Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Mating of the stichotrichous ciliate Oxytricha trifallax induces production of a class of 27nt small RNAs derived from the parental macronucleus

ABSTRACT: 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

ORGANISM(S): Oxytricha trifallax

SUBMITTER: Alan Zahler

PROVIDER: E-GEOD-37390 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Publications

Mating of the stichotrichous ciliate Oxytricha trifallax induces production of a class of 27 nt small RNAs derived from the parental macronucleus.

Zahler Alan M AM Neeb Zachary T ZT Lin Athena A Katzman Sol S

PloS one 20120810 8

Ciliated protozoans possess two types of nuclei; a transcriptionally silent micronucleus, which serves as the germ line nucleus, and a transcriptionally active macronucleus, which serves as the somatic nucleus. The macronucleus is derived from a new diploid micronucleus after mating, with epigenetic information contributed by the parental macronucleus serving to guide the formation of the new macronucleus. In the stichotrichous ciliate Oxytricha trifallax, the macronuclear DNA is highly processe ...[more]

PMID: 22900016

Similar Datasets

Project description:In Oxytricha, the somatic genome is responsible for vegetative growth, while the germline contributes DNA to the next sexual generation. Somatic nuclear development eliminates all transposons and other so-called "junk DNA", which constitute ~95% of the germline. We demonstrate that Piwi-interacting small RNAs (piRNAs) from the maternal nucleus can specify genomic regions for retention in this process. Oxytricha piRNAs map primarily to the somatic genome, representing the ~5% of the germline that is retained. Furthermore, injection of synthetic piRNAs corresponding to normally-deleted regions leads to their retention in subsequent generations. Our findings highlight small RNAs (sRNAs) as powerful transgenerational carriers of epigenetic information for genome programming. The backcross study here shows that the mating between an IES+ strain with the wild-type stain produces corresponding IES-containing sRNAs at 19 hr, and we provided the mapping to and the sequences of the specific loci of interest in the submission. As a control, wild-type cells do not produce such IES-containing sRNAs, and this analysis can be pulled out from the GSE35018 study since we provided mapping to the whole genome. The purpose of the 20 hr total sRNA sequencing study here is to show that the class of 27 nt sRNA is the major species of total sRNAs in Oxytricha at 20 hr, which we sequenced previously from Otiwi1-associated sRNAs at 12, 19, 23, and 30 hr (GSE35018). In addition, there is a less abundant class of small RNAs of 21-22 nt. These two classes are obvious by simply plotting the length distribution of the sRNA sequences. We sequenced sRNAs from Contig22226.0 IES1+ strain backcrossed to wild-type parental strain at 19hr post-mixing, and found corresponding IES-containing sRNAs. As a control, wild-type cells do not produce such IES-containing sRNAs (see GSE35018). Total RNA from the backcrossing at 19hr were isolated with mirVana small RNA extraction kit (Ambion), and directly used for making Illumina sRNA libraries. Oxytricha total small RNA (sRNA) sequencing at 20 hr post conjugation shows that a class of 27 nt, 5'-U sRNAs dominates the sRNA population at 20 hr, and this class of sRNAs associate with Otiwi1 (see GSE35018 for Otiwi1-interacting sRNAs in Oxytricha). In addition, a much less abundant class of 21-22 nt sRNAs is present according to the length distribution.

Dataset Information

Mating of the stichotrichous ciliate Oxytricha trifallax induces production of a class of 27nt small RNAs derived from the parental macronucleus

Publications

Mating of the stichotrichous ciliate Oxytricha trifallax induces production of a class of 27 nt small RNAs derived from the parental macronucleus.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets