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

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.96-97
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• 2002

Primordial germ cells (PGCs) are the progenitors of the sperms or eggs of adult. Evidence suggests that the specification of primordial germ cells (PGCs) in the mammalian embryo does not depend on maternal determinants. Recent previous studies in the mouse has shown that several bone morphogenetic proteins (BMPs) are required for the formation of PGCs. However, there is no study about the effect of BMPs on avian PGCs. Here, we studied the effects of recombinant human BMP-2 (rhBMP-2) and recombinant human BMP-4 (rhBMP-4) on chicken blastodermal cells in culture. As a results, the addition of rhBMP-2 and rhBMP-4 increased the number of SSEA-1 positive cells in dose-dependent manner. However, there is no synergic effect by using both rhBMP-2 and rhBMP-4.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.333-342
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• 2018

Intracranial germ cell tumors (iGCTs) are a heterogeneous group of tumors with peculiar characteristics clearly distinguished from other brain tumors of neuroepithelial origin. Diverse histology, similarity to gonadal GCT, predilection to one sex, and geographic difference in incidence all present enigmas and fascinating challenges. The treatment of iGCT has advanced for germinoma to date; thus, clinical attention has shifted from survival to long-term quality of life. However, for non-germinomatous GCT, current protocols provide only modest improvement and more innovative therapies are needed. Recently, next-generation sequencing studies have revealed the genomic landscape of iGCT. Novel mutations in the KIT-RAS-MAPK and AKT-MTOR pathways were identified. More importantly, methylation profiling revealed a new method to assess the pathogenesis of iGCT. Molecular research will unleash new knowledge on the origin of iGCT and solve the many mysteries that have lingered on this peculiar neoplasm for a long time.

• Applied Microscopy
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• v.23 no.1
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• pp.125-138
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• 1993

This study was carried out to investigate the effects of cadmium chloride on the spermatogenesis of male mouse. Cadmium chloride was administered as a single dose of 5mg/kg body weight by intraperitoneal injection. The testes were isolated from the experimental animals at 3 hours, 8 hours, 12 hours, and 24 hours respectively after administration of cadmium chloride. The major changes in ultrastructures of the seminiferous tubules observed after cadmium chloride administration include dilation of smooth endoplasmic reticulum, swelling of mitochondria and vacuolation in cytoplasm of the germ cells. Especially, cadmium chloride caused direct damages to spermatogonia such as degeneration of nuclei, nuclear membrane and plasma membrane. In addition, necrotic changes were observed in most germ cells at 24 hours after cadmium chloride administration. Therefore, it seems clear from these results that cadmium chloride induces acute irreversible degenerative changes in the seminiferous tubules of the mouse testis, so that the cadmium chloride ultimately causes necrosis in germ cells at all stages of the spermatogenesis.

• Fisheries and Aquatic Sciences
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• v.6 no.2
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• pp.51-58
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• 2003

The gonadal development and the gametogenic cycle and the fine structure of ripe germ cells of the cultured Pacific oyster, Crassostrea gigas were investigated using oysters monthly collected from the southern coast of Korea from October 2000 to September 2001. Monthly changes in the condition index were similar to that of meat weight rate and the highest value was observed in between April and May, and the lowest value in August. The external colors of the testis and the ovary were milky white and yellowish, respectively. The spawning period of the Pacific oyster was continued from May to September, with a peak in July. The gametogenic cycle could be classified into five successive stages: multiplicative stage (December to March), growing stage (March and April), mature stage (April to June), spawning stage (June to August) and resting stage (August to January). Variety of egg yolk granules, lipid granules, mitochondria, and endoplasmic reticula were observed in cytoplasm of ripe oocyte. The spermatozoon consisted of the head, middle piece and tail; including cap-shaped acrosome with domed structure, elliptical shaped nucleus, four mitochondria, two centrioles and flagellum.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1514-1517
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• 2000

In chicken, exogenous genes introduced into germinal crescent region (GCR) of the early developmental stage, where primordial germ cells (PGCs) were concentrated, were successfully transferred to the gonads via PGCs. The foreign genes were also confirmed to be successfully incorporated into F1 and F2 generations. We tried to incorporate the exogenous genes into PGCs by lipofection, then the DNA mixture was injected into GCR at stage 3-5 or 9-11 of embryonic development (Hamburger and Hamilton, 1951). The manipulated eggs were incubated, and hatched chicks were reared until sexual maturation. F1 generation was obtained from the DNA-treated chicken (DNA-chicken) mated with normal birds. Furthermore, F2 generation was also obtained from the F1 chicken mated with normal birds. The transfer of introduced foreign genes were confirmed by marker gene detection methods and PCR analysis in the hatched chicks, F1 and F2 generations. However, in our experiments, DNA-chickens showed abnormal characteristics such as low egg production rate, abnormal appearance and decreased number of spermatozoa. In the case of F1 chicken, low egg production and the deterioration of sperm capacity for insemination in male chicken were observed.

• Molecules and Cells
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• v.26 no.6
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• pp.621-624
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• 2008

We previously showed that Asb-4 and Asb-17 is uniquely expressed in developing male germ cells. A recent report showed that Asb-9 is specifically expressed in the kidney and testes; however, detailed expression patterns in developing germ cells have not been shown. Northern blot analysis in various tissues demonstrated that mAsb-9 was strongly expressed in the testes. Expression analysis by RT-PCR and Northern blot in developing mouse testes indicates that mAsb-9 is expressed from the fourth week after birth to adulthood, with the highest expression in round spermatids. Expression sites were further localized by in situ hybridization in the testes. Pachytene spermatocytes and spermatids expressed mAsb-9 but spermatogonia and generated spermatozoa did not. This study reveals that mAsb-9 could be a specific marker of active spermatogenesis and would be useful for studies of male germ cell development.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.557-562
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• 1995

In this study, characteristics of chick primordial germ cells (PGCs), which is the founder cell of the germline, and gonadal development of the chick embryo between 12hrs and 6 day of incubation were investigated by transverse serial sections of chick embryos under the light microscopic observation. In embryo stage 20 (3 day of incubation), there are a lot of PGCs at the mesenchym, which were moving to the thickened epithelium (gonadal ridge). The PGCs arrive at both right and left gonad primordial in equal number prior to stage 24 (4 day of incubation), but in the following stages, the distribution of the PGCs became asymmetrical. More PGCs colonized the left than the right gonad, but the reason for the unequal distribution of PGCs is uncertain. The PGCs have mostly settled in the gonadal ridge (GR) at 6 day embryo. This study was conducted to investigate characteristics of the PGC migration and gonadal formation and observe the best condition for PGC isolation, culture and to attempt the possibility of the production for transgenic germline chimeras with manipulated PGCs.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7731-7735
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• 2014

Colorectal cancer (CRC) is the third most common cause of death due to cancer in the worldwide and the incidence is also increasing in Turkey. Our present aim was to investigate any association between germ-line methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and CRC risk in Turkey. A total of 86 CRC cases and 212 control individuals of the same ethnicity were included in the current study. Peripheral blood-DNA samples were used for genotyping by StripAssay technique, based on the reverse-hybridization principle and real-time PCR methods. Results were compared in Pearson Chi-square and multiple logistic regression models. The MTHFR 677TT (homozygous) genotype was found in 20.9% and the T allele frequency 4.2-fold increased in CRC when compared with the control group.The second SNP MTHFR 1298CC (homozygous) genotype was found in 14.0% and the C allele frequency 1.4-fold elevated in the CRC group. The current data suggest strong associations between both SNPs of germ-line MTHFR 677 C>T and 1298 A>C genotypes and CRC susceptibility in the Turkish population. Now the results need to be confirmed with a larger sample size.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.187-193
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• 2009

The present study identified the favorable conditions for isolation, enrichment and in vitro culture of highly purified, undifferentiated pig spermatogonial stem cell (SSC) lines that proliferate for long periods of time in culture. The colonies displayed morphology similar to miceSSC and were positive for markers of SSC (PGP9.5), proliferating germ cell (PigVASA), pre-meiotic germ cell (DAZL) and pluripotency (OCT4, SSEA-1, NANOG, and SOX2) based on immuno-cytochemistry and RT-PCR. The purity of these colonies was confirmed by negative expression of markers for sertoli cell (GATA4 and SOX9), peritubular myoid cell (${\alpha}$-SMA), differentiating spermatogonial and germ cells (c-KIT). The colonies could be maintained with undifferentiated morphology for more than two months and passaged more than 8 times with doubling time between 6-7 days. Taken together, we conclude that pigSSC could be successfully isolated and cultured in vitro and they possess characteristics similar to miceSSC.