To search a new pig pheromonal odorant, the N1-allyl-N2-(tetrahydrofuran-2-ylmethyl)oxalamide molecule predicted by ligand based approach and molecular docking method was synthesized by nucleophilic addition-elimination reaction (AdNU-E) between N-allyloxalamic acid ethylester and tetrahydrofurylmethylamine. According to the evaluation results for efficiency of pig estrus control, the synthesized pig pheromonal N1-allyl-N2-(tetrahydrofuran-2- ylmethyl)oxalamide molecule advanced the estrus by 11.3 days (p<0.05) compared with the non-pheromone group. And from these results, it is predicted that the synthesized pig pheromonal compound will be able to increase the reproduction efficiency of pig.
This study was performed to confirm the microtubule assemblies and methylation patterns of porcine IVF and parthenogenetic embryos. Cumulus-oocyte complexes were collected and matured in vitro for 42 hr. Oocytes were fertilized by prepared fresh sperm or activated parthenogenetically by exposure to electric stimulation and 6-dimethylaminopurine. Porcine IVF and parthenogenetic embryos were cultured in vitro for 6 days. Embryos were stained by immunofluorescence staining method to observe the dynamic of nucleus and microtubules in the first mitotic phase and the methylation patterns in different developmental stages. After then, samples were confirmed and analyzed through a laser-scanning confocal microscope. IVF embryos had a centrosome originated from sperms, which was shown a ɤ-tubulin spot. However, ɤ-tubulin spot was not observed in parthenogenetic embryos. A lower methylation level was observed in IVF embryos compared to parthenogenetic ones at the morula and blastocyst stages. In conclusion, it is considered that microtubule assemblies and genetic regulation mechanism differ between parthenogenetic and IVF embryos.
The aim of this study was to examine the microtubule distributions of somatic cell nuclear transfer (SCNT) and parthenogenetic porcine embryos. Porcine SCNT embryos were produced by fusion of serum-starved fetal fibroblast cells with enucleated oocytes. Reconstituted and mature oocytes were activated by electric pulses combined with 6-dimethlyaminopurine treatment. SCNT and parthenogenetic embryos were cultured in vitro for 6 days. Microtubule assembly of embryos was examined by confocal microscopy 1 hr and 20 hr after fusion or activation, respectively. The proportions of embryos developed to the blastocyst stage were 25.7% and 30.4% in SCNT and parthenogenetic embryos, respectively. The frequency of embryos showing β-tubulins was 81.8% in parthenogenetic embryos, whereas 31.3% in SCNT embryos 1 hr after activation or fusion. The frequency of the embryos underwent normal mitotic phase was low in SCNT embryos (40.6%) compared to that of parthenogenetic ones (59.7%) 20 hr after fusion or activation (p<0.05). The rate of SCNT embryos with an abnormal mitosis pattern is about twice compared to that of parthenogenetic ones. The spindle assembly and its distribution of SCNT embryos in the first mitotic phase were not different from those of parthenogenetic ones. The result shows that although microtubule distribution of porcine SCNT embryos shortly after fusion is different from parthenogenetic embryos, and the frequency of abnormal mitosis 20 hr after fusion or activation is slightly increased in SCNT embryos, microtubule distributions at the first mitotic phase are similar in both SCNT and parthenogenetic embryos.
This study was conducted to investigate the specific expression genes in the cloned bovine tissues. Donor cells, cloned tissues were analysed by RAPD-RFLP method. The results were detected three genes (CH-U7B, CH-U7M and CH-U7P) in the cloned fetus. It was found a single copy genes by southern hybridization. Sequence analysis of CH-U7M gene was shown 99% homology to a previously reported EST from a cloned bovine fetus. The putative ORF was encode a protein of hydrophobicity index 0.03. Semi-quantitative RT-PCR by using the CH-LS001 specific primer was remarkably detected in the lung tissue of cloned fetus. Further investigation of these genes may provide one of the key information to explain the early death, abnormal fetus, large off-spring and the low pregnancy rate in the production of cloned bovine.
This study was carried out to investigate the general characteristics, such as volume, pH, sperm motility and sperm concentration of the semen collected from Beagle dogs (age 24~48 months, weight 10~15 kg) by using the method of digital manipulation of the penis, and the effect of preservation temperature and time on motility of fresh semen. Multiple ejaculates were collected from 4 male Beagles. The average volume, pH, motility and sperm concentration of the second fraction (contained with small volume of the third fraction) per ejaculation were 2.94±0.24(SD) ml, 6.43±0.42(SD), 97.04±3.50(SD)% and 1.67±0.23(SD)×108 cells/ml, respectively. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the first fraction from the ejaculate were 1.24±0.20(SD) ml, 6.03±0.26(SD), 11.30±4.02(SD)% and 7.25±1.02(SD)×105 cells/ml. Those of second fraction were 2.52± 0.32(SD) ml, 6.32±0.31(SD), 96.25±3.52(SD)% and 2.35±0.35(SD)×108 cells/ml. Those of third fraction were 2.71±0.27 (SD) ml, 6.52±0.20(SD), 95.65±2.78(SD)% and 5.72±0.29(SD)×107 cells/ml. Motility of semen was higher at 17℃ preservation temperature than 5℃ or 36℃ during preservation period. When preservation temperature was 17℃, motility was 96.54±2.05(SD)% at 1 h, 90.20±3.90(SD)% at 6 h, 89.05±2.01(SD)% at 12 h, 78.21±3.50(SD)% at 18 h, 45.24±6.25 (SD)% at 24 h and 30.75±17.24(SD)% at 30 h, respectively.
The brilliant cresyl blue (BCB) has been used to select the developmental competent oocytes in pigs, goats and cows. Growing oocytes have a higher level of active glucose-6-phosphate dehydrogenase(G6PDH) compare to mature oocytes and are rarely stained compared to mature oocytes, because G6PDH converts BCB to colorless. First polar body extrusion regard as a guideline of meoisis completion. Selection of polar body extrude oocyte is more developmental competent to blastocyst than unselected. This study was conducted to compare the BCB test to the polar body extrusion on selection of developmental competent porcine oocytes for the production of blastocyst. Cumulus-Oocytes complex were exposed to 26uM BCB stain diluted in NCSU-23 for 90 min. There was no significant difference embryo development to blastocysts between BCB treated and not treated(19.58±1.99 vs 18.75±2.27 %), which means there was no detrimental effect of BCB exposure to oocytes. Normal fertilization is not differed among treatment groups from 70.0 to 78.4% development to blastocyst, beside polyspermy did not. To compare two different selection methods, BCB test and polar body extrusion, evaluate the developmental competent of IVP embryos. BCB+PB+(blue stained and polar body extruded, 20.71±0.45%) and BCB-PB+(colorless and polar body extruded, 20.04±1.29%) groups are significantly (p<0.05) higher developed than those of BCB+PB-(blue stained and no polar body, 13.24±0.73%) and BCB-PB-(colorless and no poladbody, 7.25±0.77%). These results showed that selection of polar body extruded oocytes method is more efficient than that of BCB test.
The objectives of this study was to evaluate the efficiency of the bacteria eliminated sperm by percoll gradient method on sperm quality and embryo cleavage in vitro in pig. The semen of miniature pig collected by gloved-hand method pre-warmed (37℃) in thermos bottle, and separated by 65% percoll. Analysis of sperm ability was estimated by examining viability, capacitation and acrosome reaction using chlortetracycline (CTC) and the abnormality. Also, fertility of sperm was monitored with cleavage rate of embryo after IVF using separated and un-separated sperm by percoll. The result, viability of separated sperm was significantly(p<0.05) higher(83.6±2.0 vs 59.0±4.4%) than un- separated sperm. The results of CTC analysis showed the percentage of F- and B-patterned separated sperm was higher in separated that than un-separated sperm. On the contrary, the percentage of AR-patterned form un-separaed sperm was significantly(p<0.05) higher(13.6±0.8 vs 8.1±0.6%) than separated sperm. Also, abnormality of un-separated sperm was significantly(p<0.05) higher(20.2±0.4 vs 16.8±2.8%) than separated sperm. However, the cleavage rates of embryo using separated sperm by percoll and un-separated sperm had not significantly difference on 2 cell stage(9.25 vs 11.88%), 4 cell stage(26.76 vs 24.51%) and >4 cell stage(63.99 vs 63.61%) at 48h of IVF. Therefore, the sperm separated by percoll method showed improvement in sperm quality than un-separated sperm in miniature pig.
Placenta is the main nutrition source for the fetus during pregnancy. Thus, it has a pivotal function in the pregnant process. Many functions of the placenta have been elucidated. An abnormal placenta is associated with a high rate of pregnancy failure in somatic cloned bovine. Differentially expressed genes (DEGs) were examined in a comparison between normal and cloned bovine placenta using annealing control primer (ACP)-based GeneFishing PCR. Using 120 ACPs, nearly 80 genes were identified and the fragments of 42 DEGs were sequenced. 38 of these genes were known genes and four were unknown. To determine the DEGs result, six target clones expressing on one-side of a normal and a clone placenta were selected. Through an analysis of the target genes using the real-time PCR, the expressing pattern was found to be somewhat different from the DEGs. Additionally, several genes appeared with the same expression pattern. Taken together, this suggests that the target genes would be essential for research into what influences the placental formative mechanisms during fetal development.
The current study was designed to evaluate the effects of the reactive oxygen species (ROS) generated with a xanthine (X) and xanthine oxidase system (XO) on sperm function and DNA fragmentation in porcine spermatozoa. ROS were produced by a combination of 1,000 μM X and 50 mU/ml XO. The ROS scavengers such as superoxide dismutase (SOD) (200 U/ml) and catalase (CAT) (500 U/ml) were also tested. Spermatozoa were incubated for 2 hours in BWW medium with a combination of X-XO supplemented with or without antioxidants at 37℃ under 5% CO2 incubator. Ca-ionophore-induced acrosome reaction, the proportion of swollen spermatozoa under hypo-osmotic condition, malondialdehyde formation for the analysis of lipid peroxidation, and the proportion of DNA fragmentation were determined after 2 hours incubation. The action of ROS on porcine spermatozoa resulted in decreased Ca-ionophore-induced acrosome reaction and membrane integrity, increased the formation of malondialdehyde, and the proportion of sperm with DNA fragmentation(p<0.05). The toxic effects caused by ROS were completely alleviated by CAT in terms of sperm function and characteristics, however SOD did not serve the same scavenger effect as CAT. To conclude, the ROS can cause significant damage to porcine sperm functions and characteristics, which can be minimized by the use of antioxidants.
The epididymis in the male reproductive tract is the site where spermatozoa produced from the testis become mature. The epididymis is divided into 4 different segments, initial segment and caput, corpus, and caudal epididymis, depending upon functional and morphological features. Aquaporins (Aqps) are water channel molecules, which are present in the epididymis and play a major role in removal of epididymal water, resulting in creation of microenvironment for sperm maturation and concentration of sperms. Nandrolone decanoate (ND) is a synthetic anabolic-androgenic steroid, which is used to treat clinical diseases and improve physical ability and appearance. Even though it is well determined that the ND causes the male infertility by affecting the testis, little is known the effect of the ND on the epididymis. The present study was focused to examine the effect of ND at different treatment doses and periods on expression of Aqp1 and Aqp9 genes in the epididymis of pubertal rats. Results showed that mRNA expression of Aqp1 and Aqp9 genes among the parts of the epididymis was differentially regulated by ND treatment doses. In addition, treatment periods of ND caused differential expression of Aqp1 and Aqp9 mRNAs among segments of the epididymis. Therefore, it is believed that male infertility induced by ND could be resulted not only from malfunction of the testis but also from aberrant gene expression of Aqp1 and Aqp9 in the epididymis.
In this study we tried to construct a more efficient tetracycline-inducible gene expression system by replacing previous key elements with more advance ones. At the beginning, we substituted PGK (phophoglycerate kinase) promoter for CMV (cytomegalovirus) promoter to control “rtTA2sM2” which has been known for high induction efficiency in response to tetracycline. With this modification, expression of the EGFP marker gene under the induction condition was significantly increased. Next, we replaced “TRE” fragment with a modified version named “TRE- tight” which has been reported to have higher affinity and specificity to the transactivator by minor base change of the “TRE” DNA fragment sequence. Use of “TRE-tight” instead of “TRE” resulted in more than 10 fold increment in terms of induction efficiency and significant decrement of background expression in non-inducible condition. By combining PGK promoter and “TRE-tight” fragment, we could upgrade previous tetracycline-inducible system to show more stringent turn on/off gene switch ability and stronger expression of the gene of our interest. Use of this newly developed system must be very helpful to the studies of gene expression, especially to the transgenic animal study in which non-controllable constitutive expression of the transgene has been one of the urgent problems to be solved.