• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.305-315
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• 2001

In this study, the production of transgenic embryo was attempted by microinjection or round spermatid cultured with foreign DNA. At first, the expression of haploid spermatids specific gene, mTP1 in mouse and hPrm2 in hamster spermatids were investigated by RT-PCR method in testes of young mice and hamster testis. The specific gene expression first appeared at 18 days post partum (dpp) in mice spermatid and 20 dpp in hamster spermatid. Therefore, the round spermatids isolated from 17 dpp mice and 19 dpp hamster were used for the introduction of foreign EGFP gene into haploid round spermatids. For the introduction of EGFP gene haploid round spermatids suspended in medium including EGFP gene were treated with a different electric field strength at 0.11, 0.18 and 0.44 ㎸/cm. After electrical stimulation, viability of testicular sperm cells and 67.6%, 66.4% and 49.9%, in mice and 62.6%, 57.9% and 27% in hamster, respectively. These values were significantly lower than those of non-treated control groups 80.5% in mouse and 69.1% in hamster After 72 hrs culture, the highest expression rate of EGFP gene, 28.5% in mice and 32.1% in hamster were obtained from tile spermatogenic cells electroporated by the field strength or 0.18 ㎸/cm. Then, the ability of fertilization and embryonic development of haploid spermatids transfected with foreign EGFP gene were estimated by the microinjection of spermatids into hamster oocytes. The Irate pronuclear formation rate (77.5%) was lower than non-treated control (80%), and the cleavage rate of the treated group (58.8%) was lower than control (65%). To prove the foreign EGFP integration in hamster embryos, 2-cell stage hamster embryos were subjected to the observation under the fluorescence microscope, and the PCR analysis. As a result, about 44% of 2-cell embryos were showed the integration of EFGP gene into their genome. Therefore, These results suggest the possibility to produce transgenic hamsters by microinjection of haploid spermatid transfected with foreign DNA.

• Development and Reproduction
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• v.11 no.1
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• pp.31-41
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• 2007

The spermiogenesis of Crocidura shantungensis were studied by electron microscope. All process of spermiogenesis was divided into 11 phases 15 steps, based on the morphological features of the nucleus and cell organelles in cytoplasm of spermatids. The spermatids in Golgi and cap phases were a spherical shape. On the other hand, at the early acrosomal phase they changed into an oval shape, and the tail was created in this phase. In maturation phase, the shapes of spermatid head were thin and longish. Until step 7 the direction of spermatids head turned toward the lumen of the seminiferous tubule. From step 8 to step 15 their heads turned toward the basal lamina. In step 12, the nucleus and acrosome shown maximal elongation. From Step 13 the nucleus of spermatids became flat, simultaneously with flat expansion of the acrosome expanded, and the visible whole lengths of spermatids were tend to be shorten. Spermatid heading which arrived to step 14 was taken the final shape. The nucleus was doing the wedge shape, and the nuclear chromatins condensed completely and homogenized. In the spermiation phase, the spermatids were gradually disconnected from the cytoplasm of the Sertoli cell. In this phase, the acrosome of the spermatids were fully shorten and flat, and the spermatozoa completed the process of heading and the tailing. Considering all the results, the spermiogenesis may be useful information to analyze the differentiation of spermatogenic cells.

• Applied Microscopy
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• v.30 no.4
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• pp.403-412
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• 2000

Urechis unicinctus spermatogenic cells, sperm and spermatids, prepared from testis are investigated to identify nuclear actin using amoeba monorlonal anti-actin as the first Ab and gold particles (10 nm) conjugated mouse IgG (immunogold) as the Ab marker. The Ag-Ab reactions analyzed the localization of nuclear actin of the spermatogenic cells and the immunogold particles incorporated mainly with nuclear matrices. A few immunogold particles are merged into the acrosomes and the other architectures of spermatogenic cells, such as mitochondrion and centrioles. It is often observed and there is a tendency in which the incorporated immunogold particles are increased in number in the nuclear matrices of sperm compared with that of spermatids The increments and decrements of the incorporated immunogold particles according to developmental stages and the spermatogenic architec-tures are interpreted and discussed in aspect of acrosomal function and of nuclear condensation of spermatids.

• Development and Reproduction
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• v.17 no.2
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• pp.87-97
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• 2013

The seminiferous epithelium cycle and developmental stages of spermatids in Clethrionomys rufocanus were observed under a light microscope. The seminiferous epithelium cycle was divided into 8 stages. Type Ad spermatogonia appeared through all stages. Type Ap, In, and B spermatogonia appeared in stages I, II, III, and IV. In the first meiosis prophase, the leptotene spermatocytes appeared from stage V, the zygotene spermatocytes in stages I, VI, VII, VIII, the pachytene spermatocytes from stages II to VI, the diplotene spermatocytes in stage VII. The meiotic figures and interkinesis spermatocytes were observed in stage VIII. Developing spermatids were subdivided into 10 steps, based on the morphological characteristics such as the acrosome formation changes in spermatozoa, nucleus, cytoplasm, and spermiation changes. The C. rufocanus spermatocytogenesis and spermiogenesis results displayed similar results with Apodemus agrarius coreae and A. speciosus peninsulae. Considering all the results, the spermatogenesis may be useful information to analyze the differentiation of spermatogenic cells and the breeding season.

• Biomedical Science Letters
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• v.10 no.3
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• pp.275-283
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• 2004

The annual changes in testis weight and diameter of seminiferous tubules, and the seminiferous epithelium cycle of Tamias sibiricus were studied by light microscope. Testis weight and diameter of seminiferous tubule are significantly increased from January to July, and decreased rapidly to the size from August to December. Spermatogenesis occurs from January to July, and spermatocytogenesis are produced from August to December. The cycle of the seminiferous epithelium was divided into 12 stages during the development of spermatids as a changes of the nucleus and acrosomal structure, presence and/or absence of residual body, appearance and/or absence of sperm tail and meiotic figure and spermiation. The dark type spermatogonia (Ad) are appeared in all stages (I ~ XII), and the spermatids of step 10 are observed at I, II, X and XII stages. The spermatids of step 11 are appeared in III and IV stages, only the step 12 spermatid observed in V stage.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.39-39
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• 2001

Effects of Barodon$^{(R)}$ on body growth, histological changes in seminiferous tubules of testes and serum level of testosterone and FSH were examined in juvenile rats from 5 to 38 wks of age. All rats supplied feed and Barodon-added water(0, 0.1, 0.15, 0.3 and 1.0%) available ad libitum. DNA distribution of testicular cells from control rats obtained by flow cytometry was characterized by 4 peaks representing I : elongated, II round spermatids(1N), III: a variety of 2N cells and IV: 4N cells. Frequencies of 4 testicular cell types were calculated using cumulative DNA frequency distributions. Body growth from 18wk of age was significantly accelerated in rats supplied water with 0.15% Barodon compared to other groups. Testes weights tended to be greater in 0.15% Barodon-treated rats than in control, without significant difference. Diameter of seminiferous tubules advanced in 0.15-0.3% Barodon till 26 wk of age, but there was not significant different. Proportion of spermatids in seminiferous tubules was 48.4% at 6wk of age(round: 81.2% and elongated: 18.8% as proportion of total spermatids) and frequency of spermatids was higher in 0.3% Barodon group(57.1%) than in control(44.0%), but there was no significant difference. Serum testosterone of all groups significantly elevated at 18wk of age and level in 0.15% Barodon group was greatly higher than in others. Serum FSH at 10wks was greatly higher in 0.1-0.3% Barodon groups compared to control, but there were no significant differences. It is concluded that 0.15-0.3% Barodon treatment tended to induce precocious puberty in rats.

• Animal cells and systems
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• v.9 no.2
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• pp.65-73
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• 2005

In this study, we found that sperm ball of Urechis unicinctus consisted of a somatic cell and spermatogenic cells. After separation from the sperm ball, individual spermatid floated freely in the coelomic fluid and differentiated into a mature sperm. Because of many nuclear vacuoles, spermatid nucleus was observed to be heterogeneous. Later, the spermatid nucleus condensed into the homogeneous round nucleus of the mature sperm. Perinuclear microtubules could be seen but did not seem to be organized into manchette microtubules. To understand the nature of nuclear condensation during spermiogenesis, the sperm and spermatids (spermiogenic cells) were treated with FITC-phalloidin, or anti-actin-FITC, or labeled with antiactin immunogold particles (AAIP; 10 nm) followed by transmission electron microscopy or confocal laser scanning microscopy. The anti-actin-FITC and FITC-phalloidin reactions occurred distinctly in the nuclei of both spermiogenic cells. FITC-phalloidin reacted more intensely with acrosomes. The AAIP were incorporated mainly into nuclei of both cells sometimes showing local distribution in the nucleus. Nuclear vacuoles of spermatids disappeared progressively with condensation of the nucleus, as the number of incorporated $AAIP/{\mu}m^2$ increased. These results suggest that nuclear actin microfilaments might be closely related to nuclear condensation.

• Biomedical Science Letters
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• v.13 no.1
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• pp.61-69
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• 2007

The cycle of the seminiferous epithelium and the development of spermatids of Apodemus agrarius coreae were observed using a light microscope. The cycle of the seminiferous epithelium was divided into 10 stages, and developing spermatids were subdivided into 10 steps. The Golgi phases occurs the first two steps ($St_1,\;St_2$), and the cap phases had the next two consecutive steps ($St_3$ and $St_4$). The acrosomal phases consisted of steps $5{\sim}8$ ($St_5-St_8$), and the remaining two steps consisted the maturation ($St_9$) and spermiation ($St_{10}$) phases, respectively. Type Ad spetmatogonia are appeared in all stages (I-X). Type Ap spermatogonia appeared from stage I and II, In spermatogonia from stage III, IV and V, and B spermatogonia from stages VI. The leptotene spermatocytes appeared from stage VII, zygotene from stages I, II, VIII, IX and X, pachytene from stage III to VIII, diplotene in stage IX, and meiotic figures and secondary spermatocytes in stage X. These data are considered in relation to interspecific differences in sperm morphology.

• Applied Microscopy
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• v.31 no.3
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• pp.257-266
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• 2001

To investigate the process of spermoigenesis and glycogen effect during the spermatogenesis of Rana catesbeiana, the morphological characteristics of the testes were examined by light and transmission electron microscopy. Spermiogenesis of R. catesbeiana was divided into three stages on the basis of the features of the nucleus and the cytoplasm organelles. Except for the primary spermatogonia, the phases from the spermatocytogenesis to the spermatids before spermiation phase were surrounded by spermatocyst. Especially , the glycogen particles were not observed until in the stage of spermatocytogenesis, but from the early spermatids to the maturation phase were observed in the nucleus, acrosome and cytoplasm of the spermatids. The present result suggests that the glycogen may play an important role in the sperm maturation, and as a source of the energy in the wave-movement of sperm tail.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.7
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• pp.944-951
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• 2016

Tdrd12 is one of tudor domain containing (Tdrd) family members. However, the expression pattern of Tdrd12 has not been well studied. To compare the expression levels of Tdrd12 in various tissues, real time-polymerase chain reaction was performed using total RNAs from liver, small intestine, heart, brain, kidney, lung, spleen, stomach, uterus, ovary, and testis. Tdrd12 mRNA was highly expressed in testis. Antibody against mouse TDRD12 were generated using amino acid residues SQRPNEKPLRLTEKKDC of TDRD12 to investigate TDRD12 localization in testis. Immunostaining assay shows that TDRD12 is mainly localized at the spermatid in the seminiferous tubules of adult testes. During postnatal development, TDRD12 is differentially expressed. TDRD12 was detected in early spermatocytes at 2 weeks and TDRD12 was localized at acrosome of the round spermatids. TDRD12 expression was not co-localized with TDRD1 which is an important component of piRNA pathway in germ cells. Our results indicate that TDRD12 may play an important role in spermatids and function as a regulator of spermatogenesis in dependent of TDRD1.