Similar Datasets
Project description:In eukaryotes, 3' untranslated regions (UTRs) play important roles in regulating posttranscriptional gene expression. The 3'UTR is defined by regulated cleavage/polyadenylation of the pre-mRNA. The advent of next-generation sequencing technology has now enabled us to identify these events on a genome-wide scale. In this study, we used poly(A)-position profiling by sequencing (3P-Seq) to capture all poly(A) sites across the genome of the freshwater planarian, Schmidtea mediterranea, an ideal model system for exploring the process of regeneration and stem cell function. We identified the 3'UTRs for ?14,000 transcripts and thus improved the existing gene annotations. We found 97 transcripts, which are polyadenylated within an internal exon, resulting in the shrinking of the ORF and loss of a predicted protein domain. Around 40% of the transcripts in planaria were alternatively polyadenylated (ApA), resulting either in an altered 3'UTR or a change in coding sequence. We identified specific ApA transcript isoforms that were subjected to miRNA mediated gene regulation using degradome sequencing. In this study, we also confirmed a tissue-specific expression pattern for alternate polyadenylated transcripts. The insights from this study highlight the potential role of ApA in regulating the gene expression essential for planarian regeneration.
| S-EPMC5068929 | biostudies-literature
Project description:This study is the first to report genome-scale polyadenylation events in S.mediterranea using poly-A position profiling (3P-Seq).Various cis-acting elements such as hexameric PAS & U/GU enrichment after cleavage site were observed to be conserved in planaria.The cleavage site derived from 3P-Seq could be successfully associated with ~38-60% of transcripts (Makers -38%, oxford- 60% and Dresden- 44%).We also investigated the functional consequences of altered 3’UTRs arising from ApA. Around 97 transcripts were observed to undergo coding region alternate polyadenylation (CR-ApA) that resulted in loss of specific domains from proteins (as inferred from pfam domain search). In this study, we also demonstrated that microRNA-mediated regulation might be one of the key factors playing an important role in selection/evolution of alternate 3’UTRs. The 3’ UTR is one of the key regulatory element that decides the fate of mRNA inside a cell. Switching isoforms according to the need of cell and environmental cues could help the cell to adapt. In this study, we also attempted to study the tissue-specific role of ApA pattern in planaria. Due to the limitations associated with isolation of different tissue-specific cells from planaria, we performed a high-throughput microarray analysis across X1, X2 and Xins cell populations. We were clearly able to identify the differential expression pattern of the ApA events across cell population.
2022-10-01 | GSE78261 | GEO
Project description:This study is the first to report genome-scale polyadenylation events in S.mediterranea using poly-A position profiling (3P-Seq).Various cis-acting elements such as hexameric PAS & U/GU enrichment after cleavage site were observed to be conserved in planaria.The cleavage site derived from 3P-Seq could be successfully associated with ~38-60% of transcripts (Makers -38%, oxford- 60% and Dresden- 44%).We also investigated the functional consequences of altered 3’UTRs arising from ApA. Around 97 transcripts were observed to undergo coding region alternate polyadenylation (CR-ApA) that resulted in loss of specific domains from proteins (as inferred from pfam domain search). In this study, we also demonstrated that microRNA-mediated regulation might be one of the key factors playing an important role in selection/evolution of alternate 3’UTRs. The 3’ UTR is one of the key regulatory element that decides the fate of mRNA inside a cell. Switching isoforms according to the need of cell and environmental cues could help the cell to adapt. In this study, we also attempted to study the tissue-specific role of ApA pattern in planaria. Due to the limitations associated with isolation of different tissue-specific cells from planaria, we performed a high-throughput microarray analysis across X1, X2 and Xins cell populations. We were clearly able to identify the differential expression pattern of the ApA events across cell population.
2022-10-01 | GSE78161 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2019-05-25 | GSE121048 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2015-10-03 | GSE73701 | GEO
Project description:Planarians have emerged as excellent models for the study of key biological processes such as stem cell function and regulation, axial polarity specification, regeneration, and tissue homeostasis among others. The most widely used organism for these studies is the free-living flatworm Schmidtea mediterranea. In 2007, the Schmidtea mediterranea Genome Database (SmedGD) was first released to provide a much needed resource for the small, but growing planarian community. SmedGD 1.0 has been a depository for genome sequence, a draft assembly, and related experimental data (e.g., RNAi phenotypes, in situ hybridization images, and differential gene expression results). We report here a comprehensive update to SmedGD (SmedGD 2.0) that aims to expand its role as an interactive community resource. The new database includes more recent, and up-to-date transcription data, provides tools that enhance interconnectivity between different genome assemblies and transcriptomes, including next-generation assemblies for both the sexual and asexual biotypes of S. mediterranea. SmedGD 2.0 (http://smedgd.stowers.org) not only provides significantly improved gene annotations, but also tools for data sharing, attributes that will help both the planarian and biomedical communities to more efficiently mine the genomics and transcriptomics of S. mediterranea.
| S-EPMC4867232 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2013-10-29 | E-GEOD-51764 | biostudies-arrayexpress
Project description:Loss of heterozygosity through inbreeding or mitotic errors leads to reductions in progeny survival and fertility. Loss of heterozygosity is particularly exacerbated in geographically isolated populations, which are prone to inbreeding depression and faster rates of extinction. The regenerative capacities of the hermaphroditic biotype of the planarian Schmidtea mediterranea allowed us to perform a systematic genetic test of Mendelian segregation and study the loss of heterozygosity in the Spiralian superclade in general and planarians in particular. We discovered that ~300?Mb (~37.5%) of the genome retains heterozygosity even after ten generations of inbreeding, and show that these chromosomal regions have low diversity and recombination rates in wild populations. Our genetic and genomic analyses establish S. mediterranea as a genetically tractable system. The research also opens the door to study the evolutionary basis of non-Mendelian mechanisms, the adaptive advantages of chromosome structural heterozygotes and their potential relationship to the robust regenerative capacities of planarians.
| S-EPMC5556695 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2021-08-01 | GSE173631 | GEO
Project description:Studies of tissue regeneration and host-pathogen interactions using the model planarian Schmidtea mediterranea have been performed at an experimental temperature of 19?°C. S. mediterranea planarians exposed to 19?°C-32?°C were observed for survival, mobility, feeding and regeneration for three months and elimination of the Staphylococcus aureus pathogen over six days. S. mediterranea planarians died at 30?°C-32?°C after 18 days of observation but tolerated temperatures of 19?°C up to 28?°C with non-significant differences in mobility and feeding behavior. Genetic malleability tested by RNAi feeding was still efficient at 26?°C and 28?°C. Concerning the immune capacity of planarians, we reported an exacerbation of the immune response in worms infected by S. aureus at 26?°C and 28?°C. These observations suggest a temperature modulation of planarian stem cells and illustrate the importance of modulating experimental temperature when using planarians as model organisms to study regeneration and immune response.
| S-EPMC6175859 | biostudies-other