Paramecium tetraurelia autogamy series 2 (ND7-silenced and control cells)
Ontology highlight
ABSTRACT:
ORGANISM(S): Paramecium tetraurelia
PROVIDER: GSE18002 | GEO | 2010/07/07
SECONDARY ACCESSION(S): PRJNA153895
REPOSITORIES: GEO
Similar Datasets
Project description:At each sexual cycle, during development of the somatic macronucleus (MAC) from the germline micronucleus (MIC), the genome of the ciliate Paramecium tetraurelia is massively rearranged through the reproducible elimination of germline-specific sequences. It has been reported previously that targeting of these sequences is mediated by non-protein-coding RNAs including different classes of small RNAs and longer non-coding transcripts. Using RNA interference, we showed that TFIIS4 gene encoding development-specific TFIIS elongation factor is essential for the formation of a functional somatic genome. We demonstrated that genome rearrangements taking place during MAC development were inhibited in TFIIS4-depleted cells, which led to high lethality in the sexual progeny. The role of TFIIS4 elongation factor in coding transcription at the genome-wide level was studied by performing a microarray hybridization experiment using RNA samples extracted during vegetative growth and at five time points during the progression of the sexual cycle (autogamy).
2015-06-12 | GSE64682 | GEO
Project description:The unicellular eukaryote Paramecium tetraurelia contains functionally distinct nuclei: germline micronuclei (MICs) and a somatic macronucleus (MAC). During sexual reproduction, the MIC genome is reorganized into a new MAC genome and the old MAC is lost. Almost 45,000 unique Internal Eliminated Sequences (IESs) located throughout the genome require precise excision to guarantee a functional new MAC genome. Here, we characterize a pair of paralogous PHD finger proteins involved in DNA elimination. DevPF1, the early-expressed paralog, is present in only some of the gametic and post-zygotic nuclei during meiosis. Both DevPF1 and DevPF2 localize in the new developing MACs, where IESs excision occurs. In DevPF2 knockdown (KD), long IESs are preferentially retained and late-expressed small RNAs decrease; no length preference for retained IESs was observed in DevPF1-KD and development-specific small RNAs were abolished. The expression of at least two genes from the new MAC seems to be influenced by DevPF1- and DevPF2-KD. Thus, both PHD fingers are crucial for new MAC genome development, with distinct functionalities, potentially via regulation of non-coding and coding transcription in the MICs and new MACs.
2024-08-30 | PXD046704 | Pride
Project description:At each sexual cycle, during development of the somatic macronucleus (MAC) from the germline micronucleus (MIC), the genome of the ciliate Paramecium tetraurelia is massively rearranged through the reproducible elimination of germline-specific sequences. It has been reported previously that targeting of these sequences is mediated by non-protein-coding RNAs including different classes of small RNAs and longer non-coding transcripts. Using RNA interference, we showed that TFIIS4 gene encoding development-specific TFIIS elongation factor is essential for the formation of a functional somatic genome. We demonstrated that genome rearrangements taking place during MAC development were inhibited in TFIIS4-depleted cells, which led to high lethality in the sexual progeny. The role of TFIIS4 elongation factor in coding transcription at the genome-wide level was studied by performing a microarray hybridization experiment using RNA samples extracted during vegetative growth and at five time points during the progression of the sexual cycle (autogamy). Total RNA samples were extracted during vegetative growth and at five different time points of autogamy from mass cultures fed with bacteria producing dsRNA to induce TFIIS4 or ICL7a silencing. TFIIS4 gene encodes TFIIS elongation factor and is strongly induced during autogamy, a self-fertilization process. RNAi against TFIIS4 leads to strong lethality in post-autogamous progeny. ICL7a is a non-essential gene; the loss of function of this gene by with dsRNA feeding results in mutant phenotypes: absence of intraciliary lattice and defect in calcium-induced cell contractility.
2015-06-12 | E-GEOD-64682 | biostudies-arrayexpress
Project description:In the ciliate Paramecium tetraurelia, autogamy is a self-fertilization process, during which the zygotic nucleus results from the fusion of two identical gametic nuclei. This phenomenon occurs in response to starvation. It starts with meiosis of the germline nuclei (micronuclei or MIC) and fragmentation of the parental somatic nucleus (macronucleus or MAC). This is followed by mitotic division of one haploid nucleus issued from meiosis to yield two identical gametic nuclei, then karyogamy takes place, followed by mitosis of zygotic nucleus and differentiation of new MICs and MACs from the resulting copies of the zygotic nucleus. Within the developing new MACs, developmentally programmed DNA amplification and extensive genome rearrangements (precise excision of short non coding Internal Eliminated Sequences and chromosome fragmentation associated with the imprecise elimination of repetitive DNA) give rise to the highly polyploid somatic genome. To gain further insight into the complex regulation of these successive steps, we used whole genome microarrays to study the different gene networks that become activated throughout autogamy. Total RNA was extracted before the begining of autogamy (reference sample) and at 5 different time points during the process of autogamy. There are two biological replicates for each point.
2010-07-07 | E-GEOD-17996 | biostudies-arrayexpress
Project description:In the ciliate Paramecium tetraurelia, autogamy is a self-fertilization process, during which the zygotic nucleus results from the fusion of two identical gametic nuclei. This phenomenon occurs in response to starvation. It starts with meiosis of the germline nuclei (micronuclei or MIC) and fragmentation of the parental somatic nucleus (macronucleus or MAC). This is followed by mitotic division of one haploid nucleus issued from meiosis to yield two identical gametic nuclei, then karyogamy takes place, followed by mitosis of zygotic nucleus and differentiation of new MICs and MACs from the resulting copies of the zygotic nucleus. Within the developing new MACs, developmentally programmed DNA amplification and extensive genome rearrangements (precise excision of short non coding Internal Eliminated Sequences and chromosome fragmentation associated with the imprecise elimination of repetitive DNA) give rise to the highly polyploid somatic genome. To gain further insight into the complex regulation of these successive steps, we used whole genome microarrays to study the different gene networks that become activated throughout autogamy. Total RNA was extracted before the begining of autogamy (reference sample) and at 3 different time points during the process of autogamy.
2010-07-07 | E-GEOD-17997 | biostudies-arrayexpress
Project description:In the ciliate Paramecium tetraurelia, autogamy is a self-fertilization process, during which the zygotic nucleus results from the fusion of two identical gametic nuclei. This phenomenon occurs in response to starvation. It starts with meiosis of the germline nuclei (micronuclei or MIC) and fragmentation of the parental somatic nucleus (macronucleus or MAC). This is followed by mitotic division of one haploid nucleus issued from meiosis to yield two identical gametic nuclei, then karyogamy takes place, followed by mitosis of zygotic nucleus and differentiation of new MICs and MACs from the resulting copies of the zygotic nucleus. Within the developing new MACs, developmentally programmed DNA amplification and extensive genome rearrangements (precise excision of short non coding Internal Eliminated Sequences and chromosome fragmentation associated with the imprecise elimination of repetitive DNA) give rise to the highly polyploid somatic genome. To gain further insight into the complex regulation of these successive steps, we used whole genome microarrays to study the different gene networks that become activated throughout autogamy. Total RNA was extracted before the begining of autogamy (c3_vegetative cells : reference sample) and at 5 different time points during the process of autogamy.
2010-07-07 | E-GEOD-17998 | biostudies-arrayexpress
Project description:The Spt4-Spt5 complex is conserved and essential RNA polymerase elongation factor. To investigate the role of the Spt4-Spt5 complex in non-coding transcription during development, we used the unicellular model Paramecium tetraurelia. In this organism harboring both germline (micronucleus - MIC) and somatic nuclei (macronucleus - MAC), massive transcription of the entire germline genome takes place during meiosis. This phenomenon starts a series of events mediated by different classes of non-coding RNAs that control developmentally programmed DNA elimination. We focused our study on Spt4, a small zinc-finger protein encoded in P. tetraurelia by two genes expressed constitutively and two genes expressed during meiosis. SPT4 genes are not essential in vegetative growth, but they are indispensable for sexual reproduction, even though genes from both expression families show functional redundancy. As we were mostly interested in transcription of the germline genome in the MIC during meiosis, we decided to probe the composition of the Spt5-Spt4 complex characteristic to this nucleus. Experiments in which Spt4mB-3xFLAG was used as bait demonstrated its interaction with either Spt5m or Spt5v, which is consistent with the Spt4mB-GFP localization pattern. Interestingly, mass spectrometry revealed that Spt5m-3xFLAG (which is present only in the MIC at the analyzed stage) interacts either with the meiotic Spt4mB or with Spt4vA. Silencing of the SPT4 genes resulted in the absence of double-stranded ncRNAs and reduced levels of scnRNAs – 25 nt-long sRNAs produced from these double-stranded precursors in the germline nucleus. Moreover, we observed that the presence of a germline-specific Spt4-Spt5m complex is necessary for transfer of the scnRNA-binding PIWI protein between the germline and somatic nucleus. Our study establishes that Spt4, together with Spt5m, is essential for expression of the germline genome and necessary for developmental genome rearrangements.
2022-04-27 | PXD027748 | Pride
Project description:In the ciliate Paramecium tetraurelia, autogamy is a self-fertilization process, during which the zygotic nucleus results from the fusion of two identical gametic nuclei. This phenomenon occurs in response to starvation. It starts with meiosis of the germline nuclei (micronuclei or MIC) and fragmentation of the parental somatic nucleus (macronucleus or MAC). This is followed by mitotic division of one haploid nucleus issued from meiosis to yield two identical gametic nuclei, then karyogamy takes place, followed by mitosis of zygotic nucleus and differentiation of new MICs and MACs from the resulting copies of the zygotic nucleus. Within the developing new MACs, developmentally programmed DNA amplification and extensive genome rearrangements (precise excision of short non coding Internal Eliminated Sequences and chromosome fragmentation associated with the imprecise elimination of repetitive DNA) give rise to the highly polyploid somatic genome. To gain further insight into the complex regulation of these successive steps, we used whole genome microarrays to study the different gene networks that become activated throughout autogamy.
2010-07-07 | GSE17998 | GEO
Project description:In the ciliate Paramecium tetraurelia, autogamy is a self-fertilization process, during which the zygotic nucleus results from the fusion of two identical gametic nuclei. This phenomenon occurs in response to starvation. It starts with meiosis of the germline nuclei (micronuclei or MIC) and fragmentation of the parental somatic nucleus (macronucleus or MAC). This is followed by mitotic division of one haploid nucleus issued from meiosis to yield two identical gametic nuclei, then karyogamy takes place, followed by mitosis of zygotic nucleus and differentiation of new MICs and MACs from the resulting copies of the zygotic nucleus. Within the developing new MACs, developmentally programmed DNA amplification and extensive genome rearrangements (precise excision of short non coding Internal Eliminated Sequences and chromosome fragmentation associated with the imprecise elimination of repetitive DNA) give rise to the highly polyploid somatic genome. To gain further insight into the complex regulation of these successive steps, we used whole genome microarrays to study the different gene networks that become activated throughout autogamy.
2010-07-07 | GSE17997 | GEO
Project description:In the ciliate Paramecium tetraurelia, autogamy is a self-fertilization process, during which the zygotic nucleus results from the fusion of two identical gametic nuclei. This phenomenon occurs in response to starvation. It starts with meiosis of the germline nuclei (micronuclei or MIC) and fragmentation of the parental somatic nucleus (macronucleus or MAC). This is followed by mitotic division of one haploid nucleus issued from meiosis to yield two identical gametic nuclei, then karyogamy takes place, followed by mitosis of zygotic nucleus and differentiation of new MICs and MACs from the resulting copies of the zygotic nucleus. Within the developing new MACs, developmentally programmed DNA amplification and extensive genome rearrangements (precise excision of short non coding Internal Eliminated Sequences and chromosome fragmentation associated with the imprecise elimination of repetitive DNA) give rise to the highly polyploid somatic genome. To gain further insight into the complex regulation of these successive steps, we used whole genome microarrays to study the different gene networks that become activated throughout autogamy.
2010-07-07 | GSE17996 | GEO