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 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.

scholarly journals SIRT6 Maintains Redox Homeostasis to Promote Porcine Oocyte Maturation

2021 ◽  
Vol 9 ◽  
Author(s):  
Yu Li ◽  
Yilong Miao ◽  
Jingyue Chen ◽  
Bo Xiong
Keyword(s):  
Genome Stability ◽  
Polar Body ◽  
Redox Homeostasis ◽  
Cumulus Cell ◽  
Telomere Maintenance ◽  
Actin Dynamics ◽  
Cortical Granules ◽  
Oocyte Meiosis ◽  
Porcine Oocyte ◽  
Polar Body Extrusion

SIRT6, the sixth member of the sirtuin family proteins, has been characterized as a crucial regulator in multiple molecular pathways related to aging, including genome stability, DNA damage repair, telomere maintenance, and inflammation. However, the exact roles of SIRT6 during female germ cell development have not yet been fully determined. Here, we assessed the acquisition of meiotic competency of porcine oocytes by inhibition of SIRT6 activity. We observed that SIRT6 inhibition led to the oocyte meiotic defects by showing the impairment of polar body extrusion and cumulus cell expansion. Meanwhile, the compromised spindle/chromosome structure and actin dynamics were also present in SIRT6-inhibited oocytes. Moreover, SIRT6 inhibition resulted in the defective cytoplasmic maturation by displaying the disturbed distribution dynamics of cortical granules and their content ovastacin. Notably, we identified that transcript levels of genes related to oocyte meiosis, oxidative phosphorylation, and cellular senescence were remarkably altered in SIRT6-inhibited oocytes by transcriptome analysis and validated that the meiotic defects caused by SIRT6 inhibition might result from the excessive reactive oxygen species (ROS)-induced early apoptosis in oocytes. Taken together, our findings demonstrate that SIRT6 promotes the porcine oocyte meiotic maturation through maintaining the redox homeostasis.

scholarly journals Cytoplasmic Microtubule Organizing Centers Regulate Meiotic Spindle Positioning in Mouse Oocyte

2020 ◽  
Author(s):  
Daniela Londono Vasquez ◽  
Katherine Rodriguez-Lukey ◽  
Susanta K. Behura ◽  
Ahmed Z. Balboula
Keyword(s):  
Polar Body ◽  
Spindle Pole ◽  
Meiotic Spindle ◽  
Cytoplasmic Microtubule ◽  
Spindle Positioning ◽  
Nuclear Envelope Breakdown ◽  
Oocyte Meiosis ◽  
Polar Bodies ◽  
Polar Body Extrusion

ABSTRACTDuring oocyte meiosis, migration of the spindle and its positioning must be tightly regulated to ensure elimination of the polar bodies and provide developmentally competent euploid eggs. Although the role of F-actin in regulating these critical processes has been studied extensively, little is known whether microtubules (MTs) participate in regulating these processes. Here, we characterize a pool of MTOCs in the oocyte that does not contribute to spindle assembly but instead remains free in the cytoplasm during metaphase I (metaphase cytoplasmic MTOCs; mcMTOCs). In contrast to spindle pole MTOCs, which primarily originate from the perinuclear region in prophase I, the mcMTOCs are found near the cortex of the oocyte. At nuclear envelope breakdown, they exhibit robust nucleation of MTs, which diminishes during polar body extrusion before returning robustly during metaphase II. The asymmetric positioning of the mcMTOCs provides the spindle with a MT-based anchor line to the cortex opposite the site of polar body extrusion. Depletion of mcMTOCs, by laser ablation, or manipulating their numbers, through autophagy inhibition, revealed that the mcMTOCs are required to regulate the timely migration and positioning of the spindle in meiosis. We discuss how forces exerted by F-actin in mediating movement of the spindle to the oocyte cortex are balanced by MT-mediated forces from the mcMTOCs to ensure spindle positioning and timely spindle migration.

scholarly journals Comparison of the toxic effects of different mycotoxins on porcine and mouse oocyte meiosis

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5111 ◽  
Author(s):  
Yujie Lu ◽  
Yue Zhang ◽  
Jia-Qian Liu ◽  
Peng Zou ◽  
Lu Jia ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Animal Feed ◽  
Polar Body ◽  
Oocyte Quality ◽  
Mouse Oocyte ◽  
Toxic Effects ◽  
Mouse Oocytes ◽  
Oocyte Meiosis ◽  
Porcine Oocyte ◽  
Polar Body Extrusion

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.

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.

Knockdown of UCHL5IP causes abnormalities in γ-tubulin localisation, spindle organisation and chromosome alignment in mouse oocyte meiotic maturation

2013 ◽  
Vol 25 (3) ◽  
pp. 495 ◽  
Author(s):  
Ya-Peng Wang ◽  
Shu-Tao Qi ◽  
Yanchang Wei ◽  
Zhao-Jia Ge ◽  
Lei Chen ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Oocyte Maturation ◽  
Protein Level ◽  
Mouse Oocyte ◽  
Meiotic Spindle ◽  
Meiotic Maturation ◽  
Spindle Formation ◽  
Spindle Poles ◽  
Chromosome Alignment ◽  
Oocyte Meiotic Maturation

UCHL5IP is one of the subunits of the haus complex, which is important for microtubule generation, spindle bipolarity and accurate chromosome segregation in Drosophila and human mitotic cells. In this study, the expression and localisation of UCHL5IP were explored, as well as its functions in mouse oocyte meiotic maturation. The results showed that the UCHL5IP protein level was consistent during oocyte maturation and it was localised to the meiotic spindle in MI and MII stages. Knockdown of UCHL5IP led to spindle defects, chromosome misalignment and disruption of γ-tubulin localisation in the spindle poles. These results suggest that UCHL5IP plays critical roles in spindle formation during mouse oocyte meiotic maturation.

EZH2 is essential for spindle assembly regulation and chromosomal integrity during porcine oocyte meiotic maturation†

2020 ◽  
Author(s):  
Qingqing Cai ◽  
Keying Wen ◽  
Miao Ma ◽  
Wei Chen ◽  
Delin Mo ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Polar Body ◽  
Spindle Assembly ◽  
Meiotic Maturation ◽  
Meiotic Progression ◽  
First Polar Body ◽  
Porcine Oocyte ◽  
Polar Body Extrusion ◽  
Oocyte Meiotic Maturation ◽  
Early Occurrence

Abstract Enhancer of zeste homolog 2 (EZH2) has been extensively investigated to participate in diverse biological processes, including carcinogenesis, the cell cycle, X-chromosome inactivation, and early embryonic development. However, the functions of this protein during mammalian oocyte meiotic maturation remain largely unexplored. Here, combined with RNA-Seq, we provided evidence that EZH2 is essential for oocyte meiotic maturation in pigs. First, EZH2 protein expression increased with oocyte progression from GV to MII stage. Second, the siRNA-mediated depletion of EZH2 led to accelerated GVBD and early occurrence of the first polar body extrusion. Third, EZH2 knockdown resulted in defective spindle assembly, abnormal SAC activity, and unstable K-MT attachment, which was concomitant with the increased rate of aneuploidy. Finally, EZH2 silencing exacerbated oxidative stress by increasing ROS levels and disrupting the distribution of active mitochondria in porcine oocytes. Furthermore, parthenogenetic embryonic development was impaired following the depletion of EZH2 at GV stage. Taken together, we concluded that EZH2 is necessary for porcine oocyte meiotic progression through regulating spindle organization, maintaining chromosomal integrity, and mitochondrial function.

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.

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 Circular RNA profiling in the oocyte and cumulus cells reveals thatcircARMC4is essential for porcine oocyte maturation

2019 ◽  
Author(s):  
Zubing Cao ◽  
Di Gao ◽  
Tengteng Xu ◽  
Ling Zhang ◽  
Xu Tong ◽  
...  
Keyword(s):  
Developmental Stage ◽  
Oocyte Maturation ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Early Embryo ◽  
Meiotic Maturation ◽  
Early Embryo Development ◽  
Specific Manner ◽  
Porcine Oocyte ◽  
Oocyte Meiotic Maturation

ABSTRACTThousands of circular RNAs (circRNAs) have been recently discovered in cumulus cells and oocytes from several species. However, the expression and function of circRNA during porcine oocyte meiotic maturation have been never examined. Here, we separately identified 7,067 and 637 circRNAs in both the cumulus cell and the oocyte via deep sequencing and bioinformatic analysis. Further analysis revealed that a faction of circRNAs is differentially expressed (DE) in a developmental stage-specific manner. The host genes of DE circRNAs are markedly enriched to multiple signaling pathways associated with cumulus cell function and oocyte maturation. Additionally, most DE circRNAs harbor several miRNA targets, suggesting that these DE circRNAs potentially act as miRNA sponge. Importantly, we found that maternalcircARMC4knockdown by siRNA microinjection caused a severely impaired chromosome alignment, and significantly inhibited first polar body extrusion and early embryo development. Taken together, these results demonstrate for the first time that circRNAs are abundantly and dynamically expressed in a developmental stage-specific manner in cumulus cells and oocytes, and maternally expressedcircARMC4is essential for porcine oocyte meiotic maturation and early embryo development.

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