• Ocean and Polar Research
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• v.38 no.1
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• pp.21-33
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• 2016

Gametogenesis of the comb pen shell, Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) on the southern coast of Ulleungdo Island, Korea was assessed monthly (November 2013 to October 2014) using histology. Gametogenesis commenced in January when the surface water temperature was $12.6^{\circ}C$ and pen shells evidenced an early development phase with small oogonia from January to April, although few females exhibited ripe eggs in their follicular epithelium. In April, the oocyte diameter increased rapidly, and fully mature eggs appeared in May. First spawning males and females were observed in June as the surface water temperature reached $19.3^{\circ}C$ and July ($23.2^{\circ}C$) respectively. The spawning activity continued until the end of September. Histology indicated that the spawning peak of the females in Ulleungdo Island was July to August. During October to January, most of the pen shells were in spent and resting stages. Our data suggested that A. pectinata is a summer spawner, and their annual gametogenesis is closely associated with the seasonal variation in the surface water temperature. The present study is the first provided fundamental information on the life history of A. pectinata in Ulleungdo Island, and this can be put to good use in the management of this pen shell in the study area.

• Clinical and Experimental Reproductive Medicine
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• v.13 no.2
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• pp.101-112
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• 1986

It is now common practice to attempt ovarian hyperstimulation in vitro fertilization and embryo transfer (IVF-ET) to promote the development of multiple preovulatory follicles and to maximize the number of mature egg available. There are several drugs for hyperstimulation such as clomiphene citrate only, clomiphene citrate and human menopausal gonadotropin (HMG) and HMG only. Accumlated experience has shown that the hyperstimulation of the ovary in IVF-ET results in high pregnancy rate. But the hyperstimulation of the ovary in IVF-ET may cause the hyperandrogenism, so we must consider the adverse effect on pregnancy rate of the hyperandrogenism. Little is known about the functional significance of androgen for the follicular growth, however, the hyperandrogenism might interfere with oocyte maturation. The aim of the present investigation was to determine the serum profiles of estradiol, androstenedione and testosterone during the hyperstimulated menstrual cycles in IVF. The results were summarized as follows: 1. There was a gradual increase in the mean levels of serum estradiol, androstenedione, and testosterone approaching follicular maturation. 2. The mean serum estradiol levels in the hyperstimulated groups were significantly higher than that in the control group in late follicular phase and ovum retrieval (ovulation) day (p<0.01). 3. The mean serum androstenedione levels in the clomiphene citrate groups were significantly higher than that in the control group in late follicular phase (p<0.01). There was no statistically significant different in the mean serum androstenedione levels between the control group and the HMG group (p>0.05). 4. There was no statistically significant difference in the mean levels of testosterone among each group (p>0.05). 5. There was no statistically significant different in the mean levels of estradiol, androstenedione and testosterone between the fertilized patients and non-fertilized patients in clomiphene citrate and HMG group (p>0.05).

• Clinical and Experimental Reproductive Medicine
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• v.38 no.2
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• pp.98-102
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• 2011

Objective: To investigate the effects of pioglitazone on controlled ovarian stimulation (COS), IVF outcomes, and follicular fluid (FF) cytokine concentrations in patients with polycystic ovary syndrome (PCOS). Methods: Eighty-six infertile patients with PCOS resistant to clomiphene citrate were randomized to receive pioglitazone (30 mg/day) or placebo on the starting day of oral contraceptive (OC) pretreatment, followed by an IVF protocol using a GnRH antagonist. Pioglitazone or placebo was administered once daily from the starting day of OC to the day of hCG injection. Results: Total dose and days of recombinant follicle-stimulating hormone administered, and the numbers of retrieved and mature oocytes, were significantly lower in the pioglitazone group than in the control group. FF tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) concentrations at oocyte retrieval were also significantly lower in the pioglitazone group. The clinical pregnancy rate was higher and the incidence of severe ovarian hyperstimulation syndrome was lower in the pioglitazone group, but the differences were not statistically significant. Conclusion: Pioglitazone reduces FF TNF-${\alpha}$ and IL-6 levels, and may improve ovarian response to COS in patients with PCOS.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.300-305
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• 2020

Objective: The feasibility of a gonadotropin-releasing hormone agonist (GnRHa) trigger in normal responders is still a matter of debate. The aim of this study was to compare the number of mature oocytes, the number of good-quality embryos, and the live birth rate in normal responders triggered by GnRHa alone, GnRHa and human chorionic gonadotropin (hCG; a dual trigger), and hCG alone. Methods: A retrospective cohort study was conducted at the infertility clinic of a university hospital. Data from 200 normal responders who underwent controlled ovarian hyperstimulation and intracytoplasmic sperm injection with a GnRH antagonist protocol between January 2016 and January 2017 were reviewed. The first study group consisted of patients with cycles triggered by GnRHa alone. The second study group consisted of patients with cycles triggered by both GnRHa and low-dose hCG (a dual trigger). The control group consisted of patients with cycles triggered by hCG alone. Results: The groups were comparable in terms of demographics and cycle characteristics. The numbers of total oocytes retrieved and metaphase II oocytes were similar between the groups. The total numbers of top-quality embryos were 3.2±2.9 in the GnRHa group, 4.4±3.2 in the dual-trigger group, and 2.9±2.1 in the hCG group (p=0.014). The live birth rates were 21.4%, 30.5%, and 28.2% in those groups, respectively (p=0.126). Conclusion: In normal responders, a dual-trigger approach appears superior to an hCG trigger alone with regard to the number of top-quality embryos produced. However, no clinical benefit was apparent in terms of live birth rates.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.1-14
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• 2003

This study was conducted to investigate that the immature and mature oocytes of porcine can be cryopreserved by vitrification. Oocytes were centrifuged to polarize the cytoplasmic lipid droplets. The lipids were removed from cytoplasm by micromanipulation. Delipated oocytes were centrifuged after being preincubated with cytochalasin B(CB) fer 10 min, and lipid droplets were removed. Centrifuged oocytes were treated with CB and centrifuged to polorize lipid droplets but not delipated and control oocytes is not-treatment. Oocytes of three types were vitrified in electron microscope(EM) grids. The results of survival, maturation and cleavage rates were as follows. 1 The survival rates of immature oocytes were 15.1%, 0% and 0% in the Delipated, Centrifuged and Control after vitrification, respectively, and its rate of Delipated wassignificantly higher than Centrifuged and Control(P<.01). 2. The survival rates of mature oocytes were 12.21%, 0% and 0% in the Delipated, Centrifuged and Control after vitrification, respectively, and its rate of Delipated was significantly higher than Centrifuged and Control(P<.01). 3 The maturation rates of immature oocytes were 37.5% and 68.9% for metaphase II in the Delipated after vitrification and Non-vitrification, respectively, and its rate of Non-vitrification was significantly higher than Delipated after vitrification(P<.01). 4. The cleavage rates of immature oocytes were 12.5%, 0%, 0% and 56.1% in the Delipated, Centrifuged, Control after vitrification and Non-vitrification, respectively. It's rate of Delipated was higher than Centrifuged and Control, but there were no significant difference, and its rate of Non-vitrification was significantly higher than Delipated, Centrifuged and Control(P<.05). 5 The cleavage rates of mature oocytes were 25.0%, 0%, 0% and 67.9% in the Delipated, Centrifuged, Control after vitrification and Non-vitrification, respectively. It's rate of Delipated was higher than Centrifuged and Control, but there were no significant difference, and its rate of Non-vitrification was significantly higher than Delipated, Centrifuged and Control(P<.05).

• Journal of Aquaculture
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• v.10 no.2
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• pp.133-141
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• 1997

Gonadal maturation and annual reproductive cycle of the cultured scallop, Patinopecten yessoensis from eastern waters near of Kangwon-do province, Korea were studied on the basis of monthly variation of gonadosomatic indices (GSI) and histological observations of gonadal tissue. During the experimental period, water temperature at the depth of 20m and sunshine duration per day were ranged from $5.3^{\circ}C\;to\;18.0^{\circ}C$ and 9.4 to 14.6 hours, respectively. GSI values of femal were in a wide range from $2.8\pm0.37(August)\;to\;22.66\pm4.38(April)$. GSI values began to increase in March and reached the maxium in April, then decreased repidly. GSI values of male were in a range from $2.04\pm0.80(August)\;to\;20.46\pm1.49(April)$ and were same tendency with female's. Digestive diverticula indices (DDI) of both sex reached the maximum values in December, then deceased gradually until September. Contrary to GSI, adductor muscle indices (AMI) of both sex were the minium values in April, but began to increase rapidly until July and reached $47.71\pm3.17(female)\;and\;48.70\pm3.55(male)$. In the scallp collected hermaphroditic gonads were found. Monthly changes of oocyte diameter were in a range from 11.3 um(October) to 73.3um (April) and nuclear diameters were in a range from 8.3um (September) to 35.3um (April), similar tendency with each other. The changes in number of ovarian tubules were reciprocal tendency with those of oocyte diameter and monthly number of ovarian tubules per $\textrm{mm}^2$ in the tissue perpatation was in a range from 51 (April) to 175 (August). As the results, the annual reproductive cycle of the cultured scallolp from eastern waters of Korea could be classified into five successive stages : multiplicative (October), growing (November to February), mature (March and April), spawning (April to June) and recovery (July to September) in female ; multiplicative (October and November), growing (December and January), mature (February to April), spawning (April to June) and recovery (July to September) in male.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.71-78
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• 1997

This study was designed to investigate the number of the growing and mature follicles following gonadotrophin treatments for superovulation in mature rats. Eighteen mature rats (Sprague-Duwely, initially 190~230gm) were randomly alloted into 3 groups. One group was control group, another FSH-treated group was injected intramuscularly with 0.5 units of follicular stimulating hormone (FSH) / rat, and third PMS and HCG-treated group was intramuscularly injected with 20~25IU of pregnant mare serum (PMS) / rat and then at the 48 hrs later, with 20~25IU of human chorionic gonadotrophin (HCG) / rat. The uteri and ovaries of rats were collected and then were observed grossly and serial sections of paraffin embedding ovaries were stained with H-E. Number of ovarian follicles by following 3 grades of large, middle and small follicles from secondary and tertiary follicles were investigated by LM photography of preparations. Small follicles were classified as secondary follicles of preantral follicles with more than 2 layers of granulosa cells surrounding the oocyte and middle follicles were classified as secondary follicles with early signs of antral cavity or with more than one small cavity on either side of the oocytes and large follicles were classified as tertiary follicles with a single medium sized antral cavity or large well-formed antral cavity. In gross findings, the uteri were slightly swelling in FSH-treated group and markedly swelling or filled with fluid in the uterine lumen in PMS and HCG-treated group. In histological findings, the shape and size of the follicles were diverse in middle and large follicles of FSH-treated group and PMS and HCG-treated group, and proportion of atretic follicles was increased in FSH-treated group and PMS and HCG-treated group than those in control group. The uteri of FSH-treated group and PMS and HCG-treated group were hypertropied or filled with fluid in the lumens and walls of uteri. The wall tissue layers were flattened and their blood and lymph vessels were dilated. The mean number of follicle per ovary in control group were appeared to be $17.1{\pm}5.6$($14.0%{\pm}4.6%$), $37.8{\pm}9.1$($30.9{\pm}7.4%$) and $67.6{\pm}30.1$($55.2{\pm}24.6%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $122.5{\pm}40.0$. The mean number of follicle per ovary in FSH-treated group were appeared to be $22.8{\pm}7.0$($17.4%{\pm}5.3%$), $43.4{\pm}6.6$($33.2{\pm}5.1%$) and $64.5{\pm}13.0$($49.3{\pm}9.9%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $130.7{\pm}16.6$. The mean number of follicle per ovary in PMS and HCG-treated group were appeared to be $29.7{\pm}11.0$($16.3%{\pm}6.0%$), $61.9{\pm}17.2$($33.9{\pm}9.4%$) and $91.1{\pm}28.2$($49.9{\pm}15.4%$) respectively at large, middle and small follicles and total number of these 3 grade follicles were appeared to be $182.6{\pm}32.7$. The above findings reveal that large follicles were increased 29.8% in FSH-treated group and 73.7% in PMS and HCG-treated group than those in control group and in histologic findings, proportion of atretic follicles were more increased in ovaries with more number of more developing follicles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.599-607
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• 1998

To clarify annual reproductive cycle of Korean dark sleeper, Odontobutis platycephala (Iwata et Jeon), we examined the seasonal changes of gonadosomatic index (GSI), the proportional frequency of oocyte development stages in the ovary and the changes of sex steroid hormone levels in blood from December 1995 to November 1997. In July and August, GSI was 0.35 to 0.72 and most oocytes in the ovary were chromatin-nucleolus stage and perinucleolar stage (proportional frequency: $87\%\~96\%$). In September, GSI was 1.20 $\pm$ 0.12, some oocytes in the ovary were yolk vesifle stage (proportional frequency: $22.8\%$) and vitellogenic stage which appeared very rarely(proportional frequency: $2.2\%$). GSI increased gradually from October and reached 4.59± 0.61 to December. During this period, oocytes of vitellogenic stage increased slightly (proportional frequency in December: $22.1\%$). In January, GSI was 4.32 $\pm$ 0.72 but the proportional frequency of oocytes in vitellogenic stage increased (proportional frequency: $51.2\%$). from February, GSI was increased sharply and reached to 10.51 $\pm$ 1.04 in March, the highest value throughout the year and the proportional frequency of oocytes in vitellogenic stage also reached the highest levels (proportional frequency: $60\%$). From April, GSI was gradually decreased and fell down to 1.11 $\pm$ 0.35 in June. During this period, the proportional frequency of mature oocytes was the highest in April (proportional frequency of mature oocyte stage: $40\%$ in April, $12\%$ May, $5\%$ June) throughout the year, and atretic ovarian follicles were appeared. The blood level of estradiol-17$\beta$ ($E_2$), which stimulates the hepatic synthesis and secretion of vitellogenin, was $0.84{\pm}0.20\;ng/m{\ell}$ in August, and thereafter was not changed until December. from January, it increased sharply and reached the highest level of $ 2.85{\pm}0.35\;ng/m{\ell}$ in March throughout the year, but fell to $0.14{\pm}0.02\;ng/m{\ell}$ in July(P<0.05), 17$\alpha$-hydroxprogesterone(17$\alpha$-OHP) was the peak $13.37{\pm}0.52ng/m{\ell}$ in March, but no significant changes in other period(below $3ng/m{\ell}$, P<0.05). 17$\alpha$, 20$\beta$-dihydroxy-4-pregnen-3-one(17$\alpha$, 20$\beta$-P), which was known as the final maturation inducing hormone in teleost, was $0.74{\pm}0.09ng/m{\ell}$ in April and $0.54{\pm}0.07ng/m{\ell}$ in May, but no significant changes in other period (below $0.26\;ng/m{\ell}$, p<0.05). Taken together these results, the annual reproductive cycle of O. platycephala divided into 4 periods as follows: 1) ripe and spawning period from April to June, main spawning period was from April to May, 2) Resting period from July to August, 3) Growing period from September to December, 4) Maturing period from January to March. Moreover, It was showed that the changes of sex steroid hormone in blood played a important roles in the annual reproductive cycle of O. platycephala.

• Journal of Embryo Transfer
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• v.17 no.1
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• pp.61-65
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• 2002

This study was carried out to study the viability 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 at 10, 14 and 20 hrs after the onset of maturation, respectively). The oocytes remained vitrified for 24 hrs, and then were thawed in 3$0^{\circ}C$. Survival and cleavage rates were investigated by results of in vitro culture and aceto-orcein staining or FDA test. No difference in the incidence of diploid oocytes was observed among the control, non-vitrified group(3.6%) and oocytes vitrified at 14 hrs(6.7%) or 20 hrs(1.7%). However, more diploid oocytes were detected after vitrification at 0 hr.(26.7%) and 10 hrs(21.7%) post maturation. The survival rate of all vitrified immature oocytes(12.0~38.0%) was low, 48.0% of unvitrified oocytes and oocytes vitrified before maturation or 0~ 10 hrs after the onset of maturation were higher than that of other groups. The overall fertilization and cleavage rates of vitrified immature oocytes (32.3 ~ 64.6% and 4.6 ~ 32.3%) were low, and 55.0% of unvitrified oocytes and the rate of immature oocytes were very higher than that of mature oocytes.

• Development and Reproduction
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• v.9 no.1
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• pp.23-31
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• 2005

Vitellogenesis during oogenesis, reproductive cycle and first sexual maturity of the female Neptunea (Barbitonia) arthritica cumingii was investigated by light and electron microscope observations. In the early vitellogenic oocyte, the Golgi complex and mitochondria were involved in the formation of lipid droplets and yolk granules. In late vitellogenic oocytes, the rough endoplasmic reticulum and multivesicular bodies were involved in the formation of proteid yolk granules in the cytoplasm. A mature yolk granule was composed of three components: main body(central core), superficial layer, and the limiting membrane. The spawning season was between May and August and the main spawning occurred between June and July when the seawater temperature rose to approximately $18{\sim}23^{\circ}C$. The female reproductive cycle can be classified into five successive stages: early active stage(September to October), late active stage(November to February), ripe stage(February to June), partially spawned stage(May to August), and recovery stage(June to August). The rate of individuals reaching the first sexual maturity was 53.1% in females of 51.0 to 60.9mm in shell height, and 100% in those over 61.0mm.