Slam-seq reveals that miR-430 regulates zygotic mRNA during zebrafish embryogenesis [titration_data]
Ontology highlight
ABSTRACT: Background: Early embryonic developmental programs are guided by the coordinated interplay between maternally inherited and zygotically manufactured RNAs and proteins. Although these processes happen concomitantly and affecting gene function during this period is bound to affect both pools of mRNAs, it has been challenging to study their expression dynamics separately. Results: By employing Slam-seq, a nascent mRNA labeling transcriptomic approach, in a developmental time series we observe that over half of the early zebrafish embryo transcriptome consists of maternal-zygotic genes, emphasizing their pivotal role in early embryogenesis. We provide an hourly resolution of de novo transcriptional waves and follow nascent mRNA trajectories, finding that most de novo transcriptional events are stable throughout this period. Additionally, by blocking microRNA430 function, a key post-transcriptional regulator during zebrafish embryogenesis, we directly show that it destabilizes hundreds of de novo transcribed mRNAs from pure zygotic as well as maternal-zygotic genes. This unveils a novel miR-430 function during embryogenesis, fine-tuning zygotic gene expression, which highlights that Slam-seq can be used to disentangle transcriptional and post-transcriptional regulation of mRNA levels. Conclusion: Such valuable insights into zebrafish early embryo transcriptome dynamics emphasize the significance of post-transcriptional regulators in zygotic genome activation. These findings pave the way for future investigations into the coordinated interplay between transcriptional and post-transcriptional landscapes required for the establishment of animal cell identities and functions.
Project description:Background: Early embryonic developmental programs are guided by the coordinated interplay between maternally inherited and zygotically manufactured RNAs and proteins. Although these processes happen concomitantly and affecting gene function during this period is bound to affect both pools of mRNAs, it has been challenging to study their expression dynamics separately. Results: By employing Slam-seq, a nascent mRNA labeling transcriptomic approach, in a developmental time series we observe that over half of the early zebrafish embryo transcriptome consists of maternal-zygotic genes, emphasizing their pivotal role in early embryogenesis. We provide an hourly resolution of de novo transcriptional waves and follow nascent mRNA trajectories, finding that most de novo transcriptional events are stable throughout this period. Additionally, by blocking microRNA430 function, a key post-transcriptional regulator during zebrafish embryogenesis, we directly show that it destabilizes hundreds of de novo transcribed mRNAs from pure zygotic as well as maternal-zygotic genes. This unveils a novel miR-430 function during embryogenesis, fine-tuning zygotic gene expression, which highlights that Slam-seq can be used to disentangle transcriptional and post-transcriptional regulation of mRNA levels. Conclusion: Such valuable insights into zebrafish early embryo transcriptome dynamics emphasize the significance of post-transcriptional regulators in zygotic genome activation. These findings pave the way for future investigations into the coordinated interplay between transcriptional and post-transcriptional landscapes required for the establishment of animal cell identities and functions.
Project description:Background: Early embryonic developmental programs are guided by the coordinated interplay between maternally inherited and zygotically manufactured RNAs and proteins. Although these processes happen concomitantly and affecting gene function during this period is bound to affect both pools of mRNAs, it has been challenging to study their expression dynamics separately. Results: By employing Slam-seq, a nascent mRNA labeling transcriptomic approach, in a developmental time series we observe that over half of the early zebrafish embryo transcriptome consists of maternal-zygotic genes, emphasizing their pivotal role in early embryogenesis. We provide an hourly resolution of de novo transcriptional waves and follow nascent mRNA trajectories, finding that most de novo transcriptional events are stable throughout this period. Additionally, by blocking microRNA430 function, a key post-transcriptional regulator during zebrafish embryogenesis, we directly show that it destabilizes hundreds of de novo transcribed mRNAs from pure zygotic as well as maternal-zygotic genes. This unveils a novel miR-430 function during embryogenesis, fine-tuning zygotic gene expression, which highlights that Slam-seq can be used to disentangle transcriptional and post-transcriptional regulation of mRNA levels. Conclusion: Such valuable insights into zebrafish early embryo transcriptome dynamics emphasize the significance of post-transcriptional regulators in zygotic genome activation. These findings pave the way for future investigations into the coordinated interplay between transcriptional and post-transcriptional landscapes required for the establishment of animal cell identities and functions.
Project description:Using SLAM-seq to capture de novo synthesized polyadenylated RNAs, we quantitated changes in nascent RNA expression, as well as in total RNA expression.
Project description:During early embryogenesis, embryos undergo a massive degradation of maternally inherited mRNAs and produce new zygotic transcripts. This maternal-to-zygotic transition requires a tight interplay of mRNA transcription and degradation, but distinguishing their unique contributions remains a challenge. Here, we dissect gene regulation during the zebrafish maternal-to-zygotic transition by combining single-cell RNA-sequencing with RNA metabolic labeling and nucleotide conversion within zebrafish embryos. We decompose single-cell transcriptomes into their new (zygotic) and old (maternal) mRNA components, and elicit critical information on gene regulation as it unfolds over both time and space. We show that most cell-type restricted expression arises by zygotic transcription, but distinguish a specific role for maternal transcripts in defining germ-cell and enveloping-layer identity, two earliest specified cell identities. We recover the underlying replacement between maternal and zygotic copies of embryonic genes with a relatively constant overall mRNA level, and associate a fast replacement with genes that has a restricted zygotic expression in either cell-type or time. Our study provides a valuable resource to investigate maternal and zygotic transcriptomes and reveals post-transcriptional events that control gene regulation during early embryogenesis.
Project description:During early embryogenesis, embryos undergo a massive degradation of maternally inherited mRNAs and produce new zygotic transcripts. This maternal-to-zygotic transition requires a tight interplay of mRNA transcription and degradation, but distinguishing their unique contributions remains a challenge. Here, we dissect gene regulation during the zebrafish maternal-to-zygotic transition by combining single-cell RNA-sequencing with RNA metabolic labeling and nucleotide conversion within zebrafish embryos. We decompose single-cell transcriptomes into their new (zygotic) and old (maternal) mRNA components, and elicit critical information on gene regulation as it unfolds over both time and space. We show that most cell-type restricted expression arises by zygotic transcription, but distinguish a specific role for maternal transcripts in defining germ-cell and enveloping-layer identity, two earliest specified cell identities. We recover the underlying replacement between maternal and zygotic copies of embryonic genes with a relatively constant overall mRNA level, and associate a fast replacement with genes that has a restricted zygotic expression in either cell-type or time. Our study provides a valuable resource to investigate maternal and zygotic transcriptomes and reveals post-transcriptional events that control gene regulation during early embryogenesis.
Project description:Embryogenesis entails dramatic shifts in mRNA translation and turnover to account for gene expression differences during proliferation and cellular differentiation. Codon identity modulates mRNA stability during early vertebrate embryogenesis, but how the composition of tRNA pools adapts to the embryo s translational demand is unknown. By quantitatively profiling the tRNA repertoires of zebrafish embryos during the maternal-to-zygotic transition, here we find that maternal and zygotic tRNA pools are distinct. We show that translational activation during embryogenesis and tRNA gene derepression are temporally coordinated by TORC1 activity, which increases at gastrulation and inactivates the RNA polymerase III repressor Maf1a/b in vivo. Reshaping of tRNA pools results in differential tRNA anticodon supply, but these changes do not alter decoding rates in zebrafish embryos. Instead, our data indicate that tRNA repertoires reflect the inherent codon bias of the zebrafish mRNA transcriptome, and tRNA levels are boosted at gastrulation to ensure efficient translation as embryos enter differentiation.
Project description:Cys2-His2 Zinc finger genes (ZNFs) form the largest family of transcription factors in metazoans. Zebrafish posess a subfamily characterized by the presence of a domain dubbed Fish N-terminal Zinc finger associated (FiNZ). FiNZ-ZNFs are expressed at the onset of zygotic genome activation in zebrafishh, and blocking FiNZ-ZNF translation using morpholinos during early zebrafish embryogenesis results in a broad de-repression of young, transcriptionally active TEs.
Project description:To understand 4-TU labelling kinetics in a novel zebrafish transgenic line (lf:UPRT), we exposed adult lf:UPRT zebrafish (whereby animals have hepatocyte-specific uracil phosphoribosyltransferase expression) with 4-TU for 1, 3, 6 and 9 hours. We then dissected adult livers for SLAM-ITseq to determine the optimal 4-TU labelling time in our SLAM-ITseq workflow to allow us to study hepatocyte-specific nascent transcriptional changes.
2024-01-13 | GSE230830 | GEO
Project description:Zygotic activation of transposable elements during zebrafish early embryogenesis