In vitro embryo culture techniques provide significant contributions not only for a basic research of fertilization and early embryogenesis, but also for a low cost mass production of bovine embryos for transfer, embryo diagnosis, nuclear cloning and the production of transgenic cows. This presentation introduces newly developed serum-free media (IVD101 and IVMD101) that are effective far high yields of transferable embryos of excellent quality from in vitro-matured and fertilized oocytes. Both serum-free media are superior to a conventional serum-containing medium on the increased rates of blastocyst formation, post-thaw embryo viability, and pregnancy after transfer. Furthermore, reduced risks of calf mortality and large calf syndrome are also observed for the serum-free-derived embryos. Serum-derived embryos contain a large number of lipid droplets and immature mitochondria in their cytoplasm that may account for the lower production of transferable embryos and poor embryo quality.

There have been intensive attempts to establish reliable methods far in vitro production (IVP) methods for of porcine embryos. Although a great deal of progress has been made, our current IVP systems still need to be improved. In this review, we focused on studies about in vitro maturation and fertilization (IVM-IVF) of porcine oocytes and their in vitro culture (IVC), especially on an excellent piglets production system using modified IVP system producing porcine blastocysts with high Quality.

Epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) have been shown to stimulate proliferation and differentiation of various somatic cells, including placental trophoblasts and also to enhance fetal growth and development when maternally administered. Since an increase of the expression of placental EGF and IGF-I receptors in rat, mouse, and human with the gestation advanced, both EGF and IGF-I were considered to play pivotal roles on fetal growth by regulating some function of placental cells. Amino acids are crucial importance for both maternal and fetal requirements of energy source and essential constituent of fetal mass during pregnancy. Impaired fetal and placental uptake of amino acids has been observed in several models of growth retardation in the rat. Amino acid is concentrated in the fetal side through active transport by amino acid transporters and is one of the important metabolic fuels for the fatal growth. Therefore, at first plasma amino acid concentrations in mothers and fetuses were measured as an index of uphill transport across the placenta associated with EGF and IGF-1. The EGF administration at the concentration of 0, 0.1, or 0.2 /g to pregnant rats from day 18 to 21 of gestation apparently increased fetal/maternal ratio of serum proline concentration and also fatal growth in EGF dose-dependent manner. When IGF-I in doses of 0, 1, 2, and 4 /g were administrated, the ratio of leucine, isoleucine, tryptophan, phenylalanine, tyrosine and also fetal growth significantly increased with a dose-dependent manner. These results suggested that EGF and IGF-I enhanced fatal growth by, as one of its possible mechanisms, promoting placental activity to transfer some amino acid supplies from the mother to the fetus in late pregnancy.

In ascidians, a primitive chordate, maternal cytoplasmic factors and inductive interactions are involved in the specification of cell fate in early embryos. The larval structure of ascidians is relatively simple, and the major mesodermal tissues of the tadpole larva are notochord, muscle and mesemchyme. Formation of muscle cells is a cell-autonomous process, and localized maternal macho-1 mRNA specify muscle fate in the posterior marginal zone of the early embryo. In contrast, inductive influence from endoderm precursors plays important roles in the specification of notochord and mesenchyme fates. FGF-Ras-MAPK signaling is involved in the induction of both tissues. The difference in responsiveness of the posterior mesenchyme and anterior notochord precursors is caused by the presence or absence of the posterior-vegetal egg cytoplasm, respectively. In these cases, directed signal may polarizes the responding cells and cause asymmetric cell divisions that operate in both the anterior and posterior regions.

Cloning by nuclear transfer in mammals using somatic cells has enormous potential applications. However, somatic cloning has been inefficient in all species in which NT is successful. High abortion and fetal death rates have been observed. These developmental defects have been attributed to incomplete nuclear reprogramming by the somatic cloning process. In this review, we will discuss studies conducted in our labs to understand the nuclear reprogramming process.

The International Union for Conservation of Nature and Natural Resources (IUCN) considers the western/lowland bongo Tragelaphus eurycerus eurycerus to be a threatened species, and the eastern/mountain bongo Tragelaphus eurycerus isaaci an endangered species［1］. Although extinction is considered by many biologists to be a natural process during evolution, the exponential growth of the human population has drastically and prematurely reduced the numbers and genetic diversity of many species［2］. Species have evolved to adapt to a specific habitat or environment that meet their survival needs. Alteration or destruction of their habitat results in a species becoming incapable of adapting and hence becoming threatened with extinction. A widespread scientific and public consensus has emerged suggesting that governments should assign high priority to the maintenance of biological diversity via habitat preservation and management far species conservation［3］. Unfortunately, the loss of biological diversity far surpasses the available conservation resources and species are lost forever on a daily basis［4］. Notwithstanding the focus on habitat preservation and wildlife management, conservation biologists have also become increasingly interested in using the technologies of reproductive and developmental biology to help manage or rescue endangered species［5］.

Identification of spermatogonial stem cell-specific surface molecules is important in understanding the molecular mechanisms underlying the maintenance and differentiation of these cells. We have found that spermatogonia from busulfan treated mice expressed an autoantigen that distinguishes between undifferentiated and differentiated spermatogonia. Four to six weeks after busulfan treatment, germ cells located in the basal compartment of seminiferous epithelium show isotype-specific IgG deposits that form due to autoimmunity. Before busulfan treatment, the level of testicular IgG was very low but IgG levels began to increase after week 4 and peaked at week 6. When cells from the busulfan treated testis were analyzed using laser scanning cytomeoy (LSC), the frequency of cells positive for IgG deposits, 6-integrin, and 1-integrin were 16.53.8%, 11.82.6%, and 9.0 1.4%, respectively. Immunofluorescent staining suggested that most, if not all of the cells with IgG-deposits isolated from a laminin-coated dish, were also positive for a spermatogonial stem cell marker \ulcorner6-integrins as well as for a germ cell-specific marker TRA 98. We determined serum and intratesticular IgG levels and the soundness of seminiferous tubule basement membrane from busulfan treated mice using electron microscopy, in order to study the mechanism responsible for IgG deposits in spermatogonia. We found that the basement membranes of seminiferous tubules from busulfan treated mice were severely impaired when compared to those of normal adult, neonates and w/wv mice. Furthermore, new blood cells were observed in the surface of the damaged basement membrane along the seminiferous tubules. These results suggest that the IgG in spermatogonial stem cells accumulates from circulating blood through the impaired basement membranes induced by busulfan treatment. Taken together, our study suggests that IgG can be used as a new marker for undifferentiated spermatogonia cells.

Transgenic animals production tools have been valuable for research and purpose. The current methods of gene transfer, microinjection and nuclear transfer, which are widely used in transgenic animal production, but all most methods has only had limited success in production of larger species. Here, we report the possibility of a sperm-mediated gene transfer method in porcine embryos. Oocytes were collected from ovaries harvested at a local slaughterhouse were matured in 500 drops of TCM-199 under mineral oil at 38.5 in a humidified atmosphere of 5%CO2 in air. After 42-43h of in vitro maturation oocytes were denuded. for sperm injection into the cytoplasm of the porcine oocytes, sperm suspension in NIM medium are subjected extraction with TritonX-100 before mixing with a green fluorescent gene (GFP). Sperm with Tritonx-100 were prepared by adding TritonX-100 to a final volume of 0.05% in the sperm suspension and mixing by trituration for 60s before two wishes in NIM medium at 2. A(ter wishing, sperm were mixed with TritonX-100 at followed by washes at 2. Sperm were resuspended in ice cold NIM to a final volume of 400 and 2-20ng/ DNA were triturated on ice for 60s. All microinjection was performed in HEPES-buffered CZB medium at room temperature within 2h. After culture in NCSU-23 for 72h, percent of porcine embryos transfected GFP gene are 20.7%(6/29) in 20ng/ sperm-DNA mixed group and other groups were 3.7 %(2/54)and 4.7%(3/67). These data suggests that sperm-mediated gene transfer method should be used to the production tool of transgenic pig efficiently.

형질전환 가축을 생산하기 위하여 최근 체세포 복제 기법을 이용하고 있다. 이러한 체세포를 이용한 형질전환 동물의 생산에는 체세포내에 유전자의 도입 효율이 직접적인 영향을 주게 된다. 따라서 본 연구는 세포내 유전자의 transfection 효율을 높이고자 한우의 체세포를 이용하여 여러 가지 조건에서 유전자 도입을 실시하였다. 세포내 유전자 도입 방법은 electroporation (EP) 방법을 이용하였다. 사용한 세포는 소의 귀세포(KbESF), 태아섬유아세포 (KbFF), 그리고 대조구로서 CHO cell을 이용하여 GFP 유전자를 도입하였다. EP는 0.4 cm cuvette을 사용하였고, voltage는 0.25 kV, 그리고 field strength 는 0.625 kV/cm 조건으로 실시하였으며, pulse times은 각각 1, 2, 또는 3회를 사용하였다. KbFF와 KbESF에서는 각각 pulse times을 증가시킬수록 유전자도입 세포수가 증가하였으나 (KbFF: 81, 634, 1,065 cells/ cells, KbESF: 1,011, 5,567, 15,408 cells/ cells), CHO cell에서는 pulse times을 증가시킬 수록 오히려 유전자도입 세포수가 감소하였다 (CHO: 1,591, 687, 297 cells/ cells). 그리고 2주 동안 neo selection을 실시 한 결과 KbFF, KbESF, CHO에서 각각 93, 35, 184 colony가 선발되었으며, 이 중 65.6%, 8.6%, 4.3% 가 GFP 형광 발현 colony로 나타났다. 한편 CHO cell에서 transfection cell수가 감소된 것은 EP의 자극으로 인해 손상된 세포가 많이 발생한 것으로 나타났다. 또한 neo selection에서 선발된 colony중 GFP가 발현되지 않거나 일부만 발현되는 colony들이 많이 발생하였는데, 이것은 세포내 유전자가 transfection되지 않은 세포도 neo selection에서 선발된다는 것을 제시하고 있다. 따라서 체세포를 이용한 형질전환동물 생산을 위해서는 세포내 유전자 도입과 선발 과정에서 나타난 colony에 대하여 보다 엄격한 screen을 하는 것이 필요한 것으로 생각된다.

Promoters for milk proteins have been used far producing transgenic animals due to their temporal and spatial expression patterns. -casein, a calcium-sensitive casein, is a major milk protein that corresponds ca. 30 per cent of total milk protein. Expression of -casein is controlled by lactogenic hormones such as prolactin (PRL), composite response elements (CoREs) and transcription factors. CoREs are clusters of transcription factor binding sites containing both positive and negative regulatory elements. -casein gene promoter contains various regions (CoREs) for gene transcription. We analyzed the promoter region by mutagenesis using exonuclease III and linker-scanning. Transcription control elements usually are positioned in 5'-flanking region of the gene. However, in some cases, these elements are located in other regions such as intron 1. The nucleotide sequences of -casein promote. region has been reported (E12614). However, the properties of the promoter is not yet clear. In this study, we plan to investigate the properties of cis-regulating elements of porcine -casein by mutation analysis and expression analysis using dual-luciferase repoter assay system.

조류는 발생학적 특성상 수정과 초기 배발생을 제외한 거의 대부분의 개체발생 과정이 난각 속에서 진행된다. 그러므로 수정란에 생명 공학적 기법을 적용하는데 있어서, 포유류의 경우 여러 생명공학 기법이 적용된 수정란은 초기발생을 위한 체외배양 이후 반드시 모체에 이식되어야 하지만, 조류의 경우 인공적인 체외배양 체계가 확립되어 있어야 생명공학 기법이 적용된 수정란을 개체까지 발생시킬 수 있게 된다. 닭의 난자는 난관 누두부에 배란 후 약 15분내에 정자의 침입을 받아 수정되어 난관 팽대부에 도달하면 1세포기 수정란이 된다. 그 후 수정란이 협부에 도달하면 최초로 분할이 일어나기 시작하여, 방란시에는 그 세포수가 60,000개에 이르게 된다. 한편, 계란의 형성 과정에서는 다량의 난황을 포함한 난자가 난관 누두부로 배란되어 정자와 만나게 되면 수정란으로서 계란 형성이 계속되고 정자와 만나지 못하게 되면 무정란으로서 계란 형성을 계속하게된다. 배란된 난자가 난관누두부를 거쳐 난관팽대부에 도달되면 난자는 농후난백에 의해 둘러싸이게 되고 난관혈부에 도달되면 난각막이 형성되고 수양성 난백이 침적하게 된다. 그 후, 난관협부를 지난 난자는 난관자궁부에 도달되면 20시간이상 그곳에 머물면서 난각형성이 진행된 다음 방란된다. 따라서 수정란에 외래유전자를 미세주입하여 형질전환 닭을 생산하기 위해서는 수정란을 암탉의 난관 내에서 최초 분할되기 전에 외부로 끄집어내어야 하며, 수정란에 외래 유전자를 미세주입한 다음에는 다시 암탉의 난관내로 이식해야 하지만 현재까지 그러한 기술은 확립되어 있지 못하다. 그렇기 때문에 모체의 난관 속에서 일어나는 배 발생과 그 이후 개체까지의 발생을 위하여 인공적인 체외배양 체계가 확립되어 있어야 한다. 따라서 본 발표에서는 형질전환 닭을 생산하기 위한 양질의 1세포기 수정란 획득 방법과 획득된 수정란의 체외 배양방법에 관하여 기술적인 측면에서 고찰 해보고자 하며, 그와 같은 배양 기술을 이용하여 외래유전자를 도입한 일련의 결과에 관하여 보고 하고자한다.

Nuclear transfer (NT) techniques have advanced in the last years, and cloned animals have been produced by using somatic cells in several species including pig. However, it is difficult that the nuclear transfer porcine embryos development to blastocyst stage overcoming the cell block in vitro. Abnormal segregation of chromosomes in nuclear transferred embryos on genome activation stage bring about embryo degeneration, abnormal blastocyst, delayed and low embryo development. Thus, we are evaluated that the correlations of the frequency of embryo developmental rates and chromosome aberration in NT and In viかo fertilization (IVF) derived embryo. We are used for ear-skin-fibroblast cell in NT. If only karyotyping of embryonic cells are chromosomally abnormal, they may difficultly remain undetected. Then, we evaluate the chromosome aberrations, fluorescent in situ hybridization (FISH) with porcine chromosome 1 submetacentric specific DNA probe were excuted. In normal diploid cell nucleus, two hybridization signal was detected. In contrast, abnormal cell figured one or three over signals. The developmental rates of NT and IVF embryos were 55% vs 63%, 32% vs 33% and 13% vs 17% in 2 cell, 8 cell and blastocyst, respectively. When looking at the types of chromosome aberration, the detection of aneuploidy at Day 3 on the embryo culture. The percentage of chromosome aneuploidy of NT and IVF at 4-cell stage 40.0%, 31.3%, respectively. This result indicate that chromosomal abnormalities are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT associated with lower implantation rate, increase abortion rate and production of abnormal fetuses.

Production of u 1-antitrypsin (AT) in transgenic cows has a great value in the field of medicine. The present study was conducted to determine the effect of chemically defined KSOM media on in vitro development of bovine transgenic nuclear transfer (NT) embryos. An expression plasmid for human AT was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human AT target gene into a pcDNA3 plasmid. Cumulus cells as donor nuclei in NT were collected from a Holstein cow and transfected by lipid-mediated method using FuGene6 (Roche Molecular Biochemicals, USA) as reagent. GFP expressed cumulus cells were introduced into recipient oocytes under DIC microscopy equipped with FITC filter set. After electrical fusion and chemical activation, reconstructed embryos were cultured in 1) SOF + 0.8% BSA, 2) KSOM + 0.8% BSA, 3) KSOM + 10% FBS and 4) KSOM +0.01% PVA for 192 h at 39 with 5% , 5% and 90% in humidified condition. The development of the embryos was recorded and the GFP expression in blastocyst was determined under FITC filter. The average fusion rate was 73.8% (251/340; n=8). The development rates to 2-4 cells, morula, blastocysts and expression rates in blastocysts varied from 70.3 to 76.5%, 30.2 to 33.8%, 25.4 to 33.8% and 11.8 to 15.6%, respectively. The difference in development and expression rates of embryos among 4 culture groups was not significant (P>0.05). This study indicates that chemically defined KSOM medium is also able to support development of bovine transgenic NT embryos at similar rate of SOF or KSOM supplemented with BSA or serum.

The present study was conducted for the production of transgenic cloned cows by somatic cell nuclear transfer (SCNT) that secrete human prourokinase into milk. To establish an efficient production system for bovine transgenic SCNT embryos, the offset was examined of various conditions of donor cells including cell type, size, and passage number on the developmental competence of transgenic SCNT embryos. An expression plasmid far human prourokinase (pbeta-ProU) was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human prourokinase target gene into a pcDNA3 plasmid. Three types of bovine somatic cells including two adult cells (cumulus cells and ear fibroblasts) and fetal fibroblasts were prepared and transfected using a lipid-meidated method. In Experiment 1, developmental competence and rates of GFP expression in bovine transgenic SCNT embryos reconstructed with cumulus cells were significantly higher than those from fetal and ear fibroblasts. In Experiment 2, the effect of cellular senescence in early (2 to 4) and late (8 to 12) passages was investigated. No significant differences in the development of transgenic SCNT embryos were observed. In Experient 3, different sizes of GFP-expressing transfected cumulus cells [large (>30 ) or small cell (<30 )] were used for SCNT. A significant improvement in embryo development and GFP expression was observed when small cumulus cells were used for SCNT. Taken together, these results demonstrate that (1) adult somatic cells could serve as donor cells in transgenic SCNT embryo production and cumulus cells with small size at early passage were the optimal cell type, and (2) transgenic SCNT embryos derived from adult somatic cells have embryonic development potential.

본 실험은 Piezo-미세조작기(PrimeTech Ltd., Japan)를 사용하여 마우스 핵이식 후 재구축배를 CZB와 KSOM 두가지 배양액을 사용하여 체외배양성적을 비교 검토하였다. MII의 미수정란은 성숙한 4~5주령 B6D2Fl에 hCG 주사 후 14시간째에 과적 방법을 통해 난관의 팽대부로 부터 회수하였고, metaphase II chromosome-spindle complex와 최소량의 세포질을 내경이 10인 피펫으로 흡입하여 탈핵하였다. 핵이식에 사용된 난구세포(8-l0)는 3시간동안 12% PVP 에처리 하여 piezo-미세조작기를 이용하여 세포질에 세포의 핵을 직접 미세주입 하였다. 핵이식 후 생존한 재구축배는 2시간동안 배양한 후 10mM SrC1와 5/의 cytochalasin B가 첨가된 -free CZB에서 6시간 활성화 처리하였다, 활성화 처리 후 위전핵이 관찰된 재구축란을 CZB 와 KSOM 배지에서 배양하면서 발달률을 비교하였고, 상실배 및 배반포배로 발달한 재구축배를 day 3 대리모에 이식하였다. 표 1에서 보는 바와 같이 재구축배의 2-cell로의 발달률에 있어서 KSOM이 CZB에 비하여 유의적으로 높게 나타났으며(P<0.05), 또한 4-cell과 상실배/배반 포배로의 발달률에 있어서도 KSOM이 CZB에 비하여 유의적으로 높은 발달률을 나타내었다(P<0.01). 또한 KSOM 배지에서 배양된 상실배/배반포배를 대리모에 이식한 경우에 11.5 d.p.c에 생존한 태아가 관찰되었다. 이상의 결과로 핵이식 재구축배의 활성화 처리 후의 발생에는 KSOM 배지가 CZB 배지에 비하여 유효함을 확인 할 수 있었다.그와 같은 배양 기술을 이용하여 외래유전자를 도입한 일련의 결과에 관하여 보고 하고자한다., 이것은 세포내 유전자가 transfection되지 않은 세포도 neo selection에서 선발된다는 것을 제시하고 있다. 따라서 체세포를 이용한 형질전환동물 생산을 위해서는 세포내 유전자 도입과 선발 과정에서 나타난 colony에 대하여 보다 엄격한 screen을 하는 것이 필요한 것으로 생각된다.로 우점하였다. 여름철 식물플랑크톤 대발생에 영향은 수온과 직산염이 중요하였으나, 부유물질 크게 기여하지 못하였다.애를 확인하고 지도 관점을 파악하는 것을 포함한다. 그러나 본 논문은 역사발생적 수학 학습-지도 원리의 실제적인 적용에 관하여는 기초적인 연구에 지나지 않기 때문에, 역사발생적 원리를 학교수학에 실제적으로 적용하기 위해서는 각각의 내용에 대한 철저한 역사적 분석을 바탕으로 하는 후속 연구가 필요하다./TEX>구성교육이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.

본 연구는 체세포 및 체세포 핵이식란의 염색체 이상에 체세포의 계대의 영향성을 조사하고자 하였다. 한우 성축의 귀 조직으로 얻어진 세포를 공여세포를 체외성숙 후 제핵된 난자에 핵이식을 실시하였으며, 1.9kv/cm, 20/2times의 전기자극으로 융합후 5/ml의 ionomycin에서 4min, 1.9mM 6-DMAP에서 4h동안 배양함으로써 활성화를 유도하였다. 핵이식란은 CRlaa에서 4일간 배양 후 8 -cell단계에서 중기상의 유도를 위하여 상기 배양액 1ml당 0.05 colcemid에서 6-8시간 더 배양하였다. 이후, 6% Fetal bovine serum이 함유된 1% sodium citrate용액에 20분간 저장처리 후, methanol 5 : aceticacid 1 : distilled water 4로 1차, methanol 3: aceticacid 1 로 조성된 2차, methanol 4 : acetic acid 3 : distilled water 1의 3차고정액으로 1분간 재 침지시켰다. 고정 처리가 완료된 slide는 4% Giemsa용액으로 염색한 후 광학현미경 하에서 핵형 양상을 검경하였다. 체세포의 5계대에서는 684개의 spreads를 검경한 결과 염색체 수는 72%가 정상으로 60개이었고, 24%가 60개 이하였으며 4%가 60개 이상을 보였다. 10계대도 5계대와 비슷하여 71%가 정상, 26%가 60개 이하, 3%가 60개 이상이었고, 15계대에서는 55%가 정상이었고, 30%가 60개이하, 15%가 60개 이상을 보였다. 10계대 까지는 mixoploid의 비율의 변화가 없었으나 15계대에서 현저하게 늘어남을 볼 수 있었다. 또한 체외수정란과 핵이식란의 비교에서는 체외수정란은 250개의 spreads를 검경한 결과 염색체 수는 95.6%가 정상으로 60개이었고, 2.0%가 60개 이하, 2.4%가 60개 이상이었으나, 핵이식란은 204개를 검경하여 88%가 정상이었고, 4.9%가 60개이하, 7.1%가 60개 이상을 보임으로써, 핵이식란이 체외수정란에 비하여 염색체 이상의 비율이 높았다. 따라서 계대에 따라 체세포의 염색체이상의 비율이 상대적으로 증가하고, 체세포 핵이식에 따른 염색체 이상이 생길 수 있음을 알 수 있었다. (이 논문은 농림부 연구비에 의해 수행되었음)

The role of heat shock proteins in shielding organism from environmental stress is illustrated by the large-scale synthesis of these protein by the organism studied to date. However, recent evidence also suggests an important role for heat shock protein in fertilization and early development of mammalian embryos. Effects of elevated in vitro temperature on in vitro produced bovine embryos were analysed in order to determine its impact on the expression of heat shock protein 70 (HSP70) by control and frozen-thawed after in vitro fertilization (IVF) or nuclear transfer (NT). The objective of this study was to assess the developmental potential in vitro produced embryos with using of the various containers and examined expression and localization of heat shock protein 70 after it's frozen -thawed. For the vitrification, in vitro produced embryos at 2 cell, 8 cell and blastocysts stage after IVF and NT were exposed the ethylene glycol 5.5 M freezing solution (EG 5.5) for 30 sec, loaded on each containers such EM grid, straw and cryo-loop and then immediately plunged into liquid nitrogen. Thawed embryos were serially diluted in sucrose solution, each for 1 min, and cultured in CRI-aa medium. Survival rates of the vitrification production were assessed by re-expanded, hatched blastocysts. There were no differences in the survival rates of IVF using EM grid, cryo-loop. However, survival rates by straw were relatively lower than other containers. Only, nuclear transferred embryos survived by using cryo-loop. After IVF or NT, in vitro matured bovine embryos 2 cell, 8 cell and blastocysts subjected to control and thawed conditions were analysed by semiquantitive reverse transcription polymerase chain reaction methods for hsp 70 mRNA expression. Results revealed the expression of hsp 70 mRNA were higher thawed embryos than control embryos. Immunocytochemistry used to localization the hsp70 protein in embryos. Two, 8-cell embryos derived under control condition was evenly distributed in the cytoplasm but appeared as aggregates in some embryos exposed frozen-thawed. However, under control condition, blastocysts displayed aggregate signal while Hsp70 in frozen-thawed blastocysts appeared to be more uniform in distribution.

본 연구에서는 in vitro에서 성숙된 난자의 핵성숙(Polar Body extrusion)에 소요되는 시간과 배반포 단계로의 발달능력 사이의 관계를 비교하여 조기에 발달능력을 가진 embryo를 선발할 수 있는 IVP 체계를 개발하고자 하였으며 in vitro maturation(IVM)에 따른 first polar body(PB) 형성, IVM과 IVF 시간이 oocyte의 발달에 미치는 영향과 생산된 배반포의 세포수를 평가하였다. IVM은 TCM199 배양액을 사용하였고 in vitro fertilization(IVF)은 Fer -TALP용액을 사용하였으며 in vitro culture(IVC)는 CRlaa 배양액을 사용하여 2일까지는 0.3% BSA를 3일 부터는 10%FBS와 bovine oviduct epithelial cell을 첨가하여 배양하였다. IVM 시간에 따른 PB의 출현율은 0hr(0%), 6hr(0%), 12hr(0%), 14hr(8.7%), 16hr(40.5%), 18hr(48.0%), 20hr(65%), 22(68%) 그리고 24hr(74.5%)을 보였으며 IVM 시간에 따른 cleavage 및 8cell 발달율 사이에는 유의적인 차이가 없었으나 배반포(BL) 및 8cell에서 배반포로 발달률은 18시간(BL 316, BL/8cell 82 5%)에서 가장 높게 나타났으며 24시간(BL 172, BL/8cell 608%)과 유의적인 차이를 보였다(P<0.05). IVC 7일째 배반포의 총세포수와 trophoblast(TE) 세포수는 IVM 18시간(meanS.E.; total: 131.134.0, TE: 97.629.6)에서 24시간(total: 112.217.5, TE: 80.115.6)보다 유의하게 많은 것으로 나왔으나(P<0.05) 7일째의 inner cell mass(ICM) 숫자(18hr 33.512.8 vs 24hr 32.112.0)와 8일째 ICM, TE 그리고 총 세포수에는 유의성 있는 차이가 없었다. IVM 18시간에서 PB 형성과 8cell 발달률 사이에 높은 상관성을 보였고 배반포 및 8cell에서 배반포 단계로 높은 발달률을 보였으며 생산된 배반포의 TE 숫자와 총 세포수가 유의하게 많은 것으로 나타났다. 따라서 IVM 18시간 실시하였을 경우 보다 많은 세포수를 가진 배반포 발달 가능성이 높은 embryo를 조기에 선발 가능할 것으로 사료된다.

This study was carried out that to investigate the effects of amino acids supplemented with culture medium on development of porcine embryos cultured in vitro. Cumulus oocyte complexes (COCs) were cultured in the maturation medium containing hormones (0.5/ LH, 0.5/ FSH and 1/ estradiol-17) for 20-22 h at 39 in an atmosphere of 5% COin air. Subsequently, COCs were cultured in hormone-free maturation medium for 20-22 h. After maturation for 40-44h, oocytes were removed cumulus cells by pipetting and cultured with epididymal sperm for 5 h in the mTBM. Embryos obtained were divided in 4 groups (1) cultured in NCSU 23 containing 0.4% BSA to blastocyst stage(Control), (2) essential amino acids (EA), (3) non-essential amino acids (NA), (4) mixture of essential and non essential amino acid (EA+NA). All treated groups(2-4) were used a glucose free NCSU 23 medium supplemented with pyruvate (0.33 mM), lactate (4.5 mM) to morula stage. From morula to blastocyst stage embryos of all treated groups were cultured in NCSU 23 containing 0.4% BSA. The rates of cleaved oocytes at 48 h after IVF were from 82% to 88% in the groups of control, EA, NA and EA+NA, respectively. The in vitro developmental rates into blastocysts in the groups of EA and EA+NA were significantly (P<0.05) higher than those of group of control (35.1, 35.4 vs. 19.4%, respectively), however, no significant (P<0.05) between control and NA. In conclusion, supplemented with essential amino acid or mixture of essential and non essential amino acid in the culture medium at morula stage increased the rate of development to blastocyst on in vitro produced porcine embryos.