• Development and Reproduction
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• v.24 no.4
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• pp.249-261
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• 2020

Spermatogonial stem cells (SSCs) have stemness characteristics, including germ cell-specific imprints that allow them to form gametes. Spermatogenesis involves changes in gene expression such as a transition from expression of somatic to germ cell-specific genes, global repression of gene expression, meiotic sex chromosome inactivation, highly condensed packing of the nucleus with protamines, and morphogenesis. These step-by-step processes finally generate spermatozoa that are fertilization competent. Dynamic epigenetic modifications also confer totipotency to germ cells after fertilization. Primordial germ cells (PGCs) in embryos do not enter meiosis, remain in the proliferative stage, and are referred to as gonocytes, before entering quiescence. Gonocytes develop into SSCs at about 6 days after birth in rodents. Although chromatin structural modification by Polycomb is essential for gene silencing in mammals, and epigenetic changes are critical in spermatogenesis, a comprehensive understanding of transcriptional regulation is lacking. Recently, we evaluated the expression profiles of Yin Yang 1 (YY1) and CP2c in the gonads of E14.5 and 12-week-old mice. YY1 localizes at the nucleus and/or cytoplasm at specific stages of spermatogenesis, possibly by interaction with CP2c and YY1-interacting transcription factor. In the present article, we discuss the possible roles of YY1 and CP2c in spermatogenesis and stemness based on our results and a review of the relevant literature.

• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.61-69
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• 1996

Primordial germ cells (PGCs) were manipulated as part of the system to produce transgenic chickens. PGCs were isolated from the germinal crescent of developmental stage 6 to 8 donor emhryos of the Korean Native Ogol Chickens (KNOC). These PGCs were transfected with plasmid DNA containing the lac Z gene by liposome mediated transfection methods. The lac Z gene was transfected and expressed in the PGCs. These transfected PGCs were injected into the germinal crescent of White Leghorn embryos (stage 6 to 8). The injected transfected PGCs migrated via the circulatory system into the future gonad and expression observed in the gonads of 3 day old chick. Of the 47 embryos and 3 day old chickens, one positive PGCs gonad from sacrificed young chickens was detected by appearance of blue cells. Plasmid DNA with the foreign gene was incorporated into the population of germ cells in the gonad. These results demonstrate that PGCs can he transfected and then transferred for colonization into the gonad, and show the potential to ultimately manipulate the genetic material of the chicken gernline.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.98-99
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• 2002

Collection of large number of gonadal Primordial germ cells(gPGCs) is a prerequisite factor for improving germline transmission efficacy in the aves, In this study a magnetic-activated cell sorter(MACS) was applied for improving retrieval efficacy of quail gPGCs and the migration capacity of MACS-separated gPGCs was further examined after being transplanted to recipient embryos. We also induced germline chimeras by transfer of MACS-separated quail gPGCs at the efficiency of 17.4% on average.

• Journal of Chest Surgery
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• v.17 no.3
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• pp.497-504
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• 1984

The malignant germ cell tumor found in the gonad can originate in the anterior mediastinum. Endodermal sinus tumor[Yolk sac tumor] is a kind of malignant germ cell tumor and is derived from extra-embryonic mesoderm. We experienced a case of primary mediastinal endodermal sinus tumor occurred in 22 year old male patient. His chief complaint was anterior chest pain for 2 days. The tumor located in the anterior mediastinum and invaded upper lobe of the deft lung and pericardium. A left upper lobe resection including phrenic nerve and pericardium was performed and the tumor in the anterior mediastinum was excised. The patient has been treated with combination chemotherapy[Cis-platinum, Vincristine, Actinomycin-D, & Cyclophosphamide} and followed up for 4 months with partial remission.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.96-96
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• 2002

Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin, is known to cause toxicity of testis in male rats. To investigate whether apoptosis is involved in ZEA-induced testicular toxicity and to identify the stage and target germ cell type, 10-weeks-old Sprague-Dawley male rats were treated with a single intraperitoneal (i.p.) dose of ZEA (5mg/kg) and euthanized at 3, 6, 12, 24, and 48 h subsequently.(omitted)

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.69-70
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• 2001

Lectins have great potential as to determine the alternation of the distribution of cell surface carbohydrates during cellular development and differentiation. Here, we investigated the presence and distribution of cell surface carbohydrates on chicken primordial germ cells (PGCs) during the migration and gonadal stages using a variety of lectins. A total of six FITC-labelled lectins from several specificity classes were used: ConA (glucose/mannose), WGA (N-acetylglucosamine), STA (N-acetylglucosamine), DBA (N-acetylgalactosamine/galactose), UEA-I (fucose) and PHA-E (oilgosaccharide). As a results, PGC-specific binding was observed in STA. PGCs of migration stage (2.5- and 5.5-day embyos) were STA-positive whereas PGCs of 10-day embryonic gonad were not. The results suggest that N-acetylglucosamine residuse are present specifically in migrating chicken PGCs and changes during development.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.521-529
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• 1996

In an effort to obtain basic data of carbohydrate metabolism during spermiogenesis of the sexually-matured Jindo dog, the glycogen distribution in the testis was investigated by light and transmission electron microscopy. Periodic acid thiocarbohydrazide silver proteinate physical development(PA-TCH-SP-PD) staining method provided better results in the detection of glycogen granules from Sertoli cells and germ cells than the periodic acid schiff(PAS) staining method did. Pre-treatment of the tissue sections with ${\alpha}$-amylase elicited a significant decrease in PA-TCH-SP-PD stained granules, which suggested that the stained granules were of glycogen origin. High concentration of the glycogen granules were observed in the Sertoli cells, especially in its column, sheet-like processes, club-like processes, and tubular processes. The glycogen granules were unevenly distributed in some Sertoli cell columns. These results strongly indicated that the Sertoli cells of Jindo dogs showed vigorous activity of carbohydrate metabolism.

• Advances in pediatric surgery
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• v.19 no.1
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• pp.25-31
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• 2013

성선 외 생식세포종양은 비교적 드물어 모든 생식세포종양의 5% 미만을 차지한다. 주로 천미부생식세포종양이 골반부나 후복막으로 확장된 경우가 대부분이며, 후복막이나 복강 내에 발생하는 생식세포종양은 매우 드물다. 저자는 복부 종괴를 주소로 내원한 18개월 된 여아에서 간 전이를 동반한 복강 내 혼합 생식세포종양을 치료하였다. 복부 초음파 및 전산화 단층촬영에서 복부 좌상사분역에 석회화, 고형 및 지방 성분을 포함하고 있는 낭성 종괴와 간에 1cm 크기의 결절이 관찰되었다. 종괴는 개복 후 제거되었으며, 병리조직학적으로 대부분의 내배엽동 종양과 적은 성숙 기형종으로 구성된 혼합 생식세포종양으로 진단되었으며, 간의 전이병변도 동일하게 진단되었다. 수술 후 항암화학요법을 시행하였으며, 환자는 현재 수술 후 10년이 경과하였으나 재발의 소견은 없다.

• The Korean Journal of Malacology
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• v.26 no.1
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• pp.51-62
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• 2010

The ultrastructures of germ cells and the accessory cells during spermatogenesis and mature sperm ultrastructure in male Gomphina veneriformis, which was collected on the coastal waters of Yangyang, East Sea of Korea, were investigated by transmission electron microscope observations. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves in that it contains a short midpiece with four mitochondria surrounding the centrioles. Accessory cells are observed to be connected to adjacent germ cells, they contain a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in the supplying of the nutrients for germ cell development, while any phenomena associated with phagocytosis of undischarged, residual sperms by lysosomes in the cytoplasm of the accessory cells after spawning was not observed in this study. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylindrical and modified long cone shape, respectively. In particular, the axial filaments in the lumen of the acrosome, and subacrosomal granular materials are observed in the subacrosomal space between the anterior nuclear fossa and the beginning part of axial filaments in the acrosome. The spermatozoon is approximately $50-55{\mu}m$ in length including a long sperm nucleus (about $7.80{\mu}m$ in length), an acrosome (about $1.13{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure. Some charateristics of sperm morphology of this species in the family Veneridae are (1) acrosomal morphology, (2) the number of mitochondria in the midpiece of the sperm,. The axial filament appears in the acrosome as one of characteristics seen in several species of the family Veneridae in the subclass heterodonta, unlikely the subclass pteriomorphia containing axial rod instead of the axial filament. As some characteristics of the acrosome structures, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics belong to the family Veneridae in the subclass heterodonta, unlikely a characteristic of the subclass pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species in the family Veneridae.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2004.07a
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• pp.3-3
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• 2004