• Asian-Australasian Journal of Animal Sciences
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• v.15 no.3
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• pp.340-345
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• 2002

In this experiment, oocytes were collected from goat ovaries available in slaughterhouse by follicle puncture method. Morphologically culturable type of oocytes which having compact, multilayered cumulus granulosa cell complex and evenly granulated cytoplasm, was separated under a stereozoom microscope. Oocytes were washed thoroughly in maturation medium containing TCM-199, $1{\mu}g/ml$ estradiol-$17{\beta}$, 0.5 ${\mu}g/ml$ FSH, $100{\mu}g/ml$ LH, 3 mg/ml BSA and 10% estrus goat serum. Washed oocytes were cultured into maturation medium on granulosa cell monolayer. Culture plate was then kept into $CO_2$ incubator at $38{\pm}1^{\circ}C$, maximum humidity and 5% $CO_2$ for 18 h. After maturation the oocytes were washed thoroughly with maturation medium containing polyvinyl alcohol (PVA) without serum and BSA and further cultured for 12 h for secretory proteins of oocytes. PVA medium was collected, pooled and concentrated by 5000 cut off centrisart. Secretory proteins were separated on 12.5% SDS-PAGE. A total number of 3.41 oocytes per ovary were obtained and 2.17 culturable oocytes per ovary were cultured into maturation medium. After 18 h of maturation, 4,567 oocytes (1.82 oocytes per ovary) were further cultured into serum and BSA free PVA medium for its secretory proteins. Four secretory proteins of oocytes with approximately molecular weight of 45, 55, 65 and 95 kDa were obtained on SDS-PAGE in silver staining and three proteins with approximately molecular weight of 45, 55 and 65 kDa in Coomassie brilliant blue staining. In conclusion, four secretory proteins with approximately molecular weight of 45, 55, 65 and 95 kDa was obtained from in vitro cultured oocytes of goats.

• Journal of Veterinary Clinics
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• v.7 no.1
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• pp.419-427
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• 1990

Immature bovine oocytes were cultured to investigate whether the addition of FCS(10% or 20% ), CS (10%or 20% ) or BSA(5mg/ml) to culture medium with or without HEPES and co-culture with granulosa cells affect the frequency of in vitro maturation of extrafollicular bovine oocytes. After culture, the maturation rates were examined by the presence of 1st polar body and nuclear configuration. The maturation rate when FCS and CS as protein supplement were added to culture medium with or without HEPES was significantly higher than when BSA was added, and the maturation rate of extrafollicular bovine oocytes co-cultured with granulosa cells was higher than that cultured without granulosa cells, but there was no significant difference. FCS and CS were shown to be superior protein supplement when compared to BSA, and serum concentration, HEPES and co-culture with granulosa cells did not affect the in vitro-maturation of extrafollicular bovine oocytes.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.239-245
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• 1999

The effect of catalase on in-vitro maturation in porcine oocytes with or without cumulus cells were studied. The maturation rates were not significantly different in medium with and without catalase during in vitro maturation of oocytes. However, the maturation rates of oocytes with cumulus cells were significantly higher (P＜0.05) than in oocytes without cumulus cells regardless of the presence of catalase. On the other hand, the maturation rate in oocytes cultured with cumulus cells for 48 h (57%) was significantly (P＜0.05) higher than in oocytes with cumulus cells for first 24 h period (42%) only. In another experiment, the maturation rate was significantly (P＜0.05) higher in medium containing catalase for last 24 h period only than in medium containing catalase for first 24 h period during in vitro maturation of ooytes with or without cumulus cells. But the oocytes matured to M-II stage were observed at 24 h of culture of oocytes without cumulus cells only. When oocytes with cumulus cells were cultured for 72 h, the maturation rates was significantly (P＜0.05) higher in medium with (79%) than without (65%) catalase during in vitro maturation. These results indicate that cumulus cells are necessary for in vitro maturation of porcine oocytes, catalase have effect according to the addition periods and can prevent aging of porcine oocytes during maturation in vitro.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.191-200
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• 1994

The influence of hypoxanthine and ovarian steroids on the meiotic maturation process of mouse oocytes was investigated for the qualified application of culture medium in in vitro fertilization(IVF). Mouse oocytes were cultured in hypoxanthine and various ovarian steroids(progesterone, estradiol-17${\beta}$ and testosterone) and their effects on the oocyte maturation had been observed. When mouse oocytes were cultured in the various concentration(1-4mM) of hypoxanthine, meiotic maturation of cumulus cell-enclosed oocytes was inhibited by presence itself, which was a dose-dependent effect in meiotic arrest of mouse oocytes. The presence of progesterone, estradiol-17${\beta}$ and testosterone have made the mouse oocyte mature properly. Meanwhile maturation of cumulus cell-enclosed oocyte was severely inhibited by 3 hoursculture in the media of progesterone supplemented with hypoxanthine. However the continuous presence lasting 24 hours of progesterone even supplemented with hypoxanthine had got rid of the inhibition of oocytes maturation. Not only estradiol-17${\beta}$ supplemented with hypoxanthine but also testosterone supplemented with hypoxanthine exert the severe inhibition of the maturation of cumulus cell-enclosed oocytes for 3-hours culture. However the continuous presence lasting 24 hours of estradiol-17${\beta}$ and testosterone even supplemented with· hypoxanthine had relieved the inhibition of oocytes maturation. These results make us suggest that hypoxanthine inhibits the mouse oocyte maturation, particularly markedly in conjunction with ovarian steroids for short period, which indicated some sort of the synergistic inhibitory retationship between the ovarian steroids and hypoxanthine.

• Journal of Embryo Transfer
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• v.27 no.4
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• pp.265-270
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• 2012

In canine, oocytes are ovulated at the GV (germinal vesicle) stage and they have to fulfill maturation phase before reaching metaphase II stage. The efficiency of in vitro maturation is still very low. Therefore, the aim of this study was to investigate the effect of in vitro maturation on nuclear changes of immature canine oocytes recovered from different reproductive stages ovaries and different culture conditions. The oocytes were cultured in TCM-199 with supplement at 5% $CO_2$ and $38.5^{\circ}C$ for 72 h. The nuclear maturation of canine oocytes was evaluated with Hoechst 33342 stain under fluorescence microscope (Fig. 1). The results of this study detected differences in in vitro maturation rate between oocytes recovered from follicle status and non-follicle status ovaries. However, these differences were not significant as indicated in Table 1 and Fig. 2. In regard to the effect of culture condition with supplements, we did not found significant differences compared with control group (Table 2, Table 3). One of the reasons for this data could be the conditions that ovaries were exposed during slaughtering process or the long distant transportation of the ovaries. Although these data have not shown clearly significant differences results compared with control, furthermore the different reproductive status ovaries was beneficial for maturation of oocytes in vitro and can be a basic part of knowledge to improve in vitro maturation of canine oocytes.

• Journal of Embryo Transfer
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• v.24 no.2
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• pp.121-125
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• 2009

In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrifiedthawed bovine oocytes were examined. Also, the developmental capacity of vitrified-thawed immature oocytes following ICSI was investigated. Oocytes were cultured in TCM-199 medium supplemented with 5% FBS at $38^{\circ}$C in 5% $CO_2$ and air. The in vitro maturation rate of vitrified oocytes was 24.5 ${\pm}$ 4.2%. The in vitro maturation rate of vitrified oocytes was lower than that of the control (72.0 ${\pm}$ 3.5%, p<0.05). The in vitro maturation rate of vitrified${\sim}$thawed oocytes incubated in TCM-199 medium supplemented with 1.0${\sim}$5.0 ug CB were 26.7 ${\pm}$ 3.2%, 35.7 ${\pm}$ 3.2%, 54.0 ${\pm}$ 3.0%, 42.5 ${\pm}$ 3.6%, respectively. The in vitro maturation rate (57.0 ${\pm}$ 3.0%) of the vitrified-thawed oocytes treated with 3.0 ${\mu}$g CB for 20 min was the highest of all vitrification groups, although the maturation rate were significantly (p<0.05) lower than those of fresh oocytes. The in vitro maturation rates of the vitrified-thawed (with EDS and EDT) oocytes were 53.8 ${\pm}$ 3.4%, 51.1 ${\pm}$ 3.5%, respectively. This results were lower than the control group (72.0 ${\pm}$ 3.0%). The in vitro developmental rates of the vitrified-thawed oocytes following ICSI were 28.6 ${\pm}$ 4.5%, 25.6 ${\pm}$ 4.3%, respectively. This results were lower than the control group (40.0 ${\pm}$ 4.0%).

• Journal of Embryo Transfer
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• v.9 no.1
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• pp.1-6
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• 1994

This experiment was investigated the effect of presence of granulosa cells from follicles of different size on bovine oocyte maturation, cleavage and development to late stage. The nuclear and cytoplasmic maturation of oocytes in the IVM-IVF system are critical for subsequent embryo development. Granulosa cells when the co-cultured with oocytes may interact with cumulus-oocytes complexes and influence the development competence of the oocytes. Granulosa cells from medium (2~6 mm) and large(>1O mm) size follicles were recovered by aspiration, washed 3 times by centrifugation at 500 x g for 5 min. and used for co-culture at a concentration of 2~3 x 106 cells/mi. The oocytes were matured in vitro (IVM) for 24 hrs. in TCM-199 supplemented with 35 $\mu$g/ml FSH, 10 $\mu$g/ml LH, 1 $\mu$g/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (I VC) with bovine oviductal epithelial cells for 7 to 9 days. The assessment of maturation revealed that Grade J oocytes showed significantly(P

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1675-1677
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• 2001

The effect of the presence or absence of corpus luteum in the ovaries of slaughtered buffaloes was studied for the oocytes recovery and their subsequent maturation and fertilization in vitro. On an average, 0.41 and 0.67 oocytes per ovary were recovered from ovaries with and without corpus luteum, respectively. Immature oocytes were matured in TCM-199 medium. Significant difference was observed in maturation rate between good (74%) and fair (37%) oocytes. However, there was no significant difference in cleavage rate between the two types. The results of this study show that although the presence of corpus luteum in the ovary at the time of recovery significantly affected availability of total oocytes and in-vitro maturation, but fertilization and cleavage remained unaffected under in vitro conditions.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.121-125
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• 2005

The present study was performed to determine the ability of canine oocytes to achieve nuclear maturation according to oocyte diameter and different culture environments. All of the collected oocytes were classified by grade 1 to 3 and by their diameters such as $<100{\mu}m,\;<100{\mu}m\;to\;<110{\mu}m,\;<110{\mu}m,\;to\;<120{\mu}m,\;>120{\mu}m,$. Oocytes were cultured in culture medium supplemented with $10\%\;FBS,\;0.4\%\;BSA,\;10\%$ porcine follicular fluid (pFF), $10\%$ canine serum (CS), or $10\%$ canine estrus serum (CES). The mean number of oocytes recovered from estrus status ovaries was significantly higher than that of anestrus status ovaries (p<0.01). The maturation rate of grade 1 oocytes $(>120{\mu}m)$ was significantly higher than that of the other groups (p<0.05). Nuclear maturation to MI to MII in diameter of $>110{\mu}m$ groups was significantly higher than that in $<100{\mu}m$ group (p<0.05). The oocytes cultured in $10\%$ FBS­supplemented group were significantly higher rate of GVBD compared to the other supplemented groups (p<0.05), and oocytes maturation to MI to MII in $10\%$ FBS-, $0.4\%$ BSA-, and $10\%$ pFF-supplemented groups were significantly higher than those in $10\%$ CS-supplemented group (p<0.05). Based on these results, the estrus status and the size of oocyte affect positively to improve nuclear maturation of canine immature oocytes in vitro. Among several protein sources, porcine follicular fluid was the most effective supplementation to culture medium to achieve higher in vitro maturation rate.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.183-188
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• 2021

In vitro maturation (IVM) of oocytes is the procedure where the immature oocytes are cultivated in a laboratory until they are mature. Since IVM oocytes generally have low developmental competence as compared to those matured in vivo, development of an optimal IVM culture system by fine-tuning culture conditions is crucial to maintain high quality. In-depth knowledge and a deep understanding of the in vivo physiology of oocyte maturation are pre-requisites to accomplish this. Within ovarian follicles, various signaling pathways that drive oocyte development and maturation regulate interaction between oocytes and surrounding somatic cells. This review discusses the sonic hedgehog (SHH) signaling pathway, which has been demonstrated to be intimately involved in folliculogenesis and oocyte maturation. Advances in elucidating the role of the SHH signaling pathway in oocyte maturation will aid attempts to improve the current inferior in vitro oocyte maturation system.