Maternal and paternal genomes contribute equally to the transcriptome of early plant embryos
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE33713 | GEO | 2012/01/12
SECONDARY ACCESSION(S): PRJNA148475
REPOSITORIES: GEO
Similar Datasets
Project description:In animals, maternal gene products deposited into eggs regulate embryonic development before activation of the zygotic genome. In plants, an analogous period of prolonged maternal control over embryogenesis is thought to occur based on gene-expression studies. However, other gene-expression studies and genetic analyses show that some transcripts must derive from the early zygotic genome, implying that the prevailing model does not fully explain the nature of zygotic genome activation in plants. To determine the maternal, paternal and zygotic contributions to the early embryonic transcriptome, we sequenced the transcripts of hybrid embryos from crosses between two polymorphic inbred lines of Arabidopsis thaliana and used single-nucleotide polymorphisms (SNPs) diagnostic of each parental line to quantify parental contributions. Although some transcripts appeared to be either inherited from primarily one parent or transcribed from imprinted embryonic loci, the vast majority of transcripts were produced in near-equal amounts from both maternal and paternal alleles, even during the initial stages of embryogenesis. Results of reporter experiments and analyses of transcripts from genes that are not expressed in sperm and egg indicate early and widespread zygotic transcription. Thus, in contrast to early animal embryogenesis, early plant embryogenesis is mostly under zygotic control. Col-0 and Cvi-0 seed stocks were obtained from the Arabidopsis Biological Resource Center. Plants were grown at 22M-BM-0 C in a Conviron growth chamber with a 16-h light/8-h dark cycle. Flowers were emasculated one day before crossing, and pools of twenty 1-cell/2-cell, 8-cell and ~32-cell embryos were hand-dissected approximately 40, 64 and 78 hours after pollination, respectively. Embryo dissections, RNA isolation, linear amplification of poly(A) RNA and strand-specific RNA-Seq was as described (Nodine and Bartel, 2010, Genes & Development), except that embryos were extensively washed prior to RNA isolation. After removing adaptor sequences, reads were mapped to both the A. thaliana genome and transcript models (Col-0 genome reference, TAIR10) with the Bowtie short-read aligner. Reads were also mapped to a M-bM-^@M-^XpseudoM-bM-^@M-^Y Cvi-0 genome and Cvi-0 transcript models, in which SNPs in the Col-0 genome and transcript models were replaced with Cvi-0 variants (ftp://ftp.arabidopsis.org/home/tair/Sequences/Ecker_Cvi_snps.txt) generated by the 1,001 Genomes Project. Reads that both perfectly and uniquely matched either the genomes or transcript models were retained, and those overlapping transcribed regions of annotated genes were evaluated for overlap with SNPs. To normalize for differences in library sizes, the numbers of reads representing each transcript were divided by the total number of reads matching the genome and transcript models. SNP-overlapping reads were assigned to one of the parental genomes and tallied for each transcript, combining tallies for multiple SNPs within the same transcript.
2012-01-12 | E-GEOD-33713 | biostudies-arrayexpress
Project description:We used profiling of Arabidopsis small RNA populations present in the mature ovules to define the potential genome targets of small RNAs during reproductive development. Defining the contributions and interactions of paternal and maternal genomes during embryo development is critical to understand the fundamental processes involved in hybrid vigor, hybrid sterility, and reproductive isolation. To determine the parental contributions and their regulation during Arabidopsis embryogenesis we combined deep-sequencing-based RNA profiling and genetic analyses. At the 2-4 cell stage there is a strong, genome-wide dominance of maternal transcripts, although transcripts are contributed by both parental genomes. At the globular stage the relative paternal contribution is higher, largely due to a gradual activation of the paternal genome. We identified two antagonistic maternal pathways that control these parental contributions. Paternal alleles are initially down-regulated by the chromatin siRNA pathway, linked to DNA and histone methylation, while transcriptional activation requires maternal activity of the histone chaperone complex CAF1. Our results define maternal epigenetic pathways controlling the parental contributions in plant embryos, which are distinct from those regulating genomic imprinting. Profiling of small RNAs in wild type ovules of Arabidopsis
2011-05-15 | E-GEOD-28627 | biostudies-arrayexpress
Project description:We used profiling of Arabidopsis small RNA populations present in the mature ovules to define the potential genome targets of small RNAs during reproductive development. Defining the contributions and interactions of paternal and maternal genomes during embryo development is critical to understand the fundamental processes involved in hybrid vigor, hybrid sterility, and reproductive isolation. To determine the parental contributions and their regulation during Arabidopsis embryogenesis we combined deep-sequencing-based RNA profiling and genetic analyses. At the 2-4 cell stage there is a strong, genome-wide dominance of maternal transcripts, although transcripts are contributed by both parental genomes. At the globular stage the relative paternal contribution is higher, largely due to a gradual activation of the paternal genome. We identified two antagonistic maternal pathways that control these parental contributions. Paternal alleles are initially down-regulated by the chromatin siRNA pathway, linked to DNA and histone methylation, while transcriptional activation requires maternal activity of the histone chaperone complex CAF1. Our results define maternal epigenetic pathways controlling the parental contributions in plant embryos, which are distinct from those regulating genomic imprinting.
2011-05-15 | GSE28627 | 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 | 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:Early embryogenesis is characterized by the maternal to zygotic transition (MTZ), in which maternally deposited messenger RNAs are translated and subsequently degraded while zygotic transcription begins. Posttranscriptional gene regulation by RNA-binding proteins (RBPs) is a dominant force controlling pre-zygotic gene expression. Here we describe the first in vivo mRNA-bound proteome in early Drosophila melanogaster embryos. mRNA interactome capture using conventional (254nm) and photoactivatable ribonucleoside-enhanced UV-crosslinking (365nm) was applied to detect RBPs bound to maternal and early zygotic polydenylated transcripts within the first two hours of embryogenesis. We identified a high confidence set of 476 putative RBPs and confirmed RNA-binding activity for most of the tested candidates. The majority of the identified proteins in the early fly mRNA interactome were known RBPs, harboring canonical RBPs features. Nearly hundred of the identified proteins were previously not known to bind RNA. Interestingly, mRNAs encoding RBPs and TFs exhibit time specific expression modules, in which RBPs dominate the first hours of embryonic development. Using fly-FISH data, we could show enriched RBP localization in the posterior embryo during these first hours of fly embryogenesis, suggesting general importance germ cell maturation.
2016-04-26 | PXD002992 | Pride
Project description:The goal of the present study is to analyze the characteristics of maternal to zygotic transition (MZT) in Arabidopsis. The maternal-to-zygotic transition (MZT) is an essential developmental turning point during the alternation of generations in both plants and animals. In animals, early embryogenesis is maternally controlled and zygotic genome activation (ZGA) starts much later. However, in plants, the timing of MZT and parental contributions to the zygotic transcriptome remain unclear. To address above mentioned questions, we selected Arabidopsis as model plant for the analysis. Regarding to the characteristics of MZT, egg cells, embryos including spherical zygote, elongated zygote, 1-cell embryo and 32-cell embryo were isolated and collected for RNA sequencing. Hybrid zygotes at two representative stages from the reciprocal crosses between polymorphic Arabidopsis Columbia (Col) and Landsberg erecta (Ler) accessions were also sequenced for investigating the parental contributions. We demonstrate that plant MZT occurs during the zygote stage and is a two-step process, first involving rapid maternal transcript degradation and, second, large-scale de novo transcription. Parental contributions to the zygotic transcriptome are stage dependent over the course of zygote development; the spherical zygote is characterized by a maternally dominated transcriptome, whereas the elongated zygote genome shows equal parental contributions.
2019-05-12 | GSE121003 | GEO
Project description:During embryogenesis in animals, initial developmental processes are driven entirely by maternally provided gene products that are deposited into the oocyte. The zygotic genome is transcriptionally activated later, when developmental control is handed off from maternal gene products to the zygote during the maternal to zygotic transition (MZT). The MZT is highly regulated and conserved across all animals, and while some details change across model systems where it has been studied, most are too evolutionarily diverged to make comparisons as to how this process evolves. There are differences in maternal gene products and their zygotic complements across Drosophila species, so here we used hybrid crosses between sister species of Drosophila (D. simulans, D. sechellia, and D. mauritiana) and transcriptomics to determine how gene regulation changes in early embryogenesis across species. We find that regulation of maternal transcript deposition and zygotic transcription evolve through different mechanisms. Changes in transcript levels occur predominantly through differences in trans regulation for maternal genes, while changes in zygotic transcription occur through a combination of regulatory changes in cis, trans, and both cis and trans. We find that patterns of transcript level inheritance in hybrids relative to parental species differs between maternal and zygotic transcripts; maternal transcript levels are more likely to be conserved but both stages have a large proportion of transcripts showing dominance of one parental species. Differences in the underlying regulatory landscape in the mother and the zygote are likely the primary determinants for how maternal and zygotic transcripts evolve species.
2020-11-24 | GSE136646 | GEO
Project description:The epigenome plays critical roles in controlling gene expression and development. However, how the parental epigenomes transit to the zygotic epigenome in early development remains elusive. Here, we show parental-to-zygotic transition in zebrafish involves extensive erasure of parental epigenetic memory starting by methylating gametic enhancers. Surprisingly, this occurs even prior to fertilization for sperm. Both parental enhancers lose histone marks by the 4-cell stage, and zygotic enhancers are not activated until around zygotic genome activation (ZGA). By contrast, many promoters remain hypomethylated and, unexpectedly, acquire de novo histone acetylation as early as at the 4-cell stage. They then resolve into either activated or repressed promoters upon ZGA. Maternal depletion of histone acetyltransferases results in aberrant ZGA and early embryonic lethality. Finally, such reprogramming is largely driven by maternal factors with zygotic products contributing to embryonic enhancer activation. Thus, these data revealed widespread enhancer dememorization and promoter priming during parental-to-zygotic transition.
2018-10-25 | GSE114954 | GEO
Project description:In mammals, totipotent pre-implantation embryos are formed by fusion of highly differentiated oocytes and spermatozoa. Acquisition of totipotency concurs with remodeling of chromatin states of parental genomes (âepigenetic reprogrammingâ), changes in maternally contributed transcriptome and proteome, and zygotic genome activation. Genomes of mature germ cells are more proficient in supporting embryonic development than those of somatic cells. It is currently unknown whether transgenerational inheritance of chromatin states present in mature gametes underlies the efficacy of early embryonic development after natural conception. Here, we show that Ring1 and Rnf2, two core components of the Polycomb Repressive Complex 1 (PRC1), serve redundant gene regulatory functions during oogenesis that are required to support embryonic development beyond the two-cell stage. Numerous developmental regulatory genes that are established Polycomb targets in various somatic cell types are de-repressed in Ring1/Rnf2 double mutant (dm) fully grown germinal vesicle (GV) oocytes. Translation of tested aberrant maternal transcripts is, however, delayed until after fertilization. Exchange of maternal pro-nuclei between control and Ring1/Rnf2 maternally dm early zygotes demonstrates an essential role for Ring1 and Rnf2 during oogenesis in defining cytoplasmic and nuclear maternal contributions that are both essential for proper initiation of embryonic development. A large number of genes up-regulated in Ring1/Rnf2 dm GV oocytes harbor PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) in spermatozoa and in embryonic stem cells (ESCs), and are repressed during normal oogenesis and early embryogenesis. These data strongly support the model that Polycomb acts in the female and male germline to silence differentiation inducing genes and to program chromatin states, thereby sustaining developmental potential across generations. Expression profiling of late 2-cell embryos was performed with the following genotypes: maternal Ring1-Rnf+ (control), maternal Ring1-Rnf2- (maternal Ring1/Rnf2 double mutant). These embryos were obtained by crossing Ring1-/-Rnf2F/F control females or Ring1-/-Rnf2F/F Zp3-cre expreimental females, respectively, to Ring1+/+Rnf2F/F control males. To distinguish between maternal transcripts present in the 2-cell embryo and newly (embryonicaly) transcribed transcripts, embryos from both genotypes were either not treated (expression profiling therefore shows all maternal and embryonic transcripts) or alpha-amanitin treated (alpha-amanitin inhibits de novo transcription, therefore expression profiling of treated embryos will only show maternal transcripts). 11 samples were analyzed: 3 biological replicates (except alpha-amanitin treated maternal Ring1/Rnf2 double mutant, where only 2 replicates were analyzed) of each genotype and treatment group were analyzed. Each sample contains 40 late 2-cell embryos.
2012-05-06 | E-GEOD-28710 | biostudies-arrayexpress