• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.194-200
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• 2009

The aim of this study was to investigate the effects of donor cell passage, size and type on the development of nuclear transfer embryos. Porcine cumulus cells, fetal fibroblasts and oviductal epithelial cells from 1-2, 3-6 and 7-10 passages were used for the nuclear transfer. In the oocytes with the cumulus donor cells, fusion and cleavage rates of oocytes and cell numbers per blastocyst among the three different passage groups did not show any differences, but the rates of blastocyst formation from 1-2 and 3-6 passage groups were higher than those from 7-10 passage group. The rates of fusion, cleavage and blastocyst formation, and the cell numbers per blastocyst were higher in the embryos with the sizes of <20 and 20 ${\mu}m$ cumulus donor cells compared to the >20 ${\mu}m$ cumulus donor cell. In the oocytes with the fetal fibroblast donor cells, the rate of blastocyst formation from the 3-6 passage group was higher than from 1-2 and 7-10 passage groups. The embryos with the size of 20 $\mu{m}$ fetal fibroblast donor cell showed higher rate of blastocyst formation compared to those with <20 and >20 ${\mu}m$ donor cells. In the oocytes with the oviductal epithelial cells, the rates of blastocyst formation from 1-2 and 3-6 passage groups were higher compared to those from 7-10 passage group. The embryos with the sizes of <20 and 20 ${\mu}m$ oviductal epithelial donor cells had a higher rate of blastocyst formation compared to those with >20 ${\mu}m$ donor cell. Fusion and cleavage rates of oocytes, and cell numbers per blastocyst among the three different donor cell types from the 3-6 passage did not show any differences. However, the rate of blastocyst formation of somatic cell nuclear transfer (SCNT) embryos with the fetal fibroblast donor cell was higher than that of blastocyst formation of SCNT embryos with the cumulus and oviductal epithelial donor cells.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.482-485
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• 2006

Korean native goats have lived on the Korean peninsula for more than 2,000 years and are regarded as a valuable genetic resource for the world. As an initial step to investigate the genetic structures of this breed, phylogenetic analysis and calculation of genetic diversities have been performed using mitochondrial DNA (mtDNA) sequence variations. A total of 19 Korean native goats were grouped into six haplotypes and the large majority of haplotypes were present in 13 animals. All mtDNA of these Korean goats belonged to the mitochondrial (mt) lineage A and revealed remarkably small genetic distances within the population when compared with other Asian goat populations, indicating less genetic variation in the Korean native goats. These results indicate high-inbred status of the Korean native goats and will influence breeding and conservation strategies adopted for this breed.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.165-170
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• 2007

Elevation of homocysteine levels is a risk factor for cardiovascular diseases and liver diseases. It has been reported that both streptozotocin-induced type I diabetic rats and obese type II diabetic rats have plasma total homocysteine lower than each control rats. We determined the effects of lean type II diabetes on homocysteine levels using type 2 diabetic Goto-Kakizaki rats. The concentrations of serum glucose were increased to ${\sim}two-fold$ of control levels and the total cholesterol levels were also increased in GK rats. Hepatic aspartate, histidine, threonine, alanine and methionine levels were significantly increased in GK rats. Plasma aspartate and glutamate levels were elevated, but threonine and arginine levels were decreased in GK rats. Plasma total homocysteine levels were not changed in GK rats, but hepatic total homocysteine levels were increased to ${\sim}three-fold$ of control levels. These results suggest that hepatic metabolism of sulfur-amino acid may be altered in diabetic condition.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1076-1079
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• 2004

Antibiotics are common additives in culture media during in vitro embryo development, but their effects on oocyte maturation in vitro have not been tested. The effects of penicillin, streptomycin and gentamicin on the maturational competence and subsequent development potential of goat follicular oocytes were examined after parthenogenetic activation in vitro. Maturation rates at 24 h after in vitro maturation, and parthenogenetic development at 48 h after activation, were evaluated by observing the protruding first polar body and the 4 cell stage cleavage, respectively. When streptomycin was present in the maturation medium, the percentages of matured oocytes 24 h after activation were significantly (p<0.01) lower than those from the other groups (42.5-45.7% vs. 69.1-73.8%). Penicillin and gentamicin treatment did not affect the maturation rates or the percentages reaching the 4 cell stage 48 h after activation. There was no significant difference in cleavage rates among the different antibiotic treatments 48 h after activation. Therefore, streptomycin suppresses the in vitro maturation of immature goat oocytes, but does not influence their subsequent development.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1369-1373
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• 2004

The percentages of sperm motility and normal acrosome on the liquid boar semen diluted and preserved at $4^{\circ}C$ with lactose hydrate, egg yolk and N-acetyl-D-glucosamine (LEN) diluent were significant differences according to preservation day and incubation time, respectively. The sperm motility steadily declined from 96.9% at 0.5 h incubation to 78.8% at 6 h incubation at 1 day of preservation. However, the sperm motility rapidly declined after 4 day of preservation during incubation. The normal acrosome steadily declined from 93.3% at 0.5 h incubation to 73.8% at 6 h incubation at 1 day of preservation. However, the normal acrosome rapidly declined after 3 day of preservation during incubation. The rates of sperm penetration and polyspermy were higher in 5 and $10{\times}10^6$ sperm/ml than in 0.2 and $1{\times}10^6$ sperm/ml. Mean numbers of sperm in penetrated oocyte were highest in $10{\times}10^6$ sperm/ml compared with other sperm concentrations. The rates of blastocysts from the cleaved oocytes (2-4 cell stage) were highest in $1{\times}10^6$sperm/ml compared with other sperm concentrations. In conclusion, we found out that liquid boar sperm stored at $4^{\circ}C$ could be used for in vitro fertilization of pig oocytes matured in vitro. Also, we recommend $1{\times}10^6$sperm/ml concentration for in vitro fertilization of pig oocytes.

• Reproductive and Developmental Biology
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• v.30 no.2
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• pp.93-97
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• 2006

To study the signaling effect of insulin-like growth factor-I(IGF-1), transgenic mice containing IGF-1 Receptor (IGF-1R) cDNA fused to metallothionein promoter were produced by DNA microinjection into the pronucleus of mouse zygote. Three founders were produced with transgenic mice containing IGF-1R gene. Transgenic mice lines contained approximately $4{\sim}20$ copies of transgenes per cell and transmission of this gene into the progeny with Mendelian manner were determined. The founder mice were mated with normal mice to produce $F_1$ mice and then $F_2$ mice. Transmission rates of IGF-1R transgene in the progeny mice were $25{\sim}60%$ in $F_1$ generation and $40{\sim}50%$ in $F_2$ generation. The mRNA expression of IGF-1R transgene in liver was analyzed using RT-PCR for IGF-1R gene in liver. When body weights of transgenic pups were measured during 4, 10 and 14 weeks after birth, IGF-1R transgenic mice grew faster than non transgenic littermates. This study indicated that growth regulation by IGF-1 signaling through IGF-1R can be elucidated using IGF-1R transgenic mice.

• Reproductive and Developmental Biology
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• v.33 no.2
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• pp.113-117
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• 2009

Animals produced by somatic cell nuclear transfer (SCNT) using genetically modified cells are almost always transgenic, implying that this method is more efficient than the traditional pronuclear microinjection method. Most somatic cells for SCNT in animals are fetus-derived primary cells and successful gene integration in somatic cells will depend on transfection condition. The objective of this study is to evaluate the efficiency of electroporation (Microporator) and liposome reagents (F-6, F-HD, W-EX, W-Q, W-M) for tissue-type plasminogen activator (tPA) gene transfection and to estimate the overall efficiency of transfection of Korean native pig fetal fibroblast cells (KNPFF). Electroporation showed significantly higher transfection efficiency than liposome reagents with regard to the transfection of in vitro cultures in the early stages of development (41.7% with Microporator vs. 18.3% with F-6, 20.0% with F-HD 18.5% with W-EX, 5.0% with W-M and 6.3% W-Q,). Colonies identified as tPA-positives were treated once more with G418 for 10 to 14 days and growing colonies were selected again. When the cells of newly selected colonies were subjected to single-cell PCR, reselection of colonies following second round of G418 selection increased the rate of transgene integration per each colony. These results suggest that transfection with electroporation is the most efficient and the second rounds of G418 selection may be an effective method for transfection of porcine fetal fibroblast cells.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.789-793
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• 2012

Fertilization of the oocyte commences embryogenesis during which maternally inherited mRNAs are degraded and the embryonic genome is activated. Transcription of embryonic mRNA is initiated by embryonic genome activation (EGA). RNA polymerase II (RNA Pol II) is responsible for the synthesis of mRNAs and most small nuclear RNAs, and consists of 12 subunits, the largest of which characteristically harbors a unique C-terminal domain (CTD). Transcriptional activity of RNA Pol II is highly regulated, in particular, by phosphorylation of serine residues in the CTD. Here, we have shown the presence of RNA Pol II CTD phosphoisoforms in porcine oocytes and preimplantation embryos. The distribution pattern as well as phosphorylation dynamics in germinal vesicles and during embryogenesis differed in developmental stages with these isoforms, indicating a role of RNA Pol II CTD phosphorylation at the serine residue in transcriptional activation during both oocyte growth and embryonic genome activation. We additionally examined the effects of the RNA Pol II inhibitor, ${\alpha}$-amanitin, on embryo development. Our results show that inhibition of polymerase, even at very early stages and for a short period of time, dramatically impaired blastocyst formation. These findings collectively suggest that the functionality of maternal RNA Pol II, and consequently, expression of early genes regulated by this enzyme are essential for proper embryo development.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.307-312
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• 2007

The present study was carried out to investigate differentially expressed chicken muscle proteins using proteomics approach. More than 300 protein spots were investigated for the muscle samples in 2DE gels and the differentially expressed protein spots between pectoralis and peroneus longus muscles from Cornish and White Leghorn breeds were characterized by MALDI-TOF. In pectoralis muscles, PGAM1 protein was detected as differentially expressed between White Leghorn and Cornish breeds. On the other hand, 4 protein spots (SP22, nxf-2, SOD1, TNNI2) were differentially expressed between White Leghorn and Cornish breeds in peroneus longus muscles. These proteins assumed to be related with muscle development, growth, stress, and movements in chicken. In this experimental process, 2D reference map of the chicken muscle proteins was needed and 25 proteins, which were commonly expressed in both pectoralis and peroneus longus muscles in both breeds, were selected and characterized. Upon finishing the exact roles of the differentially expressed proteins, the identified 5 proteins will be used as valuable information for the fundamental mechanisms of muscle biology and underline genetics.

• Toxicological Research
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• v.23 no.3
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• pp.263-269
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• 2007

Although taurine (2-aminoethanesulfonic acid) can inhibit oxidative stress in both animal and epidemiological studies, it is obscure whether taurine directly scavenges oxy-radicals or indirectly regulates oxidant production and/or antioxidant defense system. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating oxy-radical scavenging capacity. The antioxidant activities of taurine and hypotaurine (2-aminoethanesulfinic acid), a precursor of taurine, against peroxyl radicals, hydroxyl radicals and peroxynitrites were determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. tert-Butylhydroperoxide or hydrogen peroxide-induced cell toxicity determined by MTT assay was markedly inhibited by 10mM taurine or hypotaurine. The tert-butylhydroperoxide- or hydrogen peroxide-induced changes in oxidative stress markers, such as cellular glutathione and malondialdehyde, were ameliorated by 10mM taurine or hypotaurine. However, specific TOSC values calculated from the slope of the linear regression for taurine against peroxyl radicals, hydroxyl radicals or peroxynitrites were all less than 1 TOSC/mM. On the other hand specific TOSC values for hypotaurine against peroxyl radicals, hydroxyl radicals or peroxynitrites were 48, 2096, or 69 TOSC/mM, respectively. These results suggest that taurine protects cells against oxidative insults, which is not ascribed to directly scavenging activity of taurine against oxy-radicals. These results support the idea that the oxidation state of sulfur in antioxidants may be a determinant of oxy-radical scavenging capacity.