• Journal of Embryo Transfer
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• v.11 no.2
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• pp.103-109
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• 1996

The aim of this study was to evaluate the effect of recombinant bovine somatotropin (bST; Boostin-S, LG Chem) treatment with FSH (Super OV) or PMSG on superovulatory response for transvaginal ultrasound-guided oocyte retrieval (TVR) in calves. Eight Korean Native Cattle(KNC) heifer calves; 150 to 240 days old; were randomly assigned to four treatment groups: 1) FSH(75 mg); 2) FSH (75 mg) + bST(500mg) 3) PMSG(1;000 IU); 4) PMSG(1, 000 IU) + bST(500 mg). Experimental calves in group 1 (n=2) and 2(n=2) were weekly superovulated for 4 consecutive weeks with daily injection of FSH for 3days and the next day subjected to TVR session. Animals in group 3 (n=2) and 4(n=2) were weekly stimulated for 4 consecutive weeks with a single dose of 1, 000 IU PMSG. TVR was performed on 72 hours after PMSG injection. Calves in group 2 and 4 was received injection of 500 mg of bST every 10 days. At each TVR session, follicle number and size were recorded; the oocytes collected and graded according to cumulus and cytoplasm investment. Collected oocyte were determined viable oocyte according to morphological quality with granulation of oocyte and number and status of cumlulus cells. IVM and IVF were performed and assessed cleavage rate on day 3 after fertilization. A Sonovet 600(Medison, Co., Ltd) realtime ultrasound scanner with a 6.5 MHz convex transducer, fixed at the tip of 500 mm estended handle equipped with a needle guide was used in collecting oocyte. Differences between groups were analysed by chi-square test. The population of large follicle ($\geq$5 nun) and aspiration rate were not significant different among the 4 groups. But, the number of small follicles (<5 mm) and aspirated oocyte in the KNC calves treated with bST were 1.3~1.6 times higher than in KNC calves treat with FSH or PMSG alone. In conclusion, the administration of bST with FSH or PMSG at superovulation for TVR in calves was increase the nurnber of small follicle which was influenced the number of aspiratable follicle.

• Journal of Embryo Transfer
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• v.18 no.3
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• pp.187-193
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• 2003

Recently a protocol was developed that precisely synchronizes the time of ovulation in Hanwoo. Cows were treated with GnRH on Day 0, PGF$_2$$\alpha$ 7 d later, GnRH 2 d later, and then time-inseminated approximately 24 h after this second treatment with GnRH. Ovarian morphology was monitored cows by trans-rectal ultrasonography 6.5MHz linear transrectal probe(Sonovet - 600., Medison co. Korea) from 24 hr to 31 hrs after second GnRH injection. The result obtained summarized as follows - 1. Induced ovulation were 24 to 31hr after the second GnRH injection, but high induced ovulation was 28hr. 2. Conception rate with HML(High meat lin) and HIL(High milk lin) treatment were 48.1％(38/79) and 43.9％(40/91), respectively. 3. Conception rate of 1∼2 parity and 3∼4 parity was 44.3％ and 55％, respectively. 4. Conception rate of spring, autumn was more increased, 47.3％ than summer.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.235-243
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• 2007

Our goal was to examine the effects of early denudation on the enucleation efficiency and developmental competence of embryos following somatic cell nuclear transfer (SCNT) and parthenogenetic activation (PA). Oocytes were denuded following 30 h of in vitro maturation (IVM) and then cultured with (D+) or without (D-) their detached cumulus cells for additional $10{\sim}14$ h. Control oocytes were denuded after $40{\sim}44$ h of IVM. The size of the perivitelline space was larger at 40 h of IVM ($11.7{\sim}11.8{\mu}m$) than at 30 h ($8.9{\mu}m;$ p<0.01). The distances between the metaphase II (M II) plates and the polar bodies (PBs) were shorter in D+ ($19.4{\mu}m$) and D- oocytes ($18.9{\mu}m$) than in control oocytes ($25.5{\mu}m;$ p<0.01). Enucleation rates following blind aspiration at 40 h of IVM were higher (p<0.01) in D+ (92%) and D- oocytes (93%) compared to controls (82%). Early denudation did not affect oocyte maturation or the in vitro development of SCNT and PA embryos. When SCNT embryos from D+ oocytes were transferred to four gilts, pregnancy was established in two pigs, and one of them farrowed three live piglets. In conclusion, early denudation of oocytes at 30 h of IVM could improve the enucleation efficiency by maintaining the M II plate and the PB within close proximity and support the in vivo development of SCNT embryos to term.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.213-218
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• 2015

In the study for a differentiation and development of spermatogonial cells, the researchers should commonly require a simple, fast and reasonable method that could evaluate the developmental stage of male germ cells without any damage and also relentlessly culture them so far as a cell stage aiming at experimental applications. For developing the efficient method to identify the stage of sperm cells, the morphological characteristics of sperm cells were investigated by staining the cells with blue fluorescent dye Hoechst 33258, and a criterion for male germ cell classification was elicited from results of the previous investigation, then the efficiency of the criterion was verified by applying it to assort the germ cells recovered from male mice in age from 6 to 35 days. As morphological characteristics, spermatogonia significantly differed from spermatocytes in size, appearance and fluorescent patches of nucleus, and spermatids could also be distinguished from spermatozoa by making a difference in the volume and shape of nucleus and the shape and fluorescence of tail. Aforesaid criterion was applicable for classifying in vitro cultured sperm cells by verifying its efficiency and propriety for assorting the stages of testicular germ cells. However, the fluorescent staining showed that germ cells in mouse testis should be dramatically differentiated and developed at 21 days and 35 days of age, which were known as times of sexual puberty and maturity in male mice, respectively. In conclusion, the results indicated that this simple criterion for sperm cell classification using fluorescence staining with Hoechst 33258 may be highly efficient and reasonable for spermatogenesis study.

• Journal of Embryo Transfer
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• v.32 no.1
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• pp.33-38
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• 2017

A 10-day-old, Holstein calf with facial mass of 10 cm in diameter at the forehead region referred to Veterinary Medical Teaching Hospital in Chungnam National University. The mass was soft and fluctuating swelling. It had normal skin and hair hanging forward from frontal region and was thought to contain cerebrospinal fluid. On the skull radiography, cauliflower like-irregular marginated, soft tissue opacity mass was identified craniodorsal to the frontal bone. The mass appeared as a cyst filled with anechoic fluid on ultrasonography. Soft tissue structures considered brain tissues were observed in the deep area of the mass. On the computed tomography, a large skull defect of left side frontal bone was found, and heterogeneous materials were exposed through the defect but exposure of cerebral meninges and brain tissue were not confirmative. On magnetic resonance imaging, herniated left brain parenchyma showed heterogenous T2 and T1 hyperinsensity. In the intracranium, T2 hyperinstense and T1 hypointense fluid was identified on the left side, instead of left cerebral parenchyma. Also leftward shift of right hemisphere and midline structure, including thalamus and midbrain, were observed. The definitive diagnosis was confirmed as a meningoencephalocele based on computed tomography and magnetic resonance imaging. The calf was euthanized and necropsy was performed. On necropsy, both hemisphere were developed unequally with different size. One side hemisphere was grown in the outside through 10 cm hole on the median plane.

• Molecules and Cells
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• v.41 no.12
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• pp.1072-1080
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• 2018

A plant-specific B3 domain and AP2 domain-containing transcription factor, RAV1 acts as a negative regulator of growth in many plant species and its transcription was down-regulated by BR and ABA. In this study, we found that RAV1-overexpressing transgenic plants showed abnormally developed ovules, resulting in reduced seed size, weight, and number in a silique. Interestingly, the endogenous expression of RAV1 fluctuated during seed development; it remained low during the early stage of seed development and sharply increased in the seed maturation stage. In plants, seed development is a complex process that requires coordinated growth of the embryo, endosperm, and maternal integuments. Among many genes that are associated with endosperm proliferation and embryo development, three genes consisting of SHB1, MINI3, and IKU2 form a small unit positively regulating this process, and their expression was regulated by BR and ABA. Using the floral stage-specific RNAs, we found that the expression of MINI3 and IKU2, the two downstream genes of the SHB1-MINI3-IKU2 cascade in the seed development pathway, were particularly reduced in the RAV1-overexpressing transgenic plants. We further determined that RAV1 directly binds to the promoter of MINI3 and IKU2, resulting in their repression. Direct treatment with brassinolide (BL) improved seed development of RAV1-overexpressing plants, but treatment with ABA severely worsened it. Overall, these results suggest that RAV1 is an additional negative player in the early stages of seed development, during which ABA and BR signaling are coordinated.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.1
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• pp.22-29
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• 2019

Objective: As paternal age increases, the quality of sperm decreases due to increased DNA fragmentation and aneuploidy. Higher levels of structural chromosomal aberrations in the gametes ultimately decrease both the morphologic quality of embryos and the pregnancy rate. In this study, we investigated whether paternal age affected the euploidy rate. Methods: This study was performed using the medical records of patients who underwent in vitro fertilization (IVF) procedures with preimplantation genetic screening (PGS) from January 2016 to August 2017 at a single center. Based on their morphological grade, embryos were categorized as good- or poor-quality blastocysts. The effects of paternal age were elucidated by adjusting for maternal age. Results: Among the 571 total blastocysts, 219 euploid blastocysts were analyzed by PGS (38.4%). When the study population was divided into four groups according to both maternal and paternal age, significant differences were only noted between groups that differed by maternal age (group 1 vs. 3, p= 0.031; group 2 vs. 4, p= 0.027). Further analysis revealed no significant differences in the euploidy rate among the groups according to the morphological grade of the embryos. Conclusion: Paternal age did not have a significant impact on euploidy rates when PGS was performed. An additional study with a larger sample size is needed to clarify the effects of advanced paternal age on IVF outcomes.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.177-182
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• 1994

Cotyledon segments of korean ginseng produced somatic embryos when cultured on MS basal medium, whereas plumule or excised axis explants did not. histological examination revealed that the cells in proximal region of cotyledon turned meristematic and densely cytoplasmic was composed of smaller and more densely cytiplasmic cells than the subepidermal cells. however, in the case both epidermis and subepidermal cells were almost the same in size and cytoplasmic density, the embryo originated from multiple cells.

• Journal of Ecology and Environment
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• v.31 no.1
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• pp.17-21
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• 2008

Mating behaviour of the gammarid amphipod, Hyale rubra, was observed. H. rubra displayed precopulatory mate guarding: males clasped females with their gnathopods during copulation, forming a pair. Males also participated in embryo care during the incubation period. The population was small, and the sex ratio was almost equal. Energy allocation for mating effort and parental effort in the two sexes appear to be almost equal. The mating system was sequentially polygamous (or promiscuous) and there was conspicuous sexual dimorphism in the size of the gnathopod, which was used for mate guarding. However, there appears to be relatively weak sexual competition for mating opportunities despite conspicuous sexual dimorphism. H. rubra did not display territorial competition or external fertilization. Nevertheless, the male provided paternal care. Since H. rubra inhabit tide pools and live on algae, the polygamous mating system of the species can be explained by the polygyny threshold model. The evolution of mate guarding and parental care may have been favored by the species' low population density and harsh environments, an interpretation consistent with the optimality model.

• Journal of Embryo Transfer
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• v.10 no.1
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• pp.45-51
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• 1995

In order to determine the optimum condition and timing for in vitro maturation of oocytes to metaphase of meiosis II (M II), the immatured follicular oocytes were recovered by puncturing the large(1.0~1.5 mm in diameter) and small(<1.0 mm in diameter) follicles in the ovaries of rabbits treated intramuscularly with a single dose of 100 TU PMSG 68 hours previously. The follicular oocytes were classified into three grades by the attachment of cumulus cells. The Grade I and II follicular oocytes from large follicles were cultured in BO-DM medium with 10% FCS, 35 $\mu$g /nl of FSH, 10 $\mu$g /ml of LH and 1 $\mu$g /ml of estradiol-17$\beta$ at 39t in a 5% $CO_2$ incubator for 11 to 23 hours. In 3 hours interval during the culture period, the oocytes were harvested and their cumulus cells were removed with hyaluronidase. The denuded oocytes were stained with Hoechst 33342 dye and their meiotic status and extrusion of the first polar body (PB) were examined under a fluorescence microscope. Also the fragmentation of the first PB and the distance between the first PB and nucleus were examined. The results obtained were as follows: 1. The mean recovery rate of follicular oocytes from the large and small follicles was 59. 9 and 31.3%, respectively. The mean number of oocytes recovered per rabbit and the Grade I percentage were 14.6 and 94.4% in large follicles, but 2.1 and 61.1% in small follicles, respectively. All the parameters examined were different significantly (p<0.05) between both the folliclular size. 2. Most of the follicular oocytes(86.8%) were matured in vitro to M II phase in 14 hours in Grade I oocytes, but the significantly(p<0.05) less oocytes(45.5%) were matured in Grade II oocytes. 3. The first PB was extruded in most of the oocytes(94.7%) in 14 hours of culture with the fragmentation rate of 29.6%, but the fragmentation rate of the first PB increased significantly (p<0.05) as the culture period for maturation was longer to 20 hours(63.5%). 4. The distance between the first PB and nucleus was increased linearly (p<0.05) as the maturation time passed from 14(7.1$\mu$rn) to 23 hours(58.4$\mu$m). 5. From the above results it was concluded that the optimum time for in vitro maturation culture might be 14 hours in the follicular oocytes from rabbit primed with PMSG for 68 hours, expecially when these follicular oocytes were used for recipient cytoplasms in embryo cloning.