Disease relevance of Oocytes

• Mice lacking either Ahr or the pro-apoptotic protein Bax have an increased number of primordial follicles, and these mutant oocytes are resistant to PAH toxicity [1].
• Expression of the mutant GluR delta2(Lc) protein in Xenopus oocytes confirmed these results, demonstrating that Lc is inherited as a neurodegenerative disorder resulting from a gain-of-function mutation in a glutamate receptor gene [2].
• Sperm function, which was judged normal by means of standard seminal analysis and mucus penetration, was confirmed by normal IVF in unexplained infertility: 63% (37/59) per oocyte and 90% (18/20) per couple [3].
• Uptake of the cytostatic drug [3H]-chlorambucil-taurocholate (S2676) was measured in Xenopus laevis oocytes injected with total messenger RNA (mRNA) from the carcinomas or peritumor tissue or with complementary RNA encoding the NTCP or the organic anion-transporting polypeptide (OATP) of human liver [4].
• During studies of the activation and inactivation of the cyclin B-p34cdc2 protein kinase (MPF) in cell-free extracts of Xenopus oocytes and eggs, we found that a bacterially expressed fusion protein between the Escherichia coli maltose-binding protein and the Xenopus c-mos protein kinase (malE-mos) activated a 42 kDa MAP kinase [5].

Psychiatry related information on Oocytes

• Postovulatory aging of oocytes was also associated with increased number of growth-retarded pups, delayed development of the righting reflex, and higher spontaneous motor activity and emotionality of F(1) offspring [6].
• Food deprivation has much the same effect on oocyte endocytosis as does estrogen [7].
• We suggest that a critical period of estrogen amplification in the preovulatory follicle underscores the capacity of its oocyte to efficiently repair DNA and therefore reconcile spontaneous infidelities in genomic integrity that inevitably occur during preimplantation embryogenesis [8].

High impact information on Oocytes

• Evidence that phosphoinositide signaling pathways control the resumption of meiosis during oocyte maturation is considered [9].
• Prior to reaching the posterior pole of the Drosophila oocyte, oskar mRNA is translationally silenced by Bruno binding to BREs in the 3' untranslated region [10].
• These data also provide unexpected links between oocyte metabolism, CaMKII, and caspase-2 [11].
• We show that pentose-phosphate-pathway generation of NADPH is critical for oocyte survival and that the target of this regulation is caspase-2, previously shown to be required for oocyte death in mice [11].
• PAR-1 also excludes Bazooka from the posterior of the oocyte, and disruption of this regulation causes anterior-posterior polarity defects [12].

Chemical compound and disease context of Oocytes

• Injection of Clostridium botulinum C3 exoenzyme, which inactivates Rho by ADP-ribosylation, induced a redistribution of virtually all intracellular sodium pumps to the plasma membrane and increased the surface area of the oocytes [13].
• By using truncated NH2-terminal RII beta fusion proteins expressed in Escherichia coli and the mitotic protein kinase p34cdc2 isolated from HeLa cells or starfish oocytes, we investigated the in vitro phosphorylation of RII beta by these kinases [14].
• Microinjection of purified pp60v-src, the transforming protein of Rous sarcoma virus, into Xenopus laevis oocytes accelerated the rate of progesterone- or insulin-induced meiotic maturation [15].
• Purified oocyte membrane preparations from X. laevis oocytes previously microinjected with C6-2B rat astrocytoma mRNA, and subsequently defolliculated, exhibited novel beta AR and forskolin-stimulated adenylate cyclase activity [16].
• Merlin, the Drosophila homologue of neurofibromatosis-2, is specifically required in posterior follicle cells for axis formation in the oocyte [17].

Biological context of Oocytes

• Phosphorylation of serine residues in phosvitin can be detected in oocytes injected with 32PO4 or gamma-32P-ATP; thus exogenously derived yolk platelet protein is further modified, or turned over, once it is within the oocyte [18].
• We show here that Mater, a mouse oocyte protein dependent on the maternal genome, is essential for embryonic development beyond the two-cell stage [19].
• Mutant ICRs in oocytes and blastocysts are not methylated, however, indicating that binding of CTCF is not required to establish the unmethylated ICR during oogenesis [20].
• Drosophila cdc25 protein from two different expression systems activates inactive cyclin-p34cdc2 and induces M phase in Xenopus oocytes and egg extracts [21].
• MPF extracted from starfish oocytes copurifies with an M phase-specific H1 histone kinase encoded by a homolog of the fission yeast cell cycle control gene cdc2+ [22].

Anatomical context of Oocytes

• We have cloned analogs of pICln from rat heart and Xenopus ovary. pICln was identified as an abundant soluble cytosolic protein (approximately 40 kd) that does not immunolocalize with the plasma membrane. pICln was found in epithelial and cardiac cells, brain, and Xenopus oocytes, forming complexes with soluble actin and other cytosolic proteins [23].
• SED1 binds specifically to the zona pellucida of unfertilized oocytes, but not to the zona of fertilized eggs [24].
• We propose that microtubule-dependent Exuperantia-bicoid mRNA complex formation in the nurse cell cytoplasm allows anterior-specific transport on a grossly nonpolar oocyte microtubule network [25].
• The anti-influenza virus drug amantadine hydrochloride significantly attenuated the inward current induced by hyperpolarization of oocyte membranes [26].
• Here we present experimental evidence demonstrating that activation of zeta PKC is not only necessary but also sufficient by itself to activate maturation in oocytes and to produce deregulation of growth control in mouse fibroblasts [27].

Associations of Oocytes with chemical compounds

• The ability of the maturation-promoting factor (Mpf) to provoke Gvbd when injected into recipient oocytes was found to be dependent upon whether the oocytes had been exposed to cholera toxin alone or to toxin and progesterone [28].
• Analysis of the mutated and wild-type alleles in Xenopus laevis oocytes confirmed the predicted effect of the mutation, a decrease in the amplitude of GABA-activated currents [29].
• Xenopus oocytes injected with alpha 9 cRNA express a homomeric receptor-channel complex that is activated by acetylcholine [30].
• Effects of cycloheximide on the "autocatalytic" nature of the maturation promoting factor (MPF) in oocytes of Xenopus laevis [31].
• We therefore performed a controlled, open trial in which treatment with buserelin, an agonist of luteinizing hormone-releasing hormone citrate and HMG in 44 consecutive women in whom no oocytes or only one had been produced by standard treatment with clomiphene and HMG [32].

Gene context of Oocytes

• We report the cloning and sequencing of staufen and show that staufen protein is one of the first molecules to localize to the posterior pole of the oocyte, perhaps in association with oskar RNA [33].
• The TGF alpha-like ligand Gurken signals from the oocyte to the receptor in the overlying somatic follicle cells [34].
• We show here that clam oocytes and embryos contain a cdc2 protein kinase [35].
• Taken together, these results suggest that BicD encodes a cytoskeleton-like protein involved in transporting or anchoring the nanos morphogen within the oocyte cytoplasm [36].
• Here, we report that a Drosophila PAR-1 homolog localizes to the posterior of the oocyte with oskar mRNA [37].

Analytical, diagnostic and therapeutic context of Oocytes

• Nucleoplasmin-coated colloidal gold particles concentrate around the nuclear envelope of Vero cells or Xenopus oocytes, and by electron microscopy of oocytes appear to be associated with fibrils attached to nuclear pore complexes [38].
• Reduced transcriptional activity was observed in maturing stages of oocyte development and after treatment with an inhibitor, actinomycin D [39].
• By means of microinjection studies in the Xenopus laevis oocyte, we have elucidated a novel pathway leading to the appearance of a processed B1-type Alu RNA species in the cytoplasm [40].
• Here we investigate how structural elements could be involved in the desensitization of the acetylcholine-gated ion channel from the chick brain alpha-bungarotoxin sensitive homo-oligomeric alpha 7 receptor, using site-directed mutagenesis and expression in Xenopus oocytes [41].
• Sequence analysis of the amplified products has revealed a single missense mutation in SGLT1 which cosegregates with the GGM phenotype and results in a complete loss of Na(+)-dependent glucose transport in Xenopus oocytes injected with this complementary RNA [42].

References