found no evidences that their activity can be considered as the main cause of hybrid sterility. We revealed complex pattern of Vasa protein expression in hybrid germline, including partial AT-chX piRNA targeting of vasasim allele and significant developmental delay of vasamel expression. We came to the conclusions that complex multi-locus genetic changes between the species were responsible for hybrid sterility phenotype.
2024-05-30 | GSE263983 | GEO
Project description:In plants and mammals, small RNAs indirectly mediate epigenetic inheritance by specifying cytosine methylation. Here, we find that small RNAs themselves serve as vectors for epigenetic information. Crosses between Drosophila strains that differ in the presence of a particular transposon can produce sterile progeny, a phenomenon called hybrid dysgenesis. This phenotype manifests itself only if the transposon is paternally inherited, suggesting maternal transmission of a factor that maintains fertility. In both P- and I-element-mediated hybrid-dysgenesis models, daughters show a markedly different content of piRNAs targeting each element, depending upon its parent of origin. Such differences persist from fertilization through adulthood. This indicates that maternally deposited piRNAs are crucial for mounting an effective silencing response and that a lack of maternal piRNA inheritance underlies hybrid dysgenesis. Mappers table contains all of the sequences in our libraries that map to the drosophila genome (release 5) Nonmappers table contains all of the sequences in our libraries that do not map to the drosophila genome(release 5)
2008-11-28 | GSE13081 | GEO
Project description:Species of the genus Drosophila have served as favorite models in speciation studies, however genetic factors of the interspecific hybrid sterility are underinvestigated to date. Here we performed the analysis of reproductive incompatibilities of hybrid females in crossing Drosophila melanogaster females and Drosophila simulans males. Using transcriptomic data analysis, molecular, cellular and genetic approaches we analyzed differential gene expression, transposable element (TE) activity, piRNA biogenesis and functional defects of oogenesis in hybrids. A premature GSC loss was a most prominent defect of oogenesis in hybrid ovaries. Owing differential expression of genes encoding components of the piRNA pathway rhino and deadlock, functional RDCmel complex in hybrid ovaries was not assembled. At the same time the activity of RDCsim complex was maintained in hybrids, independently from the genomic origin of piRNA clusters. Despite identification of a cohort of overexpressed TEs in hybrid ovaries we found no evidences that their activity can be considered as the main cause of hybrid sterility. We revealed complex pattern of Vasa protein expression in hybrid germline, including partial AT-chX piRNA targeting of vasasim allele and significant developmental delay of vasamel expression. We came to the conclusions that complex multi-locus genetic changes between the species were responsible for hybrid sterility phenotype.
2024-05-30 | GSE263982 | GEO
Project description:In the Drosophila germline, transposable elements (TEs) are silenced by PIWI-interacting RNA (piRNA) that originate from distinct genomic regions termed piRNA clusters and are processed by PIWI-subfamily Argonaute proteins. Here, we explore the variation in the ability to restrain an alien TE in different Drosophila strains. The I-element is a retrotransposon involved in the phenomenon of I-R hybrid dysgenesis in Drosophila melanogaster. Genomes of R strains do not contain active I-elements, but harbour remnants of ancestral I-related elements. The permissivity to I-element activity of R females, called reactivity, varies considerably in natural R populations, indicating the existence of a strong natural polymorphism in defense systems targeting transposons. To reveal the nature of such polymorphisms, we compared ovarian small RNAs between R strains with low and high reactivity and show that reactivity negatively correlates with the ancestral I-element-specific piRNA content. Analysis of piRNA clusters containing remnants of I-elements shows increased expression of the piRNA precursors and enrichment by the Heterochromatin Protein 1 homolog, Rhino, in weak R strains, which is in accordance with stronger piRNA expression by these regions. To explore the nature of the differences in piRNA production, we focused on two R strains, weak and strong, and showed that the efficiency of maternal inheritance of piRNAs as well as the I-element copy number are very similar in both strains. At the same time, germline and somatic uni-strand piRNA clusters generate more piRNAs in strains with low reactivity, suggesting the relationship between the efficiency of primary piRNA production and variable response to TE invasions. The strength of adaptive genome defense is likely driven by naturally occurring polymorphisms in the rapidly evolving piRNA pathway proteins. We hypothesize that hyper-efficient piRNA production is contributing to elimination of a telomeric retrotransposon HeT-A, which we have observed in one particular transposon-resistant R strain.
2017-04-05 | GSE83316 | GEO
Project description:In plants and mammals, small RNAs indirectly mediate epigenetic inheritance by specifying cytosine methylation. Here, we find that small RNAs themselves serve as vectors for epigenetic information. Crosses between Drosophila strains that differ in the presence of a particular transposon can produce sterile progeny, a phenomenon called hybrid dysgenesis. This phenotype manifests itself only if the transposon is paternally inherited, suggesting maternal transmission of a factor that maintains fertility. In both P- and I-element-mediated hybrid-dysgenesis models, daughters show a markedly different content of piRNAs targeting each element, depending upon its parent of origin. Such differences persist from fertilization through adulthood. This indicates that maternally deposited piRNAs are crucial for mounting an effective silencing response and that a lack of maternal piRNA inheritance underlies hybrid dysgenesis. Mappers table contains all of the sequences in our libraries that map to the drosophila genome (release 5) Nonmappers table contains all of the sequences in our libraries that do not map to the drosophila genome(release 5) 15 small RNA libraries were generated from total RNA of Drosophila melanogaster ovarian and embryo tissues and analyzed for this study
2008-11-28 | E-GEOD-13081 | biostudies-arrayexpress
Project description:We investigated a pool of small RNAs derived from transposon Penelope to probe the evolution of small RNA pathways in response to the transposon challenge in natural (D. virilis) and experimentally induced (D. melanogaster) colonization processes. In both species, Penelope was predominantly targeted by endo-siRNAs rather than by piRNAs. Although we observed correlations between Penelope transcription and dysgenesis, we could not correlate differences in maternally deposited Penelope piRNAs with the sterility of progeny. Instead, we found that strains, which produced dysgenic progeny, differed in their production of piRNAs from clusters in sub-telomeric regions, possibly indicating that changes in the overall piRNA repertoire underlie dysgenesis. Considered together, our data reveal unexpected plasticity in small RNA pathways in germ cells, both in the character of their responses to invading transposons and in the piRNA clusters that define their ability to respond to mobile elements.
2010-07-19 | GSE22067 | GEO
Project description:Analysis of Hybrid Dysgenesis in Drosophila virilis
| PRJNA288729 | ENA
Project description:Drosophila Piwi-family proteins have been implicated in transposon control. Here, we examine piwi-interacting RNAs (piRNAs) associated with each Drosophila Piwi protein and find that Piwi and Aubergine bind RNAs that are predominantly antisense to transposons, whereas Ago3 complexes contain predominantly sense piRNAs. As in mammals, the majority of Drosophila piRNAs are derived from discrete genomic loci. These loci comprise mainly defective transposon sequences, and some have previously been identified as master regulators of transposon activity. Our data suggest that heterochromatic piRNA loci interact with potentially active, euchromatic transposons to form an adaptive system for transposon control. Complementary relationships between sense and antisense piRNA populations suggest an amplification loop wherein each piRNA-directed cleavage event generates the 5’ end of a new piRNA. Thus, sense piRNAs, formed following cleavage of transposon mRNAs, may enhance production of antisense piRNAs, complementary to active elements, by directing cleavage of transcripts from master control loci. Keywords: small RNA libraries from Drosophila ovaries
2007-03-08 | GSE6734 | GEO