The Experts below are selected from a list of 13215 Experts worldwide ranked by ideXlab platform
Shaochen Sun - One of the best experts on this subject based on the ideXlab platform.
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Involvement of Kif4a in Spindle Formation and Chromosome Segregation in Mouse Oocytes.
Aging and disease, 2018Co-Authors: Feng Tang, Yu Zhang, Meng-hao Pan, Xiang Wan, Shaochen SunAbstract:Kif4a, a member of the kinesin superfamily, has been reported to participate in a series of cellular processes such as chromosome condensation and cytokinesis during mitosis. However, the roles of KIF4a in meiosis are still unknown. In present study we found that the Kif4a protein expression decreased in maternal aged Mouse Oocytes. We then explored the roles of Kif4a in Mouse Oocyte meiosis by knockdown analysis. Kif4a was enriched at the spindle during Mouse Oocyte maturation. By specific knock down of the Kif4a using morpholino microinjection, we found that the disruption of Kif4a caused the failure of polar body extrusion. Further analysis indicated that Kif4a might affect the spindle morphology and chromosome alignment in the Mouse Oocytes, and this might be due to the regulation of tubulin acetylation. Moreover, our results showed that an increased proportion of aneuploidy in the Kif4a knock down Oocytes, and this might be due to the loss of kinetochore-microtubule attachment. Taken together, these results suggested that Kif4a possibly regulated Mouse Oocyte meiosis through its effects on the spindle organization and accurate chromosome segregation, and the loss of Kif4a might be related with aneuploidy of aging Oocytes.
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Comparison of the toxic effects of different mycotoxins on porcine and Mouse Oocyte meiosis
PeerJ, 2018Co-Authors: Yue Zhang, Jia-qian Liu, Peng Zou, Lu Jia, Yu-rong Sun, Shaochen SunAbstract:Background Aflatoxin B1 (AFB1), deoxynivalenol (DON), HT-2, ochratoxin A (OTA), zearalenone (ZEA) are the most common mycotoxins that are found in corn-based animal feed which have multiple toxic effects on animals and humans. Previous studies reported that these mycotoxins impaired mammalian Oocyte quality. However, the effective concentrations of mycotoxins to animal Oocytes were different. Methods In this study we aimed to compare the sensitivity of Mouse and porcine Oocytes to AFB1, DON, HT-2, OTA, and ZEA for mycotoxin research. We adopted the polar body extrusion rate of Mouse and porcine Oocyte as the standard for the effects of mycotoxins on Oocyte maturation. Results and discussion Our results showed that 10 μM AFB1 and 1 μM DON significantly affected porcine Oocyte maturation compared with 50 μM AFB1 and 2 μM DON on Mouse Oocytes. However, 10 nM HT-2 significantly affected Mouse Oocyte maturation compared with 50 nM HT-2 on porcine Oocytes. Moreover, 5 μM OTA and 10 μM ZEA significantly affected porcine Oocyte maturation compared with 300 μM OTA and 50 μM ZEA on Mouse Oocytes. In summary, our results showed that porcine Oocytes were more sensitive to AFB1, DON, OTA, and ZEA than Mouse Oocytes except HT-2 toxin.
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Melatonin protects against defects induced by deoxynivalenol during Mouse Oocyte maturation.
Journal of pineal research, 2018Co-Authors: Mei Lan, Jun Han, Meng-hao Pan, Xiang Wan, Zhen-nan Pan, Shaochen SunAbstract:Deoxynivalenol (DON) is one of the most prevalent fusarium mycotoxins in feedstuff and food. DON causes detrimental effects on human and animal reproductive systems by inducing oxidative stress and apoptosis. However, melatonin is a multifunctional endogenous hormone that plays crucial roles in the development of animal germ cells and embryos as a robust deoxidizer. In this study, we explored the effects of melatonin on the DON exposure Mouse Oocytes. Our in vitro and in vivo results showed that DON adversely affected Mouse Oocyte maturation and early embryo cleavage, while melatonin administration ameliorated the toxic effects of DON. DON exposure disrupted the meiotic spindle formation and kinetochore-microtubule attachment, which induced aneuploidy in Oocytes. This might be through DON effects on the acetylated tubulin level. Moreover, we found that DON exposure caused the alteration of DNA and histone methylation level, which might affect early embryo cleavage. The toxic effects of DON on Oocytes might be through its induction of oxidative stress-mediated early apoptosis, while the treatment with melatonin significantly ameliorated these phenotypes in DON-exposed Mouse Oocytes. Collectively, our results indicated the protection effects of melatonin against defects induced by DON during Mouse Oocyte meiotic maturation.
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Kif18a regulates Sirt2-mediated tubulin acetylation for spindle organization during Mouse Oocyte meiosis
BMC, 2018Co-Authors: Feng Tang, Yu Zhang, Meng-hao Pan, Xiang Wan, Shaochen SunAbstract:Abstract Background During Oocyte meiosis, the cytoskeleton dynamics, especially spindle organization, are critical for chromosome congression and segregation. However, the roles of the kinesin superfamily in this process are still largely unknown. Results In the present study, Kif18a, a member of the kinesin-8 family, regulated spindle organization through its effects on tubulin acetylation in Mouse Oocyte meiosis. Our results showed that Kif18a is expressed and mainly localized in the spindle region. Knock down of Kif18a caused the failure of first polar body extrusion, dramatically affecting spindle organization and resulting in severe chromosome misalignment. Further analysis showed that the disruption of Kif18a caused an increase in acetylated tubulin level, which might be the reason for the spindle organization defects after Kif18a knock down in Oocyte meiosis, and the decreased expression of deacetylase Sirt2 was found after Kif18a knock down. Moreover, microinjections of tubulin K40R mRNA, which could induce tubulin deacetylation, protected the Oocytes from the effects of Kif18a downregulation, resulting in normal spindle morphology in Kif18a-knock down Oocytes. Conclusions Taken together, our results showed that Kif18a affected Sirt2-mediated tubulin acetylation level for spindle organization during Mouse Oocyte meiosis. Our results not only revealed the critical effect of Kif18a on microtubule stability, but also extended our understanding of kinesin activity in meiosis
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formin mdia1 a downstream molecule of fmnl1 regulates profilin1 for actin assembly and spindle organization during Mouse Oocyte meiosis
Biochimica et Biophysica Acta, 2015Co-Authors: Yu Zhang, Fei Wang, Yingjie Niu, Honglin Liu, Rong Rui, Xiangshun Cui, Namhyung Kim, Shaochen SunAbstract:Mammalian diaphanous1 (mDia1) is a homologue of Drosophila diaphanous and belongs to the Formin-homology family of proteins that catalyze actin nucleation and polymerization. Although Formin family proteins, such as Drosophila diaphanous, have been shown to be essential for cytokinesis, whether and how mDia1 functions during meiosis remain uncertain. In this study, we explored possible roles and the signaling pathway involved for mDia1 using a Mouse Oocyte model. mDia1 depletion reduced polar body extrusion, which may have been due to reduced cortical actin assembly. mDia1 and Profilin1 had similar localization patterns in Mouse Oocytes and mDia1 knockdown resulted in reduced Profilin1 expression. Depleting FMNL1, another Formin family member, resulted in reduced mDia1 expression, while RhoA inhibition did not alter mDia1 expression, which indicated that there was a FMNL1-mDia1-Profilin1 signaling pathway in Mouse Oocytes. Additionally, mDia1 knockdown resulted in disrupting Oocyte spindle morphology, which was confirmed by aberrant p-MAPK localization. Thus, these results demonstrated indispensable roles for mDia1 in regulating Mouse Oocyte meiotic maturation through its effects on actin assembly and spindle organization.
Qing-yuan Sun - One of the best experts on this subject based on the ideXlab platform.
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Metformin protects against Mouse Oocyte apoptosis defects induced by arecoline
Cell proliferation, 2020Co-Authors: Chuan‐jie Zang, Shen Yin, Wei Shen, Qing-yuan Sun, Minghui ZhaoAbstract:OBJECTIVES Arecoline is the main bioactive substance extracted from Areca catechu L, which has cell, neural and genetic toxicity. The function of arecoline in reproductive system has not been well explored. MATERIALS AND METHODS To investigate the toxic effects of arecoline on Oocyte development, immunofluorescence staining, qPCR, Western blotting, sperm binding assays and in vitro fertilization were performed to evaluate Oocyte meiosis competence and embryo development. RESULTS Our data revealed that arecoline exposure disrupts actin filament dynamics, spindle assembly and kinetochore-microtubule attachment stability in Mouse Oocytes, leading to aneuploidy and Oocyte meiosis arrest. In addition, arecoline treatment disturbs the distribution of mitochondria, reduces ATP production and increases the level of oxidative stress, which ultimately induces Oocyte apoptosis. Supplementation with metformin, a medicine for type 2 diabetes in the clinic, partially alleviates these damages. CONCLUSIONS Metformin has a protective effect on arecoline-induced Mouse Oocytes apoptosis.
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absence of mitochondrial dna methylation in Mouse Oocyte maturation aging and early embryo development
Biochemical and Biophysical Research Communications, 2019Co-Authors: Lihua Fan, Zhen-bo Wang, Ying-chun Ouyang, Yi Hou, Heide Schatten, Tiegang Meng, Mingzhe Dong, Qing-yuan SunAbstract:Mitochondrial DNA (mtDNA) is important for oxidative phosphorylation; dysfunctions can play a role in many mitochondrial diseases and can also affect the aging of cells and individuals. DNA methylation is an important epigenetic modification that plays a critical role in regulating gene expression. While recent studies have revealed the existence of mtDNA methylation there are still controversies about mtDNA methylation due to the special structure of mtDNA. Mitochondria and DNA methylation are both essential for regulating Oocyte maturation and early embryo development, but whether mtDNA methylation changes during this process is unknown. By employing bisulfite sequencing, we found that in the process of Mouse Oocyte maturation, postovulatory Oocyte aging, and early embryo development, all analyzed mitochondrial genes, including 16S-CpGI, DCR, ND6, 12S, and ATP8, lacked 5'mC. Thus, mtDNA methylation does not occur in the Oocyte and early embryo.
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poly adp ribose mediates asymmetric division of Mouse Oocyte
Cell Research, 2018Co-Authors: Bingteng Xie, Qing-yuan Sun, Lu Zhang, Xiaohui Zhu, Huiling Zhao, Qingyun Bai, Yong Fan, Xin Liang, Jie QiaoAbstract:Before fertilization, mammalian Oocyte undergoes an asymmetric division which depends on eccentric positioning of the spindle at the Oocyte cortex to form a polar body and an egg. Since the centriole is absent and, as a result, the polar array microtubules are not fully developed in Oocytes, microtubules have seldom been considered as required for eccentric positioning of the spindle, while actin-related forces have instead been proposed to be primarily responsible for this process. However, the existing models are largely conflicting and the underlying mechanism of asymmetric division is still elusive. Here we show that poly(ADP-ribose) (PAR) is enriched at Mouse Oocyte cortical area throughout meiosis. Specific removal of cortical PAR results in an ectopic spindle and a failure of asymmetric division. During spindle migration, when the spindle deviates from the center of Oocyte by a pushing force of cytoplasmic actin, the short polar array microtubules emanating from the juxtacortical spindle pole extend to the cortex and penetrate into cortical PAR, docking and stabilizing the spindle at the cortex which facilitates the asymmetric division. This process depends on the affinity between PAR and microtubule-associated proteins such as Spindly, which contributes to a physical link for cortical PAR and the spindle. Notably, fusing a PAR-binding domain to end-binding protein 3, a plus-end tracking protein at the polar array microtubules, restores the asymmetric division of Oocytes with Spindly knockdown. Thus, our work demonstrates a comprehensive mechanism for Oocyte spindle positioning and asymmetric division.
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rab3a rab27a and rab35 regulate different events during Mouse Oocyte meiotic maturation and activation
Histochemistry and Cell Biology, 2016Co-Authors: Wei Shen, Zhen-bo Wang, Ying-chun Ouyang, Heide Schatten, H H Wang, Q Cui, Teng Zhang, Qing-yuan SunAbstract:Rab family members play important roles in membrane trafficking, cell growth, and differentiation. Almost all components of the cell endomembrane system, the nucleus, and the plasma membrane are closely related to RAB proteins. In this study, we investigated the distribution and functions of three members of the Rab family, Rab3A, Rab27A, and Rab35, in Mouse Oocyte meiotic maturation and activation. The three Rab family members showed different localization patterns in Oocytes. Microinjection of siRNA, antibody injection, or inhibitor treatment showed that (1) Rab3A regulates peripheral spindle and cortical granule (CG) migration, polarity establishment, and asymmetric division; (2) Rab27A regulates CG exocytosis following MII-stage Oocyte activation; and (3) Rab35 plays an important role in spindle organization and morphology maintenance, and thus meiotic nuclear maturation. These results show that Rab proteins play important roles in Mouse Oocyte meiotic maturation and activation and that different members exert different distinct functions.
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Localization and function of the Ska complex during Mouse Oocyte meiotic maturation.
Cell cycle (Georgetown Tex.), 2012Co-Authors: Qing-hua Zhang, Zhen-bo Wang, Ying-chun Ouyang, Yi Hou, Heide Schatten, Cai-rong Yang, Yanchang Wei, Lei Chen, Qing-yuan SunAbstract:The Ska (spindle and kinetochore-associated) complex is composed of three proteins: Ska1, Ska2 and Ska3. It is required for stabilizing kinetochore-microtubule (KT-MT) interactions and silencing spindle checkpoint during mitosis. However, its roles in meiosis remain unclear. The present study was designed to investigate the localization and function of the Ska complex during Mouse Oocyte meiotic maturation. Our results showed that the localization and function of Ska complex in Mouse Oocyte meiosis differ in part from those in mitosis. Injection of low dose exogenous Myc-Ska mRNA showed that, instead of localizing to the kinetochores (KTs) and mediating KT-MT interactions from pro-metaphase to mid-anaphase stages as in mitosis, the members of the Ska complex were only localized on spindle microtubules from the Pro-MI to MII stages in Mouse Oocyte meiosis. Time-lapse live imaging analysis showed that knockdown of any member of the Ska complex by Morpholino injection into Mouse Oocytes resulted in spindle movement defects and enlarged polar bodies. Depletion of the whole Ska complex disrupted the stability of the anaphase spindle and influenced the extrusion of the first polar body. Taken together, these results show that the Ska complex plays an important role in meiotic spindle migration and anaphase spindle stability during Mouse Oocyte maturation.
Heide Schatten - One of the best experts on this subject based on the ideXlab platform.
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absence of mitochondrial dna methylation in Mouse Oocyte maturation aging and early embryo development
Biochemical and Biophysical Research Communications, 2019Co-Authors: Lihua Fan, Zhen-bo Wang, Ying-chun Ouyang, Yi Hou, Heide Schatten, Tiegang Meng, Mingzhe Dong, Qing-yuan SunAbstract:Mitochondrial DNA (mtDNA) is important for oxidative phosphorylation; dysfunctions can play a role in many mitochondrial diseases and can also affect the aging of cells and individuals. DNA methylation is an important epigenetic modification that plays a critical role in regulating gene expression. While recent studies have revealed the existence of mtDNA methylation there are still controversies about mtDNA methylation due to the special structure of mtDNA. Mitochondria and DNA methylation are both essential for regulating Oocyte maturation and early embryo development, but whether mtDNA methylation changes during this process is unknown. By employing bisulfite sequencing, we found that in the process of Mouse Oocyte maturation, postovulatory Oocyte aging, and early embryo development, all analyzed mitochondrial genes, including 16S-CpGI, DCR, ND6, 12S, and ATP8, lacked 5'mC. Thus, mtDNA methylation does not occur in the Oocyte and early embryo.
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rab3a rab27a and rab35 regulate different events during Mouse Oocyte meiotic maturation and activation
Histochemistry and Cell Biology, 2016Co-Authors: Wei Shen, Zhen-bo Wang, Ying-chun Ouyang, Heide Schatten, H H Wang, Q Cui, Teng Zhang, Qing-yuan SunAbstract:Rab family members play important roles in membrane trafficking, cell growth, and differentiation. Almost all components of the cell endomembrane system, the nucleus, and the plasma membrane are closely related to RAB proteins. In this study, we investigated the distribution and functions of three members of the Rab family, Rab3A, Rab27A, and Rab35, in Mouse Oocyte meiotic maturation and activation. The three Rab family members showed different localization patterns in Oocytes. Microinjection of siRNA, antibody injection, or inhibitor treatment showed that (1) Rab3A regulates peripheral spindle and cortical granule (CG) migration, polarity establishment, and asymmetric division; (2) Rab27A regulates CG exocytosis following MII-stage Oocyte activation; and (3) Rab35 plays an important role in spindle organization and morphology maintenance, and thus meiotic nuclear maturation. These results show that Rab proteins play important roles in Mouse Oocyte meiotic maturation and activation and that different members exert different distinct functions.
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Localization and function of the Ska complex during Mouse Oocyte meiotic maturation.
Cell cycle (Georgetown Tex.), 2012Co-Authors: Qing-hua Zhang, Zhen-bo Wang, Ying-chun Ouyang, Yi Hou, Heide Schatten, Cai-rong Yang, Yanchang Wei, Lei Chen, Qing-yuan SunAbstract:The Ska (spindle and kinetochore-associated) complex is composed of three proteins: Ska1, Ska2 and Ska3. It is required for stabilizing kinetochore-microtubule (KT-MT) interactions and silencing spindle checkpoint during mitosis. However, its roles in meiosis remain unclear. The present study was designed to investigate the localization and function of the Ska complex during Mouse Oocyte meiotic maturation. Our results showed that the localization and function of Ska complex in Mouse Oocyte meiosis differ in part from those in mitosis. Injection of low dose exogenous Myc-Ska mRNA showed that, instead of localizing to the kinetochores (KTs) and mediating KT-MT interactions from pro-metaphase to mid-anaphase stages as in mitosis, the members of the Ska complex were only localized on spindle microtubules from the Pro-MI to MII stages in Mouse Oocyte meiosis. Time-lapse live imaging analysis showed that knockdown of any member of the Ska complex by Morpholino injection into Mouse Oocytes resulted in spindle movement defects and enlarged polar bodies. Depletion of the whole Ska complex disrupted the stability of the anaphase spindle and influenced the extrusion of the first polar body. Taken together, these results show that the Ska complex plays an important role in meiotic spindle migration and anaphase spindle stability during Mouse Oocyte maturation.
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The SUMO pathway functions in Mouse Oocyte maturation
Cell cycle (Georgetown Tex.), 2010Co-Authors: Zhen-bo Wang, Jing-shan Tong, Liang Wei, Ying-chun Ouyang, Yi Hou, Heide Schatten, Qing-yuan SunAbstract:Sumoylation is an important posttranslational modification in which SUMO (small ubiquitin-related modifier) proteins are bonded covalently to their substrates. Studies on the roles of sumoylation in cell cycle regulation have been emerging in both mitosis from yeast to mammals and meiosis in budding yeast, but the functions of sumoylation in mammalian meiosis, especially in Oocyte meiotic maturation are not well known. Here, we examined the localization and expression of SUMO-1 and SUMO-2/3, the two basic proteins in the sumoylation pathway and investigated their roles through overexpression of Senp2 during Mouse Oocyte maturation. Immunofluorescent staining revealed differential patterns of SUMO-1 and SUMO-2/3 localization: SUMO-1 was localized to the spindle poles in prometaphase I, MI and MII stages, around the separating homologues in anaphase I and telophase I stages of first meiosis, while SUMO-2/3 was mainly concentrated near centromeres during Mouse Oocyte maturation. Immunoblot analysis uncovered the different expression profiles of SUMO-1 and SUMO-2/3 modified proteins during Mouse Oocyte maturation. Overexpression of Senp2, a SUMO-specific isopeptidase, caused changes of SUMO-modified proteins and led to defects in MII spindle organization in mature eggs. These results suggest that the SUMO pathway may play an indispensable role during Mouse Oocyte meiotic maturation.
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bubr1 is a spindle assembly checkpoint protein regulating meiotic cell cycle progression of Mouse Oocyte
Cell Cycle, 2010Co-Authors: Xingwei Liang, Ying-chun Ouyang, Qing-hua Zhang, Mo Li, Ju Yuan, Sen Li, Heide SchattenAbstract:BubR1 (Bub1-related kinase or MAD3/Bub1b) is an essential component of the spindle assembly checkpoint (SAC) and plays an important role in kinetochore localization of other spindle checkpoint proteins in mitosis. But its roles in mammalian Oocyte meiosis are unclear. In the present study, we examined the expression, localization and function of BubR1 during Mouse Oocyte meiotic maturation. The expression level of BubR1 increased progressively from germinal vesicle to metaphase II stages. Immunofluorescent analysis showed that BubR1 localized to kinetochores from the germinal vesicle breakdown to the prometaphase I stages, co-localizing with polo-like kinase 1, while it disappeared from the kinetochores at the metaphase I stage. Spindle disruption by nocodazole treatment caused relocation of BubR1 to kinetochores at metaphase I, anaphase I and metaphase II stages; spindle microtubules were disrupted by low temperature treatment in the BubR1-depleted Oocytes in meiosis I, suggesting that BubR1 monitors kin...
Yu Zhang - One of the best experts on this subject based on the ideXlab platform.
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Involvement of Kif4a in Spindle Formation and Chromosome Segregation in Mouse Oocytes.
Aging and disease, 2018Co-Authors: Feng Tang, Yu Zhang, Meng-hao Pan, Xiang Wan, Shaochen SunAbstract:Kif4a, a member of the kinesin superfamily, has been reported to participate in a series of cellular processes such as chromosome condensation and cytokinesis during mitosis. However, the roles of KIF4a in meiosis are still unknown. In present study we found that the Kif4a protein expression decreased in maternal aged Mouse Oocytes. We then explored the roles of Kif4a in Mouse Oocyte meiosis by knockdown analysis. Kif4a was enriched at the spindle during Mouse Oocyte maturation. By specific knock down of the Kif4a using morpholino microinjection, we found that the disruption of Kif4a caused the failure of polar body extrusion. Further analysis indicated that Kif4a might affect the spindle morphology and chromosome alignment in the Mouse Oocytes, and this might be due to the regulation of tubulin acetylation. Moreover, our results showed that an increased proportion of aneuploidy in the Kif4a knock down Oocytes, and this might be due to the loss of kinetochore-microtubule attachment. Taken together, these results suggested that Kif4a possibly regulated Mouse Oocyte meiosis through its effects on the spindle organization and accurate chromosome segregation, and the loss of Kif4a might be related with aneuploidy of aging Oocytes.
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vesicular transport protein arf6 modulates cytoskeleton dynamics for polar body extrusion in Mouse Oocyte meiosis
Biochimica et Biophysica Acta, 2018Co-Authors: Xing Duan, Haolin Zhang, Yu ZhangAbstract:Abstract Arf6 (ADP-ribosylation factor 6) is known to play important roles in membrane dynamics through the regulation of actin filament reorganization for multiple cellular processes such as cytokinesis, phagocytosis, cell migration and tumor cell invasion. However, the functions of Arf6 in mammalian Oocyte meiosis have not been clarified. In present study we showed that Arf6 expressed in Mouse Oocytes and was mainly distributed around the spindle during meiosis. Depletion of Arf6 by morpholino microinjection caused Oocytes failing to extrude first polar body. Further analysis indicated that Arf6 knock down caused the aberrant actin distribution, which further induced the failure of meiotic spindle movement. And the loss of Oocyte polarity also confirmed this. The regulation of Arf6 on actin filaments in Mouse Oocytes might be due to its effects on the phosphorylation level of cofilin and the expression of Arp2/3 complex. Moreover, we found that the decrease of Arf6 caused the disruption of spindle formation, indicating the multiple roles of Arf6 on cytoskeleton dynamics in meiosis. In summary, our results indicated that Arf6 was involved in Mouse Oocyte meiosis through its functional roles in actin-mediated spindle movement and spindle organization.
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Kif18a regulates Sirt2-mediated tubulin acetylation for spindle organization during Mouse Oocyte meiosis
BMC, 2018Co-Authors: Feng Tang, Yu Zhang, Meng-hao Pan, Xiang Wan, Shaochen SunAbstract:Abstract Background During Oocyte meiosis, the cytoskeleton dynamics, especially spindle organization, are critical for chromosome congression and segregation. However, the roles of the kinesin superfamily in this process are still largely unknown. Results In the present study, Kif18a, a member of the kinesin-8 family, regulated spindle organization through its effects on tubulin acetylation in Mouse Oocyte meiosis. Our results showed that Kif18a is expressed and mainly localized in the spindle region. Knock down of Kif18a caused the failure of first polar body extrusion, dramatically affecting spindle organization and resulting in severe chromosome misalignment. Further analysis showed that the disruption of Kif18a caused an increase in acetylated tubulin level, which might be the reason for the spindle organization defects after Kif18a knock down in Oocyte meiosis, and the decreased expression of deacetylase Sirt2 was found after Kif18a knock down. Moreover, microinjections of tubulin K40R mRNA, which could induce tubulin deacetylation, protected the Oocytes from the effects of Kif18a downregulation, resulting in normal spindle morphology in Kif18a-knock down Oocytes. Conclusions Taken together, our results showed that Kif18a affected Sirt2-mediated tubulin acetylation level for spindle organization during Mouse Oocyte meiosis. Our results not only revealed the critical effect of Kif18a on microtubule stability, but also extended our understanding of kinesin activity in meiosis
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formin mdia1 a downstream molecule of fmnl1 regulates profilin1 for actin assembly and spindle organization during Mouse Oocyte meiosis
Biochimica et Biophysica Acta, 2015Co-Authors: Yu Zhang, Fei Wang, Yingjie Niu, Honglin Liu, Rong Rui, Xiangshun Cui, Namhyung Kim, Shaochen SunAbstract:Mammalian diaphanous1 (mDia1) is a homologue of Drosophila diaphanous and belongs to the Formin-homology family of proteins that catalyze actin nucleation and polymerization. Although Formin family proteins, such as Drosophila diaphanous, have been shown to be essential for cytokinesis, whether and how mDia1 functions during meiosis remain uncertain. In this study, we explored possible roles and the signaling pathway involved for mDia1 using a Mouse Oocyte model. mDia1 depletion reduced polar body extrusion, which may have been due to reduced cortical actin assembly. mDia1 and Profilin1 had similar localization patterns in Mouse Oocytes and mDia1 knockdown resulted in reduced Profilin1 expression. Depleting FMNL1, another Formin family member, resulted in reduced mDia1 expression, while RhoA inhibition did not alter mDia1 expression, which indicated that there was a FMNL1-mDia1-Profilin1 signaling pathway in Mouse Oocytes. Additionally, mDia1 knockdown resulted in disrupting Oocyte spindle morphology, which was confirmed by aberrant p-MAPK localization. Thus, these results demonstrated indispensable roles for mDia1 in regulating Mouse Oocyte meiotic maturation through its effects on actin assembly and spindle organization.
Ju Yuan - One of the best experts on this subject based on the ideXlab platform.
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bubr1 is a spindle assembly checkpoint protein regulating meiotic cell cycle progression of Mouse Oocyte
Cell Cycle, 2010Co-Authors: Xingwei Liang, Ying-chun Ouyang, Qing-hua Zhang, Mo Li, Ju Yuan, Sen Li, Heide SchattenAbstract:BubR1 (Bub1-related kinase or MAD3/Bub1b) is an essential component of the spindle assembly checkpoint (SAC) and plays an important role in kinetochore localization of other spindle checkpoint proteins in mitosis. But its roles in mammalian Oocyte meiosis are unclear. In the present study, we examined the expression, localization and function of BubR1 during Mouse Oocyte meiotic maturation. The expression level of BubR1 increased progressively from germinal vesicle to metaphase II stages. Immunofluorescent analysis showed that BubR1 localized to kinetochores from the germinal vesicle breakdown to the prometaphase I stages, co-localizing with polo-like kinase 1, while it disappeared from the kinetochores at the metaphase I stage. Spindle disruption by nocodazole treatment caused relocation of BubR1 to kinetochores at metaphase I, anaphase I and metaphase II stages; spindle microtubules were disrupted by low temperature treatment in the BubR1-depleted Oocytes in meiosis I, suggesting that BubR1 monitors kin...
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bub3 is a spindle assembly checkpoint protein regulating chromosome segregation during Mouse Oocyte meiosis
PLOS ONE, 2009Co-Authors: Ju Yuan, Shaochen Sun, Zhen-bo Wang, Heide Schatten, Qing-yuan SunAbstract:In mitosis, the spindle assembly checkpoint (SAC) prevents anaphase onset until all chromosomes have been attached to the spindle microtubules and aligned correctly at the equatorial metaphase plate. The major checkpoint proteins in mitosis consist of mitotic arrest-deficient (Mad)1–3, budding uninhibited by benzimidazole (Bub)1, Bub3, and monopolar spindle 1(Mps1). During meiosis, for the formation of a haploid gamete, two consecutive rounds of chromosome segregation occur with only one round of DNA replication. To pull homologous chromosomes to opposite spindle poles during meiosis I, both sister kinetochores of a homologue must face toward the same pole which is very different from mitosis and meiosis II. As a core member of checkpoint proteins, the individual role of Bub3 in mammalian Oocyte meiosis is unclear. In this study, using overexpression and RNA interference (RNAi) approaches, we analyzed the role of Bub3 in Mouse Oocyte meiosis. Our data showed that overexpressed Bub3 inhibited meiotic metaphase-anaphase transition by preventing homologous chromosome and sister chromatid segregations in meiosis I and II, respectively. Misaligned chromosomes, abnormal polar body and double polar bodies were observed in Bub3 knock-down Oocytes, causing aneuploidy. Furthermore, through cold treatment combined with Bub3 overexpression, we found that overexpressed Bub3 affected the attachments of microtubules and kinetochores during metaphase-anaphase transition. We propose that as a member of SAC, Bub3 is required for regulation of both meiosis I and II, and is potentially involved in kinetochore-microtubule attachment in mammalian Oocytes.