• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.168-168
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• 2004

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.08a
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• pp.38-38
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• 2001

TM4 Sertoli cell의 체외 관강형성 유도에 미치는 세포외기질 (ECM) 및 hepatocyte growth factor (HGF)의 역할과 세포분화 과정에서 MMP의 발현의 변화를 조사하였다. Matrigel bed(60%, v/v) 상에서 배양한 TM4 cell은 무혈청 조건하에서 chain 분화단계를 거쳐 cord의 구조로 분화하였다. 그러나 이후의 분화는 일어나지 않았다. TM4 cell에서 c-MET (HGF receptor)의 발현을 확인하였으며 HGF를 첨가한 배양액에서 분화가 촉진되었으며, cord에서 tubule로의 분화가 유도되었다. 또한 TM4 cell의 분화는 MMP-2 및 MMP-9의 발현이 증가를 수반하였으며 HGF는 MMPs의 발현을 증가시켰다. GFR-Matrigel과 성장인자인 HGF는 무혈청 배지에서 TM4 cell의 체외에서 관강형성에 필요한 환경을 제공하며, MMP-2 및 -9은 TM4 cell의 체외분화 과정에서 조절역할을 수행하는 것으로 사료된다.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.435-445
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• 1990

Gonadotropin releasing horrnone (GnRH) is known to be extrahypothalamically localized with a broad range including gonad. It remains, however, unknown whether GnRH is locally synthesized in the gonad. The present srudy aims to identity expression and cellular localization of GnRH-Iike mRNA and immunoreactive GnRH in the rat gonad. GnRH radioimmunoassay and chromatographic extracts on G-50 sephadex column showed that rat gonadal extracts contained a substantial amount of immunoreactive GnRH similar to the hypothalamic and synthetic GnRH. Although a wide distribution of immunostainable GnRH-like molecule with different cell types in the rat ovary was observed, the major cell population hybridized with GnRH probe appears to be granulosa. theca cells and corpus luteum. Immunoreactive GnRH-Iike peptides were distributed m various regions of testis, including spermatogenic cells, Sertoli cells and Leydig cells. In situ hybridization revealed that positive signals of GnRH-Iike mRNA were predominandy present in Sertoli cells within some seminiferous tubules, but absent in the outside of seminiferous tubules in the testis. This study clearly demonstrated that GnRH-Iike molecule present in the rat gonad may be resulted from the local synthetic machinery of GnRH supporting the notion that this peptide may act as autocrine and/or paracrine role in intra-gonadal communication.

• Applied Microscopy
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• v.41 no.3
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• pp.179-188
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• 2011

Ultrahistology of spermatogenic cells on spermatogenesis were analyzed from triploid males of the mud loach, Misgurnus mizolepis. All the testis of triploid males were smaller in thickness and shorter in length than those of diploid males, but the testes developmental stages in triploid males were very similar to those of diploid males. And cytological characteristics were also almost identical to each other. Also Sertoli cells with high activity were recognized at intralobuli of the testis in triploid males during the period of spermiogenesis. And then a few matured spermatozoa were observed in testis of triploid, and interstitial cells also appeared high active in interlobuli. But nucleus sizes of spermatogenic cells of triploid male according to developmental stages were larger than those of diploid overall. Especially, spermatozoa of triploid showed abnormal morphology such as two or more tail flagella, significantly larger head sizes, nucleus size, and diameter of axial filaments etc. than those from diploid.

• Archives of Pharmacal Research
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• v.24 no.4
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• pp.360-366
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• 2001

Gangliosides are ubiquitous membrane components in mammalian cells and are suggested to play important roles in various functions such as cell-cell interaction, adhesion, cell differentiation, growth control and signaling. Among all ganglio-series gangliosides, GM3 has the simplest carbohydrate structure, and has been shown as a major gangliosides, in male reproductive system. To study GM3 distribution in the seminiferous tubule and epididymis, frozen sections were stained with specific monoclonal antibody (MAb) against ganglioside GM3. In the seminiferous tubule of testis, pachytene spermatocytes and spermmatids expressed ganglioside GM3, but not in spermatogonia and sertoli cells. Spermatogonia and sertoli cells near the basement membrane were negatively reacted to anti-GM3. In the epididymis, GM3 was expressed only in some interstitial cells. Taken togethers, these results suggest that the expression of ganglioside GM3 in rat seminiferous tubule and epididymis is spatio-temporally regu lated during spermatogenesis.

• Applied Microscopy
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• v.33 no.1
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• pp.25-39
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• 2003

Cell differentiation and ultrastructural characteristics in the seminiferous epithelium of Myotis macrodactylus was investigated with the light and electron microscopes. Spermatogenesis has begun at April and finished at September. The nuclei of A spermatogonia (dark and pale type of spermatogonia) were oval, applied to the basal lamina, and surrounded by Sertoli cells. By comparison with other types of spermatogonia, the cell and nucleus of B type of spermatogonium is globular and larger than A types of spermatogonia. The nucleolus appears as a coarse and touches the nuclear membrane. The cell and nucleus of spermatocytes was globular and larger, but primary spematocyte is larger than secondary spermatocyte. Spermiogenesis was divided according to the level of fine structural difference, into Golgi, cap, acrosomal, maturation and spermiation phases; Golgi, cap, acrosomal and spermiation phases were further subdivided into steps of early and late phase respectively, and maturation phase has only one step. Hence, the spermiogenesis has been divided into a total of nine phases. In the change of karyoplasm, the chromatin granules are condensed at late Golgi phase and completed at spermiation phase. The sperm tail began to develop in early Golgi phase and completed in spermiation phase. The process of degeneration of spermatogenic cells in the seminiferous tubules was continually observed from October, before the beginning of hibernation, to hibernation phase (November, December, January, February, March). Immatured spermatogenic cells in the seminiferous tubules have been engulfed by phagocytosis of Sertoli cells during period of degeneration. It is deduced that the adaptative strategy serves as the mechanism to regulate the effective use of energy to prepare for long hibernation and regulation of breeding cycle.

• Development and Reproduction
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• v.1 no.2
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• pp.125-132
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• 1997

To investigate the cadmium (Cd) toxicity on the testis, male rats were treated with 1, 2, 4 and 8 mg/kg of Cd by IP. According to histochemical studies, Cd-treated testis tissue showed death of spermatozoa, death of Sertoli cells, death of all the spermatogenic cells, and finally disappearance of basal lamina of seminiferous tubules with increasing doses, and showed decreased ground substances and Leydig cells, increased inflammatory cells and fibroblasts, and fibroblasts, and finally disappearance of ground substances and all the cells except fibroblasts within interstitial tissues with increasing doses. According to biochemical studies, two kinds of proteins, 25 and 45 kDa, were dramatically disappeared from the total protein of rat testis treated with Cd comparing to normal testis. The result of electrophoresis of total protein suggests that actin (45 kDa), presumed on its mmolecular weight and amount, in the testis-cells is the primary target of Cd poisoning. Although its exact mechanism is not clear, the disappearance of two proteins when testis is exposed to Cd should give some clues to understnad the mechanism of necrosis of testis tissue crumbling by heavy metal pollutant such as Cd.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.311-318
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• 2006

Ultrastructure of germ cells, the cyst epithelial cells and interstitial cells during spermatogenesis of the stone flounder, Kareius bicoloratus (Pleuronectidae) sampled on the west coast of Korea were investigated by electron microscopic observations. In the primary spermatocyte, the synaptonemal complexes appear in the zygotene stage of the prophase during maturation division. In the growing testis, especially, the interstitial cells (Leydig cells) appear near the primary, secondary spermatocytes and spermatids. Well-developed interstitial cells (steroid hormone secreting cells) which are located in the interlobular space in growing testis have three morphological characteristics of a vesicular nucleus, mitochondria with tubular cristae and smooth endoplasmic reticulum. During spermatogenesis, the primary and secondary spermatocytes attach to the cyst epithelial cell (Sertoli cell) having an elongated ovoid or triangular nucleus and several mitochondria in the cytoplasm. In the growing testis, lipid droplets, the mitochondrial rosettes and glycogen particles appear in the cytoplasm of the cyst epithelial cells near the secondary spermatocytes and spermatids. Particularly, the mitochondria, endoplasmic reticulum, little lipid droplets and the large amount of glycogen particles are present in the cytoplasm of the cyst epithelial cell in the late growing testis. In the late stage of spermiogenesis, the proximal centriole is joined to the nuclear envelope, the distal centriole forms the basal body of the flagellum and gives rise to the axial filament of the flagellum. No acrosome of the sperm is formed as seen in other teleost fish. The head of the spermatozoon is approximately $3{\mu}m$ in length and its tail is about $30{\mu}m$ in length. The axoneme of the tail flagellum of the spermatozoon consists of nine outer doublet microtubules at the periphery and two centrial singlet microtubules at the center. The spermatozoon of this species has two axonemal lateral fins. Especially, the cyst epithelial cells which located near groups of gametes in the various stages, show three functions: nutrition, phagocytosis and steroidogenesis. Especially, the nuclei of cyst epithelial cells in the recovery stage of the testicular developmental stages appear to be irregular in shape after spermiation. Of three functions of the cyst epithelial cell, several characteristics of phagocytosis are showed in the cytoplasm of the cyst epithelial cells in the recovery stage of the testicular developmental stages. At this stage, therefore, it is assumed that the cyst epithelial cells are involved in degeneration and resorption of undischarged germ cells after spermiation.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.107-111
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• 2016

Sex cord tumors with annular tubules are known to originate from the sex cord of embryonic gonads that synthesize Sertoli cells, Leydig cells, granulosa cells, and theca cells of the ovarian stroma, while ovarian small cell carcinoma of the hypercalcemic type is a type of neuroendocrine tumor. Both these tumors are uncommon, potentially malignant neoplasms in children. We report the case of a sex cord tumor with annular tubules in an 11-year-old girl and a case of small cell carcinoma of the hypercalcemic type in a 10-year-old girl. We also discuss the prognosis and management of these tumors.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.654-670
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• 2022

Spermatogenesis and testis development are highly structured physiological processes responsible for post-pubertal fertility in stallions. Spermatogenesis comprises spermatocytogenesis, meiosis, and spermiogenesis. Although germ cell degeneration is a continuous process, its effects are more pronounced during spermatocytogenesis and meiosis. The productivity and efficiency of spermatogenesis are directly linked to pubertal development, degenerated germ cell populations, aging, nutrition, and season of the year in stallions. The multiplex interplay of germ cells with somatic cells, endocrine and paracrine factors, growth factors, and signaling molecules contributes to the regulation of spermatogenesis. A cell-tocell communication within the testes of these factors is a fundamental requirement of normal spermatogenesis. A noteworthy development has been made recently on discovering the effects of different somatic cells including Leydig, Sertoli, and peritubular myoid cells on manipulation the fate of spermatogonial stem cells. In this review, we discuss the self-renewal, differentiation, and apoptotic roles of somatic cells and the relationship between somatic and germ cells during normal spermatogenesis. We also summarize the roles of different growth factors, their paracrine/endocrine/autocrine pathways, and the different cytokines associated with spermatogenesis. Furthermore, we highlight important matters for further studies on the regulation of spermatogenesis. This review presents an insight into the mechanism of spermatogenesis, and helpful in developing better understanding of the functions of somatic cells, particularly in stallions and would offer new research goals for developing curative techniques to address infertility/subfertility in stallions.