To preserve genetic materials, cryopreservation of the semen from live animals is the main technique to establish cryo-banking system which could be used for artificial insemination and embryo transfer. However, the population of Korean black goat (KBG) becomes to dwindle in number and is now faced genetic erosion by crossbreeding with non-native breeds in small KBG farms. In this study, simple freezing method was used to preserve frozen semen from KBG using spermatozoa of cauda epididymis (CE) and electro-stimulated semen (ES). The negative effects of seminal plasma on fresh sperm was confirmed using precipitation test of Triladyl egg yolk diluent and sperm viability after thawing was compared between CE and ES spermatozoa. When seminal plasma of fresh ES semen was washed with semen washing media (SWM), the rates of live sperm shown no significant difference between CE and ES spermatozoa before freezing. However, the survival rate of frozen/thawed CE sperm was higher than ES (74.6±10.6% vs 53.8±5.2%) with significant difference (p < 0.05). The results of longevity test on frozen/thawed sperm from CE showed healthier sperm than ES. Therefore, spermatozoa from CE could be used for cryo-banking system in KBG lines. The more studies are needed to increase survival rate of ES semen.

To increase the productivity of in vitro development, the antioxidants have been used for culture system of bovine oocytes and embryos. However, comparative studies on these molecules are rare and direct beneficial effects on blastocyst production cannot be discriminated for best results. The study was conducted to determine the influence of N-acetyl-L-cysteine (NAC), N-acetyl-L-cysteine amide (NACA), glutathione (GSH) and cysteamime (CYS) on maturation competence of COCs from GV to MII stage and productivity of blastocyst formation during in vitro fertilization and culture. There was no difference among maturation rates of oocytes to metaphase II with polar body with antioxidants for any of the treatment groups (p>0.05). However, the significant improvement on the rate of blastocysts (32.3±5.0%) was found in 0.1 mM CYS treatment than 0.3 mM NAC, 0.2 mM NACA or 0.5mM GSH (p<0.05). The addition of NAC (18.8±3.7%) or NACA (21.2±3.9%) did not improve development competence to morula and blastocysts than control (24.4±4.1%) and GSH (26.5±5.0%) (p>0.05). Our study showed that medium supplementation with CYS during IVM and IVC improved the rate of bovine embryo development but not with NAC, NACA and GSH addition.

The elevated temperature and high humidity has been known as main reason for heat stress on animals and cause detrimental effects on productivity of organisms and physiological conditions of normal bioactivities. The aims of this study were to evaluate the relationship between time of heat shock simulation during in vitro maturation and developmental competence of subsequent embryo after in vitro fertilization. Heat shocked cumulus-oocyte complexes (COCs) of Korean native cattle were subjected to normal conditions for 22, 21, 18 and 12 h respectively and transferred to heat stress inducing condition at 40.5 °C in other incubator for 0 (control), 1 and 4 h. After maturation for 22 h, the oocytes were fertilized and cultured in mSOF media for 8 d and examined the developmental capacity of embryos. There were no differences in maturation and cleavage rates between 0, 1 and 4 h heat socked oocytes, but blastocysts formation were lower in the 4 h heat stressed oocytes. The apoptotic cells of developed blastocysts were also increased in at day 8 with 4 h heat shocked oocytes. These results indicate that heat shock on oocytes during maturation could cause negative effects on the developmental competence of embryos.

Mobile games’ proportion in domestic game industry has been rising steadily every year and in next couple of years, it is likely to surpass online games. Considering that mobile games’ lifespan is very short compared to online games, recognizing the user’s needs at the beginning is important. However, there is a lack of research in such game field. This research is about mobile games’ initial experience importance in temporal viewpoint. Furthermore, it has verified whether this depends on user’s characteristic. I have conducted observation experiment on users of ‘Lineage M’, mobile MMORPG game, for one week starting from the game launch and deducted the importance of initial experience using AHP analysis. Moreover, by analyzing the differences in users’ proficiency, the research provides understanding of diverse users. In conclusion, this research provides basic data for improving satisfaction of initial game users and extending them to long-term game use.

Cryopreservation of germ cells from genetically proven animals could be a source of restoration tools from the risk of extinction or disappearance of wanted characteristics. Using frozen semen, the genetic gains of Korean native cattle have been increased greatly for 70 years. The preservation of genetic resources as a form of frozen semen straw has limited availability due to the numbers. To circumvent this weakness of frozen semen, we tested two re-freezing methods with different initial thawing temperatures using frozen Korean proven semen and rare breed semen from albino, black and chikso breeders. It has been known that human sperm could resist to cryo-damages by repeated freeze-thaw cycles, but not for Korean proven bulls number (KPN) or for rare breeds. Total 7 frozen semem from brindled(2), black(1), Korean Albino(2) and KPN(1) bulls were used for our research. After thawing straws under 5°C/2min or 37°C/40sec with low temperature water bath and thermo jug, spermatozoa were re-diluted with triladyl diluents after first thawing and re-frozen. Sperm motilities were compared between animals and treated groups after re-thawing. Mean values of motility and viability of refrozen/thawed sperm for expansion of the number of straws were significantly higher in 5°C than in 37°C (P< < 0.05). However, the activity of viable sperm thawed at 5°C was significantly decreased after first and second thawing. It is estimated that re-freezing of frozen semen from rare Korean native cattle is possible with resistant properties of survived spermatozoa.

농업현장에서는 각종 작물을 재배할 때, 작물 성장을 빠르고 효과적으로 하기 위하여 일정한 크기로 성장한 묘를 밭으로 옮겨 심게 되는데, 이러한 묘 정식작업을 수행할 때 채소 정식기가 사용된다. 본 채소 정식기는 인력에 의존하고 있는 채소 정식작업의 기계화를 촉진하기 위하여 2조식의 전자동 육묘 트레이 공급 및 취출된 묘를 식부호퍼에 이송할 수 있도록 개발하였다. 또한 두 가지 취출방식에 따른 묘 결주율을 비교하여 판단하였다. 핑거타입 묘 취출 시험결과 256주 묘에서 묘를 뽑아내지 못하는 경 우가 17주, 상토가 부서지는 경우가 15주 등 결주율이 13.7%로 나타났으며, 포크타입 묘 취출 시험결과 200주 묘에서 묘는 100% 뽑아내지만 이송 중 낙하되는 경우가 6개 등 결주율이 4%로 나타났다. 따라 서 전자동 2조식 정식의 묘 취출장치로서 포크타입이 적당한 것으로 판단되었다.

The current study explores the potential of the collaborative reflection of the teacher, colleagues, and students in promoting teacher expertise. To this effect, the authors first created a principled set of checklists on six domains of teacher expertise by synthesizing relevant literature. Then they developed protocols for collaborative reflection. These tools were applied to a middle school English teacher’s reflective practice, involving the teacher participating in stimulated recall sessions of her own classes, writing reflection journals, and receiving feedback from her colleagues and students. The results show that collaborative reflection has high potentials for mediating the teacher’s cognitive and affective changes, leading to behavioral ones. This suggests that collaborative reflection, when relevant institutional prerequisites are met, can take an instrumental role in promoting teacher expertise.

난자생검(Ovum pick up, 이하 OPU) 기법은 유효축군 조기확보 및 우수한우 유전자 원의 조기증식, 희소유전자원 다량확보를 위해 매우 중요한 기법으로 주목받고 있다. 이 러한 OPU기술에는 체외배양기술 외에도 현장의 환경과 시기에 따라 회수되는 난자의 수 역시 중요하다. 현재, 가축센터에서는 한우의 유전자 다양성 확보를 위한 일반 한우 외에 도 희소한우 증식을 위한 연구를 진행 중에 있다. 본 연구는 OPU기법을 활용하여 가축 유전자원센터에서 보유중인 한우 또는 칡소를 대상으로 계절별 및 모색별로 난포란의 개 수와 난자회수율의 차이를 비교 · 검토하고자 실험을 진행하였다. 실험시기는 3월에서 5 월(봄), 6월에서 8월(여름), 9월부터 11월(가을)까지 구분하여 실시하였으며, 계절별 및 모 색별로 채취되는 난자의 개수와 회수율을 분석을 하였다. 봄에는 8.20±6.57, 여름에는 5.47±4.01, 가을에는 5.88±3.65개가 회수되었으며, 또한 계통별로는 가을에 실시한 결과 한 우는 6.40±6.15개, 칡소는 2.75±0.55개가 회수되었다. 그리고, 계통별로 수정란발달률은 한 우는 난할률이 25.0±44.4%, 배반포발달률이 6.3±50.0%, 칡소의 경우 난할률이 27.3±21.0%, 배반포발달률이 9.1±16.7%로 나타났다. 계절별로 OPU를 실시한 결과 여름, 가을경에 실 시하는 것에 비해서 봄에 실시를 하였을 경우 회수되는 난자의 수가 많은 것으로 확인을 하였다. 그리고, 현재 일반한우가 칡소에 비해서 회수되는 난자가 더 많은 것으로 확인되 었다. 이에 반하여 난할률 및 배반포발달률은 차이가 없는 것으로 확인되었으나, 향후 실 험진행에 따라 정확한 결과를 도출할 것으로 사료된다.

본 연구는 칡소의 동결정액 생산 시 항산화제 첨가가 정자 생존성 및 운동성 등에 미 치는 영향을 조사하고자 수행하였다. 공시축의 사양관리는 한우사양관리(국립축산과학원, 2007) 기준에 준하여 사육하였다. 공시축은 정액채취를 위해 승가훈련이 완료된 칡소 5두 를 공시하였고 정액채취 빈도는 주 1회로 하였다. 정액 채취는 암소 보정 후 공시축의 승가를 유도한 다음 인공질에 음경을 삽입하여 채 정 후 원정액 정자가 80∼90% 생존율을 나타내는 것을 동결정액 생산에 활용하였다. 동 결보존 희석액의 기본조성은 Tris(hydroxymethyl)amino-methane 250mM, Citric-acid monohydrate 80mM, Fructose 60mM, Penicillin G Streptomycin 1%, Egg-Yolk 20%, Glycerol 7%에 항산화제인 Ascorbic-acid를 무처리, 0.5mM, 1.0mM, 2.0mM로 농도로 하 여 본 실험에 공시하였다. 동결정액의 생산은 처리군별로 원정액을 1차 희석한 다음 저온 실로 이동하여 2차 희석 및 Glycerol 평형을 유도한 다음 0.5ml Straw에 충진시켜 액체 질소를 활용한 동결을 실시하였다. 융해 후 정자 특성분석은 위상차 현미경과 컴퓨터정자 분석기(Computer Assisted Sperm Analysis)를 활용하여 생존율, 운동성, 선형성, 직진도 등을 검사한 결과 생존율은 2.0mM, 무처리, 1.0mM, 0.5mM(83.3%, 81.6%, 65%, 60%)였 고 운동성은 무처리, 2.0mM, 1.0mM, 0.5mM(97%, 96.5%, 94.4%, 91.3%)순이였고, 선형성 은 2.0mM, 무처리, 1.0mM, 0.5mM(29%, 29.7%, 32.9%, 36.4%)순으로 낮은 경향을 보였 다. 직진도는 2.0mM, 무처리, 1.0mM, 0.5mM(65.6%, 62.5%, 62.2%, 60.4%)순으로 낮은 경향을 보였다. 동결보존 희석액에 항산화제인 Ascorbic-acid 첨가함으로써 정자의 대사 과정에 따라 생성되는 활성산소의 발생 억제 등으로 인하여 동결융해 후 생존율에 영향 을 미치는 것을 감안하여 분석한다면 항산화제의 농도별로 각각 상이한 결과를 나타낸 것은 Ascorbic-acid의 첨가가 정자의 동결 융해 후 생존율 및 운동성 등에 영향을 미쳤 을 것으로 판단된다. 이와 같은 결과를 바탕으로 칡소 동결정액 생산 시 생존율 극대화를 위해 적정 항산화제 및 첨가 농도를 확립하고 이를 활용한다면 가축유전자원 보존·증식 에 기여할 것으로 사료된다.

Historically, Korea old cattle had been consisted with various lines of coat color brindle, black and white-brown breeds or more. The two rare lines of black and white coat color are maintained for animal resources and preserved critically. The present study was carried out to evaluate potential usage of cysteamine supplementation during in vitro matration (IVM) and in vitro culture/production of embryo (IVP) by transvaginal ultrasound-guided follicle aspiration (Ovum Pick-Up: OPU) for the establishment of cryo-banking system. Immature slaughterhouse-derived cumulus-oocyte complexes (SL-COCs) were matured in IVM medium supplemented with 0, 0.1, 0.3 or 0.9 mM cysteamine, and then cultured in mSOF-BAS for 8 days after in vitro fertilization. The treatment of 0.1 mM cysteamine on SL-COCs showed higher rate of blastocyst, so OPU-derived COCs from rare breeds were matured in TCM media supplemented with or without 0.1 mM cysteamine, FSH and 5% FBS. The embryos were evaluated their developmental stages on day 8. During IVM, cysteamine treatment significantly increased the embryo production rate of slaughterhouse-derived COCs (19.6% vs. 30.5%). The presence of cysteamine during IVM of OPU-derived COCs from rare Korean cattle breeds (albino white and black line) also increased embryo production rates than those from SL-COCs (27.4% vs. 41.9% and 36.4%). With these results, cysteamine treatment during IVM is one of key factors IVP of blastocysts to establish banking system of endangered rare Koarean cattle with OPU derived transferable blastocysts.

During the ovary preservation in low temperature, the cumulus oocyte complexes(COCs) lose their developmental competences after in vitro fertilization. We used phosphate-buffered saline (PBS) as a basic solutions of at various temperatures (25, 15 or 5 ℃) and supplemented them with 1mM glucose and 0.5mM glutamine as a source of carbohydrate metabolites. After recovery of COCs and in vitro fertilization, a significantly higher number of oocytes developed into blastocysts. The developmental competence of embryos that were originated from ovaries preserved at 15 ℃ was increased compared to those of 25 or 5 ℃. The maturation rate of oocytes was not differed between 24 and 36 h at 15 ℃ but showed lower than control group (71% versus 78%). In vitro-fertilized oocytes from ovaries stored at 25 ℃ for 24 h or at 5 ℃ for 24 h had a significantly decreased developmental potentials, but at 15 ℃ did not (27% versus 29% of blastocysts to develop into day 8). With these results, bovine ovaries can be preserved at 15 ℃ for 36 h without decreasing developmental capacity of in vitro-fertilized oocyte at least to the blastocyst stage. This information provides valuable information of preserving ovaries for embryo transfer or in vitro embryo production.

The objective of this study was to investigate the result of in vivo embryo collection and pregnancy rate after embryo transfer using sex-sorted sperm of Korean brindle cattle. Donor Korean brindle cattle superovulation treated by decreasing dose of FSH injection. Embryos were recovered on 7 days after the third artificial insemination. Control group semen straw used artificial insemination contained 20 million sperm. Sex-sorted semen straws contained 4 million sperm or 10 million sperm. As for the result of the recovery of the in vivo embryos derived from sex-sorted sperm, the number of transferable embryos was significantly highly recovered to be 6.20±2.28/donor from the control group and was significantly lowly recovered to be 1.57±1.72/donor from the group treated at a sperm concentration of 10×106 (p<0.05). The number of unfertilized embryo was 0.8±1.30/donor in control group which was significantly lower than the group treated at a sperm concentration of 4×106 (p<0.05). However, there was no significant difference in the number of undeveloped ova between control and treatment groups. Pregnancy rate after embryo transfer was shown to be 35.00% in control group and 12.50% in treatment group. The karyotype analysis of the calf derived from sex-sorted sperm resulted in a similar chromosomal distribution pattern (2n=60, XX) compared to those of common Korean native cattle.

체세포 복제기술을 이용한 복제가축 생산 기술은 1997년 전 세계적으로 이슈가 되었던 복제 면양 “Dolly”의 탄생을 계기로 여러 나라에서 소, 돼지, 말, 고양이, 개 등 많은 포유류에서 산자 생산에 성 공하였으며 우리나라의 체세포 복제 기술은 기술 선진국 대열에 들어서고 있다. 그러나 복제기술은 아 직까지 높은 유산율과 폐사율 등 해결해야 할 많은 근본적인 문제점 등이 있어 연구해야 할 분야는 적 지 않다고 하겠다. 체세포 복제 동물 생산기술은 당초에는 능력이 우량가축의 생산과 확대 및 조기증식 을 목적으로 이용되고 왔으나, 체세포 내로 우리가 원하는 유전자를 도입시키거나 없애는 기술 (knock-in과 knock-out)의 발달로 바이오장기 생산용 형질전환 복제 돼지의 생산을 목적으로 널리 이 용되고 있다. 또한, 최근에는 멸종위기에 있는 희소동물 유전자원을 멸실 이전에 동결 보존된 체세포를 이용하여 복원에 활용할 뿐 아니라 마약탐지견 생산 등 특수한 목적으로 활용되는 동물을 생산하는 기 술로서 기여하게 된다면 산업적으로 활용할 수 있는 분야가 더욱 확대될 것으로 기대된다. 따라서 체세 포 복제기술은 식용보다는 오히려 다양한 목적으로 복제동물을 생산하게 되면 산업적으로 활용할 수 있 는 가능성이 높을 것으로 기대되고 있다.

Recently, the market share of local vegetables is decreasing due to the high price in Korea. Futhermore, rising personnel expenses, aging population and declining in the rural population are affecting on cultivation as unfavorable factors. To promote and maintain enacted by the vegetable promotion law those only agricultural products. Cultivation of vegetables needs many of the labor because the work should be conducted shade installation, planting, weeding and crop-dusting. Especially, planting work needs many of the labor that its working periods are very short and it should be planted an angle of the 45 degrees. On account of many working hours, it needs the mechanization of vegetable processing. All phased working hours are 298.6 hours(1 time of 4 years)/10a that planting hours are 60 hours/10a which is to need many work times. When developed multi planting machine operated in the laboratory, it was electronically controlled and has operational mechanism planting device. However, it malfunctioned in the bare ground. So it needs to be changed to mechanically controlled. Therefore, for vitalizing of the transplanting work, we are analyzing multi-planting machine that is mechanically controlled.

Reproductive disorders in cows cause economic loss in livestock farms. Reproductive diseases, such as follicular cyst, luteal cyst, endometritis, pyometra, and repeat breeding cause infertility. Among these diseases, endometritis and pyometra are uterine infections that are leading causes of infertility. This study was performed to investigate the causative agents of uterine diseases using bacterial culture. Bacteria were obtained from the reproductive organs (vagina, uterine cervix, and uterine horn) of dairy cow diagnosed with endometritis or pyometra, and cultured on blood agar. The colonies obtained from cultivation for 24 hours were passaged. To identify the bacteria, the colonies grown in passaged culture Gram stained and applied to an automatic biochemical microbial identification system. Escherichia coli were commonly detected in vagina, uterine cervix, and uterine horn of dairy cows diagnosed to pyometra. The cows having endometritis showed not only Escherichia coli but also Pantoea spp. and Klebsiella spp. strains. Dairy cows that were infected with Escherichia coli in uterus caused mastitis or digestive disease. These results suggest that sanitary feeding and management beforehand are needed to prevent bacterial infections.

The purpose of this study is to produce wanted sex progeny of genetically confined White Hanwoo (albinism) with preselected sex sperm. One bull of White Hanwoo was chosen for semen donor and X sperm was sorted by MoFlo XDP cell sorter. To compare the pregnancy and birth rates, KPN straw was used as control, total number of unsorted sperm was 20×106/straw. Sexed X frozen semen with 2×106 cells or 4×106 cells per straw were in seminated twice on Hanwoo heifers. The abnormality of the sexed X semen was 24.9 ± 7.31% and distal reflex abnormality of mid piece was significantly (p<0.05) higher (11.7%) compared with that of KPN 768 (5.6%). There were no differences on the pregnancy and birth rates between 2×106 cells or 4×106 cells of X-sperm but KPN semen showed significant differences (p<0.05). The pregnancy rates of KPN 768, 2×106 cells and 4×106 cells X-sperm of White Hanwoo cattle were 85.0%, 26.3% and 50%. The birth rates were 80.0%, 15.8% and 21.4%, respectively. The female offspring rates of KPN 768, 2×106 cells and 4×106 cells X-sperm of White Hanwoo cattle were 43.8%, 100% and 100% (p<0.05). These results indicated that sex sorted White Hanwoo could be used for the production of wanted progeny with 2×106 cells/straw for AI. To increase the efficiency of calf production, the sperm number of sex sorted semen will be optimized for sex selection of White Hanwoo progeny.

2013년 11월부터 2014년 7월까지 가축유전자원시험장 장내에서 사육 중인 한우 및 칡소 206두(한우 187두, 칡소 19두)를 대상으로 연령별, 종별 그리고 성별로 각각 분류하고, 이들에 대한 혈액학적 수치를 확인하였다. 혈액학적 검사 결과에서 1년 이하에서 5년 이상으로 연령이 증가됨에 따라 RBC(12.0~9.5x106/μl로)와 PLT치(717~432x103/μl로)에서 각각 유의성 있는 감소(P＜0.05)가 인정되었다. 동일 연령(2~3년)의 한우군과 칡소군 간에서의 비교에서는 RBC(10.1~10.4x106/μl)와 HCT(44.8~42.1%), MCV(49.4~44.9 fl) 및 MCHC (28.9~31.1 g/dl)에서 두 품종 간의 차이점이 인정되었으며, MCV와 MCHC에서도 통계적 유의성이 인정되었다(P＜0.05). 또한, 백혈구계 검사 결과에서도 연령이 증가함에 따라 WBC 수치(1년 이하의 13.8에서 5년 이상의 9.5x103/μl로)가 감소하는 경향이 인정되었으며, 백혈구 분포의 백분율에서는 전반적으로 림프구가 46.2%를, 분엽형 호중구가 35.6%로 나타났다. 한우군과 칡소군 간의 백혈구계 비교에서는 칡소군의 분엽형 호중구치가 2.7x103/μl로서 한우군에 비하여 유의성 있는 저하(P＜0.05)가 인정되었으며, 림프구치는 5.2x103/μl로 4.7x103/μl 한우군에 비하여 높게 나타났다. 임신우군과 비임신우군 간의 비교 분석에서는 Hg(9.9 g/dl)과 HCT(40.5%)이 비임신군에 비하여 통계적 유의성이 있는 저하(P＜0.05)가 인정되었으며, 총 백혈구수와 분엽형 호중구수, 림프구수 모두 비임신우군에 비하여 높게 나타났지만, 통계적 유의성은 인정되지 않았다.

Sexed semen is commonly used for the production of calves of the desired gender. Gender selection is important in animal production industries. For example, female cattle are required for the dairy industry while males are preferred in the beef cattle industry. The present study was to assess the in vivo embryo production efficiency using the semen separated according to sex during superovulation in Hanwoo. Seventy Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with embryo collection medium. KPN semen straws used artificial insemination contained 20 million sperm (total number 60 million per donor). Sex-sorted semen straws contained 4 million sperm (total number 12 million per donor). The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on KPN semen 87%, and sexed semen 100%, respectively. The mean numbers of total embryos are each 12.58±8.31 and 13.25±7.86. The mean numbers of transferable embryos, sexed semen were significantly lower than KPN semen (3.75±1.98 vs. 8.23±6.07, P＜0.05). The rates of unfertilized embryos from superovulation using sexed semen were significantly higher than KPN semen (50% vs. 15%, P＜0.05). The rate of degenerated 2-cell embryos from sexed and KPN semen was 60.87% and 11.11%, respectively (p＜0.05). In conclusion, these results indicate that superovulation using sexed semen was useful, but efficient embryo production was important to reducing the damage caused by the Flowcytometer-based sperm sorting procedure.

본 연구에서 생쥐 초기 배아를 이용하여 동결 보존된 배아의 생존율 또는 발달율에 영향을 미치는 요인들의 상관관계를 알아본 결과, 배아의 발달 단계에 따른 동결 - 해동 후 생존율에 있어서는 2세포기 배아가 4~8세포기 배아보다 유의하게 높았으나(p＜0.01), 배 발달율에 있어서는 4~8세포기 배아가 유의하게(p＜0.01), 높아 생존율과 배 발달율과는 상관관계가 없는 것으로 사료된다. 또한, 동결 보호제에 따른 배아의 생존율에 있어서는 2, 4~8세포기 배아 모두 DMSO에서 유의하게 높았으나(p＜0.01), 배 발달율에 있어서는 EG가 DMSO에 비해 더 유의하게 높은 성적을 나타내어(p＜0.01, p＜0.05) 동해로 인한 상해가 적은 것으로 생각되어 2, 4~8세포기 배아에서 EG가 더 효과적인 동결 보호제로 사료되며, 동결 프로그램으로는 완만 동결 - 급속 해동법이 더 우수한 프로그램으로 보인다.

생쥐 2세포기, 4세포기, 8세포기를 각 발생 단계에서 채취하여 동결 보호제를 첨가한 서로 다른 배양액에서 배양하고, 배아의 동결 보존 및 융해 시 급속 처리와 저속 처리 단계로 비교하여 이들 조건이 배아의 생존과 발현에 미치는 영향을 조사하여 다음의 결과를 얻었다. 동결 보호제로 처리하여 배양액을 달리한 경우, 급속 단계에서는 모든 배양액에서 비슷한 발생율을 보였고, 저속단계의 4세포기와 8세포기는 D-PBS에서 높은 발생율을 보였다(P＜0.05, P＜0.01). 배아의 발생 시기에 따른 동결 보존 후, 발생율은 2, 4, 8세포기로 넘어갈수록 발생율의 증가를 보여 8세포기에서 발생율이 가장 높았다(P＜0.01). 동결 보호제의 처리단계에 따른 발생율은 2세포기의 급속 단계에서는 유사하였으나, 4세포기와 8세포기는 저속단계에서 높은 발생율을 보였으며(P＜0.05), 특히 8세포기에서 가장 높았다(P＜0.01).