Project description:Background: Early embryonic development is governed by maternal transcripts stored within the oocyte during oogenesis. Transcriptional activity of the oocyte ultimately dictates its developmental potential and may be influenced by maternal age, resulting in reduced competence of oocytes derived from women of advanced age, compared with the young. In the current study, RNA-Seq was used to perform transcriptome profiling of human GV and MII oocytes derived from young and advanced maternal age women. Participants/Materials and Methods: Cumulus dissection from donated oocytes was performed. GV and MII oocytes underwent deep RNA sequencing using the SMART-Seq v4 Ultra Low Input RNA protocol (Takara-Clontech, USA) and Nextera XT DNA library preparation kit (Illumina, USA). Data processing, quality assessment and bioinformatics analysis were performed using source-software, including FastQC, HISAT2, StringTie, edgeR and DAVID. Results: Following deep single-cell RNA-Seq on GV and MII oocytes, hundreds of transcripts were significantly differentially expressed between young maternal age (YMA) and advanced maternal age (AMA) groups, with the most significant biological processes relating to mitochondrial reserves. The GV to MII transition shares common biological processes between young and AMA groups, however, some genes involved in mitochondria function were altered during ageing. A decrease in mitochondrial-related transcripts was also observed during the GV to MII transition. However, there was a much greater reduction of mitochondrial-related transcripts in MII oocytes of AMA. This observation was confirmed when YMA MII oocytes were compared with the AMA MII group with mitochondrial-related transcripts being significantly higher expressed in the YMA group, including biological processes, such as mitochondrial electron transport and ATP biosynthetic process. These results indicate a higher energy potential in YMA MII oocytes that is decreased with age. Other significantly higher biological processes in the YMA MII group include transcripts involved in the regulation of ubiquitin-dependent degradation. Lack of these transcripts could lead to a non-appropriate removal of oogenesis remnants following fertilisation in the AMA MII group. Discussion: Understanding reproductive ageing effects at the RNA level in human oocytes may reveal differences in the mechanisms regulating the GV to MII transition that impact on oocyte quality in YMA and AMA patients. Further investigations of the up-/down-regulated transcripts during ageing could guide and improved IVF outcomes for AMA patients.
Project description:The oocyte maturation is a poorly understood process. Patl2 is involved in human bad egg syndrome and is a translation factor. The aim of this study was to assess the impact of the lack of Patl2 on the transcriptomes of GV and MII oocytes.
Project description:Two replicates of GV, GVBD, and MII oocytes were subjected to the 6-plex TMT labeling, HP-RP fractionation, and LC-MS/MS analysis. Two labeling experiments were performed for the total four replicates of each stage of oocytes.
Project description:We profiled transcriptomes from Cnot6l deadenylase knock-out mouse GV oocytes, MII eggs and 1-cell zygotes in order to analyse its function during the oocyte-to-embryo (OET) transition. Transcriptome of wild-type golden hamster GV oocytes was also profiled.
Project description:Poly-ribosomal mRNA from pools of 75 bovine oocytes at the germinal vesicle(GV) and metaphase II(MII) stages were isolated by sucrose fractionation then compared through microarray hybridization.
Project description:Poly-ribosomal mRNA from pools of 75 bovine oocytes at the germinal vesicle(GV) and metaphase II(MII) stages were isolated by sucrose fractionation then compared through microarray hybridization. 3 biological replicates from germinal vesicle(GV) and metaphase II(MII) bovine oocytes were hybridized against each other while alternating dyes. One additional technical replicate (dye-swap of one of the previous hybridizations) was added to balance dye usage. The normalized log2 ratio (GV/MII) data is provided in the 'normalized_data.txt' file. Please note that data were scanned/extracted using a different Agilent reference file, and thus the feature extraction number for a given probe (in both normalized and raw data files) is different from that in the official Agilent-041017 platform (GPL18537). The reference file used for this study is provided as a Series supplementary file (041017_D_DNAFront_BCBottom_20120517.txt).
Project description:Expression data from prepubertal, peripubertal, and adult derived mouse oocytes, and from germinal vesicle (GV), in vivo matured, and in vitro matured mouse oocytes. Oocytes derived from prepubertal females, or oocytes matured in vitro, are less developmentally competent compared to adult derived, or in vivo matured, oocytes, indicated by decreased embryonic development. One potential mechanism for decreased developmental potetential in prepubertal or in vitro matured oocytes is inadequate or inappropriate RNA degradation during oocyte maturation (progression from GV to MII). To investigate mechanisms involved in establishing oocyte cytoplasmic maturation and developmental competence, Affymetrix GeneChip microarrays were used. Keywords: Oocyte developmental competence
Project description:Expression data from prepubertal, peripubertal, and adult derived mouse oocytes, and from germinal vesicle (GV), in vivo matured, and in vitro matured mouse oocytes. Oocytes derived from prepubertal females, or oocytes matured in vitro, are less developmentally competent compared to adult derived, or in vivo matured, oocytes, indicated by decreased embryonic development. One potential mechanism for decreased developmental potetential in prepubertal or in vitro matured oocytes is inadequate or inappropriate RNA degradation during oocyte maturation (progression from GV to MII). To investigate mechanisms involved in establishing oocyte cytoplasmic maturation and developmental competence, Affymetrix GeneChip microarrays were used. Keywords: Oocyte developmental competence The study encompassed three experimental designs using female B6D2F1 mice: 1) In vitro matured oocytes were obtained from d20 (prepubertal), d26 (peripubertal), and 7-8 wk old (adult) mice; 2) in vivo and in vitro matured oocytes were obtained from d26 mice; and 3) GV, in vivo matured, and in vitro matured oocytes were obtained from 7-8 wk old mice. RNA was extracted from pools of 150 oocytes and hybridized onto the Affymetrix microarrays.
Project description:Background The suggested effects of the oocyte secreted GDF9 and BMP15 growth factors on oocyte maturation are currently based on recombinant proteins, and little is known about native GDF9 and BMP15 in humans. Methods Human immature cumulus-oocyte complexes (COCs) obtained in connection with ovarian tissue cryopreservation (OTC) underwent in vitro maturation (IVM). Oocyte-produced GDF9 and BMP15 were detected in COCs using immunofluorescence, and in fresh GV oocytes and in GV and MII oocytes after IVM by western blot. Concentrations of GDF9, BMP15 homodimers, and GDF9/BMP15 heterodimer in spent media after IVM were measured by ELISA. The relative expression of seven genes from the GDF9 and BMP15 signaling pathways (BMPR2, ALK5, ALK6, SMAD1, SMAD2, SMAD3, and SMAD5) was evaluated in fresh cumulus cells (before IVM) and in cumulus cells from GV and MII oocytes after IVM by RT-qPCR. Results We detected native pro-mature GDF9 and BMP15 in human oocytes with molecular weights (Mw) of 47 kDa and 43 kDa, respectively. Concentrations of GDF9 and BMP15 in spent media after IVM were detected in 99% and 64% of the samples, respectively. The GDF9/BMP15 heterodimer was detected in 76% of the samples. Overall, the concentration of GDF9 was approximately 10-times higher than BMP15. The concentrations of both GDF9 and BMP15 were significantly lower in spent medium from MII oocytes than in media from oocytes that remained at the GV stage. Concentrations of the GDF9/BMP15 heterodimer did not differ between GV and MII oocytes. Furthermore, BMPR2, SMAD3, and SMAD5 were significantly upregulated in cumulus cells from MII oocytes, indicating that both GDF9 and BMP15 signaling were active during oocyte meiotic resumption in vitro. Conclusion These data suggest that the driving mechanisms for oocyte nuclear maturation may involve both GDF9 and BMP15 homodimers, while the role of the GDF9/BMP15 heterodimer is questionable. Supplementary Information The online version contains supplementary material available at 10.1186/s12958-022-01000-6.