Similar Datasets
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.
2023-05-11 | GSE224918 | GEO
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.
2023-05-11 | GSE224113 | GEO
Project description:Maternally deposited mRNAs direct early development before the initiation of zygotic transcription during mid-blastula transition (MBT). To study mechanisms regulating this developmental event in zebrafish, we applied mRNA deep sequencing technology and generated comprehensive information and valuable resources on transcriptome dynamics during early embryonic (egg to early gastrulation) stages. Genome-wide transcriptome analysis documented at least 8000 maternal genes and identified the earliest cohort of zygotic transcripts. We determined expression levels of maternal and zygotic transcripts with the highest resolution possible using mRNA-seq and clustered them based on their expression pattern. We unravel delayed polyadenylation in a large cohort of maternal transcripts prior to the MBT for the first time in zebrafish. Blocking polyadenylation of these transcripts confirms their role in regulating development from the MBT onward. Our study also identified a large number of novel transcribed regions in annotated and unannotated regions of the genome, which will facilitate reannotation of the zebrafish genome. We also identified splice variants with an estimated frequency of 50%-60%. Taken together, our data constitute a useful genomic information and valuable transcriptome resource for gene discovery and for understanding the mechanisms of early embryogenesis in zebrafish.
| S-EPMC3149499 | biostudies-literature
Project description:The maternal-to-zygotic transition (MZT) is one of the most profound and tightly orchestrated processes during the early life of embryos, yet factors that shape the temporal pattern of vertebrate MZT are largely unknown. Here we show that over one-third of zebrafish maternal messenger RNAs (mRNAs) can be N6-methyladenosine (m6A) modified, and the clearance of these maternal mRNAs is facilitated by an m6A-binding protein, Ythdf2. Removal of Ythdf2 in zebrafish embryos decelerates the decay of m6A-modified maternal mRNAs and impedes zygotic genome activation. These embryos fail to initiate timely MZT, undergo cell-cycle pause, and remain developmentally delayed throughout larval life. Our study reveals m6A-dependent RNA decay as a previously unidentified maternally driven mechanism that regulates maternal mRNA clearance during zebrafish MZT, highlighting the critical role of m6A mRNA methylation in transcriptome switching and animal development.
| S-EPMC5323276 | biostudies-literature
Project description:Goal of this study is differential gene expression between wild type and MZnanog mutant during early zebrafish embryogenesis
2017-10-25 | GSE89245 | GEO
Project description:Early steps of embryo development are directed by maternal gene products and trace levels of zygotic gene activity in vertebrates. A major activation of zygotic transcription occurs together with degradation of maternal mRNAs during the midblastula transition in several vertebrate systems. How these processes are regulated in preparation for the onset of differentiation in the vertebrate embryo is mostly unknown. Here, we studied the function of TATA-binding protein (TBP) by knock down and DNA microarray analysis of gene expression in early embryo development. We show that a subset of polymerase II-transcribed genes with ontogenic stage-dependent regulation requires TBP for their zygotic activation. TBP is also required for limiting the activation of genes during development. We reveal that TBP plays an important role in the degradation of a specific subset of maternal mRNAs during late blastulation/early gastrulation, which involves targets of the miR-430 pathway. Hence, TBP acts as a specific regulator of the key processes underlying the transition from maternal to zygotic regulation of embryogenesis. These results implicate core promoter recognition as an additional level of differential gene regulation during development.
| S-EPMC1950726 | biostudies-literature
Project description:Early animal development is characterized by intense reorganization of the embryonic genome, including large-scale changes in chromatin structure and in the DNA and histone modifications that help shape this structure. Particularly profound shifts in the chromatin landscape are associated with the maternal-to-zygotic transition, when the zygotic genome is first transcribed and maternally loaded transcripts are degraded. The accessibility of the early zebrafish embryo facilitates the interrogation of chromatin during this critical window of development, making it an important model for early chromatin regulation. Here, we review our current understanding of chromatin dynamics during early zebrafish development, highlighting new advances as well as similarities and differences between early chromatin regulation in zebrafish and other species.
| S-EPMC7262572 | biostudies-literature
Project description:Transposable elements (TEs) are mobile genetic elements that can have many deleterious effects on the fitness of their host. The germline-specific PIWI pathway guards the genome against TEs, deriving its specificity from sequence complementarity between PIWI-bound small RNAs (piRNAs) and the TEs. The piRNAs are derived from so-called piRNA clusters. Recent studies have demonstrated that the piRNA repertoire can be adjusted to accommodate recent TE invasions by capturing invading TEs in piRNA loci. Thus far, no information concerning piRNA divergence is available from vertebrates. We present piRNA analyses of two relatively divergent zebrafish strains. We find that significant differences in the piRNA populations have accumulated, most notably among active class I TEs. This divergence can be split into differences in piRNA abundance per element and differences in sense/antisense polarity ratios. In crosses between animals of the different strains, many of these differences are resolved in the progeny. However, some differences remain, often leaning to the maternally contributed piRNA population. These differences can be detected at least two generations later. Our data illustrate, for the first time, the fluidity of piRNA populations in vertebrates and how the established diversity is transmitted to future generations.
| S-EPMC3677245 | biostudies-literature
Project description:Wnt/β-catenin signaling is essential for the initiation of dorsal-ventral patterning during vertebrate embryogenesis. Maternal β-catenin accumulates in dorsal marginal nuclei during cleavage stages, but its critical target genes essential for dorsalization are silent until mid-blastula transition (MBT). Here, we find that zebrafish net1, a guanine nucleotide exchange factor, is specifically expressed in dorsal marginal blastomeres after MBT, and acts as a zygotic factor to promote the specification of dorsal cell fates. Loss- and gain-of-function experiments show that the GEF activity of Net1 is required for the activation of Wnt/β-catenin signaling in zebrafish embryos and mammalian cells. Net1 dissociates and activates PAK1 dimers, and PAK1 kinase activation causes phosphorylation of S675 of β-catenin after MBT, which ultimately leads to the transcription of downstream target genes. In summary, our results reveal that Net1-regulated β-catenin activation plays a crucial role in the dorsal axis formation during zebrafish development.
| S-EPMC5339846 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2024-10-15 | GSE241755 | GEO