• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.972-979
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• 2008

It has been recently shown that expression of the LH receptor (LHR) in cumulus cells is related with FSH-induced meiotic resumption of mouse cumulus enclosed oocytes (CEOs). However, to date, it is still unclear whether LHR expression in cumulus cells plays a key role during FSH-induced oocyte maturation. The purpose of this study was to characterize the functional role of LHRs in cumulus cells. CEOs were isolated from eCG-primed preovulatory follicles and cultured in hypoxanthine (HX) arrested medium. LHR protein expression in cumulus cells was time-dependent increasing during the process of FSH-induced oocyte maturation. While the sense oligodeoxynucleotide (ODN) had no effect, antisense ODN inhibited FSH-induced LHR expression and meiotic resumption. Moreover, this antisense ODN against LHR could inhibit FSH-induced mitogen-activated protein kinase (MAPK) phosphorylation. This study suggested that LHR expression in cumulus cells is involved in FSH-induced oocyte meiotic resumption, which process is possibly regulated by MAPK cascade.

• Reproductive and Developmental Biology
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• 제36권3호
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• pp.173-181
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• 2012

Sphingosine-1-phosphate (S1P) has a many function involved proliferation, differentiation and survival of many cells. In this study, to investigate whether S1P improve the developmental competence of porcine embryos, 50 nM of S1P were supplemented during in vitro maturation (with EGF or without EGF) medium and/or in vitro culture (IVC) medium. Addition of S1P was significantly increased the rate of oocytes reaching metaphase II (MII) compared to the control (83.5 vs. 64.1%) in without EGF medium, but not with EGF medium (89.5 vs. 84.6%). When treated with $1{\mu}M$ of N1N-dimethylsphingosine (DMS), a sphingosine kinase inhibitor which is blocked endogenous generation of S1P, the meiotic progression rates to MII stage (without EGF: 45.2 and with EGF: 66.7%) were significantly decreased and degeneration rates (without EGF: 51.2 and with EGF: 30.1%) were increased in both medium compared to control group during IVM periods. Also, the rates of blastocyst formation was significantly increased in the S1P treated group compared to control group (29.0 vs. 19.2%) of EGF supplemented medium, whereas there were no effect in the EGF free medium (9.0 vs. 10.5%). After 12 h IVM, the phosphorylation of ERK1 and ERK2, which is major signaling pathway of MAP kinase, were increased in the S1P group than that of control or DMS group. When supplemented of S1P during IVC, the rates of blastocyst formation and total cell number (30.2% and 40.6) were significantly increased in S1P-treated group compared with control (20.1% and 32.5), DMS (12.3% and 25.1), and S1P plus DMS group (24.7% and 33.6). The percentage of apoptosis nuclei in the S1P group was significantly decreased than other groups. Also, the rates of blastocyst formation (26.7 vs. 14%) and total cell number (42.8 vs. 32.5) were significantly increased in the S1P group than those of control group when S1P added during the entire IVM and IVC periods. Taken together, our results indicate that S1P supplementation in IVM and/or IVC medium affects beneficial effect of meiotic maturation and subsequent developmental competence of porcine embryos.

• 한국수정란이식학회지
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• 제28권4호
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• pp.361-371
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• 2013

The present study assessed the effect of FSH and LH on oocyte meiotic, cytoplasmic maturation and on the expression level and polyadenylation status of several maternal genes. Cumulus-oocyte complexes were cultured in the presence of FSH, LH, or the combination of FSH and LH. Significant cumulus expansion and nuclear maturation was observed upon exposure to FSH alone and to the combination of FSH and LH. The combination of FSH and LH during entire IVM increased the mRNA level of four maternal genes, C-mos, Cyclin B1, Gdf9 and Bmp15, at 28 h. Supplemented with FSH or LH significantly enhanced the polyadenylation of Gdf9 and Bmp15; and altered the expression level of Gdf9 and Bmp15. Following parthenogenesis, the exposure of oocytes to combination of FSH and LH during IVM significantly increased cleavage rate, blastocyst formation rate and total cell number, and decreased apoptosis. In addition, FSH and LH down-regulated the autophagy gene Atg6 and upregulated the apoptosis gene Bcl-xL at the mRNA level in blastocysts. These data suggest that the FSH and LH enhance meiotic and cytoplasmic maturation, possibly through the regulation of maternal gene expression and polyadenylation. Overall, we show here that FSH and LH inhibit apoptosis and autophagy and improve parthenogenetic embryo competence and development.

• 한국동물생명공학회지
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• 제35권1호
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• pp.2-11
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• 2020

Assisted reproductive technologies (ART) merely depend on improving the oocyte maturation and their developmental competence to produce good quality embryos. Oocyte maturation passes through long and complex molecular steps starts from the early embryonic life and ends with sperm fertilization. Oocyte developmental competence can be attained by improving the nuclear and cytoplasmic mechanisms together with some epigenetic maturation. In this review, we highlight the cornerstones of oocyte maturation on both nuclear and cytoplasmic levels. Interfering or supporting these molecular mechanisms would help in the development of novel regulating agents for reproductive performance of humans and livestock species.

• Reproductive and Developmental Biology
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• 제39권2호
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• pp.37-41
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• 2015

The oocyte undergoes various events during maturation and requires many substances for the maturation process. Various intracellular organelles are also involved in maturation of the oocyte. During the process glucose is essential for nuclear and cytoplasmic maturation, and adenosine triphosphate is needed for reorganization of the organelles and cytoskeleton. If mitochondrial function is lost, several developmental defects in meiotic chromosome segregation and maturation cause fertilization failure. The endoplasmic reticulum, a store for $Ca^{2+}$, releases $Ca^{2+}$ into the cytoplasm in response to various cellular signaling molecules. This event stimulates secretion of hormones, growth factors and antioxidants in oocyte during maturation. Also, oocyte nuclear maturation is stimulated by growth factors such as epidermal growth factor. This review summarizes roles of organelles with focus on the Golgi apparatus during maturation in oocyte.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2001년도 제41차 추계학술대회
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• pp.100-100
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• 2001

• 한국수정란이식학회지
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• 제33권4호
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• pp.211-220
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• 2018

Nitric oxide (NO) has an important role in oocyte maturation and embryonic development in mammals. This study examined the effect of exogenous NO donor S-nitroso-N-acetylpenicillamine (SNAP) in a maturation medium on meiotic progression and embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. When oocytes were exposed to $0.1{\mu}M$ SNAP for first 22 h of in vitro maturation (IVM) in Experiment 1, SNAP significantly improved blastocyst development in both defined and standard follicular fluid-supplemented media compared to untreated control (48.4 vs. 31.7-42.5%). SNAP treatment significantly arrested meiotic progression of oocytes at the germinal vesicle stage at 11 h of IVM (61.2 vs. 38.7%). However, there was no effect on meiotic progression at 22 h of IVM (Experiment 2). In Experiment 3, when oocytes were treated with SNAP at 0.001, 0.1 and $10{\mu}M$ during the first 22 h of IVM to determine a suitable concentration, $0.1{\mu}M$ SNAP (54.2%) exhibited a higher blastocyst formation than 0 and $10{\mu}M$ SNAP (36.6 and 36.6%, respectively). Time-dependent effect of SNAP treatment was evaluated in Experiment 4. It was observed that SNAP treatment for the first 22 h of IVM significantly increased blastocyst formation compared to no treatment (57.1% vs. 46.2%). Antioxidant effect of SNAP was compared with that of cysteine. SNAP treatment significantly improved embryonic development to the blastocyst stage (49.1-51.5% vs. 34.4-37.5%) irrespective of the presence or absence of cysteine (Experiment 5). Moreover, SNAP significantly increased glutathione (GSH) content and inversely decreased the reactive oxygen species (ROS) level and mitochondrial oxidative activity in IVM oocytes. SNAP treatment during IVM showed a stimulating effect on in vitro development of SCNT embryos (Experiment 7). These results demonstrates that SNAP improves developmental competence of PA and SCNT embryos probably by maintaining the redox homeostasis through increasing GSH content and mitochondrial quality and decreasing ROS in IVM oocytes.

• 한국수정란이식학회지
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• 제7권1호
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• pp.41-47
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• 1992

1. In vitro system, LR and FSR accelerated and facilitated meiotic progression, and LH selectively improved cytoplasmic maturation which is required to promote the formation of a male pronucleus. 2. Caffeine (2mM) in the fetilization medium was required not only for inducing zona penetrating ability of boar also for developing to the male pronucleus of the penetrat- ing spermatozoa in vitro. 3. The germinal vesicle (GV)stage was observed for the first 17.6 hr;germinal vesicle break-down (GVBD)stage between 17.6~26.4 hr ;metaphase I (M-I)from 26.4 - 30. 9hr;anaphase I(A-I)ranged from 30. 9~33.4hr;telophase I(T-I) at 33.4~34.4hr; and metaphase II(M-II) at 34.4-48hr. 4. The addition of 10%(v /v) pig follicular fluid (pFF) to maturation media significantly increased the rate of nuclear maturation of pig oocytes (p<0.01), whereas the rate of nuclear maturation of pig oocytes among three different media did not differ. 5. The presence of a primary culture of POEC promotes in vitro development of early cleavage stage pig embryos.

• 한국산학기술학회논문지
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• 제11권6호
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• pp.2124-2128
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• 2010

본 연구에서는 MAPK 저해제인 U0126이 난자성숙과정에서 특히 감수분열, 미세소관 형성 그리고 액틴 필 라먼트 형성에 미치는 영향을 조사하였다. 그 결과 MAPK 단백질은 12시간째에 인산화되기 시작하여, 24시간째에 대부분 인산화 되었고 metaphase II에 이르기 까지 유지되었다. 배포단계(GV)에 있는 난자를 U0126의 $20{\mu}M$ 농도로 처리하였을 때 MAPK의 인산화가 완전히 억제되었으나 배포의 파열 단계(GVBD)로의 성숙에는 진행하였으나, metaphase I까지는 발달하지 못하였다. 또한 MAPK 저해제로 인해 비정상적인 방추사의 형성을 초래하였다. 난자를 배포의 파열단계(GVBD) 이후에 U0126을 처리하였을 때 극체의 방출은 정상 이였으나 중기 판의 배열과 염색체의 분열은 비정상적 이였다. 결론적으로, 유사분열 활성화 효소단백질인 MAPK의 활성은 돼지 난자의 체외성숙과정에서 배포단계(GV)의 염색체의 배열과 감수분열의 완성에 중요한 조절 인자임을 이번 연구를 통해 알 수 있었다.

• 한국발생생물학회지:발생과생식
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• 제13권3호
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• pp.145-153
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• 2009

Previously, we obtained the list of genes differentially expressed between GV and MII oocytes. Out of the list, we focused on functional analysis of Zap70 in the present study, because it has been known to be expressed only in immune cells. This is the first report about the expression and its function of Zap70 in the oocytes. Synthetic 475 bp Zap70 dsRNA was microinjected into the GV oocytes, and the oocytes were cultured in vitro. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression levels of transcripts of three kinases, Erk1/2, JNK, and p38, were determined. Zap70 is highly expressed in immature GV oocytes, and gradually decreased as oocyte matured. When dsRNA of Zap70 was injected into the GV oocytes, Zap70 mRNA specifically and completely decreased by 2 hr and its protein expression also decreased significantly. Absence of Zap70 resulted in maturation inhibition at meiosis I (57%) with abnormalities in meiotic spindle formation and chromosome rearrangement. Concurrently, mRNA expression of Erk2, JNK, and p38, were affected by Zap70 RNAi. Therefore, we concluded that Zap70 is involved in MI-MII transition by affecting expression of MAP kinases.