Publications by authors named "Xiang-Hong Ou"

Aneuploidy eggs are a common cause of human infertility, spontaneous abortion, or trisomy syndromes. The spindle assembly checkpoint (SAC) plays a crucial role in preventing aneuploidy in oocytes, yet it is unclear if additional mechanisms exist to ensure oocyte adherence to this checkpoint. It is now revealed that the microtubule-associated protein NUSAP can prevent oocytes from evading the SAC and regulate the speed of the cell cycle.

View Article and Find Full Text PDF

Maternal low protein diet around pregnancy reduces the primordial follicles in offspring ovary. Resolving cellular and molecular mechanisms associated with low protein diet is therefore urgently needed for the guidance of dietary interventions. Here, we utilized single-cell and spatial RNA-seq to create transcriptomic atlases of offspring ovaries from maternal low protein diet mice.

View Article and Find Full Text PDF

Maternal inheritance of mitochondrial DNA (mtDNA) is a widespread phenomenon in eukaryotes. Our earlier research indicated that sperm mtDNA is removed prior to fertilization in mice, and Endonuclease G (ENDOG) orchestrates the degradation of sperm mitochondria in Caenorhabditis elegans. However, the mechanisms underlying sperm mtDNA disposal in mammals remain poorly understood.

View Article and Find Full Text PDF

Oocyte meiotic maturation failure and chromosome abnormality is one of the main causes of infertility, abortion, and diseases. The mono-orientation of sister chromatids during the first meiosis is important for ensuring accurate chromosome segregation in oocytes. MEIKIN is a germ cell-specific protein that can regulate the mono-orientation of sister chromatids and the protection of the centromeric cohesin complex during meiosis I.

View Article and Find Full Text PDF

Histone lysine crotonylation, an evolutionarily conserved modification differing from acetylation, exerts pivotal control over diverse biological processes. Among these are gene transcriptional regulation, spermatogenesis, and cell cycle processes. However, the dynamic changes and functions of histone crotonylation in preimplantation embryonic development in mammals remain unclear.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the role of Formin-like 2 (FMNL2) in mammalian oocyte meiosis, particularly its impact on spindle migration and polar body extrusion.
  • FMNL2 is primarily located at the oocyte cortex and spindle edges; its depletion leads to defects in polar body extrusion and spindle migration due to reduced actin polymerization.
  • Additionally, FMNL2's absence affects mitochondrial and endoplasmic reticulum functions, causing mitochondrial dysfunction and ER stress, but these defects can be rescued by microinjecting FMNL2 mRNA into the affected oocytes.
View Article and Find Full Text PDF
Article Synopsis
  • Women with low ovarian reserve face a critical decision between natural and mildly stimulated IVF cycles, as the best option for embryo quality and pregnancy outcomes remains uncertain.
  • A study compared pregnancy rates and embryo quality between 478 natural cycles and 448 mildly stimulated cycles, finding that natural cycles had a significantly higher pregnancy rate (51.8% vs. 40.1%).
  • Natural cycles also yielded better embryo outcomes, including more available embryos (84.1% vs. 78.6%) and higher-quality embryos (61.8% vs. 53.2%), suggesting they may be a preferable option for these patients.
View Article and Find Full Text PDF

Objective: To reveal whether gut microbiota and their metabolites are correlated with oocyte quality decline caused by circadian rhythm disruption, and to search possible approaches for improving oocyte quality.

Design: A mouse model exposed to continuous light was established. The oocyte quality, embryonic development, microbial metabolites and gut microbiota were analyzed.

View Article and Find Full Text PDF

Sperm-induced Ca rise is critical for driving oocyte activation and subsequent embryonic development, but little is known about how lasting Ca oscillations are regulated. Here it is shown that NLRP14, a maternal effect factor, is essential for keeping Ca oscillations and early embryonic development. Few embryos lacking maternal NLRP14 can develop beyond the 2-cell stage.

View Article and Find Full Text PDF

Heavy drinking in women is known to adversely affect pregnancy and fertility. However, pregnancy is a complex process, and the adverse effects of ethanol on pregnancy does not mean that ethanol will have adverse effects on all stages from gamete to fetal formation. Similarly, the adverse effects of ethanol before and after adolescence cannot be generalized.

View Article and Find Full Text PDF

As a member of Ubiquitin-specific protease subfamily, ubiquitin specific protease 7 (USP7) has been reported to participate in a variety of cellular processes, including cell cycle, apoptosis, DNA damage response, and epigenetic modification. However, its function in preimplantation embryos is still obscure. To investigate the functions of USP7 during preimplantation embryo development, we used siRNA to degrade endogenous USP7 messenger RNA.

View Article and Find Full Text PDF

Strategies to maximize individual fertility chances are constant requirements of ART. In vitro folliculogenesis may represent a valid option to create a large source of immature ovarian follicles in ART. Efforts are being made to set up mammalian follicle culture protocols with suitable FSH stimuli.

View Article and Find Full Text PDF

Mammalian centromeres are generally composed of dispersed repeats and the satellites such as α-satellites in human and major/minor satellites in mouse. Transcription of centromeres by RNA polymerase II is evolutionary conserved and critical for kinetochore assembly. In addition, it has been found that the transcribed satellite RNAs can bind DNA repair proteins such as MRE11 and PRKDC, and excessively expressed satellite RNAs could induce genome instability and facilitate tumorigenesis.

View Article and Find Full Text PDF

With the rapid change of people's lifestyle, more childbearing couples live with irregular schedules (i.e., staying up late) and suffer from decreased fertility and abortion, which can be caused by luteal phase defect (LPD).

View Article and Find Full Text PDF

4-vinylcyclohexene diepoxide (VCD), widely used in industry, is a hazardous compound that can cause premature ovarian failure, but whether maternal VCD exposure affects the health and reproduction of offspring is unknown. Here we focused on the effects of VCD on fertility and physical health of F1 and F2 offspring in mice. The pregnant mice were injected intraperitoneally with different dosages of VCD once every day from 6.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the role of epigenetic modifications, specifically the enzyme EHMT2, during oocyte growth and meiosis in female mice.
  • Researchers found that removing EHMT2 led to infertility due to failure in homologous chromosome separation during the first meiotic division, which was not linked to the activation of the spindle assembly checkpoint.
  • Additionally, EHMT2 was shown to regulate the transcription of specific genes by influencing CTCF binding, indicating its critical function in the transition from metaphase I to anaphase I in oocyte development.
View Article and Find Full Text PDF

Mitochondrial replacement therapy (MRT) has been used to prevent maternal transmission of disease-causing mutations in mitochondrial DNA (mtDNA). However, because MRT requires nuclear transfer, it carries the risk of mtDNA carryover and hence of the reversion of mtDNA to pathogenic levels owing to selective replication and genetic drift. Here we show in HeLa cells, mouse embryos and human embryos that mtDNA heteroplasmy can be reduced by pre-labelling the mitochondrial outer membrane of a donor zygote via microinjection with an mRNA coding for a transmembrane peptide fused to an autophagy receptor, to induce the degradation of the labelled mitochondria via forced mitophagy.

View Article and Find Full Text PDF

Cell division consists of nuclear division (mitosis for somatic cells and meiosis for germ cells) and cytoplasmic division (cytokinesis). Embryonic developments are highly programmed, and thus, each cellular event during early embryo development is stable. For mouse embryos, the first time of mitosis is completed about 22 h after fertilization.

View Article and Find Full Text PDF

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis, are widespread in developed countries and gradually increasing in developing countries. Evidences showed that man with CD has a decrease of serum testosterone, but how IBD take effects on testicular testosterone synthesis is not well elucidated. To investigate the effects of IBD on testis, we analyzed testicular metabolome and transcriptome data of the dextran sulfate sodium (DSS) induced IBD mice.

View Article and Find Full Text PDF

Spontaneous abortion is an impeding factor for the success rates of human assistant reproductive technology (ART). Causes of spontaneous abortion include not only the pregnant mothers' health conditions and lifestyle habits, but also the fetal development potential. Evidences had shown that fetal chromosome aneuploidy is associated with fetal spontaneous abortion, however, it is still not definite that whether other genome variants, like copy number variations (CNVs) or loss of heterozygosity (LOHs) is associated with the spontaneous abortion.

View Article and Find Full Text PDF

Utilizing microinjection to introduce biological molecules such as DNA, mRNA, siRNA, and proteins into the cell is well established to study oocyte maturation and early embryo development . However, microinjection is an empirical technology. The cellular survival after microinjection is mainly dependent on the operator, and an experienced operator should be trained for a long time, from several months to years.

View Article and Find Full Text PDF

Within the development of ovarian follicle, in addition to cell proliferation and differentiation, sophisticated cell-cell cross talks are established among follicular somatic cells such as granulosa cells (GCs) and theca cells. To systematically reveal the cell differentiation and signal transductions in follicular somatic cells, we collected the mouse follicular somatic cells from secondary to ovulatory stage, and analyzed the single cell transcriptomes. Having data filtered and screened, we found 6883 high variable genes in 4888 single cells.

View Article and Find Full Text PDF

Insufficiency of oocyte activation impairs the subsequent embryo development in assisted reproductive technology (ART). Intracellular Ca concentration ([Ca]i) oscillations switch the oocytes to resume the second meiosis and initiate embryonic development. However, the [Ca]i oscillation patterns in oocytes are poorly characterized.

View Article and Find Full Text PDF

Break-induced replication (BIR) is essential for the repair of DNA double-strand breaks (DSBs) with single ends. DSBs-induced microhomology-mediated BIR (mmBIR) and template-switching can increase the risk of complex genome rearrangement. In addition, DSBs can also induce the multi-invasion-mediated DSB amplification.

View Article and Find Full Text PDF