• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.91-101
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• 1985

This study was conducted in order to observe the changes in cellular associations of seminiferous tubules from 8 to 20 weeks of age and to obtain the cycle and relative duration of the seminiferous epithelia from 24 to 32 weeks of age. Twenty-eight Korean native male goats were used in the experiment and divided into 7 groups, consisting of 4 goats each, with four weeks intervals from 8 to 32 weeks of age. The results were summarized as follows; 1. Gonocytes were seen at 8 weeks of age, however they were not observed as from 12 weeks. Both type A-spermatogonia and type B-spermatogonia occurred from 8 weeks, while primary spermatocytes were found from 12 weeks. Secondary spermatocytes and spermatids appeared from 16 weeks, and increased in numbers sequentially until 32 weeks of age. Spermatozoa were observed at first at 20 weeks of age. 2. Type A-spermatogonia appeared approximately twice as many at stage 2 as compared to stage 1, while the same numbers of cells were seen in both stages 1 and 8, showing the least number among 8 stages of the cycle of the seminiferous epithelia. The type B-spermatogonia were found during the stage 5 to 8, not to be detactable during stage 1 to 4. The number of primary spermatocytes of the leptotene phase increased markedly during stage 1 to 4, and decreased afterwards. The primary spermatocytes of the pachytene phase were shown the least in number at stage 4. The secondary spermatocytes could be seen only at stage 4 and the largest number of spermatids was seen at the stage 4 among 8 stages. 3. The relative frequencies of each stage among stages 1 to 8 of the cycle of the seminiferous epithelia were 27.5, 17.5, 12.8, 5.8, 8.9, 8.3, 12.0 and 7.2% respectively. 4. Some of the nuclei of Sertoli cells transformed from the "parallel" type to the "perpendicular" type. This evolution took place from stage 1 to 6, when the number of "perpendicular" type nuclei reached a peak and the number was decreased in the rest of the stages. Thus, establishment of spermatogenesis in Korean native goats was completed at the age of 20 weeks.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1347-1354
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• 2006

The aims of this study were to establish a simple and effective method for isolating male germline stem cells (GSCs), and to test the possibility of using these cells as a new approach for male infertility treatment. Testes obtained from neonatal and adult mice were manually decapsulated. GSCs were collected from seminiferous tubules by a two-step enzyme digestion method and plated on gelatin-coated dishes. Over 5-7 days of culture, GSCs obtained from neonates and adults gave rise to large multicellular colonies that were subsequently grown for 10 passages. During in vitro proliferation, oct-4 and two immunological markers (Integrin ${\beta}1,\;{\alpha}6$) for GSCs were highly expressed in the cell colonies. During another culture period of 6 weeks to differentiate to later stage germ cells, the expression of oct-4 mRNA decreased in GSCs and Sertoli cells encapsulated with calcium alginate, but the expression of c-kit and testis-specific histone protein 2B(TH2B) mRNA as well as the localization of c-kit protein was increased. Expression of transition protein (TP-l) and localization of peanut agglutinin were not seen until 3 weeks after culturing, and appeared by 6 weeks of culture. The putative spermatids derived from GSCs supported embryonic development up to the blastocyst stage with normal chromosomal ploidy after chemical activation. Thus, GSCs isolated from neonatal and adult mouse testes were able to be maintained and proliferated in our simple culture conditions. These GSCs have the potential to differentiate into haploid germ cells during another long-term culture.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.3
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• pp.136-148
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• 2010

Cadmium (Cd) is known to exert gonadotoxic and spermiotoxic effects. The present study was performed to investigate the morphological effects and metallothionein (MT) expression by zinc pretreatment in the course of time of cadmium-induced testicular injury in rat. Fifty male Spraque-Dawley rats weighing 160-180 g were divided into two groups: saline-pretreated cadmium group and zinc-pretreated cadmium group. Rats of two groups received subcutaneous injection of saline and 100 mg/kg $ZnSO_4$ at 0, 2, 5 and 8 hrs intervals respectively. Cadmium chloride (4.5 mg/kg $CdCl_2$) was administrated intraperitoneally at 2 hr after zinc injection and rats were killed 0, 12, 24, 48 and 72 hrs later. Testicular tissue damages, Interstitial (Leydig) cells status and MT expression were determined using hematoxylin-eosin stained sections and a computerized image analysis system on sections immunostained with a mouse anti-metallothionein respectively. Zinc pretreatment was significantly reduced testicular damages in five pathological categories after cadmium administation. The number of surviving interstitial cells was significantly higher in the zinc-pretreated group than in the saline-preatreated group at 48 and 72 hrs after cadmium administration. Non-damaged testis showed the positivity of MT staining in spermatogenic cells, Sertoli cells and endothelium of blood vessel, but not in the Leydig cells. The potitivity of MT staining in saline-pretreated group was significantly reduced at 24 hrs after cadmium administration, whereas zinc-pretreated group showed strong MT positive staining similar to the 0 hr by 42 hrs after cadmium administration. In damaged testis, MT positive staining was also observed in the Leydig cells of both groups. These results suggest a major preventive effect of zinc against cadmium-induced testiculat toxicity may be due to its ability to reduce the cytotoxicity of cadmium in spermatogenic cells and Leydig cells by inhibiting the susceptibility of the testis to cadmium but not MT production by cadmium.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.127-137
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• 1996

This study was performed to investigate the toxicity of DA-125 in beagle dogs, an anthracycline antitumor antibiotic. The dogs were administered DA-125 i.v. at 0.0023, 0.0375, 0.15 and 0.6 mg/kg/day, 6 days/week for 26 weeks. At 0.6 mg/kg, all male and female dogs were either sacrificed moribundly or dead during the 26-week treatment. The dogs revealed inactivity, salivation, dark bloody discharge, swelling of the subcutaneous injection site, abscess, and ulceration in the abdominal wall and legs. At 0.15 mg/kg, anorexia, salivation, and swelling of the injection site were observed. The food consumption was decreased with a statistical significance at 6 and 12 weeks treatment in males of 7.6 mg/kg. At 0.0375, 0.15 and 0.6 mg/kg, body weights were decreased significantly in a dose-related fashion after 17 weeks treatment. Total white blood cell counts for male dogs at 0.6 mg/kg were lower than those of control dogs after 13 weeks treatment, which appeared mainly due to decreased neutrophils. At 0.15 mg/kg, testicular atrophy was found in all males by gross pathology and the testicular weights were significantly decreased when compared to those of control males. Microscopically, the testis showed moderate atrophy of the seminiferous tubules and marked decrease in number of spermatozoa in the epididymal tubules. At 0.6 mg/kg, petechia or echymotic hemorrhage was observed in gastrointestinal tract, heart, lungs, and other organs at the necropsy, Marked atrophy of thymus were observed in both males and females. In addition, severe testicular atrophy was noted in all males. Microscopically, gastrointestinal tract showed hemorrhage, epithelial denudation, hypermucus secretion, and atrophy of intestinal villi. Seminiferous tubules of the atrophic testis were lined with Sertoli cells only and devoid of germ cells. Severe oligospermia or aspermia was present in the epididymal tubules. Bone marrow showed marked depletion of hemopoietic cells. In addition, marked atrophy was found in the lymphoid tissue of gastrointestinal tract, various Iymph nodes, and thymus. Injection sites showed marked inflammatory response with necrosis, necrotizing vasculitis, thrombus formation, and ulceration in the skin. According to the present results, no observed effect level appeared to be 0.0375 mg/kg. At 0.15 mg/kg, testis was a target organ, while at 0.6 mg/kg hemopoietic tissue, gastrointestinal tract, and testis were considered to be target organs. At 0.6 mg/kg the test compound seems to inflict a damage on the blood vessels causing hemorrhage in the various organs and tissues.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.613-618
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• 2007

Azoospermia factor(AZFa, b, and c) regions have been focused on their involvement in the spermatogenic process by frequent observation of microdeletion in male infertility. Among the azoospermia factors, RBMY1, CDY1, and VCY2 genes are strongly associated with the male germinal cell differentiation and development in testis. Using RT-PCR approach, expression patterns of RBMY1, CDY1, and VCY2 genes are examined in testicular biopsy specimens from 42 Korean azoospermic patients. No expression of RBMY1, CDY1, and VCY2 genes appeared as 34%, 66%, and 27% of the male infertility, respectively. Patients who had no expression of RBMY1 and VCY2 genes also showed negative expression of the CDY1 gene in their testis tissues. All Sertoli cell-only syndrome patients showed no expression of the CDY1 gene. Taken together, the CDY1 gene expression seems to be necessary factor to complete spermatogenesis in Korean population.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.2
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• pp.121-132
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• 2005

연구목적: 본 연구에서는 비폐쇄성 무정자증 환자에서 나타나는 정자형성과정의 이상과 고환세포의 세포자연사와의 연관관계 여부를 확인하였다. 또한 SELDI-TOF MS 분석을 통하여 고환 내 단백질 발현 양상을 확인하고, 질환에 따른 효과적인 biomarker 개발 가능성 여부를 확인하였다. 재료 및 방법: RT-PCR 및 면역조직화학법을 사용하여 고환에서의 Fas, FasL, Bcl-2, Bax와 Caspase-3의 발현 양상을 확인하고, in situ DNA 3'-end-labelling 방법으로 고환세포의 세포자연사 양상을 확인하였다. SELDI-TOF MS 분석법에 의한 고환의 병리학적 소견에 따른 단백질 발현 변화는 소수성 칩 ($H_4$)을 사용하여 분자량 10~100 kDa 범위 내에서 분석하였다. 결 과: 정상적인 정자형성과정을 보이는 폐쇄성 무정자증 환자의 고환에 비해 지주세포 증후군 (Sertoli cell only syndrome)과 성숙정지 (maturation arrest)를 보이는 고환 내 생식세포와 지주세포에서 세포자연사가 현저하게 증가한 것을 확인할 수 있었다. 세포자연사 관련인자들의 발현 양상을 확인한 결과, 지주세포 증후군과 성숙정지 환자군에서 Fas와 FasL mRNA의 발현이 증가하였으나, bcl-2, bax와 caspase-3 mRNA 발현의 경우에는 두 질환 모두에서 유의한 차이를 확인할 수 없었다. FasL 단백질 발현의 경우, 세포자연사의 증가가 관찰되었던 지주세포 증후군과 성숙정지를 보이는 환자의 간질세포와 지주세포에서 증가하는 양상을 나타내었다. SELDI-TOF MS 분석 결과에서 폐쇄성 무정자증 환자군에 비해 전체적인 단백질 발현양이 지주세포 증후군과 성숙정지 환자의 고환에서 감소하는 양상을 보였으며, 특히, 16.730 kDa 단백질의 현저한 감소를 확인할 수 있었다. 결 론: 본 연구결과를 통해 비폐쇄성 무정자증 환자에서 나타나는 정자형성과정의 장애는 생식세포의 비정상적인 세포자연사와 연관되어 있으며, 고환 내 Fas와 FasL의 비정상적인 발현이 주된 원인인 것을 확인할 수 있었다. 또한, SELDI-TOF MS 분석법을 통한 단백질 발현 양상의 연구는 무정자증 환자에서의 다양한 병리학적 소견을 쉽게 파악할 수 있는 biomarker 발굴뿐만 아니라 질환의 원인규명을 위한 연구에도 유용하게 이용될 수 있을 것으로 사료된다.

• Clinical and Experimental Reproductive Medicine
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• v.45 no.4
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• pp.170-176
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• 2018

Objective: To assess whether the "testicular pool" could be used for histological analysis and whether it gave more accurate information than the standard testicular biopsy. Methods: Between January 2017 and March 2018, this single-center prospective study included 60 azoospermic men undergoing conventional bilateral testicular sperm extraction. Six samples were excised from each testicle and transferred to an embryologist. One additional biopsy was randomly taken from each testis for a histological analysis. After processing, the testicular pool was also sent for a histological analysis, which showed normal spermatogenesis (NS), hypospermatogenesis (HYPO), maturation arrest (MA), Sertoli cell-only syndrome (SCOS), and tubular atrophy (TA). Results: Twenty of the 60 patients (33.3%) had obstructive azoospermia (OA), while the remaining 40 (66.6%) had nonobstructive azoospermia. Their mean age was 40.5 years. All patients with OA had previously undergone unsuccessful testicular fine-needle aspiration. Successful sperm retrieval (SSR) occurred in 93.3% of patients. Histological analysis of the testicular biopsy revealed NS in 12 patients (20%), HYPO and TA in 28 patients (46.6%), MA in eight patients (13.3%), and SCOS in 12 patients (20%). The testicular pool analysis showed NS in 12 patients (20%), HYPO and TA in 44 patients (73.3%), MA in four patients (6.6%), and SCOS in no patients. In four patients with MA (6.6% of the total sample) and 12 patients with SCOS (20% of the total sample) according to the standard testicular biopsy, the embryologist found SSR with cryopreservation. Overall, in 44 patients (73.3%), the testicular pool analysis confirmed the histological findings of the standard testicular biopsy. In the 16 cases (26.6%) with a discrepancy between the single-biopsy histological findings and SSR, the testicular pool analysis confirmed the embryological data on SSR. Conclusion: The testicular pool proved to be easily analyzable, practical, manageable, and more accurate for predicting sperm retrieval than standard testicular biopsy.

• Animal Bioscience
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• v.35 no.3
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• pp.385-398
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• 2022

Objective: The objective was to evaluate the influence of different dietary crude protein (CP) levels during the growth phase on reproductive characteristics and reproductive efficiency as well as the body development of adult male Japanese quail. Methods: Three hundred one-day-old male quails were distributed into five treatments with diets containing different CP levels (18%, 20%, 22%, 24%, and 26%) in a completely randomized design, with six replicates of ten birds each. The CP diets were applied only during the growth phase (1 to 35 days). At 36 days of age, the birds were transferred to 30 laying cages with three males and nine females each, and all birds received the same diet formulated to meet production-phase requirements until 96 days of age. Results: The growth rate of the birds increased linearly (p<0.01) with increasing dietary CP, but the age of maximum growth decreased (p<0.05). At growth maturity, all birds had the same body weight (p>0.05). At 35 days of age, higher weight gain was obtained (p<0.05) with diets containing 22% CP or higher. No effects on feed conversion were observed in this phase. The increase in dietary CP enhanced (p<0.01) nitrogen intake and nitrogen excretion but did not affect (p>0.05) nitrogen retention. Testis size, seminiferous tubular area, number of spermatogonia, and germinal epithelial height at 35 days of age increased linearly (p<0.05) with dietary CP, while the number of Leydig cells decreased (p<0.01). The Sertoli cell number at 60 days of age increased linearly (p<0.01) with dietary CP. Dietary CP levels did not affect cloacal gland size, foam weight, foam protein concentration, semen volume, or flock fertility at 90 days of age. Conclusion: Dietary CP concentration affected body and testicular development in male Japanese quails but did not affect reproductive efficiency.