• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.22-27
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• 1999

Bovine oocytes with compact and complete cumulus cells were cultured in 6 groups for up to 24h in TCM199 buffered with 25 mmol/1 HEPES and supplemented with 10% FCS, 1 mg/ml $17{\beta}$-estradiol, 20 IU/ml hCG. Half of the oocytes at each group cultured in the presence of $25{\mu}g/ml$ cycloheximide at different times during maturation (0, 6, 12, 18, 20, 22 h) were fixed at 24 h of maturation to examine the nuclear progression. The rests of them were inseminated with frozen-thawed spermatozoa in medium BO with 10 mg/ml BSA and 10 mg/ml heparin and fixed after additional 18-20 h culture to evaluate the sperm head transformation. When a protein synthesis inhibitor was added at the onset of the maturation, the oocytes were prevented to proceed GVBD. A few of the oocytes (16%) were able to be penetrated and sperm head decondensation was inhibited either. Addition of cycloheximide after 6-12 h of culture resulted in an increasing percentage of GVBCD (more than 80%), but the oocytes became arrested in M-I (69.2%). More than half of the oocytes was penetrated with a decondensing sperm head. Formation of male pronucleus was first obtained at 12 h of culture in the presence of cycloheximide. When cycloheximide was added from 18 h of culture onwards, nuclear progression to M-II was increasingly restored (80.4-85.5%). The proportion of male and female pronuclear formation increased from 17.9% to 46.2%. It is concluded that protein synthesis is necessary not only for GVBD and development from M-I to M-II, but also for sperm head decendensation and male pronuclear formation in bovine oocytes.

• Molecules and Cells
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• 제37권2호
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• pp.126-132
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• 2014

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-metaphase I (Pro-MI), and localized to spindle poles at metaphase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibition. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at centromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromosome misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein ${\gamma}$-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.

• 대한의생명과학회지
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• 제7권4호
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• pp.173-179
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• 2001

To investigate the ability to decondense sperm head penetrated into cytoplasm of the oocytes and the relationship between this ability and the level of glutatione (GSH) in mouse oocyte at various maturing stages. The fertilizability of oocytes at various stages of maturation the decondensation of sperm nucleus and the formation of male pronucleus, were observed and the levels of GSH were measured in oocyte at same stages. Besides, the relation between fertilizability and level of GSH in oocyte cytoplasm treated with L-buthionine-S, R-sulfoxmine (L-BSO), the inbitor of biosynthesis of GSH, was determined. The decondensation of sperm head was not found in GV stage and L-BSO treated oocytes. In maturing oocytes (GVBD, MI), the decondensation was found, but the formation of male pronucleus was not. The levels of GSH in oocyte cytoplasm were measured; 2.2 pmol per oocyte in the ovulated and the matured in vitro each, 1.0 pmol in GV intact oocyte, 1.3 pmol in GVBD, and 1.5 pmol in MI phase oocyte. In L-BSO treated oocytes the levels of CSH were measured 0.08~o.09 pmol per oocyte, slightly lower than GV stage oocyte. In conclusion, GSH in oocyte is supposed to be synthesized and storaged in cytoplasm during maturation. The failure of decondensation in the cytoplasm of GV stage and L-BSO treated is suggested that GSH is an essential factor in decondensing the sperm head and that the a certain level of GSH, more than in GV oocyte cytoplasm, is required in decondensation.

• Journal of Animal Science and Technology
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• 제57권8호
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• pp.27.1-27.6
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• 2015

This study was designed to investigate the effects of ${\alpha}$-tocopherol and granulosa cells monolayer on nuclear maturation and cleavage rates of ovine cumulus-oocyte complexes (COCs). The COCs (n = 2814) were matured in maturation medium supplemented with various concentration of ${\alpha}$-tocopherol (0, 5, 10, $15{\mu}g/ml$), oocytes were incubated at $39^{\circ}C$ with 5 % $CO_2$ for 24 h in three culture systems: (a) maturation medium (MM; n = 884), (b) co-cultured with granulosa cells (CG; n = 982) and (c) co-cultured with granulosa cells and cells were further cultured in MM for 12 h (CG + 12hMM; n = 948). Our results showed that ${\alpha}$-tocopherol had no effect on GVBD and MII as compared to control group, but when ${\alpha}$-tocopherol added to maturation medium the rate of cleavage decreased. This indicates interaction of above mentioned factors in any of the treatments showed no significant differences on the rate of maturation and cleavage stages (MII, GVBD and cleavage) (p > 0.05). The oocytes co-cultured with granulosa cells for 24 h had beneficial effects on cleavage rate. The maximum MII and cleavage rates were achieved when oocytes had extra 12 h culture in the maturation medium without granulosa cells. Results also showed our modified co-culture system (CG + 12hMM), improved rates of MII and the cleavage in comparison with other studied maturation systems.

• 한국해양생명과학회지
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• 제7권1호
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• pp.55-59
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• 2022

연구는 갈치 Trichiurus lepturus의 성 성숙과 생식생물학적 기초 정보를 제공하기 위해 수행하였다. 난자형성과정 동안 난모세포와 핵의 크기는 증가하였으나 핵에 대한 인의 비율은 감소하였다. H-E 염색 결과, 세포질의 염색성은 호염기성에서 호산성으로 변하였다. 난황형성개시기 난모세포의 난경은 약 63.2 (±12.7) ㎛였다. 세포질에서는 호산성의 난황핵이 관찰되었다. 성숙기 난모세포의 난경은 216.6 (±24.7) ㎛였으며, GVBD (germinal vesicle breakdown)가 관찰되었다. 완숙기 난모세포의 난경은 317.9 (±80.9) ㎛였으며, 방사대의 두께는 4.2 (±1.7) ㎛였다. 난모세포의 발달형태는 난군동기발달형에 속하며, 난황 축적은 대부분의 경골어류와 마찬가지로 외재적 방법과 내재적 방법에 의한 것으로 판단되었다.

• 한국가축번식학회지
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• 제22권4호
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• pp.385-393
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• 1998

본 연구는 돼지 미성숙 난포란을 체외에서 성숙시킬 때, cysteine (CySH) 및 glutathione (GSH) 의 첨가 배양이 난핵포붕괴 및 핵성숙율에 미치는 영향을 조사하기 위하여 실시하였다. 본 연구에서 얻은 결과를 요약하면 다음과 같다. 1. 체외성숙 배양액인 TCM-199 에 cysteine (CySH) 을 각각 0, 0.04, 0.14, 0.6 및 1.2 mM 첨가하여 36 시간 동안 체외성숙을 유기시켰을 때의 난핵포붕괴율은 각각 90.8, 89.9, 90.5, 92.0 및 91.3% 으로서 각 처리구간 유의성이 없었고, 핵성숙율은 각각 56.1, 50.7, 41.9, 49.0 및 61.5%로서 대조구에 비하여 낮은 성숙율을 보였으며, 특히 0.14 mM 및 0.6 mM 첨가군에서 유의적으로 낮은 결과를 보였다 (P＜0.05). 또한, 44시간 동안 체외성숙을 유기시켰을 때 난핵포붕괴율은 각각 90.0, 91.8, 89.8, 90.5 및 89.6%로서 처리구간 유의성이 없었고, 핵성숙율은 각각 80.2, 76.3, 69.4, 66.7 및 72.6%로서 무첨가한 대조구에 비하여 비교적 낮은 성숙율을 보였으며, 특히 0.14 mM 및 0.6 mM 첨가군에서 유의적으로 낮은 결과를 보였다 (P＜0.05). 2. 체외성숙 배양액인 TCM-199 에 glutathione (GSH) 을 0, 0.05, 0.1, 0.5 및 1.0 mM 을 첨가하여 36시간 동안 성숙을 유기시켰을 때 난핵포 붕괴율은 각각 91.0, 90.9, 89.5, 92.0 및 91.1%로서 처리구간 유의성이 없이 높은 결과를 나타냈으며, 핵성숙율은 59.0, 48.5, 47.8, 38.6 및 37.5%로서 대조구에 비하여 모든 처리구에서 유의적으로 낮은 결과를 나타냈다 (P＜0.05). 또한, 44시간 동안 성숙을 유기시켰을 때 난핵포붕괴율은 각각 91.8, 94.1, 89.1, 91.3 및 91.1%로서 모든 처리구에서 높은 결과를 나타냈으며, 핵성숙율은 각각 84.6, 57.1, 69.6, 71.3 및 64.3%로서 대조구에 비하여 모든 처리구에서 유의적으로 낮은 결과를 나타냈다 (P＜0.05).

• 한국가축번식학회지
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• 제22권4호
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• pp.375-383
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• 1998

본 연구는 돼지 미성숙 난포란을 체외에서 성숙시킬 때, $\beta$-mercaptoethanol ($\beta$-ME) 및 Cysteamine 의 첨가 배양이 난핵포붕괴 및 핵성숙율에 미치는 영향을 조사하기 위하여 실시하였다. 본 연구에서 얻은 결과를 요약하면 다음과 같다. 1. 체외성숙 배양액인 TCM-199 에 $\beta$-ME 를 0, 10, 50, 100 및 200 $\mu$M 을 첨가하여 36 시간 동안 성숙을 유기 시킬 때 난핵포붕괴율은 각각 91.6, 92.5, 91.8, 91.9 및 92.7%로서 처리구간 유의성이 없는 높은 결과를 보였고, 핵성숙율은 각각 49.6, 41. 7, 32.5, 34.1 및 35.4%로서 대조구에 비하여 비교적 낮은 성숙율을 보였으며, 특히 50, 100 및 200 $\mu$M 첨가시 유의적으로 낮은 핵성숙율을 나타냈다 (P＜0.05). 또한, 44시간 동안 체외성숙을 유기시켰을 때 난핵포 붕괴율은 각각 91.8, 90.4, 92.5, 91.2 및 93.9%로서 처리구간 유의성 없이 높은 결과를 나타냈으며, 핵성숙율은 71.9, 58.8, 56.7, 62.2 및 56.5%로서 대조구에 비하여 모든 처리구에서 유의적으로 낮은 성숙율을 나타냈다 (P＜0.05). 2. 체외성숙 배양액인 TCM-199 에 cysteamine을 0, 10, 50, 100 및 200 $\mu$M 을 첨가하여 36 시간 동안 성숙을 유기시켰을 때 난핵포붕괴율은 각각 90.6, 86.3, 88.2, 87.2 및 90.0%로서 각 처리구간 높은 결과를 나타냈고, 핵성숙율은 53.8, 45.1, 54.4, 57.5 및 63.3%로서 대조구와 비슷한 결과를 나타냈으며, 특히, 200 $\mu$M 의 첨가구에서 유의적으로 높은 성숙율을 나타냈다 (P＜0.05). 또한, 44 시간 동안 체외성숙을 유기시켰을 때 난핵포붕괴율은 각각 89.5, 93.1, 85.1, 89.8 및 3%로서 모든 처리구에서 높은 결과를 나타냈으며, 핵성숙율은 각각 84.2, 77.6, 66.0, 67.8 및 78.3%로서 대조구에 비하여 전 처리구에서 다소 낮은 결과를 보였으며, 특히 50 및 100 $\mu$M 처리구에서 유의적으로 낮은 핵성숙율을 나타냈다 (P＜0.05).

• 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.

• 한국동물학회지
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• 제35권1호
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• pp.37-44
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• 1992

북방산개구리, 참개구리 및 옴개구리를 사용하여 성숙된 난자의 세포질에서 활성을 띠는 성숙촉진요인( maturation promoting factor, MPF)을 미세주입 법으로 확인하고 이들의 성질을 조사하였다. 핵붕괴(germinal vesicle breakdown, GVBD)된 난자의 세포질을 미성숙 난자(GV난자)에 주입하고(75-100 nl) 이들을 15-24시간 배양했을 때 대부분의 GV 난자들이 핵붕괴를 일으켰으나(약 80%) 미성숙 난자(GV 난자)의 세포질을 주입했을 때에는 약 200nl의 난자들만이 핵붕괴를 일으켰다. 핵붕괴된 난자들의 crude extract를 주입했을 때에도 역시 성숙유도 효과가 있었으며 이종간에도 효과가 있었다. 난자의 성숙을 잘 일으키지 않는 옴개구리의 난자를 사용하여 MPF를 가진 세포질을 계대주입(serial transfer)하였을 때에도 MPF가 계속 활성을 띠는 것을 확인할 수 있었다. 아울러 개구리 난자의 MPF생성과 증폭과정에 CAMP의 증가나 단백질 합성의 저해가 미치는 영향을 조사한 결과. MPF의 작용이 유의하게 이들에 의해 억제되는 것을 알 수 있었다.

• 한국수정란이식학회지
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• 제11권2호
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• pp.179-191
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• 1996

In-vitro culture has provided new inforrnation on mechanisms of oocytes rnaturation and results obtained in vitro have led to new questions. In porcine, follicular and oocyte size have the crucial importance for the oocytes maturation. The addition of hormones to the culture medium was found to accelerate and facilitate meiotic maturation. The presence of some factors in serum trigger the resumption of meiosis and support the maturation of oocytes in vitro. The maturation rate of porcine oocytes was also increased by supplementation of porcine follicular fluid to the culture medium. The growth factors can stimulate nuclear maturation and enhances cytoplasnic maturation of oocytes by interaction with gonadotropins. The maturation-promoting factor brings about GVBD and the subsequent maturational events in oocytes. However, cAMP can block the spontaneous meiotic maturation of oocytes in culture. The understanding of these influences is a prerequisite to enhancing in vitro maturation of porcine oocytes.