Stereological Analysis of Mitochondria and Smooth Endoplasmic Reticulum Distribution in Human Oocytes at Prophase I

The structure of human oocytes at the different maturation stages is known based on descriptive studies of its ultrastructural composition. The tridimensional quantitative ultrastructural analysis of human oocytes would be important for understanding folliculogenesis and establishing adequate methods of in vitro oocyte maturation. In this study, stereological methods were applied to quantify the distribution of mitochondria (M) and smooth endoplasmic reticulum (SER) in oocytes at the germinal vesicle (VG) stage of prophase I.

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A stereological study on organelle distribution in human oocytes at prophase I

Zygote ◽

10.1017/s0967199415000258 ◽

2015 ◽

Vol 24 (3) ◽

pp. 346-354 ◽

Cited By ~ 2

Author(s):

Ana Sílvia Pires-Luís ◽

Eduardo Rocha ◽

Carla Bartosch ◽

Elsa Oliveira ◽

Joaquina Silva ◽

...

Keyword(s):

Zona Pellucida ◽

Smooth Endoplasmic Reticulum ◽

Molecular Data ◽

Human Oocyte ◽

Human Oocytes ◽

Prophase I ◽

Organelle Distribution ◽

Transmission Electron ◽

Maturation Stages

SummaryThe ultrastructural analysis of human oocytes at different maturation stages has only been descriptive. The aim of this study was to use a stereological approach to quantify the distribution of organelles in oocytes at prophase I (GV). Seven immature GV oocytes were processed for transmission electron microscopy and a classical manual stereological technique based on point-counting with an adequate stereological grid was used. The Kruskal–Wallis test and Mann–Whitney U-test with Bonferroni correction were used to compare the means of the relative volumes occupied by organelles in oocyte regions: cortex (C), subcortex (SC) and inner cytoplasm (IC). Here we first describe in GV oocytes very large vesicles of the smooth endoplasmic reticulum (SER), vesicles containing zona pellucida-like materials and coated vesicles. The most abundant organelles were the very large vesicles of the SER (6.9%), mitochondria (6.3%) and other SER vesicles (6.1%). Significant differences in organelle distribution were observed between ooplasm regions: cortical vesicles (C: 1.3% versus SC: 0.1%, IC: 0.1%, P = 0.001) and medium-sized vesicles containing zona pellucida-like materials (C: 0.2% versus SC: 0.02%, IC: 0%, P = 0.004) were mostly observed at the oocyte cortex, whereas mitochondria (C: 3.6% versus SC: 6.0%, IC: 7.2%, P = 0.005) were preferentially located in the subcortex and inner cytoplasm, and SER very large vesicles (IC: 10.1% versus C: 0.9%, SC: 1.67%, P = 0.001) in the oocyte inner cytoplasm. Further quantitative studies are needed in immature metaphase-I and mature metaphase-II oocytes, as well as analysis of correlations between ultrastructural and molecular data, to better understand human oocyte in vitro maturation.

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In vitro oocyte maturation in a hybrid cultured sturgeon, bester: Changes in the germinal vesicle breakdown and 17,20β-dihydroxy-4-pregnen-3-one production

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/s1095-6433(99)90350-1 ◽

1999 ◽

Vol 124 ◽

pp. S89

Author(s):

MB Amiri ◽

M Maebayashi ◽

N Omoto ◽

S Adach ◽

K Yamauchi

Keyword(s):

Oocyte Maturation ◽

Germinal Vesicle ◽

Germinal Vesicle Breakdown ◽

In Vitro Oocyte Maturation

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Platelet-activating factor acetylhydrolase 1B3 (PAFAH1B3) is required for the formation of the meiotic spindle during in vitro oocyte maturation

Reproduction Fertility and Development ◽

10.1071/rd18019 ◽

2018 ◽

Vol 30 (12) ◽

pp. 1739 ◽

Cited By ~ 1

Author(s):

L. T. M. Vandenberghe ◽

B. Heindryckx ◽

K. Smits ◽

K. Szymanska ◽

N. Ortiz-Escribano ◽

...

Keyword(s):

Oocyte Maturation ◽

Close Association ◽

Polar Body ◽

Platelet Activating Factor ◽

Germinal Vesicle ◽

Meiotic Spindle ◽

Intracellular Enzyme ◽

Human Oocytes ◽

First Polar Body

Platelet-activating factor (PAF) is a well-described autocrine growth factor involved in several reproductive processes and is tightly regulated by its hydrolysing enzyme, PAF acetylhydrolase 1B (PAFAH1B). This intracellular enzyme consists of three subunits: one regulatory, 1B1, and two catalytic, 1B2 and 1B3. PAFAH1B3 has remained uncharacterised until now. Here, we report that PAFAH1B3 is present during the different stages of the first meiotic division in bovine, murine and human oocytes. In these species, the PAFAH1B3 subunit was clearly present in the germinal vesicle, while at metaphase I and II, it localised primarily at the meiotic spindle structure. In cattle, manipulation of the microtubules of the spindle by nocodazole, taxol or cryopreservation revealed a close association with PAFAH1B3. On the other hand, disruption of the enzyme activity either by P11, a selective inhibitor of PAFAH1B3, or by PAFAH1B3 antibody microinjection, caused arrest at the MI stage with defective spindle morphology and consequent failure of first polar body extrusion. In conclusion, our results show that one of the catalytic subunits of PAFAH1B, namely PAFAH1B3, is present in bovine, murine and human oocytes and that it plays a functional role in spindle formation and meiotic progression during bovine oocyte maturation.

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Meta-analysis of the effects of smooth endoplasmic reticulum aggregation on birth outcome

BMC Pregnancy and Childbirth ◽

10.1186/s12884-021-03850-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hongqin Zhang ◽

Wenhui Hu ◽

Ying Zhong ◽

Zhenhua Guo

Keyword(s):

Endoplasmic Reticulum ◽

Oocyte Maturation ◽

Birth Outcome ◽

Smooth Endoplasmic Reticulum ◽

Meta Analysis ◽

Perinatal Complications ◽

Vitro Fertilization ◽

Healthy Infants ◽

Maturation Rate

Abstract Background Smooth endoplasmic reticulum aggregation (SERa, SER+) has been reported to increase the risk of birth malformations and other abnormal outcomes, miscarriage, and perinatal complications. Other studies, however, suggest that SER+ embryos may develop into healthy infants. One report indicates that 25% of in vitro fertilization (IVF) centers discard SER+ oocytes. Thus, we investigated the effect of SER+ on birth outcomes in IVF and intracytoplasmic sperm injection. Methods We performed a literature search using PubMed, ScienceDirect, Cochrane, Embase, Ovid, and Scopus. We found a total of 1500 relevant studies between 1978 and 2020 and conducted a meta-analysis to study the effects of SER+ on live births, birth weight, and the number of metaphase II (MII) oocytes retrieved per cycle. Results Eleven eligible studies were included. If the SER+ zygote was evaluated again at the embryo transfer (ET) stage, SER+ did not affect birth or infant body weight. Stimulated ovaries producing too many oocytes per cycle were positively correlated with SER+ (OR = 1.28, 95% CI = 0.41–2.15; p = 0.004). SER+ was positively correlated with oocyte maturation rate, and observed heterogeneity in a previous meta-analysis was likely due to maternal age. Our data also showed that SER+ cycles produced more oocytes but achieved the same number of births from ET. Conclusions The use of SER+ MII oocytes is rare, with the collection of many oocytes in 1 cycle potentially inducing SER+. SER+ may be more common than we originally thought, as some SER+ is found in all oocytes. Although SER+ positively affected oocyte maturation rate, it did not affect births. We hypothesized that this is because the best embryos are chosen at every step of the process, and the oocytes with the poorest characteristics are removed. We therefore suggest a standard method for measuring SER+. Although embryos produced from SER+ cycles can be used, they should only be transferred when no other suitable embryos are available over several cycles.

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In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050676 ◽

1974 ◽

Vol 32 ◽

pp. 132-133

Author(s):

John J. Wolosewick ◽

John H. D. Bryan

Keyword(s):

Endoplasmic Reticulum ◽

Smooth Endoplasmic Reticulum ◽

Nuclear Ring ◽

Rough Er ◽

Distal Direction ◽

In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

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Chromosome and spindle configurations of human oocytes matured in vitro after cryopreservation at the germinal vesicle stage

Fertility and Sterility ◽

10.1016/s0015-0282(97)00365-8 ◽

1997 ◽

Vol 68 (5) ◽

pp. 920-926 ◽

Cited By ~ 92

Author(s):

Sung-Eun Park ◽

Weon-Young Son ◽

Sook-Hwan Lee ◽

Kyung-Ah Lee ◽

Jung-Jae Ko ◽

...

Keyword(s):

Germinal Vesicle ◽

Human Oocytes

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Requirement of mosXe protein kinase for meiotic maturation of Xenopus oocytes induced by a cdc2 mutant lacking regulatory phosphorylation sites.

Molecular and Cellular Biology ◽

10.1128/mcb.12.7.3192 ◽

1992 ◽

Vol 12 (7) ◽

pp. 3192-3203 ◽

Cited By ~ 22

Author(s):

K M Pickham ◽

A N Meyer ◽

J Li ◽

D J Donoghue

Keyword(s):

Protein Kinase ◽

Oocyte Maturation ◽

Xenopus Oocytes ◽

Germinal Vesicle ◽

Cyclin B1 ◽

Phosphorylation Sites ◽

Germinal Vesicle Breakdown ◽

Regulatory Phosphorylation

The p34cdc2 protein kinase is a component of maturation-promoting factor, the master regulator of the cell cycle in all eukaryotes. The activity of p34cdc2 is itself tightly regulated by phosphorylation and dephosphorylation. Predicted regulatory phosphorylation sites of Xenopus p34cdc2 were mutated in vitro, and in vitro-transcribed RNAs were injected into Xenopus oocytes. The cdc2 single mutants Thr-14----Ala and Tyr-15----Phe did not induce germinal vesicle breakdown (BVBD) upon microinjection into oocytes. In contrast, the cdc2 double mutant Ala-14/Phe-15 did induce GVBD. Both the Ala-14 and Ala-14/Phe-15p34cdc2 mutants were shown to coimmunoprecipitate cyclin B1 and to phosphorylate histone H1 in immune complex kinase assays. Microinjection of antisense oligonucleotides to c-mosXe was used to demonstrate the role of mos protein synthesis in the induction of GVBD by the Ala-14/Phe-15 cdc2 mutant. Thr-161 was also mutated. p34cdc2 single mutants Ala-161 and Glu-161 and triple mutants Ala-14/Phe-15/Ala-161 and Ala-14/Phe-15/Glu-161 failed to induce GVBD in oocytes and showed a decreased binding to cyclin B1 in coimmunoprecipitations. Each of the cdc2 mutants was also assayed by coinjection with cyclin B1 or c-mosXe RNA into oocytes. Several of the cdc2 mutants were found to affect the kinetics of cyclin B1 and/or mos-induced GVBD upon coinjection, although none affected the rate of progesterone-induced maturation. We demonstrate here the significance of Thr-14, Tyr-15, and Thr-161 of p34cdc2 in Xenopus oocyte maturation. In addition, these results suggest a regulatory role for mosXe in induction of oocyte maturation by the cdc2 mutant Ala-14/Phe-15.

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