Pirna

During the last few centuries D. melanogaster populations were invaded by several transposable elements, the most recent of which was thought to be the P-element between 1950 and 1980. Here we describe a novel TE, which we named Spoink, that has invaded D. melanogaster. It is a 5216nt LTR retrotransposon of the Ty3/gypsy superfamily. Relying on strains sampled at different times during the last century we show that Spoink invaded worldwide D. melanogaster populations after the P-element between 1983 and 1993...

N-terminal arginine (NTR) methylation is a conserved feature of PIWI proteins, which are central components of the PIWI-interacting RNA (piRNA) pathway. The significance and precise function of PIWI NTR methylation in mammals remains unknown. In mice, PIWI NTRs bind Tudor domain containing proteins (TDRDs) that have essential roles in piRNA biogenesis and the formation of the chromatoid body. Using mouse MIWI (PIWIL1) as paradigm, we demonstrate that the NTRs are essential for spermatogenesis through the regulation of transposons and gene expression...

BACKGROUND: piRNAs play key roles in various diseases. However, the role of piRNAs in sporadic Parkinson's disease (PD) remains unclear. This study was conducted to explore key piRNAs that can be used as biomarkers for sporadic Parkinson's disease. METHODS: Differentially expressed piRNAs (DEPs) and their interaction were investigated using bioinformatics analysis, while the diagnostic value and expression of the selected piRNAs were detected. RESULTS: 42 DEPs were screened between PD and controls...

To maintain fertility, male mice re-repress transposable elements (TEs) that were de-silenced in the early gonocytes before their differentiation into spermatogonia. However, the mechanism of TE silencing re-establishment remains unknown. Here, we found that the DNA-binding protein Morc1, in cooperation with the methyltransferase SetDB1, deposits the repressive histone mark H3K9me3 on a large fraction of activated TEs, leading to heterochromatin. Morc1 also triggers DNA methylation, but TEs targeted by Morc1-driven DNA methylation only slightly overlapped with those repressed by Morc1/SetDB1-dependent heterochromatin formation, suggesting that Morc1 silences TEs in two different manners...

The structural organization of eukaryotic genomes is contingent upon the fractionation of DNA into transcriptionally active euchromatin and repressive heterochromatin. However, we have a limited understanding of how these distinct states are first established during animal embryogenesis. Histone 3 lysine 9 trimethylation (H3K9me3) is critical to heterochromatin formation and bulk establishment of this mark is thought to help drive large-scale remodeling of an initially naive chromatin state during animal embryogenesis...

The intermitochondrial cement (IMC) and chromatoid body (CB) are posited as central sites for piRNA activity in mice, with MIWI initially assembling in the IMC for piRNA processing before translocating to the CB for functional deployment. The regulatory mechanism underpinning MIWI translocation, however, has remained elusive. We unveil that piRNA loading is the trigger for MIWI translocation from the IMC to CB. Mechanistically, piRNA loading facilitates MIWI release from the IMC by weakening its ties with the mitochondria-anchored TDRKH...

To prevent the spread of transposable elements (TEs) hosts have developed sophisticated defense mechanisms. In mammals and invertebrates, a major defense mechanism operates through PIWI-interacting RNAs (piRNAs). To investigate the establishment of the host defence we introduced the P-element , one of the most widely studied eukaryotic transposons, into naive lines of Drosophila erecta We monitored the invasion in 3 replicates for more than 50 generations by sequencing the genomic DNA (using short and long reads), the small RNAs and the transcriptome at regular intervals...

Spermiogenesis is a critical, post-meiotic phase of male gametogenesis, in which the proper gene expression is essential for sperm maturation. However, the underFlying molecular mechanism that controls mRNA expression in the round spermatids remains elusive. Here, we identify that FBXO24, an orphan F-box protein, is highly expressed in the testis of humans and mice and interacts with the splicing factors (SRSF2, SRSF3, and SRSF9) to modulate the gene alternative splicing in the round spermatids. Genetic mutation of FBXO24 in mice causes many abnormal splicing events in round spermatids, thus affecting a large number of critical genes related to sperm formation that were dysregulated...

INTRODUCTION: Preeclampsia (PE) is a severe obstetrical syndrome characterized by new-onset hypertension and proteinuria and it is often associated with fetal intrauterine growth restriction (IUGR). PE leads to long-term health complications, so early diagnosis would be crucial for timely prevention. There are multiple etiologies and subtypes of PE, and this heterogeneity has hindered accurate identification in the presymptomatic phase. Recent investigations have pointed to the potential role of small regulatory RNAs in PE, and these species, which travel in extracellular vesicles (EVs) in the circulation, have raised the possibility of non-invasive diagnostics...

Epigenetic changes in sexually reproducing animals may be transmitted usually only through a few generations. Here we discovered a case where epigenetic change lasts 40 generations. This epigenetic phenomenon occurs in the short antennae (sa) mutation of the flour moth (Ephestia kuehniella). We demonstrate that is probably determined by a small RNA (e.g., piRNA, miRNA, tsRNA) and transmitted in this way to subsequent generations through the male and female gametes. The observed epigenetic change cancels sa mutation and creates a wild phenotype (a moth that appears to have no mutation)...

Genomic imprinting-the non-equivalence of maternal and paternal genomes-is a critical process that has evolved independently in many plant and mammalian species1,2 . According to kinship theory, imprinting is the inevitable consequence of conflictive selective forces acting on differentially expressed parental alleles3,4 . Yet, how these epigenetic differences evolve in the first place is poorly understood3,5,6 . Here we report the identification and molecular dissection of a parent-of-origin effect on gene expression that might help to clarify this fundamental question...

The mammalian mitochondrial proteome comprises over 1000 proteins, with the majority translated from nuclear-encoded messenger RNAs (mRNAs). Mounting evidence suggests many of these mRNAs are localized to the outer mitochondrial membrane (OMM) in a pre-or co-translational state. Upon reaching the mitochondrial surface, these mRNAs are locally translated to produce proteins that are co-translationally imported into mitochondria. Here, we summarize various mechanisms cells employ to localize RNAs, including transfer RNAs (tRNAs), to the OMM and recent technological advancements in the field to study these processes...

Aim: To explore the role of Piwi protein and piRNAs in DNMT3L-mediated epigenetic inheritance. Materials & methods: Transgenic Drosophila were used to examine the effect of ectopically expressed DNMT3L on the profile of piRNAs by sequencing of small RNAs. Results & conclusion: Our previous work showed accumulation and inheritance of epimutations across multiple generations in transgenic DNMT3L Drosophila . Here, we show interaction of DNMT3L with Piwi and a significant alteration in the piRNA profile across multiple generations in transgenic Drosophila ...

Myocardial ischemia/reperfusion (I/R) injury is a classic type of cardiovascular disease characterized by injury to cardiomyocytes leading to different types of cell death. The degree of irreversible myocardial damage is closely related to age, and ferroptosis is involved in cardiomyocyte damage. However, the mechanisms underlying ferroptosis regulation in aging myocardial I/R injury are still unclear. The present study aims to explore the underlying mechanism of piRNA regulation in ferroptosis. Using left anterior descending coronary artery ligation in an aging rat model and a D-galactose-induced rat cardiomyocyte line (H9C2) to construct an aging cardiomyocyte model, we investigate whether ferroptosis occurs after reperfusion injury in vitro and in vivo ...

Common detection methods in practice for diagnosing colorectal cancer (CRC) are painful and invasive leading to less participation of individuals for CRC diagnosis. Whereas, improved or enhanced imaging systems and other minimally invasive techniques with shorter detection times deliver greater detail and less discomfort in individuals. Thus, this review is a summary of the diagnostic tests, ranging from the simple potential use in developing a flexible CRC treatment to the patient's potential benefits in receiving less invasive procedures and the advanced treatments that might provide a better assessment for the diagnosis of CRC and reduce the mortality related to CRC...

Aging is a multifactorial process characterized by an age-related decline in organismal fitness. This deterioration is the major risk factor for chronic diseases such as cardiovascular pathologies, neurodegeneration or cancer, and it represents one of the main challenges of modern society. Therefore, understanding why and how we age would be a fundamental pillar to design strategies to promote a healthy aging. In the last decades, the study of the molecular bases of disease has been revolutionized by the discovery of different types of non-coding RNAs (ncRNAs) with regulatory potential...

INTRODUCTION: Anaphylaxis is the most severe manifestation of allergic disorders. Currently, an increasing number of cells, pathways and molecules involved in the etiopathogenesis of anaphylaxis are being discovered. However, there are no conclusive biomarkers to confirm its diagnosis. Small non-coding RNAs (sncRNAs) are 18-200 nucleotide molecules that can be divided into: microRNAs (miRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), small nuclear RNAs (snRNAs), transference RNA derived fragments (tRFs) and YRNA derived fragments (YRFs)...

BACKGROUND: Transitions from sexual to asexual reproduction are common in eukaryotes, but the underlying mechanisms remain poorly known. The pea aphid-Acyrthosiphon pisum-exhibits reproductive polymorphism, with cyclical parthenogenetic and obligate parthenogenetic lineages, offering an opportunity to decipher the genetic basis of sex loss. Previous work on this species identified a single 840 kb region controlling reproductive polymorphism and carrying 32 genes. With the aim of identifying the gene(s) responsible for sex loss and the resulting consequences on the genetic programs controlling sexual or asexual embryogenesis, we compared the transcriptomic response to photoperiod shortening-the main sex-inducing cue-of a sexual and an obligate asexual lineage of the pea aphid, focusing on heads (where the photoperiodic cue is detected) and embryos (the final target of the cue)...

In the male mouse germ line, PIWI-interacting RNAs (piRNAs), bound by the PIWI protein MIWI2 (PIWIL4), guide DNA methylation of young active transposons through SPOCD1. However, the underlying mechanisms of SPOCD1-mediated piRNA-directed transposon methylation and whether this pathway functions to protect the human germ line remain unknown. We identified loss-of-function variants in human SPOCD1 that cause defective transposon silencing and male infertility. Through the analysis of these pathogenic alleles, we discovered that the uncharacterized protein C19ORF84 interacts with SPOCD1...

Male reproductive functions are strictly regulated in order to maintain sperm production and fertility. All processes are controlled by precise regulation of gene expression, which creates specific gene expression programs for different developmental stages and cell types, and forms the functional basis for the reproductive system. Small non-coding RNAs (sncRNAs) are involved in gene regulation by targeting mRNAs for translational repression and degradation through complementary base pairing to recognize their targets...