In animals, the piRNA pathway preserves the integrity of gametic genomes, guarding them against the activity of mobile genetic elements. This innate immune mechanism relies on distinct genomic loci, termed piRNA clusters, to provide a molecular definition of transposons, enabling their discrimination from genes. piRNA clusters give rise to long, single-stranded precursors which are processed into primary piRNAs through an unknown mechanism. These can engage in an adaptive amplification loop, the ping-pong cycle, to optimize the content of small RNA populations via the generation of secondary piRNAs. Many proteins have been ascribed functions in either primary biogenesis or the ping-pong cycle, though for the most part the molecular functions of proteins implicated in these pathways remain obscure. Here, we link shutdown, a gene previously shown to be required for fertility in Drosophila, to the piRNA pathway. Analysis of knockdown phenotypes in both the germline and somatic compartments of the ovary demonstrate important roles for shutdown in both primary biogenesis and the ping-pong cycle. shutdown is a member of the FKBP family of immunophilins. Shu contains domains implicated in peptidyl-prolyl cis-trans isomerase activity and in the binding of HSP90-family chaperones, though the relevance of these domains to piRNA biogenesis is unknown. Overall design: Analysis of mRNA expression in Drosophila OSS cells transfected with GFP dsRNA. One sample and replicate, used to establish the OSS baseline transcriptome in the presence of exogenous RNAi activity.
shutdown is a component of the Drosophila piRNA biogenesis machinery.
Specimen part, Subject
View SamplesCombining RNAi in cultured cells and analysis of mutant animals, we probed roles of known piRNA pathway components in the initiation and effector phases of transposon silencing. Overall design: total RNA and RNA associated with Piwi was isolated and size-fractionated by PAGE into 19-29nt. These were processed and sequenced on Illumina Genome Analyzer II.
Probing the initiation and effector phases of the somatic piRNA pathway in Drosophila.
Specimen part, Subject
View SamplesPiwi proteins and their associated small RNAs are essential for fertility in animals. This is due, in part, to their roles in guarding germ cell genomes against the activity of mobile genetic elements. piRNA populations direct Piwi proteins to silence transposon targets and as such form a molecular code that discriminates transposons from endogenous genes. Information ultimately carried by piRNAs is encoded within genomic loci, termed piRNA clusters. These give rise to long, single-stranded, primary transcripts that are processed into piRNAs. Despite the biological importance of this pathway, neither the characteristics that define a locus as a source of piRNAs nor the mechanisms that catalyze primary piRNA biogenesis are well understood. We searched an EMS-mutant collection annotated for fertility phenotypes for genes involved in the piRNA pathway. Twenty-seven homozygous-sterile strains showed transposon-silencing defects. One of these, which strongly impacted primary piRNA biogenesis, harbored a causal mutation in CG5508, a member of the Drosophila glycerol-3-phosphate O-acetyltransferase (GPAT) family. These enzymes catalyze the first acylation step on the path to the production of phosphatidic acid (PA). Though this pointed strongly to a function for phospholipid signaling in the piRNA pathway, a mutant form of CG5508, which lacks the GPAT active site, still functions in piRNA biogenesis. We have named this new biogenesis factor Minotaur. Overall design: Examination of transcriptom profile in heterozygous and homozygous CG5508 mutant ovaries
Minotaur is critical for primary piRNA biogenesis.
Specimen part, Cell line, Subject
View SamplesPiwi proteins and their associated small RNAs are essential for fertility in animals. This is due, in part, to their roles in guarding germ cell genomes against the activity of mobile genetic elements. piRNA populations direct Piwi proteins to silence transposon targets and as such form a molecular code that discriminates transposons from endogenous genes. Information ultimately carried by piRNAs is encoded within genomic loci, termed piRNA clusters. These give rise to long, single-stranded, primary transcripts that are processed into piRNAs. Despite the biological importance of this pathway, neither the characteristics that define a locus as a source of piRNAs nor the mechanisms that catalyze primary piRNA biogenesis are well understood. We searched an EMS-mutant collection annotated for fertility phenotypes for genes involved in the piRNA pathway. Twenty-seven homozygous-sterile strains showed transposon-silencing defects. One of these, which strongly impacted primary piRNA biogenesis, harbored a causal mutation in CG5508, a member of the Drosophila glycerol-3-phosphate O-acetyltransferase (GPAT) family. These enzymes catalyze the first acylation step on the path to the production of phosphatidic acid (PA). Though this pointed strongly to a function for phospholipid signaling in the piRNA pathway, a mutant form of CG5508, which lacks the GPAT active site, still functions in piRNA biogenesis. We have named this new biogenesis factor Minotaur. Overall design: Examination of small RNA profile in heterozygous and homozygous CG5508 mutant ovaries
Minotaur is critical for primary piRNA biogenesis.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
General detoxification and stress responses are mediated by oxidized lipids through TGA transcription factors in Arabidopsis.
No sample metadata fields
View Samples12-oxo-phytodienoic acid (OPDA) and phytoprostane A1 (PPA1) are cyclopentenone oxylipins that are formed via the enzymatic
General detoxification and stress responses are mediated by oxidized lipids through TGA transcription factors in Arabidopsis.
No sample metadata fields
View Samples12-Oxo-phytodienoic acid (OPDA) and several phytoprostanes are structurally related cyclopentenone oxylipins that can be formed via the enzymatic jasmonate pathway and a non-enzymatic, free radical-catalyzed pathway, respectively. To elucidate the biological activities of phytoprostanes in comparison to OPDA as well as the metabolism we performed genome-wide expression analysis.
General detoxification and stress responses are mediated by oxidized lipids through TGA transcription factors in Arabidopsis.
No sample metadata fields
View SamplesNonsyndromic clefts of the palate and/or lip are common birth defects arising in about 1/700 live births worldwide. They are caused by multiple genetic and environmental factors, can only be corrected surgically and require complex post-operative care that imposes significant burdens on individuals and society. Our understanding of the molecular networks that control palatogenesis has advanced through studies on mouse genetic models of cleft palate. In particular, the transcription factor Pax9 regulates palatogenesis through the Bmp, Fgf and Shh pathways in mice. But there is still much to learn about Pax9's relationship with other signaling pathways in this process. Expression analyses and unbiased gene expression profiling studies offer a molecular explanation for the resolution of palatal defects by showing that Wnt and Eda/Edar-related genes are expressed in normal palatal tissues and that the Wnt and Eda/Edar signaling pathway is downstream of Pax9 in palatogenesis. Overall design: E13.5 mouse embryos palate were micro-dissceted, control and mutant samples were seperated and individually lyzed for the RNA extraction.
Small-molecule Wnt agonists correct cleft palates in <i>Pax9</i> mutant mice <i>in utero</i>.
Specimen part, Cell line, Treatment, Subject
View SamplesNonsyndromic clefts of the palate and/or lip are common birth defects arising in about 1/700 live births worldwide. They are caused by multiple genetic and environmental factors, can only be corrected surgically and require complex post-operative care that imposes significant burdens on individuals and society. Our understanding of the molecular networks that control palatogenesis has advanced through studies on mouse genetic models of cleft palate. In particular, the transcription factor Pax9 regulates palatogenesis through the Bmp, Fgf and Shh pathways in mice. But there is still much to learn about Pax9''s relationship with other signaling pathways in this process. Here we show alterations of Wnt expression and decreased Wnt activity in Pax9-/- palatal shelves are a likely result of Pax9''s ability to directly bind and repress the promoters of Dkk1 and Dkk2, proteins that antagonize Wnt signaling. We exploited this relationship by delivering small-molecule Dkk inhibitors into the tail-veins of pregnant Pax9+/- females from E10.5 to E14.5. Such therapies restored Wnt signaling, promoted cell proliferation, bone formation and fusion of palatal shelves in Pax9-/- embryos. These data uncover a connection between the roles of Pax9 and Wnt genes in palatogenesis and offer a new approach for treating human cleft palates. Overall design: E14 embryos of Pax9-/- and control littermates with or without WAY-262611 treatment, mouse embryos palate were micro-dissected, control and mutant samples were separated and individually lysed for the RNA extraction.
Small-molecule Wnt agonists correct cleft palates in <i>Pax9</i> mutant mice <i>in utero</i>.
Specimen part, Cell line, Treatment, Subject
View SamplesLoss of Syk in normal breast cells in vivo and in vitro: gene expression and phenotypic switch to stem-cell like with induction of invadopodia
Tumor suppressor function of Syk in human MCF10A in vitro and normal mouse mammary epithelium in vivo.
Cell line
View Samples