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  • metaphase
  • Pubmed ID: 11730913 Following penetration of the zona pellucida, the mammalian spermatozoon binds and fuses with the egg plasma membrane, thereby fertilizing the egg that is still arrested at the second metaphase. (jove.com)
  • Proteins
  • The availability of various GFP-tagged proteins means that many cellular processes can be monitored in living cells over the course of minutes or hours, and using this technique, processes such as RNP transport, epithelial morphogenesis, and tissue remodeling have been described in great detail in Drosophila oocytes 1,2 . (jove.com)
  • We also identified novel-ePAB interacting proteins in Xenopus oocytes and are currently characterizing these proteins and their mammalian orthologues as potential regulators of gene expression during early development. (yale.edu)
  • Unlike mitotic cells, mammalian oocytes lack typical centrosomes that consist of two centrioles and the surrounding pericentriolar matrix proteins, which serve as microtubule-organizing centers (MTOCs) in most somatic cells. (deepdyve.com)
  • Because of a low expression of O -GlcNAcylation in Xenopus oocyte, classical enrichment of O -GlcNAc-bearing proteins using O -GlcNAc-directed antibodies or wheat germ agglutinin lectin affinity were hard to apply, albeit these techniques allowed the identification of actin and erk2. (mcponline.org)
  • Therefore, another strategy based on an in vitro enzymatic labeling of O -GlcNAc residues with azido-GalNAc followed by a chemical addition of a biotin alkyne probe and by enrichment of the tagged proteins on avidin beads was used. (mcponline.org)
  • Bound proteins were analyzed by nano-LC-nano-ESI-MS/MS allowing for the identification of an average of 20 X. laevis oocyte O -GlcNAcylated proteins. (mcponline.org)
  • Furthermore immunofluorescence microscopy enabled the direct visualization of O -GlcNAcylation and OGT on the meiotic spindle as well as the observation that chromosomally bound proteins were enriched in O -GlcNAc and OGT. (mcponline.org)
  • chromosomes
  • Deletion of ERK3 by microinjection of ERK3 morpholino (ERK3 MO) resulted in oocyte arrest at the MI stage with severely impaired spindles and misaligned chromosomes. (jove.com)
  • This situation occurs when there is some disruption in signal transduction pathway or abnormally meiotic spindle, which is responsible for abnormal separation and segregation of chromosomes. (fertilitypedia.org)
  • The spermatozoon mostly contributes the other half of the chromosomes and it is specialized to reach and to penetrate the oocyte. (mdpi.com)
  • Introduction In the final stage of mammalian oocyte maturation, a meiotic spindle is formed within the oocyte, followed by segregation of bivalent chromosomes and extrusion of the first polar body . (deepdyve.com)
  • cyclin
  • Epab -/- oocytes failed to achieve translational activation of maternally-stored mRNAs upon stimulation of oocyte maturation, including cyclin B1 and Dazl mRNAs. (yale.edu)
  • Cyclin B1 levels were elevated ~5-fold in Fzr1 Δ/Δ oocytes, whereas securin and CDC25B, two other APC/C FZR1 substrates, were unchanged. (biologists.org)
  • segregation
  • Depleting maternal HDAC2 results in hyperacetylation of H4K16 as determined by immunocytochemistry-normal deacetylation of other lysine residues of histone H3 or H4 is observed-and defective chromosome condensation and segregation during oocyte maturation occurs in a sub-population of oocytes. (prolekare.cz)
  • In addition, the results provide additional support that histone deacetylation that occurs during oocyte maturation is critical for proper chromosome segregation. (prolekare.cz)
  • Understanding the mechanisms of MI/MII spindle formation, spindle assembly checkpoint, and chromosome segregation, in mammalian oocytes, will provide valuable insights into the molecular mechanisms of human infertility. (deepdyve.com)
  • Additionally, we review the mechanistic aspects of meiotic spindle formation and examine the factors implicated in the development of spindle abnormalities and erroneous chromosome segregation. (deepdyve.com)
  • This raises the possibility that cell volume may be the reason the SAC is weak, and chromosome segregation error-prone, in mammalian oocytes. (rupress.org)
  • Xenopus
  • Additionally, many of the techniques to overexpress or inhibit gene function in organisms such as Xenopus and zebrafish fail to sufficiently target critical maternal signaling pathways, such as Wnt signaling. (jove.com)
  • In Xenopus , manipulating gene function in cultured oocytes and subsequently fertilizing them can ameliorate these problems to some extent. (jove.com)
  • Embryonic poly(A) binding protein (ePAB), identified in Xenopus oocytes (Voeltz et al. (yale.edu)
  • In Xenopus , ePAB is present in both known protein complexes (cytopasmic polyadenylation complex and Pumilio-2/DAZL/ePAB complex) that bind and stabilize dormant mRNAs in immature oocytes. (yale.edu)
  • Using the Xenopus model, we demonstrated that ePAB is a dynamically modified phosphoprotein and showed by mutation that phosphorylation at a four-residue cluster is required for oocyte maturation. (yale.edu)
  • We have described previously the sudden O -GlcNAcylation increase occurring during the Xenopus laevis oocyte G 2 /M transition, and we have demonstrated that the inhibition of O -GlcNAc-transferase (OGT) blocked this process, showing that the O -GlcNAcylation dynamism interferes with the cell cycle progression. (mcponline.org)
  • Xenopus laevis oocyte has been widely used as a model for studying the regulation of the cell cycle. (mcponline.org)
  • aneuploidy
  • The resulting increased incidence of aneuploidy likely accounts for the observed sub-fertility of mice harboring Hdac2 −/− oocytes. (prolekare.cz)
  • The mechanisms of age-related aneuploidy have been studied extensively using the mouse oocyte as a model system . (deepdyve.com)
  • Understanding the mechanisms of meiotic spindle formation in mammalian oocytes, particularly in humans, will provide valuable information for the development of diagnostic and therapeutic strategies for aneuploidy-caused infertility. (deepdyve.com)
  • phosphorylation
  • Recombinant tUCHL1 absorbed p34(cdc2), a component of MPF, in obviously larger quantities from mature oocytes than from immature oocytes, and p13(suc1) was isolated from tUCHL1 with a dependence on the ATP regeneration system, suggesting that still other functions may be involved in their association that require phosphorylation. (jove.com)
  • PKAI activation inhibited mitogen-activated protein kinase (MAPK) phosphorylation in the oocytes of COCs, which participated in the initiation of FSH-induced meiotic maturation in vitro. (jove.com)
  • Just before FSH-induced meiotic maturation, cAMP, PKAI, and GPR3 returned to basal levels, and PDE3A activity and MAPK phosphorylation increased markedly. (jove.com)
  • In the oocyte, it is well documented that the elevated intracellular cAMP level continuously activates protein kinase A (PKA), which subsequently results in the phosphorylation and activation of nuclear kinase Weel/MytI. (springer.com)
  • mRNAs
  • This oocyte-to-embryo transition needs an efficient and tightly regulated translation of the maternally-inherited mRNAs, which likely contributes to embryonic genome activation. (mdpi.com)
  • embryonic
  • A total of 75% of surviving oocytes were able to respond to artificial activation, 44.4% of the parthenotes developed to early embryonic stage. (biomedcentral.com)
  • spindle assembly
  • In this study, we showed that resveratrol, a kind of phytoalexin found in the skin of grapes, red wine and other botanical extracts, can alleviate the adverse effects caused by methylglyoxal, such as inhibition of oocyte maturation and disruption of spindle assembly. (jove.com)
  • Most importantly, the spindle assembly checkpoint protein BubR1 could be detected on kinetochores even in oocytes cultured for 10 h. (jove.com)
  • stimulation
  • When applied after FSH stimulation, the specific phosphodiesterase 3A (PDE3A) inhibitor cilostamide immediately blocked meiotic induction, regardless of when it was administered. (jove.com)
  • competent
  • Any material of choice may be introduced into the oocyte, but because meiotically-competent oocytes are transcriptionally silent 4,5 cRNA, and not DNA, must be injected for ectopic expression studies. (jove.com)
  • These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. (wikipedia.org)