• Korean Journal of Veterinary Service
• /
• v.44 no.4
• /
• pp.227-237
• /
• 2021

Artificial insemination of Korean native cattle (KNC) is the predominant method for breed improvement. However, industrialization of embryo production and transfer is necessary to utilize the genetic potential of KNC. The aim of this study was to examine associations between KNC donor cows and ovum pick-up (OPU) conditions, in-vivo oocyte recovery, and embryo development. Oocyte recovery and blastocyst development rates were higher at 50 and 60 mmHg OPU vacuum pressure than at 40 mmHg, which was, however, not significant. Regarding follicle growth, injection of 500 ㎍ GnRH 36 hours before OPU significantly increased the number of OPU oocytes from an average of 4.6 to 7.6 (P<0.05); no significant difference in embryo development rates was observed. Significant differences were observed in the numbers of OPU oocytes, embryo development rates, and transplantable blastocysts per individual among nine KNC donors (P<0.05). Furthermore, although there was no difference in OPU oocyte recovery intervals in approximately 2~8 weeks, the number of recovered oocytes significantly decreased at the 12-week interval (P<0.05); there was no difference in embryo development rates. The number of oocytes and embryonic development rates only tended to decrease until the seventh OPU session, but decreased significantly until the eighth session (P<0.05). The average pregnancy rate after transfer of OPU-derived in-vitro embryos into recipient cows was 41.8%. To improve the efficiency of OPU egg recovery and in-vitro embryo production, considering KNC donor characteristics, vacuum pressure of 60 mmHg, GnRH pretreatment to induce follicle growth, and effective OPU egg recovery up to seven times at intervals of 2~4 weeks appears to be most suitable. This study may facilitate the industrialization of KNC embryo production and transfer using high-quality cows.

• Korean Journal of Animal Reproduction
• /
• v.5 no.1
• /
• pp.43-63
• /
• 1981

This study aimed to determine the effects of adrenalectomy on the sexual gland, the thyroid gland and the serum components. A total of 192 Wister strain albino rats were evenly divided into 4 sexually equal groups for the comparisons. Each groups was divided into a control and a treatment group by sexuality. Each tissue of the sexual gland and the thyroid gland was microscopically examined, and at the same time body weight and serum components were also examined on the 1st, 7th, 14th, 28th, 42nd, 56th, 70th and 84th day respectively following adrenalectomy. The results obtained were as follows: 1. The body weight was sufficiently retarded in decreasingly after the adrenalectomy as compared to that of control. 2. The histological change of testis started atrophy of spermatogonia and degeneration of spermatocyte. There was a, pp.ared no cell division activity. Spermatozoa in the seminiferous tuble was not noticed but degeneration of interstitial cell was started and spermatozoa in the epididymal duct disa, pp.ared. 3. Degeneration of oocyte and follicular cell was noticed as the histological change of ovary. There was not a, pp.arance of primary follicle and corpus Iuteum but interstitial cell was proliferated. 4. For the effect of adrenalectomy on the histological change of the thyroid gland, the number of small follicle decreased and that of large follicle increased as the time passed following the adrenalectomy. And the follicular epithelial cell became squamous as typical condition of functional decreased. 5. It was shown that in the total contents of serum protein no difference with control occurred with in the 70th day for male and female adrenalectomized, respectively. But the differences in protein contents were significanly decreased on the 70th day. 6. No difference occurred in the total serum lipids on the 7th day, but they decreased significantly on the 42nd day, and (P<0.01) on the 56th, and 70th day. A tendency to decrease was noted as time elapsed following adrenalectomy. 7. Increase and decrease were intercrossed in the serum cholesterol contents between the control and th treatment groups on the 28th day. But the difference significantly decreased on the 42nd, 56th, and 70th day after adrelalectomized. The contents showed tendency to decrease as time elapsed following adrenalectomy. 8. The blood glucose contents rapidly decreased with time. The difference were significant on the 28th and 42nd day, and highly significant on the 56th and 70th day for male adrenalectomized. 9. In case of solium, there was no noticeable sexual distinction. There was slight in creasing or decreasing for the control group. But the treatment group tended continuously to decrease for male and female. 10. It was shown that potassium contents tended to increase on the 28th day for male and female, but the differences were small. 11. As for chlorine, it tended to decrease rapidly on 7th day for male and female adrenalectomized, and the tendency continued.

• Fisheries and Aquatic Sciences
• /
• v.1 no.1
• /
• pp.82-93
• /
• 1998

Monthly changes of the gonad follicle index (GFI), reproductive cycle, egg-diameter composition, first sexual maturity of the Pacific oyster, Crassostrea gigas, were studied based on the samples which have been collected from the intertidal zone of Poryong west coast of Korea, from January to December, 1996. C. gigas, is dioecious, while a few individuals are alternatively hermaphroditic. Monthly variation of gonad follicle index (GFI) used for determination of spawning period, coincided with the reproductive cycle. GFI increased from April when seawater temperatures gradually increased and reached the maximum in May. And then, GFI sharply decreased from June to September due to spawning. Reproductive cycle of this species can be divided into five successive stages: in females, early active stage (March to April), late active stage (April to May), ripe stage (May to August), partially spawned stage (June to September) and spent/inactive stage (September to February); in males, early active stage (February to March), late active stage (April to May), ripe stage (May to September), partially spawned stage (June to September) and spent/ inactive stage (September to February). The diameter of fully mature eggs are approximately 50um. Spawning occurred from June to September, and two spawning peaks were observed in June and August when the seawater temperature was above $20^{\circ}C$. Percentages of the first sexual maturity of males of 20.1-25.0 mm in shell height were over $50\%$, while those of females of 25.1-30.0 mm in shell height were over $50\%$. All the males of > 30.1 mm and all the females of ^gt; 35.1 mm completed their first sexual maturity. The results suggest that C. gigas has a protandry phenomenon. Sex ratios of 919 oysters observed were 453 females $(49.29\%)$, 429 males $(46.68\%)$, 16 hermaphrodites $(1.74\%)$, and 21 indeterminate individuals $(2.29\%)$. In age class I, sex ratio of males were $64.00\%$, thus, a higher percentage than that of females. It was noted that $64.00\%$ of the young males (age class I) were more functional than females in age class I, but 2-3 year-old oysters showed higher percentage of females. Percentages of hemaphrodites in 2-3 year classes were relatively higher than those in other year classes. Histological pattern of hermaphrodites can be divided into two types: Type I (hermaphrodite having a number of newly formed developing oocytes on the oogenic tissues within a degenerating spermatogenic follicle after discharge of numerous spermatozoa) and Type II (hermaphrodite having two separate follicles in the same gonad).

• Clinical and Experimental Reproductive Medicine
• /
• v.42 no.2
• /
• pp.62-66
• /
• 2015

Objective: To evaluate the effect of a gonadotropin-releasing hormone (GnRH) antagonist protocol using corifollitropin alfa in women undergoing assisted reproduction. Methods: Six hundred and eighty-six in vitro fertilization-embryo transfer (IVF)/ intracytoplasmic sperm injection (ICSI) cycles were analyzed. In 113 cycles, folliculogenesis was induced with corifollitropin alfa and recombinant follicle stimulating hormone (rFSH), and premature luteinizing hormone (LH) surges were prevented with a GnRH antagonist. In the control group (573 cycles), premature LH surges were prevented with GnRH agonist injection from the midluteal phase of the preceding cycle, and ovarian stimulation was started with rFSH. The treatment duration, quality of oocytes and embryos, number of embryo transfer (ET) cancelled cycles, risk of ovarian hyperstimulation syndrome (OHSS), and the chemical pregnancy rate were evaluated in the two ovarian stimulation protocols. Results: There were no significant differences in age and infertility factors between treatment groups. The treatment duration was shorter in the corifollitropin alfa group than in the control group. Although not statistically significant, the mean numbers of matured (86.8% vs. 85.1%) and fertilized oocytes (84.2% vs. 83.1%), good embryos (62.4% vs. 60.3%), and chemical pregnancy rates (47.2% vs. 46.8%) were slightly higher in the corifollitropin alfa group than in the control group. In contrast, rates of ET cancelled cycles and the OHSS risk were slightly lower in the corifollitropin alfa group (6.2% and 2.7%) than in the control group (8.2% and 3.5%), although these differences were also not statistically significant. Conclusion: Although no significant differences were observed, the use of corifollitropin alfa seems to offer some advantages to patients because of its short treatment duration, safety, lower ET cancellation rate and reduced risk of OHSS.

• Korean Journal of Animal Reproduction
• /
• v.26 no.2
• /
• pp.133-142
• /
• 2002

The objective of this study was to examine maturation, fertilization and developmental rate of the in vitro-grown mouse oocytes, and to compare these results with those of oocytes grown and matured in vivo. The preantral follicles isolated from 12-day-old mice were cultured on Transwell-COL membrane inserts. After in vitro growth and maturation, 72.5 % of oocytes grown in vitro produced polar body which can be comparable to in vivo growth (70.5 %). However, the mean oocyte diameter of the in vitro group (69.6$\pm$2.1$\mu$m) was smaller than that of the in vivo group (73.3$\pm$3.0$\mu$m). The fertilization rate was significantly lower (p<0.05) in the in vitro group (76.5%) than in the in vivo group (90.2%), however, there was no difference in the percentage of monospermic and polyspermic oocytes between two groups. The capacities of in vitro grown ova to cleave and develop to blastocyst were (57.8 and 14.4%, respectively) significantly lower (p<0.001) than those of the in vivo counterpart (84.4 and 56.6%, respectively). Moreover, the mean number of cells per blastocyst was significantly lower (p<0.05) in the in vitro group (39.0$\pm$10.8) than in the in vivo group (60.5$\pm$12.5). Live young were produced from transferred 2-cell embryos derived from in vitro-grown and matured oocytes. In conclusion, the results show that in vitro-grown oocytes did not achieve the developmental capacity of in vitro-grown oocytes.

• Reproductive and Developmental Biology
• /
• v.29 no.1
• /
• pp.37-41
• /
• 2005

The aim of this study was to improve efficiency and quality of the production of Korean Native Cow embryos. We examined effects of ovarian morphology and maturation vessel on the development and cell number of blastocysts. The development rates to the 2-cell embryos from oocytes collected from the ovaries of different morphological statues were similar ranging between 70.3 and 84.1%. The development rate to the 8 cell- and blastocyst-stage embryos was the highest in the group without both corpus luteum (CL) and follicle. The inner cell mass (ICM), trophectoderm (TE) and total cell number (TCN) were significantly higher in the groups of follicular cyst and regressive CL than other treatment groups, and the same pattern was observed in the ICM/TCN ratio. The development rate to the 2-cell stage was significantly higher in 0.5-㎖ straw group than 0.25-㎖ straw group. However, the development rates to the blastocyst stage were similar between the dish and the straw group. There were no differences in the number of ICM and TE cells, TCN and ICM/TCN ratio of blastocysts from oocytes matured in the different vessels.

• Clinical and Experimental Reproductive Medicine
• /
• v.48 no.1
• /
• pp.43-49
• /
• 2021

Objective: Exercise is a risk factor for infertility in women. However, research on the effects of different intensities of exercise on folliculogenesis has not yielded clear results. This study was conducted to analyze the effects of differences in the intensity of exercise on folliculogenesis in mice. Methods: Nineteen female BALB/c mice (age, 3-4 months; weight, 13-25 g) were randomly divided into four groups: control, mild exercise, moderate exercise, and high-intensity exercise. The mice in the exercise groups engaged in swimming, with additional loads of 3%, 6%, or 9% of body weight, respectively. There were five swimming sessions per week for 4 weeks, with a gradually increasing duration every week. At the end of the treatment, ovarian extraction was carried out and hematoxylin and eosin staining was performed to identify folliculogenesis. Results: There were significant differences in the number of total follicles between the control and moderate-exercise groups (p=0.036) and between the mild- and moderate-exercise groups (p=0.005). The mean number of primary follicles was higher in the moderate-exercise group than in the mild-exercise group (p=0.006). The mean number of secondary, tertiary, and Graafian follicles did not differ significantly among groups (p≥0.05). However, the number of total follicles and follicles in each phase tended to increase after exercise, especially moderate-intensity exercise. Conclusion: Exercise of different intensities affected the total number of follicles and primary follicles. The number of follicles of each phase tended to increase after exercise. Moderate-intensity exercise had better effects than other intensities of exercise.

• Biomedical Science Letters
• /
• v.10 no.1
• /
• pp.49-54
• /
• 2004

The hair growth effect of the oriental medicine extract which is composed of Polygoni multiflori Radix, Angelica gigantis Radix and Lycii Fructus was studied biochemically and histologically. The study was conducted dividelly into three groups, control, propecia and oriental medicine extract and three groups were compared each other in skin androgen, testosterone (T) and dihydrotestosterone (DHT), content biochemically and the number of hair follicular unit and hair follicle histologically. The oriental medicine extract and propecia decreased skin DHT conetent and increased skin total (T+DHT) content compared with control. In transverse sections of skin specimens the oriental medicine extract and propecia increased total counts of follicular units and follicles compared with control. On the basis of the result, the oriental medicine extract has same hair growth effect as propecia and it is suggested that the oriental medicne extract is capable of a therapeutic agent of alopecia.

• Journal of the Korean Society of Tobacco Science
• /
• v.21 no.2
• /
• pp.171-181
• /
• 1999

We examined the ultrastructure of eupyrene and apyrene spermatogenesis in the testis of Helicoverpa assulta (Lepidoptera: Noctuidae). The spermatogenesis was progressed near the fringe adjacent to the follicular layer of the testicular follicle, surrounding the apical cell concentrically. Eupyrene and apyrene were firstly distinguished at the telophase stage of the primary spermatocyte. Chromatin was evenly scattered in eupyrene nuclei, whereas it was lumped near the nuclear envelope in apyrene spermatogenesis. Then, the nucleus of eupyrene was transformed into two daughter nuclei by meiosis, while the nucleus of apyrene was divided into many micronuclei by irregular meiosis. After the meiosis was completed, a number of mitochondria in the cytoplasm of the early spermatids of the eupyrene and the apyrene were fused into one nebenkern. Also, as axial filament was formed due to the elongation of the spermatid, the nebenkern became splitted into mitochondrial derivatives. An acrosome precursor was present only in the eupyrene, attached to nuclear envelope.

• Proceedings of the KSAR Conference
• /
• 2004.06a
• /
• pp.254-254
• /
• 2004

The aim of this study was two purpose: to compare recovery of embryos/follicle number from superovulated Holsteins(H) and Korean Native Cows(KNC) by flushing the uterine horns through insertion of the catheter and to evaluate the hormonal and superovulatory response to estradiol benzoate(EB) treatment prior to superovulation. (omitted)