Dataset Information

The landscape of H3K9me2 and CTCF in mice GV oocytes

ABSTRACT: During oocyte growth, various epigenetic modifications are gradually established, accompanied by accumulation of large amounts of mRNAs and proteins. However, little is known about the relationship between epigenetic modifications and meiotic progression. Here, by using Gdf9-Cre to achieve oocyte-specific ablation of Ehmt2 (Euchromatic-Histone-Lysine-Methyltransferase 2) from the primordial follicle stage, we found that female mutant mice were infertile. Oocyte-specific knockout of Ehmt2 caused failure of homologous chromosome separation independent of persistently activated SAC during the first meiosis. Further studies revealed that lacking maternal Ehmt2 affected the transcriptional level of Ccnb3, while microinjection of exogenous Ccnb3 mRNA could partly rescue the failure of homologous chromosome segregation. Of particular importance was that EHMT2 regulated ccnb3 transcriptions by regulating CTCF binding near ccnb3 gene body in genome in oocytes. In addition, the mRNA level of Ccnb3 significantly decreased in the follicles microinjected with Ctcf siRNA. Therefore, our findings highlight the novel function of maternal EHMT2 on the metaphase I-to-anaphase I transition in mouse oocytes: regulating the transcription of Ccnb3.

ORGANISM(S): Mus musculus

PROVIDER: GSE182557 | GEO | 2024/08/22

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

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.

Dataset Information

The landscape of H3K9me2 and CTCF in mice GV oocytes

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets