• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.53-53
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• 2002

This study was carried out to verify the incidence of oocytes when vitrified at various maturation stages. Bovine cumulus-oocyte complexes were recovered from ovaries at a slaughter and then divided into five groups: control group(unvitrified oocytes), 0 hr. group(composed of oocytes vitrified before the onset of maturation) and 10, 14, and 20 hrs groups (vitrified respectively at 10, 14 and 20 hrs after the onset of maturation). (omitted)

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.84-84
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• 2003

많은 연구에서 돼지의 난포란 혹은 배아가 낮은 온도에 대해 민감한 것은 세포질 내에 함유된 지방구와 관련이 있다고 하였으며, 이런 세포질내의 지방구를 제거함으로 동결능력이 향상된다고 하였다. 이렇게 지방구가 제거된 돼지의 난포란과 배아를 효과적으로 동결보존하기 위해서는 새로운 개념의 동결보존 기술이 필요하다고 하겠다. 따라서, 본 연구는 미성숙 단계에서 지방이 제거된 돼지 난포란의 유리화 동결에 적합한 방법을 찾기 위하여 straw를 이용한 유리화 동결법과 electron microscopic grid(EM grid)를 사용한 유리화 동결법을 실시하여 효율적인 동결방법을 검토하였다.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.279-286
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• 2000

This study was conducted to develop an improved method for oocyte pick-up(OPU) with finger-sensibility using ultrasound-guidance from ovarian follicles in Holstein heifers. Oocytes were aspirated from ovarian follicles of clear-outline (>2mm), obscure-outline and invisible($\leq$ 2mm) on ultrasound images with 3 different vacuum pressure(40, 80, 120mmHg). Total number of oocytes recovered/follicles were 309/237(130.4%). 113/80(141.3%) and 107/74(144.6%) with 40, 80 and 120 mmHg of vacuum pressure, respectively. Mean number of oocytes recovered was higher in 2 OPU/week (18.3$\pm$5.3) than 1 OPU/week(14.5$\pm$4.1), but this difference was not statistical1y significant. The recovery rates were not affected by the number of OPU as 135.6%(282 oocytes/208 follicles) in 1~20 OPU, 137.7% (168/122) in 21~40 OPU and 148.4%(92/62) in 41~60 OPU, respectively. The proportions of good oocytes (Grades I) recovered were not significantly different by the number of OPU until 40 OPU(12.4% in 1~20 OPU vs 16.7% in 21~40 OPU). However, a significantly(P<0.05) lower recovery rate resulted from more than 40 OPU compared to less than 40 OPU(7.6%). These results imply that more fertilizable oocytes can be produced from invisible-immature follicles by transvaginal aspiration with finger-sensibility from Holstein heifers.

• Korean Journal of Animal Reproduction
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• v.22 no.3
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• pp.265-276
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• 1998

In an attempt to evaluate the function of MAP kinase of porcine oocytes and to develop a method of assessment for kinase activity, we used MBP as a substrate to detect the MAP kinase activity of porcine oocytes matured in in vitro. The MAP kinase which had lower activity during the first 20 hours of culture started to show an increased amount of activity at 25 hours at which a collapse in nuclear membrane was induced. Significant (P<0.05) a, pp.ared at 30 hours of being cultured. The gel phosphorylation method, MBP which has been known to be a substrate for kinase such as cdc2 kinase, was phosphorylated at two positions corresponding to ERK 1 (44kDa) and ERK2 (42 kDa) which are known as mammalian MAP kinase. The existence of MARKK and MAP kinase were identified with western blotting at 0 hour culture of immature GV oocytes. The amount of those proteins did not increase during 40 hours of culture, which suggest that the increase of MAP kinase activity was caused by phosphorylaton rather than due to change in protein amount. MAPKK and MAP kinase were shown to be dephosporylated with deactivated at M 1 stage by inhibition of protein synthesis with cycloheximide added at the strat following the cultrue. We have reulsts that indicate the existedence of MAP kinase cascade which was activated simultaneously with start of porcine oocyte maturation (GVBD).

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.223-227
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• 2005

In vitro maturation of porcine immature cumulus-enclosed oocytes can be enhanced by co-incubation with spermatozoa even before fertilization. The aim of this study was to determine whether the addition of spermatozoa into the culture medium can stimulate the meiosis resumption of porcine cumulus-enclosed oocytes arrested at germinal vesicle (GV). Cumulus-enclosed oocytes (CEOs) were collected from follicles of 3 to 5mm diameter. Porcine CEOs were cultured in tissue culture medium containing various meiosis inhibitors and spermatozoa. Oocytes were examined for evidence of GV and GV breakdown after 24 h culture. After 24 h culture $43.8\%$ of oocytes cultured in only TCM 199 remained at GV stage whereas $56.2\%$ of oocytes were able to resume meiosis. When porcine CEOs were cultured in the medium with meiosis inhibitor such as, dibutyryl cAMP (dbcAMP) and forskolin (Fo), more than $90\%$ of oocytes were not able to resume meiosis. However, co-culture of porcine CEOs with spermatozoa was able to overcome the inhibitory effect of dbcAMP and Fo. Irrespective of the presence of 3-isobutyl-1-methylxanthine (IBMX), no difference was observed in the proportion of oocyte reached germinal vesicle breakdown (GVBD). The present study suggests that dbcAMP and Fo prevent the spontaneous maturation of competent oocyte in culture after isolation from follicles and that mammalian spermatozoa contain a substance(s) that improves meiosis resumption in vitro of porcine cumulus-enclosed oocytes.

• Development and Reproduction
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• v.24 no.3
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• pp.225-230
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• 2020

This study reports the presence of mature and bi-sexual phase gonads in red spotted grouper, Epinephelus akaara after less than a year of cultivation in a commercial indoor tank and a net cage. In December 2018, juveniles were placed in an indoor tank and cultured for five months. In June 2019, the fish were transferred to a net cage and cultured until September. The rearing temperatures ranged from 19.86℃-24.65℃ in the indoor tank and 21.86℃-27.65℃ in the net cage. During the net cage culture period, specimens were randomly selected for histological gonad examination. The highest gonadosomatic index (GSI) value was measured in July (3.38±2.53), and dramatically decreased in August (0.44±0.21) and September (0.42±0.30). In July, some mature fish showed signs of vitellogenic stage oocyte development (vitellogenic and oil droplet stage oocytes), but immature fish were in an early developmental stage containing peri-nucleolus stage (PNS) oocytes. Bi-sexual phase gonads containing spermatocytes and spermatids were observed in the lumen and several PNS oocytes. By August and September, most specimens showed early-stage ovary development. However, mature testis (in August) and bi-sexual phase gonads (in September) were also observed. These results provide evidence for early puberty and hermaphroditism in the red spotted grouper.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.35-41
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• 2014

Laparoscopic ovum pick-up (LOPU) is a convenient method for collecting oocytes in small ruminants. LOPU has the advantage of being a less invasive means of oocyte collection, thereby allowing for a repeated usage of the oocyte donor animals. A total of 25 Korean black goats were used in the winter season (December to February) and LOPU was applied to the goats which had been treated for superovulation more than two times during the last twelve months. Estrus was synchronized with an intravaginal insert containing 0.3 g progesterone for 10 to 12 days. Ovaries were hyperstimulated with eCG 1,000 IU oneshot, FSH with eCG (50 mg / 1,000 IU; 70 mg / 500 IU; 70 mg / 1,000 IU) oneshot or FSH multiple-shot with eCG oneshot ($20mg{\times}6/300IU$) given intramuscularly 72 h prior to LOPU. For these groups, the number of follicles (mean ${\pm}$ SEM) observed which developed to larger than 2 mm in diameter were $1.6{\pm}2.5$, $4.3{\pm}3.1$, $5.5{\pm}4.2$, $6.6{\pm}2.1$ and $8.8{\pm}7.8$, respectively. Oocytes were aspirated by using OPU needles and a vacuum pump. The overall oocyte retrieval rates were 41.4%. Oocytes were matured in TCM-199 supplemented with 10% (w/v) bovine serum albumin + $10{\mu}g/ml$ FSH + $1{\mu}g/ml$ $17{\beta}$-estradiol for 27 h at $39^{\circ}C$ in 5% $CO_2$ in air. Oocytes were parthenogenetically activated by ionomycin combined with 6-diethylaminopurine (6-DMAP). Total oocyte maturation and cleavage rate were 67.3% and 78.8%, respectively. In summary, LOPU is a useful oocyte collection method in Korean black goats that can provide immature oocytes for transgenesis or nuclear transfer.

• Development and Reproduction
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• v.6 no.1
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• pp.17-23
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• 2002

In oocyte retrieval, a vein anesthetic drug is commonly used for induction and maintenance of general anesthesia. Propofol and Thiopental sodium are frequently used for ultrasound-guided transvaginal oocyte retrieval. The present study aimed to assess the effects of Propofol and Thiopental on in vitro fertilization(IVF). Immature porcine oocytes were exposed to various concentrations ot Propofo1 and Thiopental sodium. The rates of oocyte maturation, fertilization and development were observed. The parthenogenetic effects of the anesthetics were also evaluated. The rate of oocyte maturation after exposure to high concentrations of the anesthetics for long time was significantly higher than that of the control. But the rate of fertilization after long-time exposure to the high concentration of the anesthetic drugs was significantly lower than that of the control. The results support that Propofo1 serves like other anesthetics described, as a parthenogenetic activator. Oocytes exposed to Thiopental sodium showed decreased rates of maturation and fertilization. These results suggest that usage of optimum concentration of anesthetic drug is important in increasing the rates of oocyte maturation, fertilization and development in IVF.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.139-146
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• 2017

The objective of this study was to determine the effect of fructose that was supplemented to a chemically defined in vitro maturation (IVM) medium on oocyte maturation and embryonic development after parthenogenesis in pigs. The base medium for in vitro maturation (IVM) was porcine zygote medium (PZM) that was supplemented with 0.05% (w/v) polyvinyl alcohol (PVA) or 10% (v/v) porcine follicular fluid (pFF). In the first experiment, when immature pig oocytes were matured in a chemically defined medium that was supplemented with 5.5 mM glucose or with 1.5, 3.0 and 5.5 mM fructose, 3.0 mM fructose resulted in a higher nuclear maturation (91.5%) than 1.5 and 5.5 mM fructose (81.9 and 81.9%, respectively) but showed a similar result with 5.5 mM glucose (94.2%). However, there was no significant differences among groups in the embryo cleavage (89.4-92.4%), blastocyst formation (37.5-41.1%), and mean cell number of blastocyst (30.8-34.2 cells). Fructose at the concentration of 3.0 mM (1.08 pixels/oocyte) resulted in a higher intra-oocyte glutathione (GSH) content than 1.5 and 5.5 mM fructose (1.00 and 0.87 pixels/oocytes, respectively) while the cumulus cell expansion was not influenced. In the second experiment, effect of individual and combined supplementation of a chemically defined maturation medium with 5.5 mM glucose or 3.0 mM fructose was examined. No significant effect was found in the nuclear maturation (86.3-92.6%). Embryo cleavage was significantly increased by the combined supplementation with glucose and fructose (95.2%) compared to that with 3.0 mM fructose only (85.7%) while blastocyst formation (37.3-42.8%) and embryonic cell number (33.3-34.1 cells) were not altered. Effect of supplementation of pFF-containing medium with glucose and fructose + glucose was examined in the third experiment. No significant effect by the supplementation with glucose and fructose or glucose alone was observed in the nuclear maturation of oocytes (90.7-94.1%) and blastocyst formation (51.0-56.5%). Our results demonstrate that 3.0 mM fructose was comparable to 5.5 mM glucose in supporting in vitro oocyte maturation and embryonic development after parthenogenesis and could be used as an alternative energy source to glucose for in vitro maturation of pig oocytes.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.7
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• pp.956-965
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• 2019

Objective: The main goal of this study was to provide a morphological indicator that could be used to select high-quality oocytes of appropriate meiotic and developmental capabilities in pig. The higher quality of immature oocytes, the higher success rates of in vitro maturation (IVM) and in vitro fertilization (IVF). Thus, prior to the IVM culture, it is important to characterize oocytes morphologically and biochemically in order to assess their quality. Two of the largest indicators of oocyte quality are the presence of cumulus cells and status of chromatin. To investigate the effects of porcine oocyte chromatin configurations on the developmental capacity of blastocysts, we assessed oocyte chromatin status according to follicle size and measured the developmental potency of blastocysts. Methods: To sort by follicle size, we divided the oocytes into three groups (less than 1 mm, 1 to 3 mm, and more than 3 mm in diameter). To assess chromatin configuration, the oocytes were assessed for their stages (surrounded nucleolus [SN] germinal vesicle [GV], non-surrounded nucleolus [NSN] GV, GV breakdown, metaphase I [MI], pro-metaphase II [proMII], and metaphase II [MII]) at different maturation times (22, 44, and 66 h). To assess the development rate, oocytes of each follicle size were subjected to parthenogenetic activation for further development. Finally, GV oocytes were grouped by their chromatin configuration (SN, SN/NSN, and NSN) and their global transcriptional levels were measured. Results: SN GV oocytes were more suitable for IVF than NSN GV oocytes. Moreover, oocytes collected from the larger follicles had a greater distribution of SN GV oocytes and a higher developmental capacity during IVM, reaching MII more quickly and developing more often to blastocysts. Conclusion: Porcine oocytes with high-level meiotic and developmental capacity were identified by analyzing the relationship between follicle size and chromatin configuration. The porcine oocytes from large follicles had a significantly higher SN status in which the transcription level was low and could be better in the degree of meiotic progression and developmental capacity.