Embryo transfer (ET) technology is of high importance in modern cattle breeding programs. ET is one step in the process of removing one or more embryos from the reproductive tract of an outstanding donor female and transferring them to one or more recipient females. Embryos also can be produced in the laboratory via techniques such as in vitro fertilization (IVF). But the actual transfer of an embryo is only one step in a series of processes that may include some or all of the following: superovulation and insemination of donors, collection of embryos, isolation, evaluation and short-term storage of embryos, micromanipulation and genetic testing of embryos, freezing of embryos and embryo transfer. Cryopreservation and direct transfer of frozen-thawed embryos is common-place with pregnancy rates near that of fresh embryos. Polymerase chain reaction (PCR) technology is currently being used for sexing embryos, and this technology will be used for “embryo diagnostics” and “embryo genomics” in the future. Although, many limitations and problems remain to overcome, these and other new technologies promise to change livestock breeding drastically in the next decade.
Recently, the transgenic animal production technique is very important for the production of bio-parmaceutical as animal bio-reactor system. However, the absence of survival evaluation in vitro produced transgenic embryos has been a problem of the low productivity of transgenic animal because of absent of pre-estimate of pregnancy after transgenic embryos transferred into recipient. Therefore, this study is conducted to improve efficiency of transgenic cattle production by improving the non-surgical embryo transfer (ET) method. Transgenic bovine embryos were produced by injection of feline immunodeficiency virus enhanced green fluorescent protein (FIV-EGFP) lentiviral vector into perivitelline space of in vitro matured MІІ stage oocytes, and then in vitro fertilization (IVF) was occured. Normal IVF and EGFP expressing blastocysts were transferred into recipients. Results indicated that 2 expanded blastocysts (34.7%) transferred group showed significantly (P<0.05) higher pregnancy rate than 1 expanded blastocyst (26.8%) transferred group. In case of parity of recipient, ET to heifer (34.9%) showed significantly (P<0.05) higher pregnancy rate than ET to multiparous recipient (21.2%). However, there are no significant differences of pregnancy rate between natural induced estrus and artificial induced estrus groups. Significantly (P<0.05) higher pregnancy rate was obtained from recipient group which have normal corpus luteum with crown group (34.8%) than normal corpus luteum without crown (13.6%). Additionally, treatment of 100 μg Gn-RH injection to recipient group (38.6%) 1 day before ET significantly (P<0.05) increase pregnancy rate than non- Gn-RH injection to recipient group (38.6%). We also transferred 2 EGFP expressing expanded blastocysts to each 19 recipients, 7 recipients were pregnant and finally 5 EGFP transgenic cattle were produced under described ET condition. Therefore, our result suggested that transfer of 2 good-quality expanded blastocysts to 100 μg of Gn-RH injected recipient which have normal corpus luteum with crown is feasible to produce transgenic cattle.
The objective of this study was to analyze the accuracy of estrus detection of heat detector and analysis of estrus behavior (mounting and mounted), and the evaluation of conditions required for improving reproductive efficiency in Holstein dairy cows fitted with a estrous detector. The heat detection system consists of estrous detector based on wireless sensor and an electric bulletin board displayed estrus behavior data. When cow mounting other cows, the accuracy of estrus behavior displayed an electric bulletin board were 87.5% (mounting other cows only), 100% (mounting other cows but not standing), 80.0% (mounting other cows with standing for 1∼4 seconds), 90.0% (mounting other cows but not standing for 1∼4 seconds), 80% (mounting other cows with standing for more than 5 seconds) and 90.0% (mounting other cows but not standing for more than 5 seconds). When cow mounted other cows, the accuracy of estrus behavior displayed an electric bulletin board were 100% (mounted other cows but not standing), 100% (mounted other cows with standing for 1∼4 seconds), 100% (mounted other cows but not standing for 1∼4 seconds) and 100% (mounted other cows with standing for more than 5 seconds). Circadian distribution of first observed in estrus were 59.1% (am 8∼pm 6) and 40.9% (pm 6∼am 8). Distribution for the number of estrus behavior were 40.9% (less than 3 times), 36.4% (4∼6 times) and 22.7% (more than 4 times). The conception rates relative to interval from first estrus behavior to insemination for estrus periods were 23.1% (less than 11 hours) and 55.6% (12∼20 hours).
The purpose of this study is to improve production efficiency of vitrified-thawed transgenic bovine embryos. Transgenic bovine embryos were produced by injection of FIV-GFP lentiviral vector into perivitelline space of in vitro matured MІІ stage oocytes, and then in vitro fertilization. EGFP-expressing transgenic bovine blastocysts were cultured in serum-containing and serum–free medium. These blsatocysts were vitrified by pull and cut (PNC) container made with 0.25 cm plastic straw. Results indicate that total developmental rates of normal IVF embryo cultured in serumcontaining and–free medium into blastocyst were not significantly different (22.3 vs 21.5%) and those of GFPexpressing transgenic bovine embryo into blastocyst showed no significant difference between serum-containing (13.9%) and–free medium (13.1%). However, developmental rate of GFP transgenic embryo was significantly (P<0.05) lower than its of normal IVF embryos. In additional study, we vitrified GFP transgenic normal bovine blastocysts using PNC vitrification method. Survival rate of vitrified-thawed GFP transgenic blastocyst (23.1%) was significantly (P<0.05) lower than its of normal blastocysts (68.9%). Although, survival rate of vitrified-thawed GFP transgenic blastocyst was lower than its of normal blastocyst, our result may suggested that PNC vitrification method is feasible to cryopreserve transgenic embryos. Our next plan will be the production of GFP express transgenic bovine derived from vitrified-thawed embryos using PNC method.
This study was designed to evaluate the effect of L-cysteine on sperm characteristics and oocyte cleavage in vitro in Korean native cattle. For this study, the freezing of diluted semen were added with Triladyl containing 20% eggyolk and/or 0, 5, 10 and 20 mM L-cysteine before cryopreservation. The viability in frozen-thawed sperm were estimated by SYBR14/PI double stain, acrosome damage with FITC-PNA, mitochondria intact with Rhodamin123 and hydrogen peroxide(H2O2) level with carboxy-DCFDA by flow-cytometry. The developmental capacity was also assessed with cleavage rates in oocytes fertilized in vitro by frozen-thawed sperm. In results, the sperm viability was significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). In addition, acrosome damage was significantly decreased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). The mitochondria intact was also significantly increased in 10 mM and 20 mM concentrations of L-cysteine than other groups (p<0.05). On the other hand, the cleavage rates were significantly increased in 0 mM, 5 mM and 10 mM groups than 20 mM concentration of L-cysteine (p<0.05). The oocyte degeneration of oocytes were significantly decreased in 0 mM, 5 mM and 10 mM groups than in 20 mM L-cysteine group (P<0.05). However, there are no significantly differences among the L-cysteine treatment groups. We suggest that concentration of 10 mM L-cysteine have beneficial impact for sperm cryopreserved in Korean native cattle. This result also could be recommended for artificial insemination program if supported by an improvement in the fertility results and required further study.
The present study was conducted to compare on embryo survival rates by blastomere isolation methods, and establish the optimal PCR procedure for perform the sexing of bovine blastocysts produced by IVF. IVF embryos used in the study was used the Bisected or Sliced methods for blastomere isolation, and the survival rates of blastocyst with rapid way of sexing PCR was assessed. In the present study for survival rates in blastocyst was the total cleavage rate was 75% and a blastocyst development among cleaved embryos was 40%. Survival rate of embryos treated with intact, bisected or sliced method was 100, 63.3 or 81.3%, respectively. Therefore, survival rate of embryos treated with sliced method was higher compared to that of embryos treated with bisected method. The sexing rate of female or male was not significantly different between S4BFBR primer and BSY + BSP primer (1.75 : 1 vs. 1.43 : 1), respectively. Because of the PCR amplification using the S4BFBR primer was simpler method than multiplex PCR amplification method. Furthermore, the accuracy of sexing rate and reduction of PCR work time between 2-step and 3-step of PCR methods was 98.0% / 1.5 hr and 97.0% / 3.5 hr, respectively. Based on these results, it can be suggested that the sliced and PCR methods we developed was very effective method to reduce time consuming and procedure of PCR amplification for sexing with the increase of survival rate on the blastocyst.
This study was carried out to examine a molecular marker system for parentage test in Jeju Black cattle (JBC). Based on the preliminarily studies, we finally selected for construction of a novel genetic marker system for molecular traceability, identity test, breed certification, and parentage test in JBC and its related industrial populations. The genetic marker system had eight MS markers, five indel markers, and two single nucleotide polymorphisms (SNPs; g.G299T and g.del310G) within MC1R gene which is critical to verify the breed specific genotypes for coat color of JBC differing from those of exotic black cattle breeds such as Holstein and Angus. The results showed lower level of a combined non-exclusion probability for second parent (NE-P2) of 4.1202×10-4 than those previously recommended by International Society of Animal Genetics (ISAG) of 5.000×10-4 for parentage, and a combined non-exclusion probability for sib identity (NE-SI) of 2.679×10-5. Parentage analysis has been successfully identified the JBC offspring in the indigenous population and cattle farms used the certified AI semens for production using the JBC-derived offspring for commercial beef. This combined molecular marker system will be helpful to supply genetic information for parentage test and traceability and to develop the molecular breeding system for improvement of animal productivity in JBC population.
Bovine coat color is decided by the melanocortin receptor 1 (MC1R) genotype mutation and melanogenesis. Specially, in the various cattle breeds, dominant black coat color is expressed by dominant genotype of ED, red or brown is expressed in the frame shift mutation of recessive homozygous e by base pair deletion and wild type of E+ is expressed in various coat colors. However, not very well known about the effected of MC1R genotype mutation on the coat color through family lines in KBC. Therefore, this study were to investigate effect of MC1R genotype mutation on the coat color, and to suggest mating breed system in accordance with of MC1R genotype for increased on brindle coat color appearance. Parents (sire 2 heads and dam 3 heads) and offspring (total : 54 heads) from crossbreeding in KBC family line with the MC1R genotype and phenotype records were selected as experimental animals. The relationship between melanocortin 1 receptor (MC1R) genotypes expression verified by PCR-RFLP, and brindle coat color appearance to the family line of the cross mating breed from MC1R genotype pattern was determined. As a result, 4MC1R genetic variations, E+/E+ (sire 1), E+/e (sire 2 and dam 3), E+/e with 4 bands of 174, 207 and 328 bp (dam 1) and E+/e with 3 bands of 174, 207, 328 and 535 bp (dam 2) from parents (sire and dam) of KBC. However, 3 genetic variations, e/e (24%), E+/E+ (22%) and E+/e (56%) were identified in offspring. Also, brindle coat color expressrated was the e/e with the 0%, E+/E+ with 67% and E+/e with 77% from MC1R genotype in offspring on the cross mating of KBC. Furthermore, when the sire had E+/e genotype and the dam had E+/E+ with the 3 bands or E+/e genotype, and both had whole body-brindle coat color, 62% of the offspring had whole body-brindle coat color. Therefore, the seresults, the mating system from MC1R genotype patterns of the sires (E+/e) and dams (E+/E+ with the 3 bands or E+/e) with brindle coat color may have the highest whole body-brindle coat color expression in their offspring.
The objective of the study is to assess temperament of a horse based on general temperament test by a questionnaire survey. Five test criteria were identified: gentleness, patience, aggressiveness, sensitivity, and friendliness, each on a 5-point scale. 114 horses bred at the National Institute of Animal Science (NIAS) in 2010, 2011 and 2012. The horses recorded scores of 3.6∼3.9 for gentleness, 3.1∼3.6 for patience, 3.4∼4.0 for aggressiveness, 2.8∼3.2 for sensitivity, and 3.4∼3.8 for friendliness, the overall score for sensitivity the lowest. Horses born in 2012 scored lower than the rest in all five areas at a statistically significant level (P<0.05). By gender, the colts scored higher than the fillies in all five areas, but the discrepancy was not statistically significant. Factor analysis yielded only one factor, and the Cronbach's α value was 0.980 for standardization of Factor 1, indicating a high reliability of internal consistency. The correlation coefficients among the test criteria ranged between 0.85 and 0.91 (P<0.01). The assessment criteria used in this study are expected to provide a useful basis designing a temperament test horses.
The objective of this study was to monitor health conditions of four genetically identical somatic cells cloned Labrador retriever puppies by estimation of body weight and analysis of hematologic and serologic characteristics. Naturally ovulated oocytes and donor cells were used for somatic cell nuclear transfer (SCNT). Donor cells and enucleated oocytes were followed by electric fusion, chemical activation and surgical embryo transfer into the oviducts of surrogate females. Two recipients became pregnant; two maintained pregnancy to term, and four live puppies were delivered by Caesarean section. The cloned Labrador retrievers were genetically identical to the nuclear donor dog. The body weight of clone-1, -2, -3, and -4 was increased from 0.66, 0.40, 0.39, and 0.37 kg at birth to 6.2, 6.6, 6.2, and 6.0 kg at 8 weeks of age, respectively. Although clone-4 had lower numbers of RBC than reference range, the most of RBC and WBC related heamatologic results of cloned puppies were not different when compared to reference range. In serological analysis, Glucose, ALP and inorganic phosphate level of four cloned puppies was significantly higher than the reference ranges. However, there was no significant difference among four cloned dogs. This study suggests that cloned puppies derived from SCNT did not have remarkable health problems, at least in the growth pattern and hematological and serological parameters.
It is generally accepted that chronic stress impairs female reproduction. It negatively affects ovarian function and the number of ovulated oocytes. Chronic stress lowers the number of retrieved oocytes. Ovarian follicular development is regulated by both pituitary-derived gonadotropins and intraovarian regulatory factors. The main corticosteroids are cortisol, cortisone, 11-deoxycortisol and corticosterone, cortisol being one of the most commonly used welfare and stress physiological indicator. In this study, we investigated the effect of cortisol level on progesterone patterns and ovulation in the dog. Cortisol and progesterone level of serum were analyzed by radioimmunoassay. The day of ovulation was considered as the day when serum progesterone concentration was 6.0∼8.0 ng/ml. In vivo dog oocytes were collected by flushing oviducts of mixed-breed bitches at three days after ovulation. We classified dogs as having group 1 (cortisol level, 0 ≤ or < 2 μg/dl), group 2 (corisol level, 2 ≤ or < 4 μg/dl), group 3 (cortisol level, 4 ≤ or < 6 μg/dl) and group 4 (cortisol level, 6 μg/dL ≤). The patterns of progesterone were not different in four cortisol groups. The average numbers of retrieved oocytes was not different in four cortisol groups. These results suggest that different cortisol levels on estrus dogs do not affect ovulation, number of ovulated oocytes and progesterone changes.
Pyracantha is a genus of thorny evergreen large shrubs in the family of Rosaceae, with common names Firethorn or Pyracantha. It's extract has also been used in cosmetics as a skin-whitening agent and functioning through tyrosinase inhibition. Recent studies have shown that pyracantha extract possesses antioxidant activities and may significantly improve lipoprotein metabolism in rats. Although the mode of action of Pyracantha extract is not fully understood, a strong relationship was observed between antioxidant and apoptosis in some types of cells. Thus, the aim of this study was to evaluated the effect of pyracantha extract on blastocysts formation and their quality of the porcine parthenogenetic embryos. After parthenogenetic activation by chemicals, presumptive porcine parthenogenetic embryos were cultured in PZM-3 medium supplemented with extracts of pyracantha leaf, stalk and root for 6 day (1, 5 and 10 μg/ml, respectively). In our results, the frequency of blastocyst formation in pyracantha root extract (5 μg/ml) treated group had increased that of other groups. Furthermore, blastocysts derived from pyracantha root extract (5 μg/ml) treated group had increased the total cell numbers and reduced apoptotic index. Blastocyst development was significantly improved in the pyracantha root extract (5 μg/ml) treated group when compared with the H2O2 treated group (p<0.05). Subsequent evaluation of the intracellular levels of ROS in pyracantha root extract (5 μg/ml) treated groups under H2O2 induced oxidative stress were decreased (p<0.05). In conclusion, our results indicate that treatment of pyracantha root extract may improve in vitro development of porcine parthenogenetic embryos through its antioxidative and antiapoptotic effects.
The present study was performed to investigate the effect of Hh-Ag1.5, a small-molecule chemical agonist of SMOothened receptor, on the in vitro maturation and development of in vitro fertilized (IVF) embryos in pigs. Oocytes or fertilized embryos were cultured in a maturation or embryo culture medium supplemented with 0 (control), 25, 50 or 100 nM of Hh-Ag1.5, respectively. Although the maturation rate were not different among treatment groups, the blastocyst formation rate in the group treated with 25 nM Hh-Ag1.5 was significantly increased compared to other groups (P<0.05). While the highest dose of Hh-Ag1.5 (100 nM) did negatively affect to the embryo development and cell number in blastocysts compared to other groups (P<0.05), the apoptotic cell index in blastocysts was significantly lower in 25 and 50 nM groups than in control and 100 nM groups (P<0.05). The mRNA expression of the proapoptotic gene Bax and the ratio of Bax/Bcl-XL decreased in among treatment groups compared to control (P<0.05). The embryo quality related genes, Tert and Zfp42, were significantly decreased in 50 and 100 nM groups compared with control and 25 nM groups (P<0.05). In conclusion, the addition of 25 nM Hh-Ag1.5 to in vitro maturation and culture medium can enhance the developmental potential as well as quality of IVF embryos in pig.
The endometrium undergoes a cyclic growth and tissue remodeling as changes of epithelial cells, and plasminogen activators (PAs) are related to endometrium tissue remodeling. This study was to evulate expression of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) in porcine uterine epithelial cells. In results, the uPA and tPA were expressed in uterine tissue, epithelium and secretory glands in porcine endometrial cell. In addition, the uPA and tPA were expressed in cultured epithelial cells, and it were mainly expressed in cytoplasm. In porcine uterine tissue and epithelial cells, uPA activity was higher than activity in tPA. In PAs mRNA expression levels, uPA mRNA level was significantly higher than tPA mRNA level (P<0.05). The fluorescence intensity of uPA protein was also higher than fluorescence intensity of tPA protein, and uPA protein expression was significantly higher than in tPA protein expression (P<0.05). Therefore, we suggest that a physiological function in porcine uterine epithelial cells should be more influenced by uPA than in tPA during pre-ovulatory phase.
The endometrium undergoes a cyclic growth and tissue remodeling as changes of epithelial cells, and plasminogen activators (PAs) are related to endometrium tissue remodeling. This study was to evulate expression of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) in porcine uterine epithelial cells. In results, the uPA and tPA were expressed in uterine tissue, epithelium and secretory glands in porcine endometrial cell. In addition, the uPA and tPA were expressed in cultured epithelial cells, and it were mainly expressed in cytoplasm. In porcine uterine tissue and epithelial cells, uPA activity was higher than activity in tPA. In PAs mRNA expression levels, uPA mRNA level was significantly higher than tPA mRNA level (P<0.05). The fluorescence intensity of uPA protein was also higher than fluorescence intensity of tPA protein, and uPA protein expression was significantly higher than in tPA protein expression (P<0.05). Therefore, we suggest that a physiological function in porcine uterine epithelial cells should be more influenced by uPA than in tPA during pre-ovulatory phase.
Cryopreservation and in vitro fertilization (IVF) protocols are important in genetic studies and applications to transgenic animals. Various studies about boar sperm cryopreservation have been studied for a long time. Those were about the use of extenders, the choice of sugars, the cooling and warming rates. The factors that influence the boar sperm are the dramatic changes in temperatures, osmotic and toxic stresses, and reactive oxygen species (ROS) generation. Among these factors, ROS generation is the main damage to DNA which is a principal genetic material and the most important for the practical applications. So we wondered whether ROS generation could be reduced. In previous study, monothioglycerol (MTG) was essential for the culture of embryo stem cells. Therefore we added MTG in the freezing extender based on lactose-egg yolk (LEY) with trehalose. For the assessment of the frozen-thawed sperm, we focused onmotility, membrane integrity and DNA damage. First, we used a computer-aided sperm analysis system for overall conditions of sperm such as motility and viability. Then we performed the sperm chromatin structure assay for DNA integrity and hypo-osmotic swelling test for membrane integrity. And our result showed the existence of MTG in the freezing extender caused less damage to DNA and higher motility in frozen-thawed boar sperm. Also we checked a relative antioxidant activity of MTG in modified Modena B extender. We concluded that this reagent can activate sperm mitochondria at MTG 0.2 μM, contribute to sperm motility and DNA integrity but there was no significant difference on membrane integrity. Also antioxidant activity of MTG in modified Modena B extender was proved.
Cryopreservation of epididymal spermatozoa offers a potential tool for rescuing genetic material from males of genetically elite populations. Castration, catastrophic injury, sudden death or any other event that makes semen collection or mating impossible may prematurely terminate a stallion reproduction. Stallion epididymal spermatozoa vary widely in the loss of progressive motility, acrosomal integrity, and viability during freezing and thawing. The objective of this work was to investigate the effect of (1) freezing package types on cryopreservation efficiency, (2) thawing temperatures (37, 56 or 70℃) on Computer Assisted Sperm Analysis (CASA) parameters and (3) post-thawing incubation time (0, 1, 2 or 4h) on castrated stallion epididymis. Post-thawed sperm motility ranged between 59.69% and 64.28% (56℃ and 37℃) in various thawing temperatures. When stallion epididymis sperm was frozen, straw was better than freezing tube on VCL (Velocity of Curvilinear Line) and VAP (Velocity of Average Path) parameter. Higher percentage of motility was observed at 37℃ thawing temperature even though no significant difference was observed among various temperatures. The motility, VCL, ALH (Amplitude of Lateral Head displacement), VAP, BCF (Beat-Cross Frequency) and STR (Straightness index) parameter of post-thawed sperm were significantly decreased by increasing the incubation time for all thawing temperatures. The present study showed that type of freezing package (Straw vs. Freezing tube) was not significantly different on cryopreservation efficiency. Furthermore, stallion epididymal spermatozoa frozen-thawed at 37℃ for 1 min resulted the highest proportion of motility and velocity movement. In addition, motility and viability of frozen-thawed stallion epididymal spermatozoa were also decreased by incubation.
The aim of this study was to establish a three dimensional (3D) culture system of endometrial cells and to examine the plasminogen activators (PAs) activity in porcine uterine. The 3D culture system in porcine endometrial cells was composed to mixture 3D gel, stromal cells and epithelial cells. The 3D culture system was used to identify normal structure search as uterine tissue and PAs expression in this study. In results, porcine endometrium epithelial cells forming a top monolayer and endometrium stromal cells developed as fibroblast-like within 3D matrix scaffold. Expression of urokinase-type PA (uPA) and tissue-type PA (tPA) were observed during the 3D culture using immunofluorescence. PA activity in 3D-cultured endometrial cells was no significant difference between the tissue type, but 2D culture system were significantly lower than in 3D-cultured endometrial cells (P<0.05). Therefore, basic system and functional aspect of 3D culture could be established with similar system of endometrium tissue. We suggest that this study was assumed applicable as baseline data to investigate mechanism between porcine uterus cells in vitro.
A major barrier to progress in pig to primate organ transplantation or cell therapy is the presence of terminal α -1,3-galactosyl epitopes on the surface of pig cells. Therefore, the purpose of this experiment was to establish and cha- racterize mesenchymal stromal/stem cells (MSCs) derived from α-1,3-galactosyltransferase (GalT) knock out (GalT KO) pig to confirm their potential for cell therapy. Bone marrow (BM)-MSCs from GalT KO pig of 1 month old were isolated by Ficoll-Paque PLUS gradient and cultured with A-DMEM + 10% FBS on plastic dishes in 5% CO2 incubator at 38.5. GalT KO BM-MSCs were analyzed for the expression of CD markers (CD45-, 29+, 90+ and 105+) and in vitro differentiation ability (adiopogenesis and osteogenesis). Further, cell proliferation capacity and cell aging of GalT KO BM-MSCs were compared to Wild BM-MSCs by BrdU incorporation assay (Roche, Germany) using ELISA at intervals of two days for 7 days. Finally, the cell size was also evaluated in GalT KO and Wild BM-MSCs. Statistical analysis was performed by T-test (P<0.05). GalT KO BM-MSCs showed fibroblast-like cell morphology on plastic culture dish at passage 1 and exhibited CD45-, 29+, 90+ and 105+ expression profile. Follow in ginduction in StemPro adipogenesis and osteogenesis media for 3 weeks, GalT KO BM-MSCs were differentiated into adipocytes, as demonstrated by Oilred Ostaining of lipid vacuoles and osteocytes, as confirmed by Alizarinred Sstaining of mineral dispositions, respectively. BrdU incorporation assay showed a significant decrease in cell proliferation capacity of GalT KO BM-MSCs compared to Wild BM-MSCs from 3 day, when they were seeded at 1×103 cells/well in 96-well plate. Passage 3 GalT KO and Wild BM-MSCs at 80% confluence in culture dish were allowed to form single cells to calculate cell size. The results showed that GalT KO BM-MSCs (15.0 ± 0.4 μm) had a little larger cell size than Wild BM-MSCs (13.5 ± 0.3 μm). From the above findings, it is summarized that GalT KO BM-MSCs possessed similar biological properties with Wild BM-MSCs, but exhibited a weak cell proliferation ability and resistance to cell aging. Therefore, GalT KO BM-MSCs might form a good source for cell therapy after due consideration to low proliferation potency in vitro.
Xenotransplantation of pig organs into primates results in fatal damage, referred as hyperacute rejection (HAR), and acute humoral xenograft rejection (AHXR), to the organ graft mediated by antibodies pre-existing and newly-producing in primates against their cognate pig antigens. Functional ablation of α1,3-galactosyltransferase (Gal-T KO) of pig which is an enzyme involved in synthesis of Gala1-3Galb1-4GlcNAc-R antigen is essentially required to prevent HAR. Moreover, additional genetic modification under Gal-T KO background for enforced expression of human complement regulatory proteins which can inhibits complement activation is known to effectively imped HAR and AHXR. In this study, we constructed a membrane cofactor protein (MCP) expression cassette under control of human EF1α promoter. This cassette was inserted between homologous recombination regions corresponding to Gal-T locus. Subsequently this vector was introduced into ear skin fibroblasts of female pig by nucleofection. We were able to obtained 40 clones by neomycin selection and 4 clones among them were identified as clones targeted into Gal-T locus of MCP expression cassette by long-range PCR. Real time RT-PCR was shown to down-regulation of Gal-T expression. From these results, we demonstrated human EF1α promoter could induce efficient expression of MCP on cell surface of fibroblasts of female pig.