• 대한생식의학회:학술대회논문집
• /
• 2007.11a
• /
• pp.113-114
• /
• 2007

• Journal of Animal Reproduction and Biotechnology
• /
• v.34 no.3
• /
• pp.139-147
• /
• 2019

Stem cells are progenitor cells that are capable of self-renewal and differentiation into various cells. Especially, pluripotent stem cells (PSCs) have in vivo and in vitro differentiation capacity into three germ layers and can proliferate infinitely. The differentiation ability of PSCs can be applied for regenerative medicine and tissue engineering. In domestic animals, their PSCs have a potential for preclinical therapy as well as the production of transgenic animals and agricultural usage such as cultured meat. Among several domestic animals, a pig is considered as an ideal model for biomedical and agricultural purposes mentioned above. In this reason, studies for pig PSCs including embryonic stem cells (ESCs), embryonic germ cells (EGCs) and induced pluripotent stem cells (iPSCs) have been conducted for decades. Therefore, this review will discuss the history of PSCs derived from various origins and recent progress in pig PSC research field.

• Clinical and Experimental Reproductive Medicine
• /
• v.35 no.1
• /
• pp.39-48
• /
• 2008

Objective: The aim of this study was to investigate whether multipotent germline stem cells (MGSCs) can be established from neonatal mouse testis. Methods: Various cells containing MGSCs were collected from neonatal testis of ICR mice and allocated to plates for in vitro culture. After 7 days in culture, the cells were passed to a fresh culture plate and continuously cultured. From the third or fourth passage, the presumed MGSCs were cultured and maintained on mitomycin C-inactivated STO feeder cells. The MGSCs were cultured in a condition where mouse embryonic stem cells (ESCs) are cultured. Characteristics of the MGSCs were evaluated by RT-PCR, immunocytochemistry, alkaline phosphatase activity, karyotyping, and transmission electron microscopy. Results: Two MGSCs lines were established from 9 pooled sets of neonatal testicular cells. MGSCs colonies were morphologically undistinguishable from ESCs colonies and both MGSC lines as well as ESCs expressed undifferentiated stem cell markers, such as Thy-1, Oct-4, Nanog, Sox2 and alkaline phosphatase. Fine structure of undifferentiated MGSCs were similar to those of ESCs and 60% of MGSCs (12/20) had normal karyotype at passage 10. They were able to form embryoid bodies (EBs) and MGSC-derived EBs expressed marker genes of three germ layers. Conclusion: We could establish the MGSCs from neonatal mouse testis and they were differentiated to multipotent lineages of three germ layers. Molecular characteristics of MGSCs were similar to those of ESCs. Our results suggest a possibility that multipotent stem cells derived from testis, the MGSCs, could replace the ESCs in biotechnology and regenerative medicine.

• Korean Journal of Poultry Science
• /
• v.16 no.1
• /
• pp.1-8
• /
• 1989

This experiment was conducted to improve the performance of chickens by the precise separation and analysis of chromosomes which are integrated genetic materials, and by the use of gene manipulation techniques. Following are the main results obtained. 1. When the chromosomes were separated through the leucocyte culture and analyzed by Giemsa banding techniques (especially by the method in which 20 layers of banding patterns could be found in chromosome ＃1), the normal Patterns of chromosomes ＃l-9 and sex chromosomes, and the location of constitutive heterochromatin without any gene activities in all chromosomes were discovered. 2. To utilize the primodial germ cells (PGC) as the genetic vector which is one of the most important gene manipulation techniques, PGC's from triploid were transplanted to normal host embryos. Since the donor PGC's(3n) were found in the gonads of growing host embryos gene manipulation in poultry using PGC's, seemed to be possible.

• Advances in pediatric surgery
• /
• v.13 no.2
• /
• pp.169-178
• /
• 2007

Teratomas arising from totipotential primitive germ cell are composed of 2 or 3 germ cell layers. We reviewed the records of 166 children who underwent the operation for teratoma from Jan, 1990 through April, 2007. There were 40 boys and 126 girls (average age $6.93{\pm}5.83$ years). Primary sites were ovary (n = 88), sacrococcygeum (n = 24), testis (n = 16), retroperitoneum (n = 16), mediastinum (n = 8), brain (n = 4), thymus (n = 3) and a single tumor involved the adrenal gland, neck, middle ear, oropharynx, stomach, pelvis, omentum, chest wall and scalp. Teratomas were mature in 141 patients, and immature in 25. Six patients who had ovarian immature teratomas grade 2 or 3 with peritoneal gliomatosis underwent adjuvant chemotherapy. During follow up period, 6 mature teratomas recurred at sacrococcygeal area (n = 1) and contralateral ovary (n = 5). Five patients of them underwent reoperation and diagnosed as a mature teratoma, but one who had underwent a left salpingooophrectomy with right ovary cystectomy at initial operation was observed carefully. Teratomas were dominant in female patients and developed at various organs. Complete excision was needed for good prognosis. In case of immature teratoma, complete excision and appropriate chemotherapy according to grading can contribute to favorable results.

• Journal of Korean Neurosurgical Society
• /
• v.41 no.3
• /
• pp.180-181
• /
• 2007

Intracranial teratomas are diagnosed mostly in young population and usually involve midline structure. We report a case of mature teratoma in an adult patient with unusual location in cerebellar hemisphere. A 47-year-old woman presented with severe headache and nausea. Computed tomography and magnetic resonance imaging demonstrated a posterior fossa lesion with cerebellar hemispheric location not involving midline. Histological examination of surgical specimen showed fully matured representative tissues of the three germ layers confirming teratoma. This is a rare example of mature teratoma with unusual age of the patient and location.

• Journal of Chest Surgery
• /
• v.28 no.5
• /
• pp.530-532
• /
• 1995

The teratomas seem to be the most common mediastinal tumor in Korea. However, the immature teratomas are the rarest type of these mediastinal teratomas. A case of immature teratoma of the mediastinum occurring in a newborn male is reported. He suffered from severe dyspnea since birth. Simple chest X-ray and chest sonogram revealed huge mass shadow in fight whole lung field. On 6th day after birth, the operation was done and the mass was completely excised. Biopsy showed elements of mature tissues derived from 3 germ cell layers including immature neuronal components. The baby is well without evidence of disease till now.

• Archives of Plastic Surgery
• /
• v.33 no.4
• /
• pp.495-498
• /
• 2006

Purpose: Trichoblastic fibroma originates from hair germ layer tumor which is a benign tumor mixture of epidermal and mesodermal factor. Trichoblastic fibroma was found only in adults and showed equal occurrence rate between men and women. Since it is a rare tumor, we report a case of a trichoblastic fibroma which developed on the right cheek. Methods: A 72 year-old male was treated with excisional operation 17 years ago due to a solitary tumor that developed on the same site. He returned to the hospital with an asymptomatic mass which have been increasing in size for the last 3 months. Results: In computerized tomography, a size of $2.7{\times}2.3{\times}0.8cm$ tumor was found in the subcutaneous tissue layer. Grossly, the mass was well-circumscribed, smooth-surfaced and flesh colored, and was lobulated and fragile. Pathologic observation showed diverse shaped and sized tumor cell nests and fibrocellular stroma consisting basophilic cells in dermal and subdermal layers. Immunohistopathologic staining showed positive reaction on pancytokeratin, CK-5/6, and bcl-2. Conclusion: By having no connection to the epidermis, and being positioned in the dermal and epidermal layers, typical pathologic findings make it possible to differentiate this tumor with basal cell carcinoma. This lesion is not clear whether it is a local recurrence or not, and it is necessary to observe a new recurrence in the future.

• Molecules and Cells
• /
• v.37 no.1
• /
• pp.31-35
• /
• 2014

Induced pluripotent stem cells (iPSCs) are capable of unlimited self-renewal and can give rise to all three germ layers, thereby providing a new platform with which to study mammalian development and epigenetic reprogramming. However, iPSC generation may result in subtle epigenetic variations, such as the aberrant methylation of the Dlk1-Dio3 locus, among the clones, and this heterogeneity constitutes a major drawback to harnessing the full potential of iPSCs. Vitamin C has recently emerged as a safeguard to ensure the normal imprinting of the Dlk1-Dio3 locus during reprogramming. Here, we show that vitamin C exerts its effect in a manner that is independent of the reprogramming kinetics. Moreover, we demonstrate that reprogramming cells under 2i conditions leads to the early upregulation of Prdm14, which in turn results in a highly homogeneous population of authentic pluripotent colonies and prevents the abnormal silencing of the Dlk1-Dio3 locus.

• Journal of Animal Reproduction and Biotechnology
• /
• v.39 no.1
• /
• pp.19-30
• /
• 2024

Background: Although an understanding of the proliferation and differentiation of fish female germline stem cells (GSCs) is very important, an appropriate threedimensional (3D) research model to study them is not well established. As a part of the development of stable 3D culture system for fish female GSCs, we conducted this study to establish a 3D aggregate culture system of ovarian cells in marine medaka, Oryzias dancena. Methods: Ovarian cells were separated by Percoll density gradient centrifugation and two different cell populations were cultured in suspension to form ovarian cell aggregates to find suitable cell populations for its formation. Ovarian cell aggregates formed from different cell populations were evaluated by histology and gene expression analyses. To evaluate the media supplements, ovarian cell aggregate culture was performed under different media conditions, and the morphology, viability, size, gene expression, histology, and E2 secretion of ovarian cell aggregates were analyzed. Results: Ovarian cell aggregates were able to be formed well under specific culture conditions that used ultra-low attachment 96 well plate, complete mESM2, and the cell populations from top to 50% layers after separation of ovarian cells. Moreover, they were able to maintain minimal ovarian function such as germ cell maintenance and E2 synthesis for a short period. Conclusions: We established basic conditions for the culture of O. dancena ovarian cell aggregates. Additional efforts will be required to further optimize the culture conditions so that the ovarian cell aggregates can retain the improved ovarian functions for a longer period of time.