MRNA and Ribosome Profiling in Four Nematode Species Traversing a Shared Developmental Transition
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ABSTRACT:
ORGANISM(S): Caenorhabditis elegans Caenorhabditis remanei Caenorhabditis briggsae Caenorhabditis brenneri
PROVIDER: GSE48140 | GEO | 2013/06/21
SECONDARY ACCESSION(S): PRJNA208993
REPOSITORIES: GEO
Similar Datasets
Project description:mRNA and Ribosome Profiling in Four Nematode Species Traversing a Shared Developmental Transition mRNA-seq and Ribo-seq
2013-06-21 | E-GEOD-48140 | biostudies-arrayexpress
Project description:mRNA and Ribosome Profiling in Four Nematode Species Traversing a Shared Developmental Transition
| PRJNA208993 | ENA
Project description:Nematodes of the genus Caenorhabditis enter a developmental diapause state after hatching in the absence of food. To better understand the relative contributions of distinct regulatory modalities to gene expression changes associated with this developmental transition, we characterized genome-wide changes in mRNA abundance and translational efficiency associated with L1 diapause exit in four species using ribosome profiling and mRNA-seq. We found a strong tendency for translational regulation and mRNA abundance processes to act synergistically, together effecting a dramatic remodeling of the gene expression program. While gene-specific differences were observed between species, overall translational dynamics were broadly and functionally conserved. A striking, conserved feature of the response was strong translational suppression of ribosomal protein production during L1 diapause, followed by activation upon resumed development. On a global scale, ribosome footprint abundance changes showed greater similarity between species than changes in mRNA abundance, illustrating a substantial and genome-wide contribution of translational regulation to evolutionary maintenance of stable gene expression.
| S-EPMC3789828 | biostudies-literature
Project description:We have performed small RNA sequencing in the nematodes Caenorhabditis elegans, C. briggsae, C. remanei and Pristionchus pacificus, which have diverged up to 400 million years ago, to establish the repertoire and evolutionary dynamics of miRNAs in these species. In addition to previously known miRNA genes from C. elegans and C. briggsae we demonstrate expression of many of their homologs in C. remanei and P. pacificus, and identified in total more than 100 novel expressed miRNA genes, the majority of which belong to P. pacificus. More than half of all identified miRNA genes were found to be conserved at the seed level in all four nematode species, whereas only a few miRNAs appear to be species-specific. In our compendium of miRNAs we observed evidence for known mechanisms of miRNA evolution, including antisense transcription and arm switching, as well as miRNA family expansion through gene duplication. In addition, we identified a novel mode of miRNA evolution, termed ‘hairpin shifting’, in which an alternative hairpin is formed with up- or downstream sequences, leading to shifting of the hairpin and creation of novel miRNA* species. Finally, we identified 21U-RNAs in all four nematodes, including P. pacificus, where the upstream 21U-RNA motif is more diverged. However, the genomic distribution of 21U-RNA clusters in P. pacificus appears more scattered throughout the genome as compared to C. elegans. The identification and systematic analysis of small RNA repertoire in four nematode species described here provides a valuable resource for understanding the evolutionary dynamics of miRNA-mediated gene regulation.
2009-09-08 | GSE15169 | GEO
Project description:We have performed small RNA sequencing in the nematodes Caenorhabditis elegans, C. briggsae, C. remanei and Pristionchus pacificus, which have diverged up to 400 million years ago, to establish the repertoire and evolutionary dynamics of miRNAs in these species. In addition to previously known miRNA genes from C. elegans and C. briggsae we demonstrate expression of many of their homologs in C. remanei and P. pacificus, and identified in total more than 100 novel expressed miRNA genes, the majority of which belong to P. pacificus. More than half of all identified miRNA genes were found to be conserved at the seed level in all four nematode species, whereas only a few miRNAs appear to be species-specific. In our compendium of miRNAs we observed evidence for known mechanisms of miRNA evolution, including antisense transcription and arm switching, as well as miRNA family expansion through gene duplication. In addition, we identified a novel mode of miRNA evolution, termed ‘hairpin shifting’, in which an alternative hairpin is formed with up- or downstream sequences, leading to shifting of the hairpin and creation of novel miRNA* species. Finally, we identified 21U-RNAs in all four nematodes, including P. pacificus, where the upstream 21U-RNA motif is more diverged. However, the genomic distribution of 21U-RNA clusters in P. pacificus appears more scattered throughout the genome as compared to C. elegans. The identification and systematic analysis of small RNA repertoire in four nematode species described here provides a valuable resource for understanding the evolutionary dynamics of miRNA-mediated gene regulation. Small RNAs were cloned from mixed stage animals. Sequencing was performed using the 454 GS FLX platform.
2009-09-07 | E-GEOD-15169 | biostudies-arrayexpress
Project description:Evolutionary theory assumes that genetic variation is uniform and gradual in nature, yet morphological and gene expression studies have revealed that different life-stages exhibit distinct levels of cross-species conservation. In particular, a stage in mid-embryogenesis is highly conserved across species of the same phylum, suggesting that this stage is subject to developmental constraints, either by increased purifying selection or by a strong mutational bias. An alternative explanation, however, holds that the same ‘hourglass’ pattern of variation may result from increased positive selection at the earlier and later stages of development. To distinguish between these scenarios, we examined gene expression variation in a population of the nematode C. elegans using an experimental design that eliminated the influence of positive selection. By measuring gene expression for all genes throughout development in twenty strains, we found that variations were dramatically uneven throughout development, with a significant depletion during mid-embryogenesis. In particular, the family of homeodomain transcription factors, whose expression generally coincides with mid-embryogenesis, evolved under high constraint. Our data further shows that genes responsible for the integration of germ layers during morphogenesis are the most constrained class of genes. Together, these results provide the first evidence for developmental constraints as the mechanism underlying the hourglass model of animal evolution. Understanding the pattern and mechanism of developmental constraints provides a framework to understand how evolutionary processes have interacted with embryogenesis and led to the diversity of animal life on earth.
2017-04-04 | GSE87528 | GEO
Project description:Repertoire and evolution of miRNA genes in four divergent nematode species
| PRJNA114977 | ENA
Project description:To experimentally-validate the non-coding status of annotated lncRNAs, we performed ribosome profiling over a developmental timecourse that matched our previously-published (Pauli et al. 2012) developmental transcriptome. We find that many previously-annotated lncRNAs appear to be translated, but in a pattern more akin to 5' leaders of coding genes. Ribosome profiling over 8 stages in early zebrafish development: 2-4 cell, 256 cell, 1K cell, Dome, Shield, Bud, 28hpf and 5dpf
2013-05-23 | E-GEOD-46512 | biostudies-arrayexpress
Project description:The overall goal of this investigation was to investigate X-content of sex-biased genes in several nematode species. The following species of nematode were investigated: *C. elegans, *N2; *C. brenneri, *PB2801; *C. briggsae, *AF16; *C. remanei*, PB4641; *P. **pacificus, *PS312*.* Genomic DNA sequencing data was used to assign X and autosomal - linkage to unassembled sequencing contigs. Male and female RNA seq data was then generated and used to determine sex-biased expression. For both DNA and RNA experiments, 50bp paired-end (DNA) or single-end (RNA) reads were generated on the Illumina HiSeq 2500. Sequencing lanes were multiplexed. Genomic DNA was isolated from 50-100 hand-picked young adult worms. At least two replicates for each sex were prepared. DNA was sheared via sonication and 350-500 bp sequencing libraries were prepared following the Illumina protocol. Total RNA was isolated from at least 1000 hand-picked L4/young adult worms (*C. **elegans, *N2) or J4/young adult worms (*P. pacificus, *PS312*). *PolyA beads were used to enrich for mRNA. Stranded RNAseq libraries were prepared via incorporation of dUTPs during cDNA synthesis, following the protocol detailed in Parkhomchuk et al, 2009. DNAseq and RNAseq reads were aligned to the appropriate WS228 reference genomes.
2014-04-17 | GSE53144 | GEO