Project description:Role of alternative polyadenylation in muscle development remains largely undetermined. Our WTTS-seq approach to capture 3'-end of RNAs clearly revealed alternaitve polyadenylation events responsible for reduced muscle mass in AMPK α1, but increased muscle mass in AMPK α2 knockout mice.
Project description:We applied our recently released Whole Transcriptome Termini Site sequencing protocol to profile usage of alternative polyadenylation sites in Xenopus tropicalis.
Project description:Role of alternative transcription start sites in muscle growth and development remains largely undetermined. Our WTSS-seq (whole transcriptome start site sequencing) approach to capture 5'-end of RNAs clearly revealed alternative transcription start events responsible for increased muscle mass in AMPK α2 knockout mice.
Project description:We have developed both WTSS-seq (whole transcriptome start site sequencing) and WTTS-seq (whole transcriptome termini site sequencing) methods to capture either 5’- or 3’-ends of transcripts. HATT-seq (head and tail tag sequencing) is still under development, which can be used to capture both 5’- and 3’ ends of each transcript simultaneously. Iso-seq was used to produce full-length transcripts, which can be used to validate both alternative transcription start sites and alternative polyadenylation sites. CAGE-seq was used to confirm alternative transcription start sites only.
Project description:Alternative polyadenylation (APA) is an important post-transcriptional modification implicated in development. Female germline stem cell (FGSC) is unipotent and capable of giving rise to oocyte. However, whether alternative polyadenylation plays a role in self-renew and cell fate determination of FGSCs remain elusive. Here, we used 3T-Seq developed in our lab to profile genome-wide 3a termini of transcripts and delineate APA sites in mouse FGSCs and explored the biological significance of APA modulation in FGSC identity.
Project description:Alternative polyadenylation (APA) creates distinct transcripts from the same gene by cleaving the pre-mRNA at poly(A) sites that can lie within the 3' UTR, introns, or exons. Most studies focus on APA within the 3' UTR, but here we show that CPSF6 insufficiency alters protein levels and causes a developmental syndrome by deregulating APA throughout the transcript. In neonatal humans and zebrafish larvae, CPSF6 insufficiency shifts poly(A) site usage between the 3'UTR and internal sites in a pathway-specific manner. Genes associated with neuronal function undergo mostly intronic APA, reducing their expression, while genes associated with heart and skeletal function mostly undergo 3' UTR APA and are upregulated. This suggests that, in healthy conditions, cells toggle between internal and 3'UTR APA to modulate protein expression.
Project description:Alternative polyadenylation has been implicated as an important regulator of gene expression. In some cases, alternative polyadenylation is known to couple with alternative splicing to influence last intron removal. However, it is unknown whether alternative polyadenylation events influence alternative splicing decisions at upstream exons. Knockdown of the polyadenylation factors CFIm25 or CstF64 was used as an approach in identifying alternative polyadenylation and alternative splicing events on a genome-wide scale. Although hundreds of alternative splicing events were found to be differentially spliced in the knockdown of CstF64, genes associated with alternative polyadenylation did not exhibit an increased incidence of alternative splicing. These results demonstrate that the coupling between alternative polyadenylation and alternative splicing is usually limited to defining the last exon. The striking influence of CstF64 knockdown on alternative splicing can be explained through its effects on UTR selection of known splicing regulators such as hnRNP A2/B1, thereby indirectly influencing splice site selection. We conclude that changes in the expression of the polyadenylation factor CstF64 influences alternative splicing through indirect effects. HeLa cell line was stably transfected with shRNA plasmids targeting CstF64. Total RNA was isolated from CstF64 KD cells and wild-type control cells using Trizol according to manufacturerâs protocols. Samples were deep sequenced in duplicate using the Illumina GAIIx system.