Project description:We used Nimblegen arrays with design 2007-11-06_Smed_ESTs_4_exp to measure changes in gene expression during a timecourse of regeneration of one side of the head in Schmidtea mediterranea flatworms. Following amputation of one side of the head, samples were collected from both the regeneration blastema and non-regenerating side of the head on days 2, 3, and 4 post-amputation. Gene expression in these samples was compared to that in non-regenerating control samples collected at the time of amputation.
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.
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.
Project description:Planarian flatworms can regenerate every organ after amputation. Adult pluripotent stem cells drive the ability to regenerate, but how injury activates these cells and directs them into the appropriate lineages is not understood. To study the regeneration response in a simplified context, we selectively induced the ejection of the planarian pharynx by briefly exposing animals to sodium azide followed by microarray analysis. Tissue surrounding the wound site was examined at 6, 12, 18, 24, 48, and 72 hours post amputation by comparison to tissue isolated immediately after amputation (time zero). Stem cells are required for the regeneration process, and can be eradicated by exposure to radiation. A parallel time course was also performed on worms that had been irradiated with 10k rads of gamma irradiation. Two time courses consisting of irradiated or unirradiated worms following chemical amputation of the pharynx. Tissue samples taken at 6, 12, 18, 24, 48 and 72 hours are each compared to a reference sample at time zero. The experiment was performed in triplicate for a total of 42 samples on 36 arrays.