scholarly journals RASD1 Knockdown Results in Failure of Oocyte Maturation

2016 ◽  
Vol 40 (6) ◽  
pp. 1289-1302 ◽  
Author(s):  
Youngeun Lee ◽  
Kyeoung-Hwa Kim ◽  
Hyemin Yoon ◽  
Ok-Hee Lee ◽  
Eunyoung Kim ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Oocyte Maturation ◽  
Iron Homeostasis ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Germinal Vesicle ◽  
Time Lapse ◽  
Small Gtpases ◽  
Spindle Formation ◽  
Chromosome Alignment

Background: Ras dexamethasone-induced protein (RASD1) is a member of Ras superfamily of small GTPases. RASD1 regulates various signaling pathways involved in iron homeostasis, growth hormone secretion, and circadian rhythm. However, RASD1 function in oocyte remains unknown. Methods: Using immunohistochemistry, immunofluorescence, and quantitative real-time RT-PCR, RASD1 expression in mouse ovary and RASD1 role in oocyte maturation-related gene expression, spindle formation, and chromosome alignment were analyzed. RNAi microinjection and time-lapse video microscopy were used to examine the effect of Rasd1 knockdown on oocyte maturation. Results: RASD1 was highly detected in oocytes transitioning from primordial to secondary follicles. Rasd1 was highly expressed in germinal vesicle (GV), during GV breakdown, and in metaphase I (MI) stage as oocytes mature, and its expression was significantly downregulated in MII stage. With knockdown of Rasd1, maturation in GV oocytes was arrested at MI stage, showing disrupted meiotic spindling and chromosomal misalignment. In addition, Obox4 and Arp2/3, engaged in MI-MII transition and cytokinesis, respectively, were misregulated in GV oocytes by Rasd1 knockdown. Conclusion: These findings suggest that RASD1 is a novel factor in MI-MII oocyte transition and may be involved in regulating the progression of cytokinesis and spindle formation, controlling related signaling pathways during oocyte maturation.

scholarly journals Knockdown of PRKAR2B Results in the Failure of Oocyte Maturation

2018 ◽  
Vol 45 (5) ◽  
pp. 2009-2020 ◽  
Author(s):  
Hyemin Yoon ◽  
Hoon Jang ◽  
Eun-Young Kim ◽  
Sohyeon Moon ◽  
Sangho Lee ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Time Lapse ◽  
Pentose Phosphate ◽  
Regulatory Subunit ◽  
Spindle Formation ◽  
Qrt Pcr ◽  
Dependent Protein

Background/Aims: Cyclic adenosine monophosphate (cAMP)-dependent type 2 regulatory subunit beta (Prkar2b) is a regulatory isoform of cAMP-dependent protein kinase (PKA), which is the primary target for cAMP actions. In oocytes, PKA and the pentose phosphate pathway (PPP) have important roles during the germinal vesicle (GV) stage arrest of development. Although the roles of the PKA signal pathway have been studied in the development of oocyte, there has been no report on the function of PRKAR2B, a key regulator of PKA. Methods: Using reverse transcription polymerase chain reaction (RT-PCR), quantitative real-time PCR (qRT-PCR), immunohistochemistry, and immunofluorescence, we determined the relative expression of Prkar2b in various tissues, including ovarian follicles, during oocyte maturation. Prkar2b-interfering RNA (RNAi) microinjection was conducted to confirm the effect of Prkar2b knockdown, and immunofluorescence, qRT-PCR, and time-lapse video microscopy were used to analyze Prkar2b-deficient oocytes. Results: Prkar2b is strongly expressed in the ovarian tissues, particularly in the growing follicle. During oocyte maturation, the highest expression of Prkar2b was during metaphase I (MI), with a significant decrease at metaphase II (MII). RNAi-mediated Prkar2b suppression resulted in MI-stage arrest during oocyte development, and these oocytes exhibited abnormal spindle formation and chromosome aggregation. Expression of other members of the PKA family (except for Prkaca) were decreased, and the majority of the PPP factors were also reduced in Prkar2b-deficient oocytes. Conclusion: These results suggest that Prkar2b is closely involved in the maturation of oocytes by controlling spindle formation and PPP-mediated metabolism.

Behavior of γ-tubulin during spindle formation in Xenopus oocytes: requirement of cytoplasmic dynein-dependent translocation

Zygote ◽  
2005 ◽  
Vol 13 (3) ◽  
pp. 219-226 ◽  
Author(s):  
Tomoya Kotani ◽  
Masakane Yamashita
Keyword(s):  
Oocyte Maturation ◽  
Late Stage ◽  
Xenopus Oocytes ◽  
Germinal Vesicle ◽  
Cytoplasmic Dynein ◽  
Microtubule Organization ◽  
Germinal Vesicle Breakdown ◽  
Spindle Formation ◽  
Bipolar Spindle

Vertebrate oocytes do not contain centrosomes and therefore form an acentrosomal spindle during oocyte maturation. γ-Tubulin is known to be essential for nucleation of microtubules at centrosomes, but little is known about the behaviour and role of γ-tubulin during spindle formation in oocytes. We first observed sequential localization of γ-tubulin during spindle formation in Xenopus oocytes. γ-Tubulin assembled in the basal regions of the germinal vesicle (GV) at the onset of germinal vesicle breakdown (GVBD) and remained on the microtubule-organizing centre (MTOC) until a complex of the MTOC and transient-microtubule array (TMA) reached the oocyte surface. Prior to bipolar spindle formation, oocytes formed an aggregation of microtubules and γ-tubulin was concentrated at the centre of the aggregation. At the late stage of bipolar spindle formation, γ-tubulin accumulated at each pole. Anti-dynein antibody disrupted the localization of γ-tubulin, indicating that the translocation described above is dependent on dynein activity. We finally revealed that XMAP215, a microtubule-associated protein cooperating with γ-tubulin for the assembly of microtubules, but not γ-tubulin, was phosphorylated during oocyte maturation. These results suggest that γ-tubulin is translocated by dynein to regulate microtubule organization leading to spindle formation and that modification of the molecules that cooperate with γ-tubulin, but not γ-tubulin itself, is important for microtubule reorganization.

scholarly journals The Effects of Polyadenylation Status on MPFs During In Vitro Porcine Oocyte Maturation

2016 ◽  
Vol 39 (5) ◽  
pp. 1735-1745 ◽  
Author(s):  
Huiyu Liu ◽  
Yan Gao ◽  
Bo Zhai ◽  
Hao Jiang ◽  
Yu Ding ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Cyclin B1 ◽  
Spindle Formation ◽  
Large Follicle ◽  
Maturation In Vitro ◽  
First Polar Body ◽  
Chromosome Alignment ◽  
Porcine Oocyte ◽  
Maternal Mrnas

Aims: This study aims to clarify the effects of polyadenylation status on M-phase promoting factors (MPFs) during in vitro porcine oocyte maturation. Methods: In this study, porcine follicular oocytes from large follicles (> 5 millimeter (mm)) and small follicles (< 3 mm) were examined at different follicular developmental stages. The polyadenylation of maternal mRNAs was inhibited by the addition of 3'-deoxyadenosine (3'-da) during the germinal vesicle (GV)(0 h), GV breakdown (GVBD)(18 h), metaphase I (MI)(28 h), and metaphase II (MII) (44 h) stages. In addition, the expression levels and poly-(A) tail lengths of the maternal mRNAs Cyclin B1 and cell division cycle 2 (Cdc2) were determined by real-time quantitative PCR. Immunofluorescence was used to assess spindle formation and chromosome alignment in the examined oocytes. Results: In large-follicle oocytes, the effects of inhibiting polyadenylation caused the percentage of mature to be significantly lower for the treated group than for the untreated group (p < 0.01). 3'-da can significantly improve the rate of small oocyte maturation in vitro and inhibits Cdc2 polyadenylation. Cyclin B1 plays a significant role in promoting the maturation of large-follicle oocytes. Polyadenylation contributes to the formation of dominant follicles and facilitates the selection of dominant follicles. However, the inhibition of adenylation affected spindle formation-related propulsion and chromosome alignment in both large- and small-follicle oocytes. The first polar body could not be extruded in certain large follicles. Conclusions: 3'-da can significantly improve the rate of small oocyte maturation in vitro, but it can also affect spindle formation-related propulsion and chromosome alignment.

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.

THE EFFECT OF BETA-RECEPTOR BLOCKADE ON EXERCISE AND ARGININE-INDUCED GROWTH HORMONE SECRETION IN MAN

1974 ◽  
Vol 77 (1_Suppl) ◽  
pp. S6 ◽  
Author(s):  
S. Raptis ◽  
H. Hirth-Schmidt ◽  
K. E. Schröder ◽  
E. F. Pfeiffer
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Receptor Blockade ◽  
Beta Receptor ◽  
Beta Receptor Blockade
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