• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.311-319
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• 2009

Objective: Human embryonic stem cells (hESCs) have the capacity to differentiate into all of the cell types and therefore hold promise for cell therapeutic applications. In order to utilize this important potential of hESCs, enhancement of currently used technologies for handling and manipulating the cells is required. The cryopreservation of hESC colonies was successfully performed using the vitrification and slow freezing-rapid thawing method. However, most of the hESC colonies were showed extremely spontaneous differentiation after freezing and thawing. In this study, we were performed to rapidly collect of early passage hESCs, which was thawed and had high rate of spontaneously differentiation of SNUhES11 cell line. Methods: Four days after plating, partially spontaneously differentiated parts of hESC colony were cut off using finely drawn-out dissecting pipette, which is mechanical separation method. Results: After separating of spontaneously differentiated cells, we observed that removed parts were recovered by undifferentiated cells. Furthermore, mechanical separation method was more efficient for hESCs expansion after thawing when we repeated this method. The recovery rate after removing differentiated parts of hESC colonies were 55.0%, 74.5%, and 71.1% when we have applied this method to three passages. Conclusion: Mechanical separation method is highly effective for rapidly collecting and large volumes of undifferentiated cells after thawing of cryopreserved early passage hESCs.

• Journal of Embryo Transfer
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• v.21 no.4
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• pp.331-338
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• 2006

This survey was carried out to investigate the occurrence of reproductive disorders in Korean native cattle (Hanwoo). The general management status such as barn type, feed intake, parity and type of reproductive disorders were examined in the Hanwoo farms. In this survey, the total incidence of reproductive disorders that was assessed from 54 Hanwoo farms was 11.6% (73/ 631). We first examined the incidence of reproductive disorders following herd size per farm. The rates of reproductive disorders in under 10 heads, 10 to 20 heads and over 20 heads were 25.2%, 9.4% and 8.3%, respectively (P<0.05). The rate of reproductive disorders in tie stall barn was significantly (P<0.05) higher than that in free stall barn (14.9% vs. 8.1%). The major types of reproductive disorders were follicular cysts (21.8%), fat necrosis (21.8%), and repeat breeding (17.8%). The rate of reproductive disorders assessed by the parity tended to decrease as the parity increased. The relationship between incidence of reproductive disorders and body condition score (BCS) was investigated in 203 Hanwoo. The incidence of reproductive disorder was 80.0%, 8.8%, 9.4%, 10.0%, 33.3% and 57.1% at 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 of BCS, respectively. These data show that the increase of herd size, barn type and BCS affect the incidence of reproductive disorders such as follicular cysts, fat necrosis and repeat breeding in Hanwoo.

• Clinical and Experimental Reproductive Medicine
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• v.6 no.1_2
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• pp.29-36
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• 1979

A good animal model that simulates the human subject has not been available for the evaluation of the in vivo effectiveness of vaginal contraceptives. After careful consideration, The stumptailed macaque (Macaca arctoides) was studied for its applicability since it has a reproductive tract similar to that of the woman, is easy to handle, does not require tranquilization or anesthesia when the contraceptive is deposited, and breeds and conceives readily under caged conditions. The reported observations show the usefulness of this animal. Both postcoital sperm motility studies and breeding experiments were performed with the use of Delfen vaginal cream and K-Y jelly. K-Y jelly had no effect on the motility of vaginal spermatozoa or on the conception rate of the primates. Although Delfen vaginal cream consistently immobilized all spermatozoa in the postcoital test, half of the animals became pregnant within an average of 3.7 breeding cycles. These results illustrate the discrepancy between spermicidal tests and fertility measurements, and it is recommended that primate-breeding experiments be performed before a spermicide is evaluated in women as a contraceptive. (AM J. OBSTET. GYNECOL, 129:368, 1977.)

• Clinical and Experimental Reproductive Medicine
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• v.49 no.3
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• pp.159-167
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• 2022

As the resolution and accuracy of diagnostic techniques for preimplantation genetic testing for aneuploidy (PGT-A) are improving, more mosaic embryos are being identified. Several studies have provided evidence that mosaic embryos have reproductive potential for implantation and healthy live birth. Notably, mosaic embryos with less than 50% aneuploidy have yielded a live birth rate similar to euploid embryos. This concept has led to a major shift in current PGT-A practice, but further evidence and theoretically relevant data are required. Proper guidelines for selecting mosaic embryos suitable for transfer will reduce the number of discarded embryos and increase the chances of successful embryo transfer. We present an updated review of clinical outcomes and practice recommendations for the transfer of mosaic embryos using PGT-A.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.213-222
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• 2023

Cryopreservation is an option for the preservation of pre- or post-pubertal female or male fertility. This technique not only is beneficial for human clinical applications, but also plays a crucial role in the breeding of livestock and endangered species. Unfortunately, frozen germ cells, including oocytes, sperm, embryos, and spermatogonial stem cells, are subject to cryoinjury. As a result, various cryoprotective agents and freezing techniques have been developed to mitigate this damage. Despite extensive research aimed at reducing apoptotic cell death during freezing, a low survival rate and impaired cell function are still observed after freeze-thawing. In recent decades, several cell death pathways other than apoptosis have been identified. However, the relationship between these pathways and cryoinjury is not yet fully understood, although necroptosis and autophagy appear to be linked to cryoinjury. Therefore, gaining a deeper understanding of the molecular mechanisms of cryoinjury could aid in the development of new strategies to enhance the effectiveness of the freezing of reproductive tissues. In this review, we focus on the pathways through which cryoinjury leads to cell death and propose novel approaches to enhance freezing efficacy based on signaling molecules.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.120-126
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• 2020

Objective: This study was conducted to determine the effects of dietary supplementation with Pediococcus acidilactici (P. acidilactici) ZPA017 as a probiotic on reproductive performance, fecal microbial flora and serum indices in sows during late gestation and lactation. Methods: A total of 94 sows (Large White×Yorkshire, average 4.50 parities) were randomly allotted to two dietary treatments: control diet and the diet supplemented with P. acidilactici ZPA017 (2.40×10⁹ colony-forming unit/kg of diets). The study started at d 90 of gestation and conducted until d 28 of lactation. Results: Compared to sows fed the control diet, supplementation of P. acidilactici ZPA017 increased the number of weaning piglets, weaning weight of litter and piglets, survival rate of piglets at weaning (p<0.05), and decreased diarrhea rate of piglets in lactation (p<0.05). Dietary P. acidilactici ZPA017 increased fecal Lactobacillus populations (p = 0.030) and reduced fecal Escherichia coli and Staphylococcus aureus populations (p<0.05) of sows at weaning. Moreover, the supplementation of P. acidilactici ZPA017 increased serum concentrations of immunoglobulin G, immunoglobulin A and total protein (p<0.05), while decreased serum haptoglobin concentration and alanine aminotransferase activity (p<0.05) of sows at weaning. Conclusion: Administration of P. acidilactici ZPA017 in diets during late gestation and lactation had positive effects on the reproductive performance, intestinal microflora balance and immunity of sows.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.3
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• pp.175-184
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• 2022

Objective: The aim of this study was to evaluate the impacts of platelet-rich plasma (PRP) and conditioned medium (CM) derived from endometrial stromal cells on mouse preantral follicle culture in a two-dimensional system to produce competent mature oocytes for fertilization. Methods: In total, 240 preantral follicles were isolated from female mouse ovarian tissue and divided into four groups. The preantral follicles were isolated three times for each group and then cultured, respectively, in the presence of alpha minimum essential medium (control), PRP, CM, and PRP+CM. The in vitro growth, in vitro maturation, and cleavage percentage of the preantral follicles were investigated. Immunocytochemistry (IHC) was also conducted to monitor the meiotic progression of the oocytes. Additionally, the mRNA expression levels of the two folliculogenesis-related genes (Gdf9 and Bmp15) and two apoptosis-related genes (Bcl2 and Bax) were investigated using real-time polymerase chain reaction. Results: In the PRP, CM, and PRP+CM groups, the preantral follicle maturation (evaluated by identifying polar bodies) were greater than the control group. The cleavage rate in the CM, and PRP+CM groups were also greater than the control group. IHC analysis demonstrated that in each treatment group, meiotic spindle was normal. In the PRP+CM group, the gene expression levels of Bmp15, Gdf9, and Bcl2 were greater than in the other groups. The Bax gene was more strongly expressed in the PRP and control groups than in the other groups. Conclusion: Overall, the present study suggests that the combination of CM and PRP can effectively increase the growth and cleavage rate of mouse preantral follicles in vitro.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.432-442
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• 2022

The purpose of this study was to analyse the effects of light colour on rabbit reproductive performance and the expression of key follicular development genes. Rabbits (n = 1,068, 5 months old, 3.6-4.4 kg live body weight) were divided randomly into four groups, housed individually in wire mesh cages and exposed to red, green, blue, and white light-emitting diode (LED) light (control). The lighting schedule was 16 L : 8 D-15 d / 150 lx / 6:00 am-22:00 pm (3 d preartificial insemination to 12 d postartificial insemination). Red light and white light affected the conception rate and kindling rate and increased the total litter size at birth (p < 0.05). The effects of red light on litter size at weaning, litter weight at weaning, and individual weight at weaning increased compared with the green and blue groups. The effects of red light on live litter size at birth were increased compared with those in the blue group (p < 0.05). Compared to white light, green and blue light reduced the number of secondary follicles (p < 0.05). Compared to red light, green and blue light reduced the number of tertiary follicles (p < 0.05). Compared with white light, red LED light resulted in greater ovarian follicle stimulating hormone receptor and luteinizing hormone receptor mRNA expression (p < 0.05). Compared with green and blue LED light, red LED light resulted in greater B-cell lymphom-2 mRNA expression (p < 0.05). Compared with green LED light, red LED light inhibited FOXO1 mRNA expression in rabbit ovaries (p < 0.05). Red light can affect the reproductive performance of female rabbits and the expression of key genes for follicular development.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2083-2087
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• 2014

Between May and September 2014, a total of 226 serotine bats (Eptesicus serotinus) were captured and subsequently released at a site 50 km distant from the site of capture, in order to determine the homing ability of the bats and changes in the homing rate according to the season. The bats were captured from a nursery colony at a bridge in An-dong (Gyeongbuk, Korea), and then released at a similar site in Yeong-Ju (Gyeongbuk, Korea). We found that 115 of the 226 bats released (51%) returned to the capture site. However, there was a difference in the homing ability of the serotine bats depending on the season and reproductive status. We found that the homing rate was the highest in June during late pregnancy and the lowest in August after the lactation period.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.375-376
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• 2000

Sex ratio of a population is a key factor to determine reproductive rate of the population. If the population has skewed sex ratio to the male, the population size may decline gradually at an area which it inhabits, and, furthermore, if a species plays an ecologically important role in its community (e.g., a keystone species in Paine, 1966), its potential reproductive rate will be to form a characterized community because community structure is strongly influenced by the abundance of the ecologically important species (Hughes, 1986). A number of workers (e.g., Bryan et al., 1986 in Nucella lapillus; Spence et al., 1990 in Thais haemastoma) suggested that high frequency and/or late stage of imposex might affect the female mortality and normal reproduction adversely. Consequently, the imposex could affect sex ratio of natural population of some neogastropod including thaisid species. (omitted)