Project description:Eukaryotic mRNAs are subject to multiple types of tailing that critically influence mRNA stability and translatability. To investigate RNA tails at the genomic scale, we previously developed TAIL-seq, but its low sensitivity precluded its application to biological materials of minute quantity. In this study, we report a new version of TAIL-seq (mRNA TAIL-seq [mTAIL-seq]) with enhanced sequencing depth for mRNAs (by ∼1000-fold compared with the previous version). The improved method allows us to investigate the regulation of poly(A) tails in Drosophila oocytes and embryos. We found that maternal mRNAs are polyadenylated mainly during late oogenesis, prior to fertilization, and that further modulation occurs upon egg activation. Wispy, a noncanonical poly(A) polymerase, adenylates the vast majority of maternal mRNAs, with a few intriguing exceptions such as ribosomal protein transcripts. By comparing mTAIL-seq data with ribosome profiling data, we found a strong coupling between poly(A) tail length and translational efficiency during egg activation. Our data suggest that regulation of poly(A) tails in oocytes shapes the translatomic landscape of embryos, thereby directing the onset of animal development. By virtue of the high sensitivity, low cost, technical robustness, and broad accessibility, mTAIL-seq will be a potent tool to improve our understanding of mRNA tailing in diverse biological systems.
Project description:Eukaryotic mRNAs are subject to multiple types of tailing which critically influence mRNA stability and translatability. To investigate RNA tails at the genomic scale, we previously developed TAIL-seq, but its low sensitivity precluded its application to biological materials of minute quantity. In this study, we report a new version of TAILseq (mRNA TAIL-seq or mTAIL-seq) with enhanced sequencing depth for mRNAs (by ~1000 fold compared to the previous version). The improved method allows us to investigate the regulation of poly(A) tail in Drosophila oocytes and embryos. We find that maternal mRNAs are polyadenylated mainly during late oogenesis, prior to fertilization, and that further modulation occurs upon egg activation. Wispy, a noncanonical poly(A) polymerase, adenylates the vast majority of maternal mRNAs with a few intriguing exceptions such as ribosomal protein transcripts. By comparing mTAILseq data with ribosome profiling data, we find a strong coupling between poly(A) tail length and translational efficiency during egg activation. Our data suggest that regulation of poly(A) tail in oocytes shapes the translatomic landscape of embryos, thereby directing the onset of animal development. By virtue of the high sensitivity, low cost, technical robustness, and broad accessibility, mTAIL-seq will be a potent tool to improve our understanding of mRNA tailing in diverse biological systems. Two sets of RNA-seq on 3 developmental stages (immature oocyte, mature oocyte, and activated egg) of wild type and wispy mutant of Drosophila melanogaster.
Project description:Eukaryotic mRNAs are subject to multiple types of tailing which critically influence mRNA stability and translatability. To investigate RNA tails at the genomic scale, we previously developed TAIL-seq, but its low sensitivity precluded its application to biological materials of minute quantity. In this study, we report a new version of TAILseq (mRNA TAIL-seq or mTAIL-seq) with enhanced sequencing depth for mRNAs (by ~1000 fold compared to the previous version). The improved method allows us to investigate the regulation of poly(A) tail in Drosophila oocytes and embryos. We find that maternal mRNAs are polyadenylated mainly during late oogenesis, prior to fertilization, and that further modulation occurs upon egg activation. Wispy, a noncanonical poly(A) polymerase, adenylates the vast majority of maternal mRNAs with a few intriguing exceptions such as ribosomal protein transcripts. By comparing mTAILseq data with ribosome profiling data, we find a strong coupling between poly(A) tail length and translational efficiency during egg activation. Our data suggest that regulation of poly(A) tail in oocytes shapes the translatomic landscape of embryos, thereby directing the onset of animal development. By virtue of the high sensitivity, low cost, technical robustness, and broad accessibility, mTAIL-seq will be a potent tool to improve our understanding of mRNA tailing in diverse biological systems.
Project description:Eukaryotic mRNAs are subject to multiple types of tailing which critically influence mRNA stability and translatability. To investigate RNA tails at the genomic scale, we previously developed TAIL-seq, but its low sensitivity precluded its application to biological materials of minute quantity. In this study, we report a new version of TAILseq (mRNA TAIL-seq or mTAIL-seq) with enhanced sequencing depth for mRNAs (by ~1000 fold compared to the previous version). The improved method allows us to investigate the regulation of poly(A) tail in Drosophila oocytes and embryos. We find that maternal mRNAs are polyadenylated mainly during late oogenesis, prior to fertilization, and that further modulation occurs upon egg activation. Wispy, a noncanonical poly(A) polymerase, adenylates the vast majority of maternal mRNAs with a few intriguing exceptions such as ribosomal protein transcripts. By comparing mTAILseq data with ribosome profiling data, we find a strong coupling between poly(A) tail length and translational efficiency during egg activation. Our data suggest that regulation of poly(A) tail in oocytes shapes the translatomic landscape of embryos, thereby directing the onset of animal development. By virtue of the high sensitivity, low cost, technical robustness, and broad accessibility, mTAIL-seq will be a potent tool to improve our understanding of mRNA tailing in diverse biological systems. Ten separate sets of TAIL-seq experiments were performed. Two sets of HeLa cells are untransfected normal cells. Eight sets of fly sample include a pair of wild type and mutant.
Project description:Eukaryotic mRNAs are subject to multiple types of tailing which critically influence mRNA stability and translatability. To investigate RNA tails at the genomic scale, we previously developed TAIL-seq, but its low sensitivity precluded its application to biological materials of minute quantity. In this study, we report a new version of TAILseq (mRNA TAIL-seq or mTAIL-seq) with enhanced sequencing depth for mRNAs (by ~1000 fold compared to the previous version). The improved method allows us to investigate the regulation of poly(A) tail in Drosophila oocytes and embryos. We find that maternal mRNAs are polyadenylated mainly during late oogenesis, prior to fertilization, and that further modulation occurs upon egg activation. Wispy, a noncanonical poly(A) polymerase, adenylates the vast majority of maternal mRNAs with a few intriguing exceptions such as ribosomal protein transcripts. By comparing mTAILseq data with ribosome profiling data, we find a strong coupling between poly(A) tail length and translational efficiency during egg activation. Our data suggest that regulation of poly(A) tail in oocytes shapes the translatomic landscape of embryos, thereby directing the onset of animal development. By virtue of the high sensitivity, low cost, technical robustness, and broad accessibility, mTAIL-seq will be a potent tool to improve our understanding of mRNA tailing in diverse biological systems.
Project description:Poly(A)-tail-mediated post-transcriptional regulation of maternal mRNAs is vital in the oocyte-to-embryo transition (OET). Nothing is known about poly(A) tail dynamics during the human OET. Here, we show that poly(A) tail length and internal non-A residues are highly dynamic during the human OET, using poly(A)-inclusive RNA isoform sequencing (PAIso-seq). Unexpectedly, maternal mRNAs undergo global remodeling: after deadenylation or partial degradation into 3'-UTRs, they are re-polyadenylated to produce polyadenylated degradation intermediates, coinciding with massive incorporation of non-A residues, particularly internal long consecutive U residues, into the newly synthesized poly(A) tails. Moreover, TUT4 and TUT7 contribute to the incorporation of these U residues, BTG4-mediated deadenylation produces substrates for maternal mRNA re-polyadenylation, and TENT4A and TENT4B incorporate internal G residues. The maternal mRNA remodeling is further confirmed using PAIso-seq2. Importantly, maternal mRNA remodeling is essential for the first cleavage of human embryos. Together, these findings broaden our understanding of the post-transcriptional regulation of maternal mRNAs during the human OET.