• Korean Journal of Poultry Science
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• v.26 no.2
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• pp.109-118
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• 1999

Hen's eggs have been regarded as one of the best animal bioreactors to produce biologically active peptides originated from many organisms including human. Despite the last decade's efforts to produce transgenic chicken for any commercial purposes, the results so far reported are very disappointing, indicating that hen's eggs are very difficult to crack for transgenesis. Comparatively large female gamete with enormous amount of yolk may be one of the major obstacles in achieving a similar feat to those of other vertebrate species including mouse, sheep, fish and frog. The delay or less efficiency evidenced may instruct to try an alternative way of gens transfer into chicken egg. Sperm-mediated gene transfer is one of them, and may require a great deal of understanding of mechanisms involved in early fertilization and embryonic development. In other animals where the technique was successful, basic mechanisms have been well studied and established only by painstaking efforts for decades. This paper discusses the accumulated knowledge on early fertilization mechanism in the chicken and how can this information be utilitzed to find the alternative gene transfer in making transgenic chicken.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.21-28
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• 2007

During early embryo development, Oct-4 is an important transcription factor for the early differentiation the present study was first examined methylation status in distal enhancer and promoter region of Oct-4 during mouse pre-implantation embryo development. In oocyte and sperm, high methylation was observed in both distal and proximal of promoter in Oct-4. Following fertilization relatively high methylation level remained until 8-cell stage embryos, but decreased at the morula and blastocyst stage. Specific gene knock down of Oct-4 by siRNA injection into zygote induced higher methylation rates of both distal and proximal region of promoter of Oct-4. These results suggest a functional link between the DNA methylation status of distal and promoter resign in the Oct-4 gene and the gene sequence-specific transcriptional silencing by exogenous siRNA injection during mouse preimplantation embryos.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.1-8
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• 2008

The testis and epididymis are important organs of the male reproductive system; the functionis to produce, mature, transport, and store sperm. It is important to understand the localization and expressionof specific proteins based for the studies of its physiological processes. In this study, we investigated theexpression and distribution of galectin-3, one of beta-galactoside-binding proteins, in the testis andepididymis of mouse using western blot and imunohistochemistry. Western blot analysis revealed that theexpression of galectin-3, 29 kDa protein, was low in the testis. In the epididymis, high expression wasdetected in the body and tail part, but moderate expression in the head part. By immunohistochemicalanalysis, we found that positive localization of galectin-3 was detected in some myoid cells and Leydigin the epithelium of epididymis, especially in the epithelium of both body and tail of epididymis. Collectively,these results suggest that galectin-3 is constitutively expressed in the testis and epididymis of mouse withvarying intensity, and the role of galectin-3 in the male reproductive organ may be involved in the specificfunction of its structures.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.30-30
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• 2003

The present study examined the developmental ability of embryonic stem (ES) cells aggregated with mouse parthenogenetic embryos. Oocytes obtained from superovulated female mouse (BCF1) were treated with 7% ethanol and 5 $\mu\textrm{g}$/$m\ell$ cytochalasin B (CB) for producing pathenotes and in vitro fertilized with fresh sperm for producing normal embryos. The reporter vector (pNeoEGFP) were inserted into ES cells (129S4/svJae) by electroporation. At the 8-cell stage, in vitro fertilized embryos and pathenotes, which the zona pellucida was removed, were co-cultured with 5~10 ES cells for 4 hr. After in vitro fertilized embryos and parthenotes aggregated with ES cells were incubated to blastocyst stage, and these blastocysts transferred into the uterus of pseudopregnant recipients. The fertilized embryos aggregated with ES cells were successfully developed to offspring, but the parthenotes aggregated with ES cells failed to develop offsprings. However, genomic DNA of ES cells was detected in the pathenogenetic fetus by polymerase chain reactions at 15 day post gestation. In this study, results indicated that parthenotes aggregated with ES cells showed possible development to fetus. In the future, this method may help to produce transgenic chimera from parthenotes aggregated with ES cells.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.217-224
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• 1992

These studies were carried out ot investigate on the transferred embryo development following ultrarapid frozen for 8-cell and morula of in vitro fertilization mouse embryos. The post-thaw embryo survival was evaluated and compared by cell stage of embryos and by equilibration time before ultrarapid freezing. The results obatined were summerized as follows: 1. The effects of equilibration time of 3 vs. 6 minutes before ultrarapid freezing and after thawing on the morphological survival and the viability of 8-cell and morulas embryos were not significant. 2. When the ultrarapid frozen-thawed 32 eight-cell and 33 morula embryos, and 30 fresh blastocysts were transferred to pseudopregnant recipient mice, the number of normal offsprings produced were 9(28.1%), 14(42.4%) and 18(60.0%), respectively. From the above resutls, it was concluded that the optimal conditions of pH osmolality of the media for mouse IVF and embryo culture, and the period of sperm preincubation might be 7.1, 310 mOsm and 120 min., respectively,a nd somewhat high conception rate might be resulted from transfer of frozen embryos of morula stage and fresh embryos of blastocyst stage.

• Korean Journal of Animal Reproduction
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• v.26 no.4
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• pp.353-360
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• 2002

Although successful pronuclear formation and apposition were seen in porcine oocytes following mouse sperm injection, little is known on the morphology of male and female pronuclei following sperm injection. The objective of this study is to describe the ultrastructure of porcine zygote following murine sperm injection in relation to the chronology of pronuclear S phase. At 40h ~ 44h following in vitro maturation, Cumulus cells were removed in TCM-HEPES with 0.1% hyaluronidase. Then, spermatozoa was injected into the cytoplasm of oocytes. After. injection, all oocytes were transferred to NCSU23 medium and cultured at 39$^{\circ}C$ under 5% $CO_2$ in air. Oocytes were fixed in 2% glutaraldehyde in Dulbeccos phosphate-buffered saline and observed by Transmission Electron Microscopy. Nuclear precursor bodies were observed in each pronucleus. A cluster of large and small granules was attached in the nucleolus precursor body. After the apposition of male and female chromatin, chromatin condensation was observed throughout the nucleoplasm and nucleolus precursor bodies and condensed chromatin in contact with clusters of small and large granules and the nuclear envelope were found in apposed pronuclear regions. These results suggest that non-species specific nuclear cytoplasmic interactions take place during pronuclear formation and apposition following sperm injection.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.935-944
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• 2021

It has been suggested that bisphenol A (BPA), a known endocrine disruptor, interferes with the endocrine system, causing reproductive dysfunction. Recently, BPA has been found in waste water due to incomplete sewage purification, possibly threatening health through its ingestion via tap water. In this study, young male mice (6 - 7 weeks old) were administered water containing BPA (50 mg·kg^-1) for four weeks, while control mice consumed water without BPA. Serum, epididymal spermatozoa and testicular sections were assessed after sacrificing the mice on day 28. No significant differences were obtained between the groups in the body, testis and seminal vesicle weights. However, the epididymal sperm motility and count levels were significantly reduced in BPA-fed mice. Significantly higher hepatotoxicity levels were also observed in mice ingesting BPA as compared to the control mice. The level of serum testosterone was reduced, and testicular sections revealed incomplete and irregular spermatogenesis in BPA-ingested mice. The sperm proteasomal-proteolytic activity level has been implicated in sperm function and is measured in motile spermatozoa using fluorometric substrates. High ubiquitin C-terminal hydrolase activity levels were observed in the control mice without BPA. During a mating trial, a low pregnancy rate (71.4%) was observed in females mated with males who had consumed BPA (100% in the control mice). Overall, BPA adversely affected spermatogenesis and quality, as indicated by decreased sperm motility, concentration and serum testosterone levels, resulting in reduced fertility competence.

• 대한생식의학회:학술대회논문집
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• 2005.11a
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• pp.119-119
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• 2005

• Development and Reproduction
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• v.1 no.1
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• pp.57-65
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• 1997

생쥐의 부정소에서 진행되는 정자 성숙과정 동안의 첨체반응 능력의 변화를 조사하였다. 자발적 첨체반응 및 난포액, 프로게스테론, 또는 A23187에 의해 유발되는 첨체반응은 모두 정자의 성숙에 의존저긍로 일어났다. 두부 부정소의 매우 적은 정자만이 난포액 및 프로게스테론에 반응하여 첨체반응을 일으켰으며 체부 및 미부 부정소간에 첨체반응율에 차이가 없었다. 반면 A23187 처리시 상당수의 두부 부정소 정자가 첨체반응을 진행하였다. 이러한 결과에서 두부 부정소를 거쳐 체부 부정소에 도달한 생쥐 정자는 첨체반응 능력을 획득하여 이 과정에서 정자의 원형질막 표면에서는 첨체반응을 유발하는 물질과 상호작용에 필요한 변화가 진행되는 것으로 사료된다. 반면 정자내로의 $Ca^{2+}$ 유입 후 진행되는 막융합과 첨체내용물의 분비에 필요한 능력은 두부 부정소 정자도 일부 갖고 있는 것으로 사료된다.

• Development and Reproduction
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• v.26 no.2
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• pp.59-69
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• 2022

Many efforts have been made to study the expression of aquaporins (AQP) in the mammalian reproductive system, but there are not enough data available regarding their localized expression to fully understand their specific roles in male reproduction. The present study investigated the expression and localization patterns of different AQP subtypes in the adult mouse testes and testicular spermatozoa using an immunofluorescence assay. All the studied AQPs were expressed in the testes and revealed subtype-specific patterns in the intensity and localization depending on the cell types of the testes. AQP7 was the most abundant and intensive AQP subtype in the seminiferous tubules, expressing in Leydig cells and Sertoli cells as well as all stages of germ cells, especially the spermatids and testicular spermatozoa. The expression pattern of AQP3 was similar to that of AQP7, but with higher expression in the basal and lower adluminal compartments rather than the upper adluminalcompartment. AQP8 expression was limited to the spermatogonia and Leydig cells whereas AQP9 expression was exclusive to tails of the testicular spermatozoa and elongated spermatids. Taken together, the abundance and distribution of the AQPs across the different cell types in the testes indicating to their relavance in spermatogenesis, as well as in sperm maturation, transition, and function.