• Clinical and Experimental Reproductive Medicine
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• 제44권3호
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• pp.126-131
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• 2017

Objective: Oocyte degeneration often occurs after intracytoplasmic sperm injection (ICSI), and the risk factor is low-quality oocytes. The follicular fluid (FF) provides a crucial microenvironment for oocyte development. We investigated the relationships between the FF volume aspirated from individual follicles and oocyte retrieval, oocyte maturity, oolemma stretchability, fertilization, and development. Methods: This retrospective study included data obtained from 229 ICSI cycles. Ovarian stimulation was performed according to a gonadotropin-releasing hormone antagonist protocol. Each follicle was individually aspirated and divided into six groups according to FF volume ( < 1.0, 1.0 to < 2.0, 2.0 to < 3.0, 3.0 to < 4.0, 4.0 to < 5.0, and ${\geq}5.0mL$). Oolemma stretchability during ICSI was evaluated using a mechanical stimulus for oolemma penetration, that is, the stretchability was assessed by oolemma penetration with aspiration (high stretchability) or without aspiration (low stretchability). Results: Oocyte retrieval rates were significantly lower in the < 1.0 mL group than in the ${\geq}1.0mL$ groups (46.0% [86/187] vs. 67.5%-74.3% [172/255 to 124/167], respectively; p< 0.01). Low oolemma stretchability was significantly more common in the < 1.0 mL group than in the ${\geq}1.0mL$ groups during ICSI (22.0% [13/59] vs. 5.8%-9.4% [6/104 to 13/139], respectively; p= 0.018). There was a relationship between FF volume and oolemma stretchability. However, there were no significant differences in the rates of fertilization, cleavage, ${\geq}7$ cells at day 3, and blastocyst development among all groups. Conclusion: FF volume is potentially associated with the stretchability of metaphase II oolemma during ICSI. Regarding oolemma stretchability, ensuring a uniform follicular size during ovarian stimulation is crucial to obtain good-quality oocytes.

• Fisheries and Aquatic Sciences
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• 제21권11호
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• pp.34.1-34.13
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• 2018

Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.

• 한국발생생물학회지:발생과생식
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• 제16권3호
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• pp.185-193
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• 2012

For the gonadal sex management of younger longtooth grouper (Epinephelus bruneus), this work investigated the timing and histological process of ovary differentiation and oocyte development of longtooth grouper larvae and juvenile. Specimens (from 1 to 365 DAH) were collected for gonadal histological study from June 2008 to August 2009. Rearing water temperature was ranged from 20 to $24^{\circ}C$. The primordial germ cells could be observed from 10 to 15 DAH, while undifferentiated gonad occurs from 20 to 50 DAH in longtooth grouper. The initial ovarian phase was 60 to 110 DAH with the formation of ovarian cavity and the increased in size of gonad. The ovarian phase started at 140 DAH with appearance of oogonia. The gonad at 365 DAH appeared to have full of oogonia and primary growth stage oocyte. Formation of ovarian cavity indicates that the ovarian differentiation beginning at 60 DAH in longtooth grouper. The gonads in longtooth grouper differentiated directly into ovaries in all fish examined.

• Asian-Australasian Journal of Animal Sciences
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• 제21권4호
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• pp.532-537
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• 2008

In order to investigate the factors affecting the culture of mouse preantral follicles in vitro, we examined the effect of culture media, protein supplements, and culture period on their growth. The oocyte diameter (initial size: $55.6{\pm}2.5{\mu}m$) was progressively increased during culture, and the maximum size ($72.0{\pm}2.4{\mu}m$) was reached on day 10 of the in vitro culture. The chromatin configuration in the germinal vesicle (GV) oocyte progressively shifted from a non-surrounded nucleolus (NSN) to a surrounded nucleolus (SN). On day 10 of the culture, most of the oocytes progressed to the SN pattern. The survival and metaphase II rates of the oocytes in alpha-minimal essential medium (alpha-MEM) were significantly higher (p<0.05) than those in Waymouth and tissue culture medium (TCM)-199. As a protein source, fetal bovine serum (FBS) was more suitable for the culture of mouse preantral follicles as compared to human follicular fluid (hFF) and bovine serum albumin (BSA); the optimal concentration of FBS was 5%. These results suggest that in a culture of mouse preantral follicles, alpha-MEM and 5% FBS are an optimal medium and a protein source, respectively; further, the 10 days of culture is required for the complete growth of oocytes in this culture system.

• Animal cells and systems
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• 제3권4호
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• pp.375-383
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• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• Reproductive and Developmental Biology
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• 제29권2호
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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.

• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.174-178
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• 2004

The objectives of this study were to investigate the ovarian responsiveness of juvenile calves to exogenous gonadotropin treatments and to establish the oocyte retrieval technique for prepubertal heifers. Three 78-day-old calves were treated with 4 doses (40, 30, 30 and 30 mg) of FSH (Folltropin V) at 12 h interval up to 229 day-old. Surgical oocyte retrieval was performed 24 h after the last injection of FSH. Calves with good ovarian responses to FSH treatment had an average ovarian size of $5{\times}3$ cm compared to $3{\times}2$ cm in the less-responsive animals. Large variations were observed in the number of total follicles ($51{\pm}45$), aspirated follicles ($39{\pm}36$), oocytes recovered ($23{\pm}25$) and usable oocytes recovered ($11{\pm}19$) during 78 to 229 day-old. Oocytes derived from prepubertal calves had significantly lower maturation rate than those from cows (34 vs. 100%, p<0.05). Mean diameters of calf oocytes ($144{\pm}1{\mu}m$) and ooplasm ($110{\pm}1 {\mu}m$) were significantly lower than those of cows ($149{\pm}1$ and $25{\pm}1{\mu}m$, respectively). The diameter of the ooplasm also increased significantly after in vitro maturation (IVM) ($108{\pm}1$ vs. $112{\pm}1{\mu}m$). However, further studies are required to optimize the IVP system for the oocytes derived from prepubertal heifers.

• Journal of Veterinary Science
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• 제23권2호
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• pp.31.1-31.13
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• 2022

Background: Compared to medium containing 108 mM sodium chloride (NaCl), in vitro maturation (IVM) using a simple medium with reduced (61.6 mM) NaCl increases the cytoplasmic maturation and embryonic development of pig oocytes. Objectives: This study determines the effect of a complex medium containing reduced NaCl on the IVM and embryonic development of pig oocytes. Methods: Pig oocytes were matured in Minimum Essential Medium Eagle-alpha modification (αMEM) supplemented with 61.6 (61αMEM) or 108 (108αMEM) mM NaCl, and containing polyvinyl alcohol (PVA) (αMEMP) or pig follicular fluid (PFF) (αMEMF). Medium-199 (M199) served as the control for conventional IVM. Cumulus cell expansion, nuclear maturation, intra-oocyte glutathione (GSH) contents, size of perivitelline space (PVS), and embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) were evaluated after IVM. Results: Regardless of PVA or PFF supplementation, oocytes matured in 61αMEM showed increased intra-oocyte GSH contents and width of PVS (p < 0.05), as well as increased blastocyst formation (p < 0.05) after PA and SCNT, as compared to oocytes matured in 108αMEMP and M199. Under conditions of PFF-enriched αMEM, SCNT oocytes matured in 61αMEMF showed higher blastocyst formation (p < 0.05), compared to maturation in 108αMEMF and M199, whereas PA cultured oocytes showed no significant difference. Conclusions: IVM in αMEM supplemented with reduced NaCl (61.6 mM) enhances the embryonic developmental competence subsequent to PA and SCNT, which attributes toward improved oocyte maturation.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2006년도 The 6th Intermational Symposium on Developmental Biotechnology
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• pp.100-101
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• 2006

• 한국패류학회지
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• 제23권2호
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• pp.209-216
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• 2007

소라, Batillus cornutus의 난소구조와 난모세포 발달단계를 광학현미경과 투과전자현미경 (TEM) 을 이용하여 관찰하였다. 전라남도 완도군 연안에서 다이버에 의해 채집된 소라는 자웅이체로서 난소는 소화맹낭부에서 꼬리돌기 끝까지 간췌장의 외측을 싸고 발달되어 있었으며, 성숙 시기에 난소는 녹색을 나타내었다. 난소의 내부 구조는 다수의 난소소엽으로 구성되어 있었으며, 난소소엽은 상피세포와 간충결합조직으로 구성되어 있었다. 난원세포는 큰 핵과 전자밀도가 높은 인을 포함하고 있었다. 난황형성 전기의 난모세포는 세포질에 전자밀도가 낮았고, 작은 구형의 난황 과립이 산재해 있었다. 난황형성개시기의 난모세포는 난병에 의해 난소소엽과 연결되어 있었으며, 투과전자현미경 관찰 결과, 세포질에는 잘 발달된 골지체, 조면소포체, 미토콘드리아와 같은 세포소기관과 전자밀도와 크기가 다양한 난황과립이 다수 존재하였다. 이들 난황과립의 전자밀도와 크기는 전단계의 난모세포보다 증가하였다. 후기 난황형성활성기의 난모세포의 난막 두께는 약 4.4 ${\mu}m$였다. 성숙한 난모세포는 세포질에 전자밀도가 높은 단백질성의 난황과립과 전자밀도가 낮은 지질성의 난황과립으로 가득 차 있었으며 두께 약 6.5 ${\mu}m$인 난막에 의해 둘러싸여 있었다.