• 한국가축번식학회지
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• 제16권3호
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• pp.261-267
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• 1992

The reproductive performance of SPF ICR mice under single paired mating were examined to get reproductive background data and to establish single paired rotational mating system. The results obtained were as follows : average litter size was 15.4$\pm$2.0 heads ; average weaning rate was 95.7$\pm$4.9% ; sex ratio(male/female) was 1.09$\pm$0.26 ; aveage delivery interval was 23.0$\pm$2.4 days. It was given the largest litter size at the age of 121~150 days and in 2nd~4th parities, but at the age of under 90 days and in 1st parity weaning rate and delivery interval were higher and shorter than those of the other ages and parities, respectively. In sex ratio, the number of male litters was slightly increased from that of female litters. The weaning rate of litters from dams which nuresed 12 litters was the highest among those of different litter sizes, and it was decreased dependent upon increment of litter size. There were no difference among 4 groups for reproductive performance, therefore the present study could have important sources for animal breeders who produce mice using the single paired rotational mating system.

• 한국가축번식학회지
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• 제16권3호
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• pp.277-284
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• 1992

The cattle follicular oocytes matured for 26~28h in culture condition were examined at 4, 5, 6, 7, 8, 10, 12, 14, 16 and 18h after insemination with bull spermatozoa preincubated for 4.5h in the uter isolated from estrous hamsters. After further culture with spermatozoa for 4~18 h, 73~89% of the total oocytes had matured to the second metaphase. None of the follicular oocytes matured in culture, were fertilized 5h after insemination. But when the oocytes were examined at 6, 8, 10, 14 and 18h after insemination, 60, 73, 82, 80 and 87% of oocytes were fertilized, respectively. The majority of the fertilized oocytes had enlarged sperm head at 6h after insemination and a part of the fertilized oocytes begun to develop from enlarged sperm head to male pronuclear stage at 8h after insemination, and most of them developed to male and female pronuclear stage at 10h after insemination. The results suggest that the penetration of spermatozoa into the oocytes may occur earlier than 6h after insemination and development of their pronuclear stage may occur at 8h after insemination.

• 한국동물생명공학회지
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• 제36권4호
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• pp.247-252
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• 2021

Embryo transfer (ET) in the animal is an important procedure to generate genetically engineered animals and conserve genetic resources. For ET experiments in mice, pseudopregnant recipients are usually prepared with proestrus stage of females and vasectomized males. However, this conventional method is inefficient because the size of female colonies should be large to select only the proestrus stage in the estrous cycle and the surgical procedures are required to generate vasectomized males. In this study, we established a simple and efficient protocol to prepare ET recipients using the estrous synchronization with hormone injection and the mating with wild male mice. The delivery rate of ET recipients tended to be increased with estrous synchronization using hormone injection (100%) compared to the conventional method (71%). Further, natural pregnancy of the recipients, induced by mating with a wild male, significantly enhanced the birth rate of ET offspring than the conventional method (33% vs. 13%). Based on the results, we concluded that our new protocol using hormone injection to ET recipients and mating with wild males could be more efficient and simpler compared to the conventional method.

• 한국동물생명공학회지
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• 제37권2호
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• pp.149-154
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• 2022

Busulfan is the most commonly used drug for preconditioning during the transplantation of hematopoietic stem cells and male germ cells. Here, we describe side effects of high doses of busulfan in male mongrel dogs. Busulfan was intravenously administered to three groups of dogs at doses of 10, 15, and 17.5 mg/kg body weight. The total white blood cell, neutrophil, eosinophil, lymphocyte, monocyte, and platelet counts steadily reduced in a dose-dependent manner following busulfan treatment. The white blood cell, neutrophil, and monocyte counts recovered after 6 weeks of busulfan treatment, however, the eosinophil, lymphocyte, and platelet counts remained unaltered. Additionally, there was one fatality in the each of the groups that were administered 15 and 17.5 mg/kg busulfan. The gross lesions included severe hemorrhage in the stomach, intestinal tracts, mesentery and urinary bladder. Microscopic investigation revealed severe pulmonary edema and hemorrhage in the lungs, and severe multifocal to coalescing transmural hemorrhage in the intestines and urinary bladder. These results indicated that treatment with busulfan at doses higher than 15 mg/kg initiates severe bleeding in the internal organs and can have fatal results.

• 한국발생생물학회지:발생과생식
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• 제7권1호
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• pp.35-40
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• 2003

성선자극호르몬 분비호르몬은 시상하부에서 분비되며, 포유동물의 생식에 중추적인 역할을 담당한다. 골든 햄스터는 계절적으로 번식하는 포유동물이며, 생식 활동은 광주기(하루 중 낮의 길이)에 의해 결정된다. 장주기(12.5 시간 이상의 빛)는 생식 능력을 유지시키지만, 단주기(12시간 이하의 빛)는 생식 기능을 억제한다. 성선자극호르몬 분비호르몬과 광주기의 상호 관계를 자세히 조사하기 위하여 랫트 성선자극호르몬 분비호르몬 cDNA를 포함하는 벡터를 여러 농도로 골든 햄스터의 수컷에 주입하고 단주기에 유지하여 생식 활동을 개별적으로 조사하였다. 벡터를 고농도로 처리한 그룹의 골든 햄스터는 기타 실험 그룹에 비해 정소 퇴화가 의미있게(P<0.05) 가속되었다. GnRH의 맥동적 분비가 생식 능력을 유지하는 관점에서 보면, GnRH-cDNA를 포함하는 벡터는 GnRH를 일정하게 고농도로 분비했다고 사료된다. 이 결과는 GnRH를 포함하는 벡터가 뇌하수체 전엽을 desensitization시켜 정소 퇴화를 가속시켰음을 암시한다.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.289-297
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• 2013

Bisphenol A (BPA) is an estrogenic endocrine disrupter. However, depending on a way of treatment, the harmful effects of BPA have not been confirmed. Also, trans-generational effects of BPA on male reproduction are still controversial. Because the reabsorption of testicular fluid in the efferent ductules (ED) and initial segment (IS) is important for sperm maturation, the present study was designed to determine trans-generational effect of BPA administrated orally on expression of water transport-related molecules in the mouse ED and IS. Ethanol-dissolved BPA was diluted in water to be 100 ng (low), $10{\mu}g$ (medium), and $1mg/m{\ell}$ water (high). BPA-containing water was provided for two generations. Expression of ion transporters and water channels in the ED and IS were measured by relative real-time PCR analysis. In the ED, BPA treatment caused expressional increases of carbonic anhydrase II, cystic fibrosis transmembrane regulator, $Na^+/K^+$ ATPase ${\alpha}1$ subunit, and aquaporin (AQP) 1. No change of $Na^+/H^+$ exchange (NHE) 3 expression was detected. BPA treatment at medium dose resulted in an increase of AQP9 expression. In the IS, the highest expressional levels of all molecules tested were observed in medium-dose BPA treatment. Generally, high-dose BPA treatment resulted in a decrease or no change of gene expression. Fluctuation of NHE3 gene expression by BPA treatment at different concentrations was detected. These findings suggest that trans-generational exposure to BPA, even at low dose, could affect gene expression of water-transport related molecules. However, such effects of BPA would be differentially occurred in the ED and IS.

• 한국발생생물학회지:발생과생식
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• 제8권2호
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• pp.69-75
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• 2004

1930년대 이후부터 소위 여성호르몬이라 지칭되는 에스트로겐이 남성 생식에 유해함이 잘 알려져 왔다. 그러나 에스트로겐 수용체를 녹아웃한 형질전환생쥐(estrogen receptor knockout, ERKO)를 사용한 연구들에 의해 에스트로겐이 남성 생식에서 주용한 역할을 담당함이 밝혀졌다. 본 논문의 목적은 정자를 포함한 설치류 수컷 생식기관에서 에스트로겐 수용체의 분포, 발현 및 기능에 대한 근간의 연구들을 요약하고, 아울러 녹아웃 생쥐 모델과 그 표현형에 대한 정보를 제공함에 있다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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• pp.56-56
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• 2001

This study was carried out to investigate on the improvement of fertilizing and developing ability of in vitro matured oocytes from individuals of bulls, sperm type, pretreatment of sperm or oocytes obtained by intracytoplasmic sperm injection(ICSI). 1. The male pronuclear formation and developmental rates of oocytes obtained by ICSI treated individual of bulls were 73.9%-87.0% and 33.3%-60.9%, respectively. 2. The male pronuclear formation and developmental rates of oocytes obtained by ICSI treated fresh and frozen sperm, tail-cutting and tail-scoring sperm were 82.0%, 78.0%, 42.2%, 51.1% and 56.0%, 42.0%, 17.8%, 22.2% respectively. and these values of fresh sperm injection were higher than that of frozen sperm, tail-cutting and tail-scoring. 3. The male pronuclear formation and developmental rates of oocytes obtained by sperm pretreated heparin, BFF(bovine follicula fluid), His, Ca Ionophore(Ⅰ) and Ⅰ ＋ caffeine methods were 66.7%-82.2% and 33.3%-60.6%, respectively. and these values of treatment of Ⅰ＋ caffeine were higher than that of other methods. 4. The male pronuclear formation and developmental rates of oocytes obtained by ICSI treated with or without zona pellucida were 80.0%, 72.0% and 46.0%, 36.0%, respectively.

• 한국초등과학교육학회지:초등과학교육
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• 제24권4호
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• pp.351-359
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• 2005

The aims of this research are to analyze elementary preservice teacher's conception and causes of their misconceptions on biological reproduction and inheritance. In future, it would be also to provide useful data for the effective teaching-teaming method in the elementary school as well as opportunities to correct their misconceptions, which help elementary preservice teachers have the appropriate scientific conceptions. Thirty kinds of test questions were designed in science curriculum for elementary students and biology textbook for university students in order to develop reproduction and inheritance's concepts. The questionnaire was given to 166 junior students of university of education in a local city. All statistical analysis was performed using SPSS version 10.0 program. The major results are as follows: Among 30 test questions, 2 questions in plants, 5 questions in animals and 2 questions in gene were appeared as misconceptions over $50\%$. The major reason to hold the misconceptions was influenced by 'learning up to now' category. The selection reasons of response were significantly different between scientific conceptions and misconceptions in 10 questions by analysis of variance. The gender also showed statistically significant differences between scientific conception and misconception in 3 questions by $\chi^2$ test. The selection reasons according to gender were significantly different between male and female students in 5 questions. For the reasons in forming misconceptions, they may cause by stereotype, conscious priority, differences of experiences, interest or attention, lack of professional Knowledge, and so on. Therefore, it was concluded that this research may help elementary preservice teachers to reconsider their conception for reproduction and inheritance and to be successful in science instructions fur elementary students.

• Animal cells and systems
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• 제11권2호
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• pp.215-225
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• 2007

The azooxanthellate soft coral Dendronephthya suensoni (Holem, 1895) is distributed mainly around Jejudo Island, Korea. This species was determined as gonochoric with a sex ratio of 2:1 (female:male). Both female and male colonies have one gametogenic cycle a year. The annual reproductive cycle of D. suensoni is dependent on the seawater temperature. In particular, reproduction of the male colony showed a higher positive correlation between seawater temperature and the mean diameter of the spermaries. Gametogenesis in females and males took 6 months and 12 months, respectively. The mean diameter of a mature oocyte was $249.29\;{\pm}\;36.24\;{\mu}m$, with a maximum size of $354.45\;{\mu}m$. Spawning could have occurred in the fall after the seawater temperature began to decrease.