This study was conducted to analyze the transgenic efficiency and sex ratio in -1,3-galactosyltransferase (GalT) knock-out (KO) transgenic pigs according to generation. GalT KO piglets were produced by artificial insemination or natural mating. The transgenic confirmation of GalT KO was evaluated by PCR amplification using specific primers. After electrophoresis, three types of bands were detected such as 2.3 kb single band (Wild), 2.3 and 3.6kb double bands (GalT KO -/+; heterozygote), and 3.6kb single band (GalT KO -/-; homozygote). Transgenic efficiency in F1 generation was 64.5% (23/35) of GalT KO (-/+). In F2 generation, GalT KO transgenic efficiency was 36.4% (21/57, Wild), 47.5% (28/57, GalT KO -/+), and 16.1% (8/57, GalT KO -/-), respectively. Interestingly, no homozygote piglets were born in 6 deliveries among total 11 deliveries, although they were pregnant between male (M) and female (F) heterozygote. In the 5 litters including at least one GalT KO -/- piglet, the transgenic efficiency was 13.3% (2/24, Wild), 51.3% (14/24, GalT KO -/+), and 35.3% (8/24, GalT KO -/-), respectively. The sex ratio of M and F was 40:60 in and 49:51 in generation, respectively. Based on these results, GalT KO transgenic pigs have had a reproductive ability with a normal range of transgenic efficiency and sex ratio.

The purpose of this study was undertaken to evaluate of cryopreservation efficiency in α 1,3-galactosyltransferase knock-out(GalT KO) cloned miniature pig sperm. To compare ability of frozen-thawed sperm characteristics, three different pig strains (GalT KO) cloned miniature pig, PWG miniature pig and Duroc were used. The ejaculated semen from the three pig species was diluted with same volume extender and added to LEY solution for freezing. The diluted semen was placed in 0.5 ml straws, and freezing was initiated by exposing the straws to liquid nitrogen (LN2) vapours for 10 min before placing them into LN2 for cryopreservation. A fter thawing, the sperm ability were assessed for viability (SYBR-14/PI staining), abnormality (Rose Bengal staining), and acrosome status (intactness, intensity and capacitation) (chlorotetracycline, CTC staining). The viability of frozen-thawed GalT KO pig sperm had no significant difference as compared with Duroc and PWG miniature pig sperm. However, The CTC pattern of frozen-thawed GalT KO cloned miniature pig spermatozoa showed significantly lower rates in F pattern and AR pattern (p<0.05) and significantly higher rates in B pattern than Duroc and PWG miniature pig (p<0.05). The abnormality of GalT KO cloned miniature pig sperm was significantly lower as compared to Duroc and PWG miniature pig sperm (p<0.05). In conclusion, GalT KO cloned miniature pig semen can be cryopreserved successfully and used for artificial insemination reasonably.

This study was conducted to examine the effect of oocyte donor age and micromanipulation medium on the development of mouse cloned embryos receiving cumulus cells. Mouse oocytes were obtained from 6 to 11 week-old mice BDF1 female mice(experiment 1) and cumulus cells were used as donor cells. Micromanipulation procedures for nuclear transfer(NT) were performed in FHM, M2 or Hepes-buffered TCM199(TCM199) medium(experiment 2). After nuclear transfer, the reconstructed oocytes were activated by 10 mM SrCl2 in Ca-free CZB medium in the presence of 5 μg/ml cytochalasin B for 5 h and cultured in KSOM medium for 4 days. In experiment 1, the survival rate of oocytes after injection of cumulus cells were significantly(p<0.05) lower in oocytes from 6～7 week-old mice(53.3%) than in oocytes from 8～9(80.9%) and 10～11 week-old mice(77.1%). In experiment 2, the survival rate of oocytes after cell injection were significantly(p<0.05) higher in FHM and M2 medium(71.7% and 76.9%) than in TCM199 medium (51.2%). The activation rates of cloned embryos were not different among the micromanipulation media. However, the embryos developed to blastocyst stage were significantly(p<0.05) higher in FHM medium(13.9%) than in M2 and TCM199 medium(0.0% and 0.0%). In conclusion, the present study suggest that oocytes from above 8 week-old mice are superior to oocytes from 6～7 week-old mice as a source of recipient cytoplasm and FHM is superior to M2 and TCM199 as a micromanipulation medium for mouse somatic cell cloning.

The overexpression of Phosphoprotein Enriched in Astrocytes (PEA15) gene is commonly found in human diabetic patients. The overexpression of this gene in skeletal muscle and fat tissues have been reported to cause insulin resistance, thereby impairing insulin stimulated glucose uptake. We introduced a gene of mouse PEA15 (mPEA15) and enhanced green fluorescent protein (EGFP) into fertilized one cell pig zygotes using microinjection, and produced a piglet that showed overexpression of mPEA15 in the muscle tissues and expression of EGFP in the ear tissues and hooves. RT-PCR RFLP, southern blot and FISH analysis showed that the tissues carried the transgene. Real-time RT-PCR and western blots demonstrated that PEA15 gene was overexpressed in the various tissues and muscle tissues, respectively. These facts suggest that expression vector system is normally expressed in the trnasgenic (TG) pigs. To use as animal diseases model for type 2 diabetes, further study is necessary to confirm whether diabetes occur in these TG pigs, especially insulin resistance.

This study was conducted to investigate the effects of donor cell treatments on the production of transgenic cloned piglets. Ear fibroblast cell obtained from NIH MHC Inbred minipig was used as control. The GalT knock-out/CD46 knock-in (GalT/CD46) transgenic cell lines were established and used as donor cells. The reconstructed GalT/CD46 embryos were surgically transferred into oviduct of naturally cycling surrogate sows (Landrace × Yorkshire) on the second day of standing estrus. Unlike control (1.2 kV/cm,, 75.4%), the fusion rate of the GalT/CD46 donor cells was significantly higher in 1.5 kV/cm, (84.5%) than that of 1.25 kV/cm, (20.2%) (p<0.01). When the number of the transferred embryos were more than 129, the pregnancy and delivery rates were increased to 13/20 (65%) and 5/20 (25%) compared to less than 100 group [1/6 (16.7%) and 0/6 (0%)], respectively. To analyze the effect of donor cell culture condition on pregnancy and delivery rates, the GalT/CD46 donor cells were cultured with DMEM or serum reduced medium. In serum reduced medium group, the pregnancy and delivery rates were improved to 8/12 (66.7%) and 5/12 (41.7%) compared to DMEM group [3/7 (42.9%) and 0/7 (0%)], respectively. In conclusion, it can be postulated that an appropriate fusion condition and culture system is essential factors to increase the efficiency of the production of transgenic cloned piglets.

This study was performed to identify the differentially methylated region (DMR) and to examine the mRNA expression of the imprinted H19 gene in day 35 of SCNT pig fetuses. The fetus and placenta at day 35 of gestation fetuses after natural mating (Control) or of cloned pig by somatic cell nuclear transfer (SCNT) were isolated from a uterus. To investigate the mRNA expression and methylation patterns of H19 gene, tissues from fetal liver and placenta including endometrial and extraembryonic tissues were collected. The mRNA expression was evaluated by real-time PCR and methylation pattern was analyzed by bisulfite sequencing method. Bisulfite analyses demonstrated that the differentially methylated region (DMR) was located between -1694 bp to -1338 bp upstream from translation start site of the H19 gene. H19 DMR (-1694 bp to -1338 bp) exhibits a normal mono allelic methylation pattern, and heavily methylated in sperm, but not in oocyte. In contrast to these finding, the analysis of the endometrium and/or extraembryonic tissues from SCNT embryos revealed a complex methylation pattern. The DNA methylation status of DMR Region In porcine H19 gene upstream was hypo methylated in SCNT tissues but hypermethylated in control tissues. Furthermore, the mRNA expression of H19 gene in liver, endometrium, and extraembryonic tissues was significantly higher in SCNT than those of control (p<0.05). These results suggest that the aberrant mRNA expression and the abnormal methylation pattern of imprinted H19 gene might be closely related to the inadequate fetal development of a cloned fetus, contributing to the low efficiency of genomic reprogramming.

This study was performed to comprehend the plasma proteins expressed specifically during early pregnancy in pregnant or non-pregnant Hanwoo using proteomic analysis technique. Plasma samples (0, 2, 3, 4, 7, and 11 weeks after AI) were obtained from pregnant (P, n=3) or non-pregnant (NP, n=4) Hanwoo, respectively. To evaluate proteins differentially expressed, 2-dimensional electrophoresis (2DE) was conducted. Normalized protein spots were selected for the significant expression variation deviated over two fold in its expression level between two groups. Molecular functions of the proteins were DNA binding, protein binding, hemoglobin binding, ferrochelatase and transporter activity and arylestera, respectively. According to western blotting, haptoglobin was specifically expressed only in NP group during early pregnancy; however, paraoxonase 1 was highly expressed in pregnant group. Based on these results, pregnancy was maintained successfully by the activation of specific plasma proteins associated with immune system and antioxidant regulation during early pregnancy in Hanwoo

This study was conducted to investigate the variation of growth characteristics and reproductive physiology in cloned Hanwoo male calves during growing stage. The hematological parameters, body weight, and plasma hormonal levels, birth to 12 months, were analyzed in the cloned calves (n=3). Differences among treatment means were determined by a student t-test. A probability of P<0.05 was considered statistically significant. The hematological parameters, such as white blood cell, red blood cell, and platelet, were not different in both normal and cloned calves. The difference of body weight, however, was significantly higher in the cloned calves, months (p<0.05) and months (p<0.01), than that of the comparators, respectively. The plasma IGF-1 level was statistically significant in the cloned calves, months, compared to that of the normal calves (p<0.05). However, the plasma testosterone level was not different in both normal and clone calves according to growing stage. Taken together, the cloned Hanwoo male calves are growing faster and maintaining a normal reproductive physiology.

형질전환 동물의 유선에서 특이적으로 인간 TPO가 발현되도록 고안된 pBT-L 외래유전자가 삽입되어 한 계통으로 확립된 형질전환 생쥐에서 이 유전자가 장기 세대까지 안정적으로 전이되고, 또한 발현 수준도 지속적으로 유지되는지를 조사 하였다 이를 위해 제 5세대의 수컷 pBT-L 형질전환 생쥐를 실험에 공시하였고, 제 10세대까지의 전이율과 인간 TPO의 발현수준을 분석하였다. 제 8세대 생쥐의 계대 번식에 의한 자손 중 51.3±18.98%가 형질전환 생쥐로 판명되었다. 또한 제9세대에서 외래 유전자의 전이율은 43.8±18.98%이었고, 제 10세대에서는 71.4±26.98%의 전이율을 나타내었다. 이러한 결과로 pBT-L 형질전환 생쥐는 그 외래유전자의 유전적 손상이 없이 장기 세대까지 안정적으로 전이되는 것으로 판단된다. 제 9세대외 10세대의 3마리의 암컷 형질전환 생쥐로 부터 유즙내 인간 TPO의 발현 수준을 분석하였을때, 그 농도는 모두 평균 1.1 mg/ml의 수준에서 측정되었다. 이러한 수준은 제 2세대의 것과 유사한 결과로 pBT-L 형질전환 생쥐에서 인간 TPO 유전자의 발현은 최소한 10세대까지 지속적으로 유지된다는 것을 알 수 있었고, 더 긴 장기 세대까지도 발현 수준이 유지될 것으로 추정된다. 이러한 연구결과는 계통으로 확립된 형질전환동물에 부여된 새로운 유전형질은 장기 세대까지 유전될 수 있음을 보여주는 것이다.