MIWI catalysis is required for piRNA amplification-independent LINE1 transposon silencing [microarray]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE32180 | GEO | 2011/11/30
SECONDARY ACCESSION(S): PRJNA154867
REPOSITORIES: GEO
Similar Datasets
Project description:Here we show that MIWI is a small RNA-guided ribonuclease (Slicer) that requires extensive complementarity for target cleavage in vitro. Disruption of its catalytic activity in mice by a single point mutation results in male infertility and displays increased accumulation of LINE1 transposon transcripts.
2011-11-30 | GSE32184 | GEO
Project description:Here we show that MIWI is a small RNA-guided ribonuclease (Slicer) that requires extensive complementarity for target cleavage in vitro. Disruption of its catalytic activity in mice by a single point mutation results in male infertility and displays increased accumulation of LINE1 transposon transcripts. Round spermatids were purified from adult mouse testes of indicated Miwi genotypes. Total RNA was extracted and subjected to microarray analysis for gene expression profiling.
2011-11-30 | E-GEOD-32180 | biostudies-arrayexpress
Project description:Here we show that MIWI is a small RNA-guided ribonuclease (Slicer) that requires extensive complementarity for target cleavage in vitro. Disruption of its catalytic activity in mice by a single point mutation results in male infertility and displays increased accumulation of LINE1 transposon transcripts. MIWI-associated piRNAs from different genotypes were sequenced. Total RNA from purified round spermatids were subjected to Ribozero purification and strand-specific RNAseq lib prepared. Global 5' RACE library was prepare from indicated genotypes.
2011-11-30 | E-GEOD-32184 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE32180: MIWI catalysis is required for piRNA amplification-independent LINE1 transposon silencing [microarray] GSE32184: MIWI catalysis is required for piRNA amplification-independent LINE1 transposon silencing [deep sequencing] Refer to individual Series
2011-11-30 | E-GEOD-32183 | biostudies-arrayexpress
Project description:MIWI catalysis is required for piRNA amplification-independent LINE1 transposon silencing
| PRJNA147395 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below.
2011-11-30 | GSE32183 | GEO
Project description:PIWI proteins and their associated piRNAs act to silence transposons and promote gametogenesis. Murine PIWI proteins MIWI, MILI, and MIWI2 have multiple arginine and glycine (RG)-rich motifs at their N-terminal domains. Despite being known as docking sites for the TDRD family proteins, the in vivo regulatory roles for these RG motifs in directing PIWI in piRNA biogenesis and spermatogenesis remain elusive. To investigate the functional significance of RG motifs in mammalian PIWI proteins in vivo, we genetically engineered an arginine to lysine (RK) point mutation of a conserved N-terminal RG motif in MIWI in mice. We show that this tiny MIWI RG motif is indispensable for piRNA biogenesis and male fertility. The RK mutation in the RG motif disrupts MIWI-TDRKH interaction and impairs enrichment of MIWI to the intermitochondrial cement (IMC) for efficient piRNA production. Despite significant overall piRNA level reduction, piRNA trimming and maturation are not affected by the RK mutation. Consequently, MiwiRK mutant mice show chromatoid body malformation, spermatogenic arrest, and male sterility. Surprisingly, LINE1 transposons are effectively silenced in MiwiRK mutant mice, indicating a LINE1-independent cause of germ cell arrest distinctive from Miwi knockout mice. These findings reveal a crucial function of the RG motif in directing PIWI proteins to engage in efficient piRNA production critical for germ cell progression and highlight the functional importance of the PIWI N-terminal motifs in regulating male fertility.
| S-EPMC10681313 | biostudies-literature
Project description:The piRNA machinery is known for its role in mediating epigenetic silencing of transposons. Recent studies suggest that this function also involves piRNA-guided cleavage of transposon-derived transcripts. As many piRNAs also appear to have the capacity to target diverse mRNAs, this raises the intriguing possibility that piRNAs may act extensively as siRNAs to degrade specific mRNAs. To directly test this hypothesis, we compared mouse PIWI (MIWI)-associated piRNAs with experimentally identified cleaved mRNA fragments from mouse testes, and observed cleavage sites that predominantly occur at position 10 from the 5' end of putative targeting piRNAs. We also noted strong biases for U and A residues at nucleotide positions 1 and 10, respectively, in both piRNAs and mRNA fragments, features that resemble the pattern of piRNA amplification by the 'ping-pong' cycle. Through mapping of MIWI-RNA interactions by CLIP-seq and gene expression profiling, we found that many potential piRNA-targeted mRNAs directly interact with MIWI and show elevated expression levels in the testes of Miwi catalytic mutant mice. Reporter-based assays further revealed the importance of base pairing between piRNAs and mRNA targets and the requirement for both the slicer activity and piRNA-loading ability of MIWI in piRNA-mediated target repression. Importantly, we demonstrated that proper turnover of certain key piRNA targets is essential for sperm formation. Together, these findings reveal the siRNA-like function of the piRNA machinery in mouse testes and its central requirement for male germ cell development and maturation.
2015-04-09 | GSE67683 | GEO
Project description:The piRNA machinery is known for its role in mediating epigenetic silencing of transposons. Recent studies suggest that this function also involves piRNA-guided cleavage of transposon-derived transcripts. As many piRNAs also appear to have the capacity to target diverse mRNAs, this raises the intriguing possibility that piRNAs may act extensively as siRNAs to degrade specific mRNAs. To directly test this hypothesis, we compared mouse PIWI (MIWI)-associated piRNAs with experimentally identified cleaved mRNA fragments from mouse testes, and observed cleavage sites that predominantly occur at position 10 from the 5' end of putative targeting piRNAs. We also noted strong biases for U and A residues at nucleotide positions 1 and 10, respectively, in both piRNAs and mRNA fragments, features that resemble the pattern of piRNA amplification by the 'ping-pong' cycle. Through mapping of MIWI-RNA interactions by CLIP-seq and gene expression profiling, we found that many potential piRNA-targeted mRNAs directly interact with MIWI and show elevated expression levels in the testes of Miwi catalytic mutant mice. Reporter-based assays further revealed the importance of base pairing between piRNAs and mRNA targets and the requirement for both the slicer activity and piRNA-loading ability of MIWI in piRNA-mediated target repression. Importantly, we demonstrated that proper turnover of certain key piRNA targets is essential for sperm formation. Together, these findings reveal the siRNA-like function of the piRNA machinery in mouse testes and its central requirement for male germ cell development and maturation. CLIP-Seq (Crosslinking Immunoprecipitation coupled with high-throughput sequencing) experiments targeting Miwi in isolated round spermatids from mouse testis.
2015-04-09 | E-GEOD-67683 | biostudies-arrayexpress
Project description:Piwi proteins and their associated piRNAs are essential in the germline where they repress transposition, regulate translation, and guide epigenetic programming. Little is known, however, about the molecular mechanisms through which Piwi proteins and piRNAs mediate these processes. Here, we show that an evolutionarily conserved Tudor and KH-domain containing protein, Tdrkh (a.k.a. Tdrd2), partners with Miwi and Miwi2 in mice via symmetrically dimethylated arginine residues in Miwi and Miwi2. Tdrkh is localized to pi-bodies and piP-bodies and is required for nuclear localization of Miwi2. Genetic deletion of Tdrkh arrests meiosis at the zygotene stage, demethylates Line1 DNA, and up-regulates Line1 transposition, but does not promote apoptosis. Furthermore, Tdrkh mutants have severely reduced levels of mature piRNAs. Specifically, in Tdrkh mutants, piRNAs accumulate as a distinct population of 5’U-containing 31-37nt RNA that largely complements the missing mature piRNAs. These results demonstrate that the primary piRNA biogenesis pathway involves 3à5’ processing of the 31-37nt intermediates and that Tdrkh is required for this final step of piRNA biogenesis. However, Tdrkh is not required for the secondary piRNA biogenesis pathway (i.e., the ping pong cycle). These results shed light on mechanisms underlying primary piRNA biogenesis, an area in which information is conspicuously absent. Tdrkh-floxed mice were generated by the University of Connecticut Gene Targeting and Transgenic Facility. The targeting vector utilized C57Bl6 Tdrkh genome sequences from BAC clone RP23-263K17 (Chori BACPAC) and floxed exons 2-4 (the start codon is in exon 2) and was electroporated into D2 ES cells, a male hybrid C57Bl6/129SEV line. Clones that survived positive selection with G418 and negative selection with gancyclovir were expanded and screened by PCR with primers recognizing endogenous and exogenous (vector-derived) sequences. Positive clones were fused to CD-1 embryos, and germline transmission from resulting pups was confirmed by test crosses to CD-1 mice (which also confirmed that all gametes were derived from the targeted clones). Positive animals were bred to FLP mice to delete the neomycin-targeting cassette, resulting in Tdrkh cKO mice on a C57Bl6/129 background. cKO mice were bred with EIIa-Cre transgenic mice to excise the floxed exons 2-4 and generate Tdrkh +/- animals. Heterozygous animas were intercrossed to remove the EIIA transgene. Two independent knockout lines were generated from independent cKO founder lines and showed identical phenotypes in all experiments performed.
2013-09-01 | E-GEOD-47151 | biostudies-arrayexpress