In vitro production of mammalian embryos has been achieved with the oocytes derived from middle-size follicles (MF, mainly 3-6 mm in diameter) in many species including domestic animals. In the ovaries, however, there are more small-size follicles with less than 3 mm in diameter (SF). If we can develop an efficient system to produce embryos in vitro from the oocytes from SF. In this presentation, I would like to review about embryo production in vitro from the oocytes derived from SF. As well as the diameter of oocytes, the number of cumulus cells surrounding the oocyte derived from SF is significantly smaller those of oocytes from MF. The comparative analysis in electrophoresis about secretions of cumulus-oocyte complexes derived from SF and MF demonstrated a significant difference in the proteins with a molecular weight. Proteins secreted from cumulus cells, vascular endothelial growth factor (VEGF), are 34- to 42-kDa proteins, including seven family members. The molecular weight of VEGF was similar with the secretion we observed. Supplementation of medium for in vitro maturation with VEGF significantly improved the oocytes competence not only to complete the meiosis in vitro but also to develop to the blastocyst stage following parthenogenetical activation. Removing cumulus cells 20 h after the start of culture for in vitro maturation also significantly improved the competence of oocytes derived from SF to achieve the meiosis. A combination of these new techniques may improve more the meiotic and developmental competences.

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.

This study was carried out to investigate the effects of tissue inhibitor of matalloproteinase-1 (TIMP-1), Activin A and Heparin binding epidermal growth factor (HB-EGF) on in vitro production of bovine embryos. In experiment 1, presumptive zygotes were cultured in the medium supplemented with TIMP-1 (0.5 μg/ml), Activin A (100 ng/ml), or HB-EGF (100 ng/ml) at 39 ℃ in a humidified atmosphere of 5% (v/v) CO2, 5% (v/v) O2 and 90% (v/v) N2. In experiment 2, TIMP-1 + HB-EGF or Activin A + HB-EGF combinations were supplemented in the culture medium. The developmental rate to blastocysts, hatching rate and total cell numbers of the blastocysts were evaluated in both experiments. The embryos cultured in medium without growth factor supplementation was used as control group. In experiment 1, the embryos cultured in medium supplemented with TIMP-1 and Activin A showed significantly higher developmental rate to blastocysts than those cultured with HB-EGF and control (36.9%, 34.1%, 21.2% and 23.1%, respectively) (P<0.0001). However, the hatching rate of blastocyst was significantly higher in embryos with HB-EGF than those with TIMP-1, Actvin A and Control groups (84.4%, 58.8%, 51.4% and 49.3%, respectively) (P<0.001). Total cell number per blastocyst was also significantly higher in embryos with HB-EGF group (174.3±2.5) than those with TIMP-1, Activin A (149.7 and 150.0, respectively) (P<0.05) and Control (119.0) (P<0.001). In experiment 2, embryos cultured with combined treatment of Activin A and HB-EGF resulted in significantly higher rates of blastocysts formation (48.0%), hatching rate (89.7%) and total cell number in blastocyst (182.3±2.1) than those with TIMP-1 and HB-EGF combination group (32.0%, P<0.001; 76.6%, P<0.05; 165.7±4.2, P<0.001, respectively). Our data demonstrate that in vitro production of bovine embryos could be improved by combined supplementation of Activin A and HB-EGF in culture medium.

본 연구는 돼지의 난포란을 체외성숙하여 세포질내정자주입(ICSI)에 의해 생산된 체외수 정란의 체외발달율을 평가하기 위하여 실시하였다. 세포질내정자주입에 의한 체외수정란의 발달율은 서로 다른 보존상태의 정자인 신선정자, 액상정자 및 동결-융해된 정자를 이용하 더라도 수정율과 배발달율에는 영향을 미치지 않는 것으로 나타났다. 세포질내정자주입 후 난자의 전기적 활성화를 처리한 실험군이 활성화를 처리하지 않은 실험군에 비해 수정율과 배반포기배로의 발달율에 있어서는 높은 경향을 나타내었으나, 체외수정 실험군 및 전기적 활성화를 처리한 실험군과 전기적 활성화를 처리하지 않은 실험군간 배반포기배의 할구수는 유의적인 차이를 나타내지 않았다. 또한 각각의 실험군에서 얻은 배반포기배의 염색체를 분 석한 결과, 정상 이배체 염색체상의 비율에 있어서도 유의성을 나타내지 않았다.

This study was carried out to investigate effective condition for producing somatic cell nuclear transfer (SCNT) embryos of Jeju native cattle. As donor cells for SCNT, ear skin cells from Jeju native cattle were used. In experiment 1, the effect of recipient oocyte sources on the development of Jeju native cattle SCNT embryos were examined. Fusion rate of recipient oocyte and donor cell was not different between the Hanwoo and Holstein recipient oocytes (86.0% vs 89.9%). The rate of embryos developing to the blastocyst stage was significantly (p<0.05) higher in Hanwoo recipient oocytes than in Holstein recipient ones (28.2% vs 14.7%). Blastocysts derived from Hanwoo recipient oocytes contained higher numbers of total cells than those derived from Holstein ones ( vs ), although there were no significant difference. The mean proportion of apoptotic cells in blastocyst was not different between the sources of recipient oocytes. In experiment 2, the development of Jeju native cattle and Hanwoo SCNT embryos were compared. Hanwoo oocytes were used as the recipient oocytes. Fusion rate was not different between the Jeju native cattle and Hanwoo SCNT embryos (92.1% vs 92.9%). The blastocyst rate of SCNT embryos was significantly (p<0.05) lower in Jeju native cattle than in Hanwoo (16.9% vs 31.0%). Blastocysts derived from Jeju native cattle SCNT embryos contained smaller numbers of total cells than those derived from Hanwoo ones ( vs ), but there were no significant difference. The mean proportion of apoptotic cells in blastocyst was not different between the Jeju native cattle and Hanwoo SCNT embryos. The present study demonstrated that Hanwoo recipient oocytes were more effective in supporting production of Jeju native cattle SCNT embryos, although Jeju native cattle SCNT embryos showed reduced developmental capacity when compared to Hanwoo SCNT embryos.

The production of transgenic animals using somatic cell nuclear transfer (SCNT) has been widely described. A critical problem in the production of transgenic animals is the uncontrolled constitutive expression of the foreign gene which occasionally results in serious physiological disorders in the transgenic animal. In this study, we designed three different expression vectors that express the hEPO gene. hEPO is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. For the in vitro production of transgenic embryos, the different expression vectors were transduced into holstein ear fibroblast cells, respectively, and GFP expressed donor cells were transferred into enucleated oocytes, and then the reconstructed SCNT embryos were developed into pre-implantation stage. From three replicates, GFP expressed 112 transgenic SCNT embryos were produced. When their cleavage rate and blastocyst rate were compared with non-transgenic SCNT embryos, the results were presented into 73.2% vs. 76.9% and 26.8% vs. 30.6%, respectively, there were no differences. Also, total cell number and ICM cell numbers of day 8 blastocysts were statistically not different between the transgenic SCNT groups (120.6±7.9 and 31.4±8.2) and control SCNT group (128.3±4.8 and 35.3±4.0). The GFP expression levels were presented consecutively high during the culture of transgenic SCNT embryos. By analysis of semi-quantitative RT-PCR, the relative expression levels of hEPO mRNA and pluripotent gene were determined. These results demonstrated that the hEPO expressed transgenic bovine embryos can be efficiently produced in vitro by SCNT technique, while their potential of cloned animal production have to be examined in further study.

In the first part of this study, a novel culture device the named oil-free micro tube culture (MTC) system for in vitro culture (IVC) of murine and porcine embryos was introduced. Parthenogenetic mouse and porcine embryos were placed into 0.2-mL thinwall flat cap PCR tubes and cultured to the blastocyst stage. Conventional drop culture was used as the control. Murine embryos in MTC had a higher blastocyst formation rate and larger population of cells in the blastocysts. This was due to higher numbers of trophectoderm (TE) cells rather than inner cell mass cells. On the other hand, the 'MTC' system in the pig showed similar (in 20 μl medium volume) or lower (in 10 μl medium volume) blastocyst formation rate when compared with drop culture system. In the second part of this study, dexamethasone (DEX) and leukemia inhibitory factor (LIF), which suppress PGF2α, were directly supplemented into ET media, and transfer of the embryos to surrogate was followed. In the cattle industry, embryo transfer technology has been used to produce the most valuable cows or bulls. Numerous factors such as heat stress, mastitis, manipulating female reproductive tract may contribute to early embryonic loss through premature increases of uterine luminal concentrations of PGF2α in cows. Furthermore, addition of PGF2α to culture medium has been shown to inhibit the development and hatching of mammalian embryos. When DEX and LIF were supplemented, the pregnancy rate (6 month post-ET) was increased from 56.0% to 68.3%. In IVC experiment, DEX and LIF supplementation supported hatching of bovine embryos in the presence of PGF2α in the medium (from 16.9% to 40.6%). Additional ET experiments using alternative drugs are currently under investigation. The present work was supported by the Technology Development Program for Agriculture and Forestry, Ministry for Food, Agriculture, Forestry and Fisheries (MIFAFF; 109020-3).

As a simple and economical method for in vitro produced embryos, we have used BSA instead of serum for the production and embryo transfer of Hanwoo in vitro fertilized (IVF) embryos and obtained the following results: 1) When using serum (FBS; fetal bovine serum) or BSA-containing culture media as the initial culture media for immature oocytes, it is regarded as inappropriate to add only BSA to the culture solutions from maturation of the immature oocytes to development stage culture, but serum still needs be added though there is no significant difference in the concentration, with a change from 5% to 10%. 2) The results of culturing IVF embryos after development (4 cell stage) in the Medium199 solutions containing BSA instead of serum (FBS) showed that 0.3% BSA concentration is not optimal and 0.5% or higher BSA concentration has no significant difference among 0.5%, 0.7%, 1% and 2% (p > 0.05). 3) The post-freezing survival ratio after development in 5% FBS-Medium199 showed that 1% BSA concentration of the culture solution is the most suitable in the BSA concentrations of 0.3% (51%), 0.5% (67%), 0.7% (69%), 1% (77%) and 2% (75%). 4) The pregnancy rates of the transplanted fresh(not frozen) blastocyst had no significant concentration dependency (p > 0.5), and the average pregnancy rate was 63.8%. 14% of overweight calves were found among the calves given birth to by the transfer of IVF blastocysts cultured in the serum-added culture solution, but none was found in the experimental groups in which BSA was added instead of serum.

It is not easy for porcine embryos produced by in vitro systems to develop into blastocysts with high quality. To solve this problem, many researchers have developed novel culture methods. However, the formation of blastocysts with high quality is still low. In this study, we aimed to produce piglet following transfer of in vitro produced early embryos ( cell stage embryos) or morula and blastocyst. The cell stage embryos were transferred to five estrus-synchronized recipients (200 embryos per recipient). One of the five sows farrowed three piglets, which contain two live piglets and one dead piglet, 114 days after embryo transfer. However, two recipients transferred with morula and blastocysts did not farrow. Microsatellite analysis confirmed that the genomic DNA of two live piglets were not genetically identical to that of the recipient. These results indicate that it is possible to obtain piglets by transfer of early embryos produced by in vitro production (IVP) systems.

The ability to preselect the sex of piglets is advantageous in the pig industry. The objective of this study was to examine the feasibility of using intracytoplasmic sperm injection (ICSI) with sorted spermatozoa to produce piglets with a preselected sex. Pig embryos were produced by ICSI of frozen X- and Y-sperm that had been separated by flow cytometry. The developmental competence of the embryos was investigated in vitro and in vivo. The populations of X- and Y-spermatozoa were 52.7% and 47.3%, respectively in our samples. The in vitro development of ICSI embryos was enhanced by longer of in vitro maturation of oocytes ( vs. ). Their cleavage () and blastocyst formation () rates were not significantly different between male and female ICSI embryos, or between sorted and unsorted sperm-derived embryos. One pregnancy was established in a recipient that was transferred with 110 female ICSI embryos, but the pregnancy was terminated on Day 89 of gestation. Our results suggest that the separation X- and Y-spermatozoa by flow cytometric sorting can be a useful tool in combination with ICSI for the production of pig embryos and piglets of preselected sex.

본 연구는 한우 체외 수정란의 성 감별과 신선란, 동결란 및 성 감별 수정란을 이식한 후 수태율, 분만율과 유산율, 생시 체중, 임신 기간을 조사하기 위하여 수행하였다 Aspiration과 punching법으로 biopsied한 수정을 24시간 배양 후 생존율은 각각 80.0%와 90.0%로 유의적인(p>0.05) 차이는 없었다. 수정란을 성 감별한 결과, 웅성 수정란과 자성 수정란의 비율은 각각 42.1%와 52.6%였으며, 5.3%는 수정란의 성을

한우 및 젖소에서 체외 수정란을 생산하여 수란 우에 이식하기 위해 도축장에서 난소를 채취하여 난자를 회수한 후 체외 성숙, 체외 수정, 체외 배양과정을 거쳐 수정란을 생산하였다. 체외 수정시 난자는 난구세포 부착 정도에 따라 난할율을 조사하였고, 한우와 젖소에서 체외수정 후 배반포율을 조사하였다. 신선 및 동결 수정란을 수란우에 각각 이식하여 산자 분만에 따른 수태율을 조사하였다. 1. 한우 난소 2,021개에서 20,387개의 난자를 회수하여 체외 수

본 연구는 체외성숙/체외수정 유래의 돼지 난자를 이용하여 체외발달시 배양액의 종류나 교체에 따른 영향을 구명하고자 수행하였다. mNCSU-23에서 체외성숙시킨 다음 mTBM에서 체외수정시킨 난자를 목적에 따라 두 가지로 나누어 실험한 결과는 다음과 같다. 1. 체외성숙/체외수정란을 NCSU-23에서 배양액 교체없이 7일 동안 배양하거나 CZB에서 4일 배양한 다음 Pig-MEM으로 옮겨서 나머지 3일간 배양한 결과, 난분할율은 배양액간 차이를 보이지 않

본 연구는 mNCSU-23에서 체외성숙시킨 난자를 이용하여 돼지 체외수정시 적절한 배양액과 정자농도를 구명하고자 수행하였다. 정액은 액상정액을 이용하였고 체외수정배양액으로 mTBM과 mTLP-PVA, 정자농도는 운동정자수 5, 1 , 5 sperm/로 체외수정 한 다음 NCSU-23에서 체외발달을 유도한 결과는 다음과 같다. 1. 돼지 체외성숙란을 mTBM 또는 mTLP-PVA에서 운동정자수 1 sperm/로 체외수정시킨 다음 체외발달시킨 결과, 정자침

본 연구는 pFF, cysteine, -mercaptoethanol, 성선자극호르몬 등 여러 가지 체외성숙 촉진 물질이 첨가딘 성숙배양액에 EGF 첨가가 돼지 미성숙 난포란의 체외성숙에 효과적인지 또한 그 효가는 배양소적당 COC의 수에 영향을 받는지을 구명하고자 EGF의 첨가 유무와 배양소적당 COC수(50개 또는 15개)를 조합한 요인시험을 실시했다. 도축돼지의 난소에서 채취한 COCs를 각 처리별로 mNCSU-23 에서 성숙배양하고 mTBM에서 운

본 연구는 보다 안정된 돼지 체외수정란 생산시스템 확립을 목적으로 체외성숙배양액 mNCSU-37, mNCSU-23 및 TCM-199 가 각각 미성숙 난포란의 체외성숙, 체외수정, 체외발달에 미치는 영향을 구명하기 위하여 수행하였다. 도축돼지의 난소에서 채취한 COCs를 10% pFF가 포함된 각각의 성숙배양액에서 최종동도가 의 농도로 체외수정 시킨 다음, NCSU-23 에서 체외발달을 유도한 결과는 다음과 같다. 1. TCM-199에서 성숙시킨 난자가

활성화를 통한 수핵란의 대량확보를 위해 44시간동안 체외 성숙된 돼지 난자를 ethanol, Ca/sup 2+/-ionophore, 6-DMAP 및 cycloheximide의 화학물질들을 사용하여 단위발생을 유기한 후 그들의 가장적합한 처리농도 및 노출 시간을 규명하였다. 1. Ethanol은 10%, 10분 처리가 전핵형성율, 난할율 및 배발달율에 있어 각각 약 53.4%, 51.6%, 그리고 39.9%로 가장 적합한 조건으로 판명되었다. 2. Ca/sup 2+/-ionophore 가장 적합한 난활성화 조건은 25μM에서 2분간 처리한 것이며, 전핵형성율, 난할율 및 배발달율은 각각 약 59.7%, 62.2%, 그리고 43.9%를 보였다. 3. 6-DMAP를 처리하여 돼지 난자의 활성화를 유기하였을 경우 2mM의 농도에서 각각 약 57.3%, 58.4% 및 29.0%의 전핵형성율, 난할율, 그리고 배발달율을 보여 가장 적합한 조건을 보였으며 2시간∼4.5시간 사이의 노출에는 영향을 받지 않았다. 4. Cycloheximide는 5㎍/ml의 농도가 전핵형성율 2.1%, 난할율 47.7%, 배발달율 31.8%로 가장 은 효율을 보였고, 노출시간에서는 4시간∼6시간 동안 처리하였을 때 60.5∼65.8%, 63.6∼66.7% 및 39.0∼39.5%로 가장 적합한 조건으로 판명되었다. 이상의 결과들은 돼지 체외 성숙 난자의 활성화에 있어 각 화학물질들의 적합한 조건을 바탕으로한 중복처리 및 병용처리 조건 확립 및 효율적인 수핵란의 확보에 기여할 수 있을 것이다.