scholarly journals ZAR1 and ZAR2 are required for oocyte meiotic maturation by regulating the maternal transcriptome and mRNA translational activation

2019 ◽  
Vol 47 (21) ◽  
pp. 11387-11402 ◽  
Author(s):  
Yan Rong ◽  
Shu-Yan Ji ◽  
Ye-Zhang Zhu ◽  
Yun-Wen Wu ◽  
Li Shen ◽  
...  
Keyword(s):  
Polar Body ◽  
Underlying Mechanism ◽  
Cyclin B1 ◽  
Meiotic Spindle ◽  
Meiotic Maturation ◽  
Maternal Mrna ◽  
Translational Activity ◽  
Maternal Mrnas ◽  
Translational Activation ◽  
Oocyte Meiotic Maturation

Abstract Zar1 was one of the earliest mammalian maternal-effect genes to be identified. Embryos derived from Zar1-null female mice are blocked before zygotic genome activation; however, the underlying mechanism remains unclear. By knocking out Zar1 and its homolog Zar2 in mice, we revealed a novel function of these genes in oocyte meiotic maturation. Zar1/2-deleted oocytes displayed delayed meiotic resumption and polar body-1 emission and a higher incidence of abnormal meiotic spindle formation and chromosome aneuploidy. The grown oocytes of Zar1/2-null mice contained decreased levels of many maternal mRNAs and displayed a reduced level of protein synthesis. Key maturation-associated changes failed to occur in the Zar1/2-null oocytes, including the translational activation of maternal mRNAs encoding the cell-cycle proteins cyclin B1 and WEE2, as well as maternal-to-zygotic transition (MZT) licensing factor BTG4. Consequently, maternal mRNA decay was impaired and MZT was abolished. ZAR1/2 bound mRNAs to regulate the translational activity of their 3′-UTRs and interacted with other oocyte proteins, including mRNA-stabilizing protein MSY2 and cytoplasmic lattice components. These results countered the traditional view that ZAR1 only functions after fertilization and highlight a previously unrecognized role of ZAR1/2 in regulating the maternal transcriptome and translational activation in maturing oocytes.

scholarly journals LIMK1/2 inhibitor LIMKi 3 suppresses porcine oocyte maturation

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2553 ◽  
Author(s):  
Ru-Xia Jia ◽  
Xing Duan ◽  
Si-Jing Song ◽  
Shao-Chen Sun
Keyword(s):  
Oocyte Maturation ◽  
Polar Body ◽  
Meiotic Spindle ◽  
Actin Dynamics ◽  
Immunofluorescent Staining ◽  
Meiotic Maturation ◽  
Spindle Positioning ◽  
Oocyte Meiosis ◽  
Porcine Oocyte ◽  
Oocyte Meiotic Maturation

LIMKi 3 is a specific selective LIMK inhibitor against LIMK1 and LIMK2, while LIMK1 and LIMK2 are the main regulators of actin cytoskeleton to participate in many cell activities. However, the effect of LIMKi 3 in porcine oocyte meiosis is still unclear. The present study was designed to investigate the effects of LIMKi 3 and potential regulatory role of LIMK1/2 on porcine oocyte meiotic maturation. Immunofluorescent staining of p-LIMK1/2 antibody showed that LIMK1/2 was localized mainly to the cortex of porcine oocyte, which co-localized with actin. After LIMKi 3 treatment, the diffusion of COCs became weak and the rate of polar body extrusion was decreased. This could be rescued by moving oocytes to fresh medium. After prolonging the culture time of oocytes, the maturation rate of porcine oocyte increased in LIMKi 3 groups, indicating that LIMKi 3 may suppress the cell cycle during porcine oocyte maturation. We also found that after LIMKi 3 treatment actin distribution was significantly disturbed at porcine oocyte membranes and cytoplasm, indicating the conserved roles of LIMK1/2 on actin dynamics. Next we examined the meiotic spindle positioning in porcine oocyte, and the results showed that a majority of spindles were not attached to the cortex of porcine oocyte, indicating that LIMKi 3 may affect actin-mediated spindle positioning. Taken together, these results showed that LIMK1/2 inhibitor LIMKi 3 had a repressive role on porcine oocyte meiotic maturation.

scholarly journals Maternal mRNAs with distinct 3′ UTRs define the temporal pattern ofCcnb1synthesis during mouse oocyte meiotic maturation

2017 ◽  
Vol 31 (13) ◽  
pp. 1302-1307 ◽  
Author(s):  
Ye Yang ◽  
Cai-Rong Yang ◽  
Seung Jin Han ◽  
Enrico Maria Daldello ◽  
Ara Cho ◽  
...  
Keyword(s):  
Temporal Pattern ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Maternal Mrnas ◽  
Oocyte Meiotic Maturation

JNK2 Participates in Spindle Assembly during Mouse Oocyte Meiotic Maturation

2011 ◽  
Vol 17 (2) ◽  
pp. 197-205 ◽  
Author(s):  
Xin Huang ◽  
Jing-Shan Tong ◽  
Zhen-Bo Wang ◽  
Cai-Rong Yang ◽  
Shu-Tao Qi ◽  
...  
Keyword(s):  
Polar Body ◽  
Specific Inhibitor ◽  
Germinal Vesicle ◽  
Spindle Assembly ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Cytoplasmic Microtubule ◽  
Spindle Poles ◽  
First Polar Body ◽  
Oocyte Meiotic Maturation

AbstractIt is well known that c-Jun N-terminal kinase (JNK) plays pivotal roles in various mitotic events, but its function in mammalian oocyte meiosis remains unknown. In this study, we found that no specific JNK2 signal was detected in germinal vesicle stage. JNK2 was associated with the spindles especially the spindle poles and cytoplasmic microtubule organizing centers at prometaphase I, metaphase I, and metaphase II stages. JNK2 became diffusely distributed and associated with the midbody at telophase I stage. Injection of myc-tagged JNK2α1 mRNA into oocytes also revealed its localization on spindle poles. The association of JNK2 with spindle poles was further confirmed by colocalization with the centrosomal proteins, γ-tubulin and Plk1. Nocodazole treatment showed that JNK2 may interact with Plk1 to regulate the spindle assembly. Then we investigated the possible function of JNK2 by JNK2 antibody microinjection and JNK specific inhibitor SP600125 treatment. These two manipulations caused abnormal spindle formation and decreased the rate of first polar body (PB1) extrusion. In addition, inhibition of JNK2 resulted in impaired localization of Plk1. Taken together, our results suggest that JNK2 plays an important role in spindle assembly and PB1 extrusion during mouse oocyte meiotic maturation.

Global Analysis of Maternal mRNA Translation during Mouse Oocyte Meiotic Maturation.

2010 ◽  
Vol 83 (Suppl_1) ◽  
pp. 327-327
Author(s):  
Jing Chen ◽  
Collin Melton ◽  
NaYoung Suh ◽  
Robert Blelloch ◽  
Marco Conti
Keyword(s):  
Global Analysis ◽  
Mrna Translation ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Maternal Mrna ◽  
Oocyte Meiotic Maturation

234 MECHANISMS OF SPONTANEOUS ACTIVATION IN RAT OOCYTES

2009 ◽  
Vol 21 (1) ◽  
pp. 215
Author(s):  
T. Chebotareva ◽  
J. Mullins ◽  
I. Wilmut
Keyword(s):  
In Vitro Culture ◽  
Polar Body ◽  
Metaphase Plate ◽  
Cyclin B1 ◽  
Female Rats ◽  
Meiotic Spindle ◽  
Epifluorescence Microscopy ◽  
Spontaneous Activation ◽  
Cdc2 Activity

MII-arrested rat oocytes spontaneously resume meiotic maturation soon after recovery from oviducts. Time elapsed post oocyte retrieval, environmental factors, certain genetic background have been implied to promote spontaneous release from MII arrest in rat oocytes. The precise mechanism behind this process is unknown. This study was undertaken to explore signaling pathways, which may be involved in spontaneous activation in rat oocytes. Using triple immuno-staining and epifluorescence microscopy we have described morphological changes in the meiotic spindle of rat oocytes during 6h of in vitro culture (immature CD female rats from Charles River Laboratories). An ELISA-based method was used to evaluate cdc2 activity in rat oocytes subjected to in vitro culture. SDS-PAGE and western blotting were performed to study levels of phosphorylated and total p42/p44 MAPK, phosphorylated on Tyr15 and total cdc2, cyclin B1 and β actin. Expression of Emi2 was analysed by RT-PCR. Data were analyzed using GLMM or ANOVA followed by t-test. Freshly collected oocytes contained well-preserved spindle with chromosomes aligned in metaphase plate. After being in culture for 2 h oocytes demonstrated signs of activation, such as spindle rotation, preparing to extrude second polar body, and some oocytes had entered anaphase. In the majority of oocytes cultured for 6 h spindles had disintegrated and chromosomes were scattered in the oocyte cytoplasm; microtubules were found around condensed chromosomes. Significant drop in cdc2 activity was detected in oocytes after 2 h of in vitro culture. In oocytes cultured for additional 4h of cdc2 activity returned to the level observed in freshly collected oocytes. Inhibitory phosphorylation of cdc2 on Tyr 15 was not associated with cdc2 inactivation. We were not able to detect changes in the level of cyclin B1 during the MII to MIII transition. Phosphorylated forms of activated p42/p44 MAPK in eggs were present throughout in vitro culture. Emi2 is a novel candidate cytostatic factor in vertebrate eggs. Expression of Emi2 was detected at mRNA level in rat eggs and zygotes with no expression at later stages of preimplantation development. Taken together, the onset of spontaneous activation in rat oocytes is correlated with a sharp decline in cdc2 activity and stable level of phosphorylated p42/p44 MAPK. Dynamics of cdc2 and p42/p44 MAPK activity during spontaneous activation resembles that during the MI to MII transition, although spontaneously activated rat oocytes do not form MIII spindle. Molecular factors involved in spindle assembly may be missing during the MII to MIII transition. Persistence of p42/p44 MAPK in spontaneously activated rat oocytes could account for the absence of pronuclear formation. The role of Emi2 remains to be investigated. This work is supported by the CMVM, ORS, Mary Orr Paterson studentships and the Framework 6 activity EURATOOLS.

Doxorubicin Exposure Affects Oocyte Meiotic Maturation through DNA Damage-Induced Meiotic Arrest

2019 ◽  
Vol 171 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Zhi-Ming Ding ◽  
Shou-Xin Zhang ◽  
Xiao-Fei Jiao ◽  
Li-Ping Hua ◽  
Muhammad Jamil Ahmad ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cancer Patients ◽  
Polar Body ◽  
Young Female ◽  
Meiotic Maturation ◽  
Antitumor Antibiotic ◽  
Meiotic Arrest ◽  
First Polar Body ◽  
Female Cancer Patients ◽  
Oocyte Meiotic Maturation

Abstract Developments in chemotherapeutics have enhanced the survival rate of cancer patients, however, adverse effects of chemotherapeutics on ovarian functions causes the fertility loss in young female cancer patients. Doxorubicin (DOX), as an anthracycline antitumor antibiotic, is extensively used to cure various malignancies. Recent studies have suggested that DOX can cause ovarian damage and affect the oocyte maturation, nevertheless the mechanism by which DOX on oocytes meiosis is poorly understood. In this study, we explored the mechanism for DOX-induced oocytes meiotic failure in vitro at human relevant exposure levels and time periods. Results described that DOX (100 nM) can interrupt the mouse oocytes meiotic maturation directly with reduced first polar body extrusion. Cell cycle analysis showed that most oocytes were arrested at metaphase I (MI) stage. However, DOX treatment had no effect on spindle structure but chromosomal misalignment. We observed that kinetochore-microtubule structure was affected and the spindle assemble checkpoint was provoked after DOX treatment. Moreover, severe DNA damage was found in DOX-treated oocytes indicated by the positive γ-H2A.X foci signal, which then may trigger oocytes early apoptosis. Besides, metaphase II oocytes with disorganized spindle morphologies and misaligned chromosomes were observed after DOX treatment. In conclusion, DOX have the potential to disrupt oocyte meiotic maturation through DNA damage induced meiotic arrest mediated by spindle assemble checkpoint activation. These findings can contribute to design the new therapies to alleviate DNA damage to preserve fertility for young female cancer patients with chemotherapeutics.

scholarly journals Cyclins regulating oocyte meiotic cell cycle progression†

2019 ◽  
Vol 101 (5) ◽  
pp. 878-881 ◽  
Author(s):  
Jian Li ◽  
Wei-Ping Qian ◽  
Qing-Yuan Sun
Keyword(s):  
Cell Cycle Progression ◽  
Germinal Vesicle ◽  
Cyclin B1 ◽  
Meiotic Maturation ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Meiotic Progression ◽  
Gonadotropin Surge ◽  
Oocyte Meiotic Maturation ◽  
Maturation Promoting Factor

Abstract Oocyte meiotic maturation is a vital and final process in oogenesis. Unlike somatic cells， the oocyte needs to undergo two continuous meiotic divisions (meiosis I and meiosis II) to become a haploid gamete. Notably, oocyte meiotic progression includes two rounds of unique meiotic arrest and resumption. The first arrest occurs at the G2 (germinal vesicle) stage and meiosis resumption is stimulated by a gonadotropin surge; the second arrest takes place at the metaphase II stage, the stage from which it is released when fertilization takes place. The maturation-promoting factor, which consists of cyclin B1 (CCNB1) and cyclin-dependent kinase 1 (CDK1), is responsible for regulating meiotic resumption and progression, while CDK1 is the unique CDK that acts as the catalytic subunit of maturation-promoting factor. Recent studies showed that except for cyclin B1, multiple cyclins interact with CDK1 to form complexes, which are involved in the regulation of meiotic progression at different stages. Here, we review and discuss the control of oocyte meiotic progression by cyclins A1, A2, B1, B2, B3, and O.

The Distribution and Possible Role of ERK8 in Mouse Oocyte Meiotic Maturation and Early Embryo Cleavage

2013 ◽  
Vol 19 (1) ◽  
pp. 190-200 ◽  
Author(s):  
Shang-Wu Yang ◽  
Hao Huang ◽  
Chen Gao ◽  
Lei Chen ◽  
Shu-Tao Qi ◽  
...  
Keyword(s):  
Polar Body ◽  
Germinal Vesicle ◽  
Early Embryo ◽  
Mouse Oocyte ◽  
Meiotic Maturation ◽  
Germinal Vesicle Breakdown ◽  
First Polar Body ◽  
Embryo Cleavage ◽  
Polar Body Extrusion ◽  
Oocyte Meiotic Maturation

AbstractIt is well known that extracellular signal-regulated kinase 8 (ERK8) plays pivotal roles in various mitotic events. But its physiological roles in oocyte meiotic maturation remain unclear. In this study, we found that although no specific ERK8 signal was detected in oocyte at the germinal vesicle stage, ERK8 began to migrate to the periphery of chromosomes shortly after germinal vesicle breakdown. At prometaphase I, metaphase I (MI), anaphase I, telophase I, and metaphase II (MII) stages, ERK8 was stably detected at the spindles. By taxol treatment, we clarified that the ERK8 signal was stained on the spindle fibers as well as microtubule asters in MI and MII oocytes. In fertilized eggs, the ERK8 signal was not observed in the two pronuclei stages. At prometaphase, metaphase, and anaphase of the first mitosis, ERK8 was detected on the mitotic spindle. ERK8 knock down by antibody microinjection and specific siRNA caused abnormal spindles, failed chromosome congression, and decreased first polar body extrusion. Taken together, our results suggest that ERK8 plays an important role in spindle organization during mouse oocyte meiotic maturation and early embryo cleavage.

mInscuteable regulates meiotic spindle organization during mouse oocyte meiotic maturation

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 45-50
Author(s):  
Zhuoni Xiao ◽  
Jiali Peng ◽  
Meiting Xie ◽  
Jing Yang ◽  
Wangming Xu
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Asymmetric Division ◽  
Mouse Oocyte ◽  
Meiotic Spindle ◽  
Meiotic Maturation ◽  
Cellular Polarity ◽  
Germinal Vesicle Breakdown ◽  
Key Events ◽  
Oocyte Meiotic Maturation

SummaryEstablishment of cellular polarity is one of the key events during oocyte maturation. Inscuteable (Insc) has been identified as a key regulator of cell polarity during asymmetric division in Drosophila. However, the function of its evolutionarily conserved mammalian homologue, mInscuteable (mInsc), in mouse meiotic maturation is not clear. In this study, we investigated the roles of mInsc in mouse oocyte maturation. mInsc was detected at all stages of oocyte maturation. The protein level of mInsc was slightly higher at the germinal vesicle breakdown (GVBD) stage and remained constant during mouse oocyte maturation. The subcellular localization of mInsc overlapped with spindle microtubules. Disruption of microtubules and microfilaments caused changes in the localization of mInsc. Depletion or overexpression of mInsc significantly decreased the maturation rates of mouse oocytes. Depletion of mInsc significantly affected asymmetric division, spindle assembly, alignments of chromosomes and actin cap formation. Taken together, our results demonstrated that mInsc regulates meiotic spindle organization during mouse meiotic maturation.

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