Similar Datasets
Project description:Fully-grown oocytes are transcriptionally silent and must stably maintain mRNAs needed for oocyte meiotic maturation and early embryonic development. However, where and how mammalian oocytes store maternal mRNAs is unclear. Here, we report that mammalian oocytes accumulate mRNAs in a mitochondria-associated ribonucleoprotein domain (MARDO). MARDO assembly around mitochondria was promoted by the RNA-binding protein ZAR1, and directed by an increase in mitochondrial membrane potential during oocyte growth. MARDO foci coalesced into hydrogel-like matrices that clustered mitochondria. Maternal mRNAs stored in the MARDO were translationally repressed. Loss of ZAR1 disrupted the MARDO, dispersed mitochondria, and caused a premature loss of MARDO-localized mRNAs. Thus, a mitochondria-associated membraneless compartment controls mitochondrial distribution and regulates maternal mRNA storage, translation and decay to ensure fertility in mammals.
2022-10-25 | PXD036974 | Pride
Project description:Mammalian oocytes store mRNAs in a mitochondria-associated membraneless compartment
| PRJNA880587 | ENA
Project description:To investigate the transcriptomic profile of Padi6 -/- and Tle6 -/- oocytes
2023-11-02 | GSE222809 | GEO
Project description:Oocytes must accumulate and store maternal factors such as proteins during growth to sustain the first stages of embryonic development. How mammalian oocytes store maternal proteins is not understood. Here, we show that mouse and human oocytes store proteins on cytoplasmic lattices. With super-resolution light microscopy and electron tomography, we demonstrate that cytoplasmic lattices are twisted filament bundles formed by proteins of the subcortical maternal complex, filling the entire ooplasm. The lattices were associated with many proteins that have crucial functions during early embryo development, including proteins controlling genome methylation. Loss of cytoplasmic lattices prevented the accumulation of these proteins and resulted in early embryonic arrest. Thus, cytoplasmic lattices are important for storage of essential maternal proteins and the developmental success of early mammalian embryos.
2023-10-23 | PXD038575 | Pride
Project description:Mammalian oocytes store proteins in cytoplasmic lattices
| PRJNA923596 | ENA
Project description:Zar1 was the first mammalian maternal-effect gene to be identified. Embryos derived from Zar1-null female mice are blocked before zygotic genome activation; however, the underlying mechanism remains unclear. By knocking out Zar1 and its homolog Zar2 in mice, we revealed a novel function of these genes in oocyte meiotic maturation. Zar1/2-deleted oocytes displayed delayed meiotic resumption and polar body-1 emission and a higher incidence of abnormal meiotic spindle formation and chromosome aneuploidy. The grown oocytes of Zar1/2-null mice contained fewer total mRNAs and displayed a reduced level of protein synthesis. Key maturation-associated changes failed to occur in the Zar1/2-null oocytes, including the translational activation of maternal mRNAs encoding the cell cycle proteins cyclin B1 and WEE2, as well as maternal-to-zygotic transition (MZT) licensing factor BTG4. Consequently, maternal mRNA decay was impaired and MZT was abolished. ZAR1/2 bound mRNAs to regulate the translational activity of their 3ʹ-UTRs and interacted with other oocyte proteins, including mRNA-stabilizing protein MSY2 and cytoplasmic lattice components. These results countered the traditional view that ZAR1 only functions after fertilization and highlight a previously unrecognized role of ZAR1/2 in regulating the maternal transcriptome and translational activation in maturing oocytes.
2019-09-25 | GSE135787 | GEO
Project description:Postovulatory aging leads to the decline in oocyte quality and subsequent impairment of embryonic development, thereby reducing the success rates of assisted reproductive technology (ART). Nevertheless, potential preventative strategies to improve aging oocytes quality and the associated underlying mechanisms warrant further investigation. In this study, we identify cordycepin, an natural nucleoside analogue, as having the potential to restore the postovulatory aging-induced decline in oocyte quality, including aspects such as oocyte fragmentation, embryonic developmental competence, spindle/chromosomes morphology and mitochondrial function. Proteomic and RNA sequencing analyses revealed that cordycepin inhibited the degradation of several crucial maternal proteins and mRNAs caused by aging. Mechanistically, cordycepin was found to suppress the elevation of DCP1A protein levels by inhibiting polyadenylation during postovulatory aging, consequently impeding the decapping of maternal mRNAs. In humans, the increased degradation of DCP1A and total mRNA during aging was also inhibited by cordycepin. Collectively, our findings demonstrate that cordycepin may prevent postovulatory aging of mammalian oocytes by inhibition of maternal mRNAs degradation via DCP1A polyadenylation suppression, thereby promoting the successful rates of ART procedure.
2024-01-26 | PXD042600 | Pride
Project description:In mammals, oocytes are formed in the female embryo and need to be preserved in the ovary to ensure the viability of the next generation. How oocytes are maintained for decades is unclear. Here, we combined pulse-chase stable isotope labelling coupled with mass spectrometry, single-cell RNA-seq, microscopy and NanoSims to create an atlas of protein homeostasis in mouse oocytes and ovaries over the entire reproductive lifespan. Our results show that protein turnover in the ovary is much slower than in other organs, with hundreds of extremely long-lived proteins across a broad range of complexes and pathways, including mitochondria, ribosomes and the cytoskeleton. We propose that slow protein turnover helps to maintain proteostasis in oocytes and the ovary over long periods, protecting the germline across generations.
2023-07-26 | MSV000092528 | MassIVE
Project description:Germ cells of most animals critically depend on piRNAs and Piwi proteins. Surprisingly, piRNAs in mouse oocytes are relatively rare and dispensable. We present compelling evidence for strong Piwi-piRNA expression in oocytes of other mammals. Human fetal oocytes express PIWIL2 and transposon-enriched piRNAs. Oocytes in adult human ovary express PIWIL1 and PIWIL2, while those in bovine ovary just express PIWIL1. In human, macaque and bovine ovaries we find piRNAs that resemble testis-borne pachytene piRNAs. Isolated bovine follicular oocytes were shown to contain abundant, relatively short piRNAs that preferentially target transposable elements. Using label-free quantitative proteome analysis we show that these maturing oocytes strongly and specifically express the thus-far uncharacterized PIWIL3 protein, alongside other known piRNA-pathway components. In bovine early embryos these piRNAs are still abundant, revealing a potential impact of piRNAs on mammalian embryogenesis. Our results reveal unexpected, highly dynamic piRNA pathways in mammalian oocytes and early embryos. Analyses of multiple small RNA libraries obtained from fetal/adult oocytes, cumulus cells, ovary, testis and 2-4 cell stage ivf embryos of multiple mammalian species.
2015-03-27 | E-GEOD-64942 | biostudies-arrayexpress
Project description:Germ cells of most animals critically depend on piRNAs and Piwi proteins. Surprisingly, piRNAs in mouse oocytes are relatively rare and dispensable. We present compelling evidence for strong Piwi-piRNA expression in oocytes of other mammals. Human fetal oocytes express PIWIL2 and transposon-enriched piRNAs. Oocytes in adult human ovary express PIWIL1 and PIWIL2, while those in bovine ovary just express PIWIL1. In human, macaque and bovine ovaries we find piRNAs that resemble testis-borne pachytene piRNAs. Isolated bovine follicular oocytes were shown to contain abundant, relatively short piRNAs that preferentially target transposable elements. Using label-free quantitative proteome analysis we show that these maturing oocytes strongly and specifically express the thus-far uncharacterized PIWIL3 protein, alongside other known piRNA-pathway components. In bovine early embryos these piRNAs are still abundant, revealing a potential impact of piRNAs on mammalian embryogenesis. Our results reveal unexpected, highly dynamic piRNA pathways in mammalian oocytes and early embryos.
2015-03-27 | GSE64942 | GEO