Mus musculus
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ABSTRACT:
PROVIDER: PRJNA100385 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Nearly half of the mammalian genome is composed of repeated sequences. In Drosophila, PIWI proteins exert control over transposons. However, mammalian PIWI proteins, Miwi and Mili, partner with piRNAs that are depleted of repeat sequences, raising questions about a role for mammalian PIWIs in transposon control. A search for murine small RNAs that might program PIWI proteins for transposon suppression revealed developmentally regulated piRNA loci, some of which resemble transposon master control loci of Drosophila. We also find evidence of an adaptive amplification loop in which PIWI catalyzes formation of piRNA 5’ ends. Mili mutants de-repress L1 and IAP and lose DNA methylation of L1 elements, demonstrating an evolutionarily conserved role for PIWI proteins in transposon suppression. Keywords: small RNA profile, piRNA
2007-04-20 | GSE7414 | GEO
Project description:In mice, the PIWI-piRNA pathway is essential to re-establish transposon silencing during male germline reprogramming. The cytoplasmic PIWI protein MILI mediates piRNA-guided transposon RNA cleavage as well as piRNA amplification. MIWI2-bound piRNAs and its nuclear localization are proposed to be dependent upon MILI function. Here, we demonstrate the existence of a piRNA biogenesis pathway that in the absence of MILI that sustains partial MIWI2 function and reprogramming activity.
2017-04-25 | E-MTAB-5561 | biostudies-arrayexpress
Project description:Piwi proteins and piRNAs have conserved functions in transposonM- silencing. The murine Piwi proteins Mili and Miwi2 direct epigeneticM- LINE1 (L1) and intracisternal A particle (IAP) transposon silencingM- during genome reprogramming in the embryonic male germline. PiwiM- proteins are proposed to be piRNA-guided endonucleases that initiateM- secondary piRNA biogenesis . However the actual contribution of theirM- endonuclease activities to piRNA biogenesis and transposon silencingM- remain unknown. To investigate the role of Piwi-catalyzedM- endonucleolytic activity, we engineered point mutations in the mouseM- that substitute the second D to an A in the catalytic triad (DDH) ofM- Mili and Miwi2, generating the MiliDAH and Miwi2DAH alleles,M- M- respectively. Analysis of Mili-bound piRNAs from homozygous MiliDAHM- fetal gonadocytes revealed the failure of transposon piRNA amplification resulting in the stark reduction of piRNA bound withinM- Miwi2 ribonuclear particles (RNPs). We find that Mili-mediated piRNA amplification is selectively required for L1 but not IAP silencing.M- The defective piRNA pathway in MiliDAH mice results in spermatogenic failure and sterility. Surprisingly, homozygous Miwi2DAH mice areM- fertile, transposon silencing is established normally and no defectsM- in secondary piRNA biogenesis are observed. In addition, the hallmarks of piRNA amplification are observed in Miwi2-deficient gonadocytes. WeM- conclude that cycles of intra-Mili secondary piRNA biogenesis fuelM- piRNA amplification that is selectively required for L1 silencing.M-
2011-10-28 | E-MTAB-730 | biostudies-arrayexpress
Project description:We examined the construction of the piRNA system in the restricted developmental window in which methylation patterns are set during mammalian embryogenesis. We find robust expression of two Piwi family proteins, MIWI2 and MILI. Their associated piRNA profiles reveal differences from Drosophila wherein large piRNA clusters act as master regulators of silencing. Instead, in mammals, dispersed transposon copies initiate the pathway, producing primary piRNAs, which predominantly join MILI in the cytoplasm. MIWI2, whose nuclear localization and association with piRNAs depend upon MILI, is enriched for secondary piRNAs antisense to the elements that it controls. The Piwi pathway lies upstream of known mediators of DNA methylation, since piRNAs are still produced in Dnmt3L mutants, which fail to methylate transposons. This implicates piRNAs as specificity determinants of DNA methylation in germ cells. Examination of total small RNA and MILI associated piRNAs in embryonic and post-birth mouse testes, MIWI2-associated piRNAs in embryonic testes.
2008-10-01 | E-GEOD-12757 | biostudies-arrayexpress
Project description:We examined the construction of the piRNA system in the restricted developmental window in which methylation patterns are set during mammalian embryogenesis. We find robust expression of two Piwi family proteins, MIWI2 and MILI. Their associated piRNA profiles reveal differences from Drosophila wherein large piRNA clusters act as master regulators of silencing. Instead, in mammals, dispersed transposon copies initiate the pathway, producing primary piRNAs, which predominantly join MILI in the cytoplasm. MIWI2, whose nuclear localization and association with piRNAs depend upon MILI, is enriched for secondary piRNAs antisense to the elements that it controls. The Piwi pathway lies upstream of known mediators of DNA methylation, since piRNAs are still produced in Dnmt3L mutants, which fail to methylate transposons. This implicates piRNAs as specificity determinants of DNA methylation in germ cells.
2008-10-01 | GSE12757 | GEO
Project description:In mammals, piRNA populations are dynamic throughout male germ cell development. Embryonic piRNAs consist of both primary and secondary species and are mainly directed toward transposons. In meiotic cells, however, the piRNA population is transposon-poor and restricted to primary piRNAs derived from pachytene piRNA clusters. The mechanism controlling which piRNAs are present at each developmental stage is poorly understood. Here we show that RNF17 shapes adult meiotic piRNA content by suppressing the production of secondary piRNAs. In the absence of RNF17, ping-pong (secondary amplification) occurs inappropriately in meiotic cells – aberrantly targeting protein-coding genes and lncRNAs. Our data indicate that RNF17 comprises one component of a “refereeing” mechanism that prevents deleterious activity of the meiotic piRNA pathway by ensuring the selective loading of PIWI proteins with products of meiotic piRNA clusters. Examination of 5'RACE in heterozygous and homozygous RNF17 adult testes or MIWI/MILI immunoprecipitates
2014-12-17 | E-GEOD-53915 | biostudies-arrayexpress
Project description:In mammals, piRNA populations are dynamic throughout male germ cell development. Embryonic piRNAs consist of both primary and secondary species and are mainly directed toward transposons. In meiotic cells, however, the piRNA population is transposon-poor and restricted to primary piRNAs derived from pachytene piRNA clusters1-6. The mechanism controlling which piRNAs are present at each developmental stage is poorly understood. Here we show that RNF17 shapes adult meiotic piRNA content by suppressing the production of secondary piRNAs. In the absence of RNF17, ping-pong (secondary amplification) occurs inappropriately in meiotic cells – aberrantly targeting protein-coding genes and lncRNAs. Our data indicate that RNF17 comprises one component of a “refereeing” mechanism that prevents deleterious activity of the meiotic piRNA pathway by ensuring the selective loading of PIWI proteins with products of meiotic piRNA clusters. Examination of small RNAs isolated from MIWI and MILI IPs of heterozygous and homozygous RNF17 adult testes
2014-12-17 | E-GEOD-57241 | biostudies-arrayexpress
Project description:In developing male germ cells, prospermatogonia, two Piwi proteins, MILI and MIWI2, use piRNA guides to repress transposable element (TE) expression and ensure genome stability and proper gametogenesis. In addition to their roles in post-transcriptional TE repression, both proteins are required for DNA methylation of TE sequences. Here we analyzed the effect of Miwi2 deficiency on piRNA biogenesis and transposon repression. Miwi2-deficiency had only a minor impact on piRNA biogenesis; however, the piRNA profile of Miwi2-knockout mice indicated overexpression of several LINE1 TE families that led to activation of the ping-pong piRNA cycle. Furthermore, we found that MILI and MIWI2 have distinct functions in TE repression in the nucleus. MILI is responsible for DNA methylation of a larger subset of TE families than MIWI2 suggesting that the proteins have independent roles in establishing DNA methylation patterns.
2015-07-11 | GSE70731 | GEO
Project description:In developing male germ cells, prospermatogonia, two Piwi proteins, MILI and MIWI2, use piRNA guides to repress transposable element (TE) expression and ensure genome stability and proper gametogenesis. In addition to their roles in post-transcriptional TE repression, both proteins are required for DNA methylation of TE sequences. Here we analyzed the effect of Miwi2 deficiency on piRNA biogenesis and transposon repression. Miwi2-deficiency had only a minor impact on piRNA biogenesis; however, the piRNA profile of Miwi2-knockout mice indicated overexpression of several LINE1 TE families that led to activation of the ping-pong piRNA cycle. Furthermore, we found that MILI and MIWI2 have distinct functions in TE repression in the nucleus. MILI is responsible for DNA methylation of a larger subset of TE families than MIWI2 suggesting that the proteins have independent roles in establishing DNA methylation patterns. Small RNA profiles (19-30 nt range) of embryonic (E16.5) and post-natal (P10) testis of Miwi2 mutant mice and matched heterozygote controls. mRNA profiles of embryonic testis (E16.5) of heterozygote control mice and of postnatal testis (P10) of Miwi2 and Mili mutants and heterozygote controls. CpG methylation BS-seq profile of postnatal (P10) spermatocytes of Miwi2 mutant mice and matched heterozygote controls.
2015-07-11 | E-GEOD-70731 | biostudies-arrayexpress
Project description:PIWI proteins and their associated small RNAs called PIWI-interacting RNAs (piRNAs) restrict transposon activity in animal gonads to ensure fertility. Distinct biogenesis pathways load piRNAs into the PIWI proteins MILI and MIWI2 in the mouse male embryonic germline. While most of MILI piRNAs derive via a slicer-independent pathway, a MILI slicer endonuclease-initiated pathway loads nuclear MIWI2 with a series of phased piRNAs. Tudor domain-containing 12 (TDRD12) and its interaction partner Exonuclease domain-containing 1 (EXD1) are required for loading MIWI2, but only Tdrd12 is essential for fertility, leaving us with no explanation for the physiological role of Exd1. Using an artificial piRNA precursor, we demonstrate that MILI-triggered piRNA biogenesis is greatly reduced in the Exd1 mutant. The situation deteriorates in the sensitized Exd1 mutant (Exd1-/-; Tdrd12+/-), where diminished MIWI2 piRNA levels de-repress LINE1 retrotransposons, causing infertility. Thus, EXD1 enhances slicing-triggered MIWI2 piRNA biogenesis via a functional interaction with TDRD12.
2018-09-27 | GSE119447 | GEO