17 research outputs found
The discovery, distribution, and evolution of viruses associated with drosophila melanogaster
Drosophila melanogaster is a valuable invertebrate model for viral infection and antiviral immunity, and is a focus for studies of insect-virus coevolution. Here we use a metagenomic approach to identify more than 20 previously undetected RNA viruses and a DNA virus associated with wild D. melanogaster. These viruses not only include distant relatives of known insect pathogens, but also novel groups of insect-infecting viruses. By sequencing virus-derived small RNAs we show that the viruses represent active infections of Drosophila. We find that the RNA viruses differ in the number and properties of their small RNAs, and we detect both siRNAs and a novel miRNA from the DNA virus. Analysis of small RNAs also allows us to identify putative viral sequences that lack detectable sequence similarity to known viruses. By surveying >2000 individually collected wild adult Drosophila we show that more than 30% of D. melanogaster carry a detectable virus, and more than 6% carry multiple viruses. However, despite a high prevalence of the Wolbachia endosymbiont—which is known to be protective against virus infections in Drosophila—we were unable to detect any relationship between the presence of Wolbachia and the presence of any virus. Using publicly available RNA-seq datasets we show that the community of viruses in Drosophila laboratories is very different from that seen in the wild, but that some of the newly discovered viruses are nevertheless widespread in laboratory lines and are ubiquitous in cell culture. By sequencing viruses from individual wild-collected flies we show that some viruses are shared between D. melanogaster and D. simulans. Our results provide an essential evolutionary and ecological context for host-virus interaction in Drosophila, and the newly reported viral sequences will help develop D. melanogaster further as a model for molecular and evolutionary virus research
Морфологические аспекты апоплексии яичника при хронических воспалительных заболеваниях репродуктивной системы у женщин
Мета роботи — визначити роль запальних захворювань органів малого таза у жінок у розвитку апоплексії яєчника.We have performed a retrospective analysis of 63 clinical cases of ovarian apoplexy in women receiving in-patient treatment in the gynecological clinic of the Military Medical Clinical Center of South Region from 2004 to 2008 year. The age of observed patients was 25,7±2,1 years. We have studied structural peculiarities in ovarian apoplexy, determined the dependence of development of ovarian apoplexy on presence of concomitant chronic inflammatory diseases of the reproductive system. It was proved that chronic oophoritis is found most often in women with ovarian apoplexy.Проведен ретроспективный анализ 63 клинических случаев апоплексии яичника у женщин, находившихся на стационарном лечении в клинике гинекологии Военно-медицинского клинического центра Южного региона с 2004 по 2008 гг. Возраст наблюдаемых пациенток составил (25,7±2,1) года. Были изучены структурные особенности яичников при апоплексии, опреде- лялась зависимость возникновения апоплексии яичника от наличия сопутствующих хронических воспалительных заболеваний репродуктивной системы женщины. Установлено, что хронический оофорит встречается наиболее часто у женщин с апоплексией яичников
Морфологические особенности желтого тела при апоплексии яичника с минимальный и умеренным внутрибрюшным кровотечением
Досліджувалось 16 клінічних випадків апоплексії яєчника з об’ємом внутрішньочеревної кровотечі від 150,0 до 500,0 мл. У 75% випадків джерелом апоплексії було жовте тіло в стадії розквіту. Морфологічні зміни в тканині яєчника та жовтому тілі зумовлені порушеннями гемоциркуляції, які пов’язані зі змінами судин яєчника.16 clinical cases of ovarian apoplexy were investigated with the volume of intraabdominal bleeding from 150,0 ml to 500,0 ml. In 75 % of the cases the source of apoplexy was the corpus luteum at the stage of flourishing. Morphological changes in the ovarian tissue and corpus luteum were caused by blood circulation disorders associated with changes of the ovarian vessels.Исследовалось 16 клинических случав апоплексии яичника с объемом внутрибрюшного кровотечения от 150,0 до 500,0 мл. В 75 % случаев источником апоплексии яичника было желтое тело в стадии расцвета. Морфологические изменения в ткани яичника и желтом теле были обусловлены нарушениями гемоциркуляции, связанные с изменениями сосудов яичника
iCLIP of the PIWI Protein Aubergine in Drosophila Embryos.
International audiencePiwi-interacting RNAs (piRNAs) are a class of small noncoding RNAs bound to specific Argonaute proteins, the PIWI proteins. piRNAs target mRNAs by complementarity to silence them; they play an important role in the repression of transposable elements in the germ line of many species. piRNAs and PIWI proteins are also involved in diverse biological processes through their role in the regulation of cellular mRNAs. In the Drosophila embryo, they contribute to the maternal mRNA decay occurring during the maternal-to-zygotic transition. CLIP (UV cross-linking and immunoprecipitation) techniques have been used to identify target mRNAs of Argonaute proteins. Here we describe the iCLIP (individual-nucleotide resolution CLIP) protocol that we have adapted for the PIWI protein Aubergine in Drosophila embryos
A unique cluster of roo insertions in the promoter region of a stress response gene in Drosophila melanogaster
Transposable elements (TEs) are not randomly distributed in the genome. A genome-wide analysis of the D. melanogaster genome found that differences in TE density across 50 kb genomic regions was due both to transposition and duplication. At smaller genomic scales, promoter regions of hsp genes and the promoter region of CG18446 have been shown to accumulate TE insertions. In this work, we have further analyzed the promoter region of CG18446. We screened 218 strains collected in 15 natural populations, and we found that the CG18446 promoter region contains 20 independent roo insertions. Based on phylogenetic analysis, we suggest that the presence of multiple roo insertions in this region is likely to be the result of several bursts of transposition. Moreover, we found that the roo insertional cluster in the CG18446 promoter region is unique: no other promoter region in the genome contains a similar number of roo insertions. We found that, similar to hsp gene promoters, chromatin accessibility could be one of the factors explaining the recurrent insertions of roo elements in CG18446 promoter region.This work was funded by the European Commission (H2020-ERC-2014-CoG-647900). C.I. was funded by an ERASMUS+ fellowship. We acknowledge the support of the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de laGeneralitat de Catalunya (GRC 2017 SGR 880). We also acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)
Genome-wide identification of long noncoding RNA genes and their potential association with fecundity and virulence in rice brown planthopper, Nilaparvata lugens
Data from: Small RNAs from a big genome: the piRNA pathway and transposable elements in the salamander species Desmognathus fuscus
Most of the largest vertebrate genomes are found in salamanders, a clade of amphibians that includes 686 species. Salamander genomes range in size from 14 to 120 Gb, reflecting the accumulation of large numbers of transposable element (TE) sequences from all three TE classes. Although DNA loss rates are slow in salamanders relative to other vertebrates, high levels of TE insertion are also likely required to explain such high TE loads. Across the Tree of Life, novel TE insertions are suppressed by several pathways involving small RNA molecules. In most known animals, TE activity in the germline is primarily regulated by the Piwi-interacting RNA (piRNA) pathway. In this study, we test the hypothesis that salamanders’ unusually high TE loads reflect the loss of the ancestral piRNA-mediated TE-silencing machinery. We characterized the small RNA pool in the female and male adult gonads, testing for the presence of small RNA molecules that bear the characteristics of TE-targeting piRNAs. We also analyzed the amino acid sequences of piRNA pathway proteins from salamanders and other vertebrates, testing whether the overall patterns of sequence divergence are consistent with conserved pathway function across the vertebrate clade. Our results do not support the hypothesis of piRNA pathway loss; instead, they suggest that the piRNA pathway is expressed in salamanders. Given these results, we propose hypotheses to explain how the extraordinary TE loads in salamander genomes could have accumulated, despite the expression of TE-silencing machinery