A retrotransposon-driven Dicer variant enhances endogenous RNAi in mouse oocytes
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE41207 | GEO | 2013/11/07
SECONDARY ACCESSION(S): PRJNA176163
REPOSITORIES: GEO
Similar Datasets
Project description:Mammals have one Dicer gene required for biogenesis of small RNAs in microRNA (miRNA) and RNA interference (RNAi) pathways. Yet, endogenous RNAi is highly active in oocytes but not in somatic cells. Here, we provide a mechanistical explanation for high RNAi activity in mouse oocytes. The main Dicer isoform in oocytes is transcribed from an intronic MT-C retrotransposon, which functions as a promoter of an oocyte-specific Dicer isoform (denoted DicerO). DicerO lacks an N-terminal helicase domain and has a higher cleavage activity than the full-length Dicer from somatic cells. DicerO can rescue the miRNA pathway and, in addition, it efficiently produces small RNAs from long dsRNA substrates. Thus, control of endogenous RNAi activity in mice occurs via alternative Dicer isoform and the phylogenetic origin of DicerO demonstrates evolutionary plasticity of RNA silencing pathways. NIH3T3 cells or mouse embryonic stem cells expressing oocyte-specific or somatic form of Dicer were transiently transfected with a plasmid expressing long double-stranded RNA (within the 3'-UTR of EGFP reporter) or left without transfection for controls.
2013-11-07 | E-GEOD-41207 | biostudies-arrayexpress
Project description:Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made from long double-stranded RNA (dsRNA) by RNase III Dicer. RNAi has different functions in eukaryotes including gene regulation, antiviral innate immunity or defense against transposable elements. In mammals, RNAi is constrained by inefficient cleavage of dsRNA by Dicer because it is adapted to produce microRNAs, a different class of small RNAs. An exception of the rule is highly active RNAi in mouse oocytes, which employs a truncated Dicer isoform (ΔHEL1). A homozygous mutation of murine Dicer to express only the truncated variant causes major dysregulation of microRNAs and perinatal lethality. Here, we report the phenotype and RNAi activity in DicerΔHEL1/wt mice, which are viable, fertile, slightly smaller, and show minimal miRNome changes. At the same time, endogenous siRNA levels are increased by an order of magnitude in DicerΔHEL1/wt mice. We show that siRNA abundance is limited by available dsRNA but not by the Protein Kinase R, an innate immunity factor shown to limit siRNA biogenesis in cultured cells. Using dsRNA expressed from a transgene, functional RNAi in vivo was successfully induced in the heart. DicerΔHEL1/wt mice thus represent a new model for researching mammalian canonical RNAi in vivo and offer an unprecedented platform for addressing earlier claims about its biological roles.
2024-04-08 | GSE259395 | GEO
Project description:Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made from long double-stranded RNA (dsRNA) by RNase III Dicer. RNAi has different functions in eukaryotes including gene regulation, antiviral innate immunity or defense against transposable elements. In mammals, RNAi is constrained by inefficient cleavage of dsRNA by Dicer because it is adapted to produce microRNAs, a different class of small RNAs. An exception of the rule is highly active RNAi in mouse oocytes, which employs a truncated Dicer isoform (ΔHEL1). A homozygous mutation of murine Dicer to express only the truncated variant causes major dysregulation of microRNAs and perinatal lethality. Here, we report the phenotype and RNAi activity in DicerΔHEL1/wt mice, which are viable, fertile, slightly smaller, and show minimal miRNome changes. At the same time, endogenous siRNA levels are increased by an order of magnitude in DicerΔHEL1/wt mice. We show that siRNA abundance is limited by available dsRNA but not by the Protein Kinase R, an innate immunity factor shown to limit siRNA biogenesis in cultured cells. Using dsRNA expressed from a transgene, functional RNAi in vivo was successfully induced in the heart. DicerΔHEL1/wt mice thus represent a new model for researching mammalian canonical RNAi in vivo and offer an unprecedented platform for addressing earlier claims about its biological roles.
2024-04-08 | GSE242870 | GEO
Project description:Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made from long double-stranded RNA (dsRNA) by RNase III Dicer. RNAi has different functions in eukaryotes including gene regulation, antiviral innate immunity or defense against transposable elements. In mammals, RNAi is constrained by inefficient cleavage of dsRNA by Dicer because it is adapted to produce microRNAs, a different class of small RNAs. An exception of the rule is highly active RNAi in mouse oocytes, which employs a truncated Dicer isoform (ΔHEL1). A homozygous mutation of murine Dicer to express only the truncated variant causes major dysregulation of microRNAs and perinatal lethality. Here, we report the phenotype and RNAi activity in DicerΔHEL1/wt mice, which are viable, fertile, slightly smaller, and show minimal miRNome changes. At the same time, endogenous siRNA levels are increased by an order of magnitude in DicerΔHEL1/wt mice. We show that siRNA abundance is limited by available dsRNA but not by the Protein Kinase R, an innate immunity factor shown to limit siRNA biogenesis in cultured cells. Using dsRNA expressed from a transgene, functional RNAi in vivo was successfully induced in the heart. DicerΔHEL1/wt mice thus represent a new model for researching mammalian canonical RNAi in vivo and offer an unprecedented platform for addressing earlier claims about its biological roles.
2024-04-08 | GSE242869 | GEO
Project description:Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made from long double-stranded RNA (dsRNA) by RNase III Dicer. RNAi has different functions in eukaryotes including gene regulation, antiviral innate immunity or defense against transposable elements. In mammals, RNAi is constrained by inefficient cleavage of dsRNA by Dicer because it is adapted to produce microRNAs, a different class of small RNAs. An exception of the rule is highly active RNAi in mouse oocytes, which employs a truncated Dicer isoform (ΔHEL1). A homozygous mutation of murine Dicer to express only the truncated variant causes major dysregulation of microRNAs and perinatal lethality. Here, we report the phenotype and RNAi activity in DicerΔHEL1/wt mice, which are viable, fertile, slightly smaller, and show minimal miRNome changes. At the same time, endogenous siRNA levels are increased by an order of magnitude in DicerΔHEL1/wt mice. We show that siRNA abundance is limited by available dsRNA but not by the Protein Kinase R, an innate immunity factor shown to limit siRNA biogenesis in cultured cells. Using dsRNA expressed from a transgene, functional RNAi in vivo was successfully induced in the heart. DicerΔHEL1/wt mice thus represent a new model for researching mammalian canonical RNAi in vivo and offer an unprecedented platform for addressing earlier claims about its biological roles.
2024-04-08 | GSE242868 | GEO
Project description:Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made from long double-stranded RNA (dsRNA) by RNase III Dicer. RNAi has different functions in eukaryotes including gene regulation, antiviral innate immunity or defense against transposable elements. In mammals, RNAi is constrained by inefficient cleavage of dsRNA by Dicer because it is adapted to produce microRNAs, a different class of small RNAs. An exception of the rule is highly active RNAi in mouse oocytes, which employs a truncated Dicer isoform (ΔHEL1). A homozygous mutation of murine Dicer to express only the truncated variant causes major dysregulation of microRNAs and perinatal lethality. Here, we report the phenotype and RNAi activity in DicerΔHEL1/wt mice, which are viable, fertile, slightly smaller, and show minimal miRNome changes. At the same time, endogenous siRNA levels are increased by an order of magnitude in DicerΔHEL1/wt mice. We show that siRNA abundance is limited by available dsRNA but not by the Protein Kinase R, an innate immunity factor shown to limit siRNA biogenesis in cultured cells. Using dsRNA expressed from a transgene, functional RNAi in vivo was successfully induced in the heart. DicerΔHEL1/wt mice thus represent a new model for researching mammalian canonical RNAi in vivo and offer an unprecedented platform for addressing earlier claims about its biological roles.
2024-04-08 | GSE242867 | GEO
Project description:Canonical RNA interference (RNAi) is sequence-specific mRNA degradation guided by small interfering RNAs (siRNAs) made from long double-stranded RNA (dsRNA) by RNase III Dicer. RNAi has different functions in eukaryotes including gene regulation, antiviral innate immunity or defense against transposable elements. In mammals, RNAi is constrained by inefficient cleavage of dsRNA by Dicer because it is adapted to produce microRNAs, a different class of small RNAs. An exception of the rule is highly active RNAi in mouse oocytes, which employs a truncated Dicer isoform (ΔHEL1). A homozygous mutation of murine Dicer to express only the truncated variant causes major dysregulation of microRNAs and perinatal lethality. Here, we report the phenotype and RNAi activity in DicerΔHEL1/wt mice, which are viable, fertile, slightly smaller, and show minimal miRNome changes. At the same time, endogenous siRNA levels are increased by an order of magnitude in DicerΔHEL1/wt mice. We show that siRNA abundance is limited by available dsRNA but not by the Protein Kinase R, an innate immunity factor shown to limit siRNA biogenesis in cultured cells. Using dsRNA expressed from a transgene, functional RNAi in vivo was successfully induced in the heart. DicerΔHEL1/wt mice thus represent a new model for researching mammalian canonical RNAi in vivo and offer an unprecedented platform for addressing earlier claims about its biological roles.
2024-04-08 | GSE242866 | GEO
Project description:Ribonuclease Dicer generates small RNAs for RNA interference (RNAi) and microRNA (miRNA) pathways. Mammalian Dicer produces miRNAs but its tripartite N-terminal helicase domain inhibits processing of double-stranded RNA for RNAi. Mouse oocytes express Dicer, which enhances RNAi because it lacks the helicase’s proximal subdomain HEL1. Here we show that genetic removal of HEL1 in mice causes embryonic growth retardation, defects in the cardiopulmonary system, and perinatal lethality. HEL1 suppresses biogenesis of mirtrons, a non-canonical low-abundant class of miRNAs, and is required for high-fidelity cleavage and strand selection during biogenesis of canonical miRNAs. Essential is the HEL1 structure, not its helicase activity, because mutations of critical aminoacids do not affect viability or fertility and have minimal impact on miRNA biogenesis. Altogether, HEL1 is a critical structural component of Dicer in its role of a highly conserved structural “mold” that ensures high-fidelity processing and adaptive evolution of mammalian miRNA precursors.
2024-04-10 | GSE243016 | GEO
Project description:The RNase III enzyme DICER generates both microRNAs (miRNAs) and endogenous short interfering RNAs (endo-siRNAs). Dicer deletion in mouse oocytes leads to female infertility due to defects during meiosis I. Because miRNA function is suppressed in mouse oocytes, it has been proposed that endo-siRNAs may have a role during female meiosis. By utilizing a catalytically inactive knock-in allele of AGO2 specifically in oocytes, we disrupt the function of siRNAs and analyze the transcriptome of these oocytes in comparison with Ago2 null, and Dicer null oocytes.
2015-01-20 | GSE57514 | GEO
Project description:Dicer, which is required for the processing of both microRNAs (miRNAs) and small interfering RNAs (siRNAs), is essential for oocyte maturation. Oocytes express both miRNAs and endogenous siRNAs (endo-siRNAs). To determine whether the abnormalities in Dicer knockout oocytes during meiotic maturation are secondary to the loss of endo-siRNAs and/or miRNAs, we deleted Dgcr8, which encodes a RNA binding protein specifically required for miRNA processing. In striking contrast to Dicer, Dgcr8 deficient oocytes matured normally and, when fertilized with wild-type sperm, produced healthy appearing offspring, even though miRNA levels were reduced to similar levels as Dicer deficient oocytes. Furthermore, the deletion of both maternal and zygotic Dgcr8 alleles did not impair preimplantation development including the determination of the inner cell mass (ICM) and trophectoderm. Most surprisingly, the mRNA profiles of wild-type and Dgcr8 null oocytes were essentially identical while Dicer null oocytes showed hundreds of misregulated transcripts. These findings show that miRNA function is globally suppressed during oocyte maturation and preimplantation development and that endo-siRNAs, rather than miRNAs, underlie the Dicer knockout phenotype in oocytes. We used microarrays to understand at the global level how loss of miRNAs and/or siRNAs is impacting mRNA levels in mouse oocytes.
2010-02-05 | GSE19894 | GEO