Detection of oocyte mRNA in starfish polar bodies.
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ABSTRACT:
SUBMITTER: Klatsky PC
PROVIDER: S-EPMC3190191 | biostudies-literature | 2010 May
REPOSITORIES: biostudies-literature
Publications
Detection of oocyte mRNA in starfish polar bodies.
Klatsky Peter C PC Carson Sandra A SA Wessel Gary M GM
Molecular reproduction and development 20100501 5
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Project description:Oocyte maturation is a process that occurs in the ovaries, where an immature oocyte resumes meiosis to attain competence for normal fertilization after ovulation/spawning. In starfish, the hormone 1-methyladenine binds to an unidentified receptor on the plasma membrane of oocytes, inducing a conformational change in the heterotrimeric GTP-binding protein ?-subunit (G?), so that the ?-subunit binds GTP in exchange of GDP on the plasma membrane. The GTP-binding protein ??-subunit (G??) is released from G?, and the released G?? activates phosphatidylinositol-3 kinase (PI3K), followed by the target of rapamycin kinase complex2 (TORC2) and 3-phosphoinositide-dependent protein kinase 1 (PDK1)-dependent phosphorylation of serum- and glucocorticoid-regulated kinase (SGK) of ovarian oocytes. Thereafter, SGK activates Na+/H+ exchanger (NHE) to increase the intracellular pH (pHi) from ~6.7 to ~6.9. Moreover, SGK phosphorylates Cdc25 and Myt1, thereby inducing the de-phosphorylation and activation of cyclin B-Cdk1, causing germinal vesicle breakdown (GVBD). Both pHi increase and GVBD are required for spindle assembly at metaphase I, followed by MI arrest at pHi 6.9 until spawning. Due to MI arrest or SGK-dependent pHi control, spawned oocytes can be fertilized normally.
| S-EPMC7072822 | biostudies-literature
Project description:PurposeTo demonstrate that a euploid embryo derived from an oocyte with reciprocal aneuploid polar bodies is capable of producing a chromosomally normal child.MethodsA case report of maternal MI error compensation where single nucleotide polymorphism (SNP) microarray based comprehensive chromosome screening (CCS) was performed on the 1st and 2nd polar body, the resulting embryo, and newborn DNA.ResultsCCS performed after embryo transfer identified a chromosomally normal embryo that resulted from an oocyte with reciprocal aneuploid polar bodies. The first polar body was found to be missing a single chromatid derived from chromosome 21 and the second polar body possessed an extra chromatid derived from chromosome 21. Compensation of the maternal meiotic error was verified by CCS analysis of a trophectoderm biopsy from the resulting blastocyst which was euploid for all 23 pairs of chromosomes. DNA fingerprinting and CCS of the resulting newborn confirmed a chromosomally normal child, demonstrating the developmental potential of an oocyte with reciprocal aneuploid polar bodies.ConclusionsThis is the first case report demonstrating the reproductive potential of a chromosomally normal embryo derived from an oocyte which had undergone meiosis I error. Systematic investigation into the frequency of meiosis I error compensation and the negative predictive value of polar body aneuploidy screening for reproductive potential should be conducted in order to confirm clinical relevance.
| S-EPMC3370038 | biostudies-literature
Project description:The objective of the present study was to develop an approach that could assess the chromosomal status and the mitochondrial DNA (mtDNA) content of oocytes and their corresponding polar bodies (PBs) with the goal of obtaining a comparative picture of the segregation process both for nuclear and mtDNA. After Whole Genome Amplification (WGA), sequencing of the whole mitochondrial genome was attempted to analyze the segregation of mutant and wild-type mtDNA during human meiosis. Three triads, composed of oocyte and corresponding PBs, were analyzed and their chromosome status was successfully assessed. The complete mitochondrial genome (mitogenome) was almost entirely sequenced in the oocytes (95.99% compared to 98.43% in blood), while the percentage of sequences obtained in the corresponding PB1 and PB2 was lower (69.70% and 69.04% respectively). The comparison with the mtDNA sequence in blood revealed no changes in the D-loop region for any of the cells of each triad. In the coding region of blood mtDNA and oocyte mtDNA sequences showed full correspondence, whereas all PBs had at least one change with respect to the blood-oocyte pairs. In all, 9 changes were found, either in PB1 or PB2: 4 in MT-ND5, 2 in MT-RNR2, and 1 each in MT-ATP8, MT-ND4, MT-CYTB. The full concordance between oocyte and blood in the 3 triads, and the relegation of changes to PBs, revealed the unexpected coexistence of different variants, giving a refined estimation of mitochondrial heteroplasmy. Should these findings be confirmed by additional data, an active mechanism could be postulated in the oocyte to preserve a condition of 'normality'.
| S-EPMC4102503 | biostudies-literature
Project description:Three new sulfated steroid monoglycosides, leptaochotensosides A-C (1-3), and a new sulfated polyhydroxylated steroid (4) were isolated from the alcoholic extract of the Far Eastern starfish Leptasterias ochotensis. The structures of compounds 1-4 were established by extensive nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESIMS) analyses and chemical transformations. Although the isolated compounds did not show any apparent cytotoxicity against melanoma RPMI-7951 and breast cancer T-47D cell lines, leptaochotensoside A (1) demonstrated inhibition of T-47D cell colony formation in a soft agar clonogenic assay at nontoxic doses. In addition, this compound decreased the epidermal growth factor (EGF)-induced colony formation of mouse epidermal JB6 Cl41 cells. The cancer preventive action of 1 is realized through regulation of mitogen-activated protein kinase (MAPK) signaling pathway.
| S-EPMC4515625 | biostudies-literature
Project description:ObjectiveTo test the hypothesis that quantification of messenger RNAs originating from the second polar body (PB(2)) provides a noninvasive tool for assessing embryo quality.DesignProspective study.SettingHospital-based academic research laboratory.Animal(s)CD1 female mice.Intervention(s)Metaphase II oocytes obtained from 7- to 8-week-old mice after pregnant mare's serum gonadotropin and hCG priming. After in vitro fertilization, the PB(2) was biopsied from zygote, followed by reverse transcription. Real-time polymerase chain reaction was performed to quantify gene expression levels in single PB(2). The sibling zygotes were continuously cultured to blastocyst stage.Main outcome measure(s)Embryo developmental competence and six maternal-effect gene (Dnmt1, Mater, Nobox, Npm2, Tcl1, and Zar1) transcripts in the PB(2).Result(s)Second polar body messenger RNA was detected in all candidate genes. Transcripts that were present in greater abundance in the zygote were more likely to be detected in quantitative polymerase chain reaction replicates from single PB(2). Four candidate genes (Dnmt1, Nobox, Npm2, and Tcl1) expression levels in PB(2) between two groups (two-cell embryo vs. blastocyts) approached statistical significance.Conclusion(s)Second polar bodies may contain a representative transcript profile to that of the zygote after fertilization. Differences in gene expression in PB(2) may be potential biomarkers of embryo quality.
| S-EPMC3672332 | biostudies-literature
Project description:Clinicians need additional metrics for predicting quality of human oocytes for IVF procedures. Human polar bodies reflect the oocyte transcript profile. Quantitation of polar body mRNAs could allow for both oocyte ranking and embryo preferences in IVF applications. The transcriptome of a polar body has never been reported, in any organism.
2011-10-12 | GSE32689 | GEO
Project description:PURPOSE: To gain insight into the morphology of the first polar body (1 PB) in ICSI patients and to explore whether it could predict mature oocyte viability and performance in this setting. METHODS: Seventy two consecutive women planned to perform ICSI treatment were prospectively recruited for this study. All oocytes retrieved underwent evaluation for nuclear maturity and accurate assessment of 1 PB morphology. MII oocytes were cultured in separate groups in each woman in accordance with two different categories of 1 PB morphology. Category A included normal intact round or ovoid 1 PB and category B included abnormal fragmented 1 PB. Each oocyte was followed throughout fertilization, embryo cleavage and embryo transfer. Cycles that reached embryo transfer, were divided into three groups in accordance with 1 PB morphology. Group I included only category A 1 PB embryos, group II included categories A and B 1 PB embryos, whereas group III included only category B 1 PB embryos. RESULTS: A total of 687 oocytes were aspirated and 553 MII oocytes underwent ICSI leading to 410 zygotes showing normal fertilization on day one. Three hundred ninety seven embryos cleaved on day two and a total of 176 embryos were replaced into the uterus. Clinical implantation and pregnancy rates were significantly correlated with the morphology of the 1 PB corresponding to 31%, 9% and 2% and 61%, 24% and 5%, in groups I, II and III respectively. CONCLUSIONS: Our findings demonstrate that 1 PB morphology is related to mature oocyte viability and it has the potential to predict oocyte performance and pregnancy achievement in infertile women undergoing ICSI treatment.
| S-EPMC2799563 | biostudies-other
Project description:Clinicians need additional metrics for predicting quality of human oocytes for IVF procedures. Human polar bodies reflect the oocyte transcript profile. Quantitation of polar body mRNAs could allow for both oocyte ranking and embryo preferences in IVF applications. The transcriptome of a polar body has never been reported, in any organism. Eight total samples. There are 2 biological replicates of the following four conditions: pooled oocytes and their sister polar bodies and a single oocyte and its sister polar body.
2011-10-12 | E-GEOD-32689 | biostudies-arrayexpress
Project description:Improved methods are needed to reliably and accurately evaluate oocyte quality prior to fertilization and transfer into the woman of human embryos created through in vitro fertilization (IVF). All oocytes that are retrieved and matured in culture are exposed to sperm with little in the way of evaluating the oocyte quality. Furthermore, embryos created through IVF are currently evaluated for developmental potential by morphology, a criterion lacking in quantitation and accuracy. With the recent successes in oocyte vitrification and storage, clear metrics are needed to determine oocyte quality prior to fertilizing. The first polar body (PB) is extruded from the oocyte before fertilization and can be biopsied without damaging the oocyte. Here, we tested the hypothesis that the PB transcriptome is representative of that of the oocyte. Polar body biopsy was performed on metaphase II (MII) oocytes followed by single-cell transcriptome analysis of the oocyte and its sibling PB. Over 12,700 unique mRNAs and miRNAs from the oocyte samples were compared with the 5,431 mRNAs recovered from the sibling PBs (5,256 shared mRNAs or 97%, including miRNAs). The results show that human PBs reflect the oocyte transcript profile and suggests that mRNA detection and quantification through high-throughput quantitative PCR could result in the first molecular diagnostic for gene expression in MII oocytes. This could allow for both oocyte ranking and embryo preferences in IVF applications.
| S-EPMC3220517 | biostudies-literature