Mouse oocyte meiosis is disturbed by knockdown of Suv4-20h

2013 ◽  
Vol 25 (3) ◽  
pp. 503 ◽  
Author(s):  
Kai Xiong ◽  
Wei Wu ◽  
Xuguang Wang ◽  
Xueshan Ma ◽  
Jie Chen ◽  
...  
Keyword(s):  
Rna Interference ◽  
Polar Body ◽  
Chromosome Behaviour ◽  
Histone H4 ◽  
Aberrant Chromosome ◽  
Meiotic Progression ◽  
Mammalian Oocyte ◽  
Chromosome Distribution ◽  
Oocyte Meiosis ◽  
Chromosome Alignment

Suv4-20h was initially characterised as a histone methyltransferase (HMTase) that catalyses lysine 20 of histone H4 dimethylation (H4K20me2) and trimethylation (H4K20me3). In the present study, using RNA interference (RNAi), we found that Suv4-20h activity is required for the fidelity of chromosome distribution during meiosis in the mammalian oocyte. Knockdown of Suv4-20h resulted in attenuation of H4K20me3 and the accumulation of H4K20me1. After Suv4-20h knockdown, oocytes exhibited an increasing percentage of aberrant chromosome alignment in MI, together with a decreasing percentage of polar body I extrusion. We conclude that Suv4-20h may be required for normal chromosome behaviour and that it is crucial for proper meiotic progression in mammalian oocytes.

scholarly journals WAPL orchestrates porcine oocyte meiotic progression via control of spindle assembly checkpoint activity

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Changyin Zhou ◽  
Yilong Miao ◽  
Xue Zhang ◽  
Bo Xiong
Keyword(s):  
Chromosome Segregation ◽  
Spindle Assembly Checkpoint ◽  
Polar Body ◽  
Spindle Assembly ◽  
Protein Levels ◽  
Meiotic Progression ◽  
Oocyte Meiosis ◽  
Chromosome Alignment ◽  
Porcine Oocyte ◽  
Polar Body Extrusion

Abstract Background In mitotic cells, WAPL acts as a cohesin release factor to remove cohesin complexes from chromosome arms during prophase to allow the accurate chromosome segregation in anaphase. However, we have recently documented that Wapl exerts a unique meiotic function in the spindle assembly checkpoint (SAC) control through maintaining Bub3 stability during mouse oocyte meiosis I. Whether this noncanonical function is conserved among species is still unknown. Methods We applied RNAi-based gene silencing approach to deplete WAPL in porcine oocytes, validating the conserved roles of WAPL in the regulation of SAC activity during mammalian oocyte maturation. We also employed immunostaining, immunoblotting and image quantification analyses to test the WAPL depletion on the meiotic progression, spindle assembly, chromosome alignment and dynamics of SAC protein in porcine oocytes. Results We showed that depletion of WAPL resulted in the accelerated meiotic progression by displaying the precocious polar body extrusion and compromised spindle assembly and chromosome alignment. Notably, we observed that the protein level of BUB3 was substantially reduced in WAPL-depleted oocytes, especially at kinetochores. Conclusions Collectively, our data demonstrate that WAPL participates in the porcine oocyte meiotic progression through maintenance of BUB3 protein levels and SAC activity. This meiotic function of WAPL in oocytes is highly conserved between pigs and mice.

Ndc80 Regulates Meiotic Spindle Organization, Chromosome Alignment, and Cell Cycle Progression in Mouse Oocytes

2011 ◽  
Vol 17 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Shao-Chen Sun ◽  
Ding-Xiao Zhang ◽  
Seung-Eun Lee ◽  
Yong-Nan Xu ◽  
Nam-Hyung Kim
Keyword(s):  
Spindle Assembly Checkpoint ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Mouse Oocyte ◽  
Meiotic Spindle ◽  
Immunofluorescent Staining ◽  
Mrna Levels ◽  
Mouse Oocytes ◽  
Oocyte Meiosis ◽  
Chromosome Alignment

AbstractNdc80 (called Hec1 in human), the core component of the Ndc80 complex, is involved in regulation of both kinetochore-microtubule interactions and the spindle assembly checkpoint in mitosis; however, its role in meiosis remains unclear. Here, we report Ndc80 expression, localization, and possible functions in mouse oocyte meiosis. Ndc80 mRNA levels gradually increased during meiosis. Immunofluorescent staining showed that Ndc80 was restricted to the germinal vesicle and associated with spindle microtubules from the Pro-MI to MII stages. Ndc80 was localized on microtubules and asters in the cytoplasm after taxol treatment, while Ndc80 staining was diffuse after disruption of microtubules by nocodazole treatment, confirming its microtubule localization. Disruption of Ndc80 function by either siRNA injection or antibody injection resulted in severe chromosome misalignment, spindle disruption, and precocious polar body extrusion. Our data show a unique localization pattern of Ndc80 in mouse oocytes and suggest that Ndc80 may be required for chromosome alignment and spindle organization, and may regulate spindle checkpoint activity during mouse oocyte meiosis.

EB1 Is Essential for Spindle Formation and Chromosome Alignment During Oocyte Meiotic Maturation in Mice

2021 ◽  
pp. 1-7
Author(s):  
Dongjie Zhou ◽  
Zheng-Wen Nie ◽  
Xiang-Shun Cui
Keyword(s):  
Cell Shape ◽  
Control Cell ◽  
Meiotic Maturation ◽  
Junctional Complex ◽  
Spindle Formation ◽  
Oocyte Meiosis ◽  
Polarized Cell Growth ◽  
Chromosome Alignment ◽  
Oocyte Meiotic Maturation

The cytoskeleton plays an orchestrating role in polarized cell growth. Microtubules (MTs) not only play critical roles in chromosome alignment and segregation but also control cell shape, division, and motility. A member of the plus-end tracking proteins, end-binding protein 1 (EB1), regulates MT dynamics and plays vital roles in maintaining spindle symmetry and chromosome alignment during mitosis. However, the role of EB1 in mouse oocyte meiosis remains unknown. Here, we examined the localization patterns and expression levels of EB1 at different stages. EB1 protein level was found to be stable during meiosis. EB1 mainly localized along the spindle and had a similar localization pattern as that of α-tubulin. The EB1 protein was degraded with a Trim-Away method, and the results were further confirmed with western blotting and immunofluorescence. At 12 h of culture after EB1 knockdown (KD), a reduced number of mature MII oocytes were observed. EB1 KD led to spindle disorganization, chromosome misalignment, and missegregation; β-catenin protein binds to actin via the adherens junctional complex, which was significantly reduced in the EB1 KD oocytes. Collectively, we propose that the impairment of EB1 function manipulates spindle formation, thereby promoting chromosomal loss, which is expected to fuel aneuploidy and possibly fertilization failure.

scholarly journals Ral GTPase is essential for actin dynamics and Golgi apparatus distribution in mouse oocyte maturation

Cell Division ◽  
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ming-Hong Sun ◽  
Lin-Lin Hu ◽  
Chao-Ying Zhao ◽  
Xiang Lu ◽  
Yan-Ping Ren ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Oocyte Maturation ◽  
Polar Body ◽  
Mouse Oocyte ◽  
Actin Dynamics ◽  
Mouse Oocytes ◽  
Oocyte Meiosis ◽  
Ral Gtpase ◽  
Polar Body Extrusion ◽  
Cytoskeleton Dynamics

Abstract Background Ral family is a member of Ras-like GTPase superfamily, which includes RalA and RalB. RalA/B play important roles in many cell biological functions, including cytoskeleton dynamics, cell division, membrane transport, gene expression and signal transduction. However, whether RalA/B involve into the mammalian oocyte meiosis is still unclear. This study aimed to explore the roles of RalA/B during mouse oocyte maturation. Results Our results showed that RalA/B expressed at all stages of oocyte maturation, and they were enriched at the spindle periphery area after meiosis resumption. The injection of RalA/B siRNAs into the oocytes significantly disturbed the polar body extrusion, indicating the essential roles of RalA/B for oocyte maturation. We observed that in the RalA/B knockdown oocytes the actin filament fluorescence intensity was significantly increased at the both cortex and cytoplasm, and the chromosomes were failed to locate near the cortex, indicating that RalA/B regulate actin dynamics for spindle migration in mouse oocytes. Moreover, we also found that the Golgi apparatus distribution at the spindle periphery was disturbed after RalA/B depletion. Conclusions In summary, our results indicated that RalA/B affect actin dynamics for chromosome positioning and Golgi apparatus distribution in mouse oocytes.

FASCIN regulates actin assembly for spindle movement and polar body extrusion in mouse oocyte meiosis

2021 ◽  
Author(s):  
Lin‐Lin Hu ◽  
Meng‐Hao Pan ◽  
Feng‐Lian Yang ◽  
Zi‐Ao Zong ◽  
Feng Tang ◽  
...  
Keyword(s):  
Polar Body ◽  
Mouse Oocyte ◽  
Actin Assembly ◽  
Oocyte Meiosis ◽  
Polar Body Extrusion

scholarly journals Cytoplasmic dynein participates in meiotic checkpoint inactivation in mouse oocytes by transporting cytoplasmic mitotic arrest-deficient (Mad) proteins from kinetochores to spindle poles

Reproduction ◽  
2007 ◽  
Vol 133 (4) ◽  
pp. 685-695 ◽  
Author(s):  
Dong Zhang ◽  
Shen Yin ◽  
Man-Xi Jiang ◽  
Wei Ma ◽  
Yi Hou ◽  
...  
Keyword(s):  
Spindle Checkpoint ◽  
Germinal Vesicle ◽  
Cytoplasmic Dynein ◽  
Mitotic Arrest ◽  
Checkpoint Proteins ◽  
Meiotic Progression ◽  
Spindle Poles ◽  
Anaphase Onset ◽  
Oocyte Meiosis ◽  
And Function

The present study was designed to investigate the localization and function of cytoplasmic dynein (dynein) during mouse oocyte meiosis and its relationship with two major spindle checkpoint proteins, mitotic arrest-deficient (Mad) 1 and Mad2. Oocytes at various stages during the first meiosis were fixed and immunostained for dynein, Mad1, Mad2, kinetochores, microtubules, and chromosomes. Some oocytes were treated with nocodazole before examination. Anti-dynein antibody was injected into the oocytes at germinal vesicle (GV) stage before the examination of its effects on meiotic progression or Mad1 and Mad2 localization. Results showed that dynein was present in the oocytes at various stages from GV to metaphase II and the locations of Mad1 and Mad2 were associated with dynein’s movement. Both Mad1 and Mad2 had two existing states: one existed in the cytoplasm (cytoplasmic Mad1 or cytoplasmic Mad2), which did not bind to kinetochores, while the other bound to kinetochores (kinetochore Mad1 or kinetochore Mad2). The equilibrium between the two states varied during meiosis and/or in response to the changes of the connection between microtubules and kinetochores. Cytoplasmic Mad1 and Mad2 recruited to chromosomes when the connection between microtubules and chromosomes was destroyed. Inhibition of dynein interferes with cytoplasmic Mad1 and Mad2 transportation from chromosomes to spindle poles, thus inhibits checkpoint silence and delays anaphase onset. These results indicate that dynein may play a role in spindle checkpoint inactivation.

scholarly journals OLA1 is responsible for normal spindle assembly and SAC activation in mouse oocytes

2019 ◽  
Author(s):  
Di Xie ◽  
Juan Zhang ◽  
JinLi Ding ◽  
Jing Yang ◽  
Yan Zhang
Keyword(s):  
Spindle Assembly Checkpoint ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Spindle Assembly ◽  
Mouse Oocyte ◽  
Immunofluorescent Staining ◽  
Germinal Vesicle Breakdown ◽  
Oocyte Meiosis ◽  
Polar Body Extrusion ◽  
Spread Analysis

Background. OLA1 is a member of the GTPase protein family, unlike other members, it can bind and hydrolyze ATP more efficiently than GTP. OLA1 participates in cell proliferation, oxidative response and tumorigenesis. However, whether OLA1 is also required for oocyte meiosis is still unknown. Methods. In this study, the localization, expression, and functions of OLA1 in the mouse oocyte meiosis were examined. Immunofluorescent and confocal microscopy were used to explore the location pattern of OLA1 in the mouse oocyte. Moreover, nocodazole treatment was used to confirm the spindle-like location of OLA1 during mouse meiosis. Western blot was used to explore the expression pattern of OLA1 in the mouse oocyte. Microinjection of siRNA was used to explore the OLA1 functions in the mouse oocyte meiosis. In addition, chromosome spreading was used to investigate the spindle assembly checkpoint (SAC) activity. Results. Immunofluorescent staining showed that OLA1 evenly distributed in the cytoplasm at germinal vesicle (GV) stage. After meiosis resumption (GVBD), OLA1 co-localized with spindles, which was further identified by nocodazole treatment experiments. Knockdown of OLA1 impaired the germinal vesicle breakdown progression and finally resulted in a lower polar body extrusion rate. Immunofluorescence analysis indicated that knockdown of OLA1 led to abnormal spindle assembly, which was evidenced by multipolar spindles in OLA1-RNAi-oocytes. After 6 h post-GVBD in culture, an increased proportion of oocyte which has precociously entered into anaphase/telephase I (A/TI) was observed in OLA1-knockdown oocytes, suggesting that loss of OLA1 resulted in the premature segregation of homologous chromosomes. In addition, the chromosome spread analysis suggested that OLA1 knockdown induced premature anaphase onset was due to the precocious inactivation of SAC. Taken together, we concluded that OLA1 plays important role in GVBD, spindle assembly and SAC activation maintenance in oocyte meiosis.

scholarly journals Cyclin B3 promotes anaphase I onset in oocyte meiosis

2019 ◽  
Vol 218 (4) ◽  
pp. 1265-1281 ◽  
Author(s):  
Mehmet E. Karasu ◽  
Nora Bouftas ◽  
Scott Keeney ◽  
Katja Wassmann
Keyword(s):  
Mammalian Cells ◽  
Fruit Fly ◽  
Cyclin B1 ◽  
Biochemical Properties ◽  
Anaphase Promoting Complex ◽  
Cellular Functions ◽  
Meiotic Progression ◽  
Oocyte Meiosis ◽  
Sterile Mutant ◽  
Cyclin B3

Meiosis poses unique challenges because two rounds of chromosome segregation must be executed without intervening DNA replication. Mammalian cells express numerous temporally regulated cyclins, but how these proteins collaborate to control meiosis remains poorly understood. Here, we show that female mice genetically ablated for cyclin B3 are viable—indicating that the protein is dispensable for mitotic divisions—but are sterile. Mutant oocytes appear normal until metaphase I but then display a highly penetrant failure to transition to anaphase I. They arrest with hallmarks of defective anaphase-promoting complex/cyclosome (APC/C) activation, including no separase activity, high CDK1 activity, and high cyclin B1 and securin levels. Partial APC/C activation occurs, however, as exogenously expressed APC/C substrates can be degraded. Cyclin B3 forms active kinase complexes with CDK1, and meiotic progression requires cyclin B3–associated kinase activity. Cyclin B3 homologues from frog, zebrafish, and fruit fly rescue meiotic progression in cyclin B3–deficient mouse oocytes, indicating conservation of the biochemical properties and possibly cellular functions of this germline-critical cyclin.

scholarly journals Yng2p-dependent NuA4 Histone H4 Acetylation Activity Is Required for Mitotic and Meiotic Progression

2001 ◽  
Vol 276 (47) ◽  
pp. 43653-43662 ◽  
Author(s):  
John S. Choy ◽  
Brian T. D. Tobe ◽  
Joon H. Huh ◽  
Stephen J. Kron
Keyword(s):  
Histone H4 ◽  
Meiotic Progression ◽  
Histone H4 Acetylation
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