Project description:Here we report that soon after mating of Oxytricha trifallax, abundant 27nt small RNAs are produced that are not present prior to mating. We performed next generation sequencing of these 27nt RNAs from various times after mating. Using sequence comparisons between macronuclear and micronuclear versions of genes, we found that this 27nt RNA class derives from the parental macronucleus, not the developing macronucleus. These small RNAs are produced equally from both strands of macronuclear nanochromosomes, but in a highly non-uniform distribution along the length of the nanochromosome, and with a particular depletion in the 30 nt telomere-proximal positions. Unlike the Tetrahymena scanRNAs, the Oxytricha macronuclear-derived 27mers are not modified by 2'O-methylation at their 3' ends. Examination of small RNAs produced in Oxytricha trifallax during vegetative growth and at various timepoints during the mating process
Project description:Here we report that soon after mating of Oxytricha trifallax, abundant 27nt small RNAs are produced that are not present prior to mating. We performed next generation sequencing of these 27nt RNAs from various times after mating. Using sequence comparisons between macronuclear and micronuclear versions of genes, we found that this 27nt RNA class derives from the parental macronucleus, not the developing macronucleus. These small RNAs are produced equally from both strands of macronuclear nanochromosomes, but in a highly non-uniform distribution along the length of the nanochromosome, and with a particular depletion in the 30 nt telomere-proximal positions. Unlike the Tetrahymena scanRNAs, the Oxytricha macronuclear-derived 27mers are not modified by 2'O-methylation at their 3' ends.
Project description:We report the existence of both methylcytosine and hydroxymethylcytosine in the genomic DNA of the ciliate Oxytricha trifallax during its genome rearrangement process. These modifications are dynamically added, de novo, to sequences targeted for elimination and are not present after the rearrangement process (in vegetative cells). We performed methyl-DNA immunoprecipitation-sequencing (meDIP-seq) with antibodies against methylcytosine and hydroxymethylcytosine.
