Project description:5-methyl-cytosine DNA methylation regulates gene expression and developmental programming in a broad range of eukaryotes. However, its presence and potential roles in ciliates, complex single-celled eukaryotes with germline-somatic genome specialization via nuclear dimorphism, are largely uncharted. While canonical cytosine methyltransferases have not been discovered in published ciliate genomes, recent studies performed in the stichotrichous ciliate Oxytricha trifallax suggest de novo cytosine methylation during macronuclear development. In this study, we applied bisfulfite genome sequencing, DNA mass spectrometry and antibody-based fluorescence detection to investigate the presence of DNA methylation in Paramecium tetraurelia. While the antibody-based methods suggest cytosine methylation, DNA mass spectrometry and bisulfite sequencing reveal that levels are actually below the limit of detection. Our results suggest that Paramecium does not utilize 5-methyl-cytosine DNA methylation as an integral part of its epigenetic arsenal.
2018-04-01 | GSE111621 | GEO
Project description:High-throughput amplicon analysis of free-living anaerobic ciliate-associated prokaryotes
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.
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.