• Reproductive and Developmental Biology
• /
• v.33 no.1
• /
• pp.13-18
• /
• 2009

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 $\beta$-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.

• Journal of Embryo Transfer
• /
• v.20 no.2
• /
• pp.113-121
• /
• 2005

This study was conducted to investigate the effects of different hexoses (glucose, mannose, galactose and fructose) on in vitro development of parthenogenetic embryos in the pigs. When the parthnogenetic embryos were cultured in medium with concentrations of 5mM glucose or 1mM galactose, the rates of embyos developed to morula and blastocyst stages were significantly higher than those in another culture conditions (P<0.05). However, high concentration of galactose inhibited development to morula and blastocyst stages. Addition of hexoses at early stage of porcine parthenogenetic embryos were effective for in vitro development. Especially, the embryos cultured in medium with glucose at early stage were effective for development to 2-cell $(72\%)$ and blastocyst $(19\%)$ stages compared with embryo cultured without glucose. From the present results, it is suggested that development of porcine parthenogenetic embryos can improve in medium with 5mM glucose. The concentration of 1mM galactose was also effective for development of porcine parthenogenetic embryos. It also show that parthenogenetic embryos cultured with glucose at early stage can improve in vitro development.

• Journal of Animal Science and Technology
• /
• v.61 no.4
• /
• pp.225-233
• /
• 2019

The aim of this study was to produce porcine tetraploid (4N) parthenogenetic embryos using various methods and evaluate their developmental potential. In method 1 (M1), porcine 4N parthenogenetic embryos were obtained by inhibiting extrusion of both first (PB1) and second (PB2) polar bodies; in methods 2 (M2) and 3 (M3), 4N parthenogenetic embryos were obtained by electrofusion of 2-cell stage diploid parthenogenetic embryos derived from inhibition of PB2 or PB1 extrusion, respectively. We found no differences in the rates of cleavage or blastocyst formation or the proportion of 4N embryos among M1, M2, and M3 groups. The different methods also did not influence apoptosis rates (number of TUNEL-positive cells/number of total cells) or expression levels of apoptosis-related BAX and BCL2L1 genes. However, total cell and EdU (5-ethynyl-2'-deoxyuridine)-positive cell numbers in 4N parthenogenetic blastocysts derived from M1 were higher (p < 0.05) than those for M2 and M3 groups. Our results suggest that, although porcine 4N parthenogenetic embryos could be produced by a variety of methods, inhibition of PB1 and PB2 extrusion (M1) is superior to electrofusion of 2-cell stage diploid parthenogenetic embryos derived from inhibition of PB2 (M2) or PB1 (M3) extrusion.

• Reproductive and Developmental Biology
• /
• v.37 no.1
• /
• pp.51-55
• /
• 2013

The present study was conducted to examine the effect of antioxidant treatment during parthenogenetic activation procedure on the reactive oxygen species (ROS) levels and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by a combination of electric stimulus and 2 mM 6-dimethylaminopurine (6-DAMP) before in vitro culture. During the activation period, oocytes were treated with $50{\mu}M$ ${\beta}$-mercaptoethanol (${\beta}$-ME), $100{\mu}M$ L-ascorbic acid (Vit. C) or $100{\mu}M$ L-glutathione (GSH). To examine the ROS level, porcine parthenogenetic embryos were stained in $10{\mu}M$ dichlorohydrofluorescein diacetate ($H_2DCFDA$) dye 20 h after culture, examined under a fluorescence microscope, and the fluorescence intensity (pixels) were analyzed in each embryo. The parthenogenetic embryos were cultured for 6 days to evaluate the in vitro development. The apoptosis was measured by TUNEL assay. The $H_2O_2$ levels of parthenogenetic embryos were significantly lower in antioxidant treatment groups ($26.9{\pm}1.6{\sim}29.1{\pm}1.3$ pixels/embryo, p<0.05) compared to control ($33.2{\pm}1.7$ pixels/embryo). The development rate to the blastocyst stage was increased in antioxidant treatment groups (32.0~32.5%) compared to control (26.9%, p<0.05), although, there was no difference in apoptosis among groups. The result suggests that antioxidant treatment during parthenogenetic activation procedure can inhibit the ROS generation and enhance the in vitro development of porcine parthenogenetic embryos.

• Reproductive and Developmental Biology
• /
• v.33 no.1
• /
• pp.7-11
• /
• 2009

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 $\gamma$-tubulin spot. However, $\gamma$-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.

• Reproductive and Developmental Biology
• /
• v.37 no.2
• /
• pp.57-64
• /
• 2013

Developmental potential of cloned embryos is related closely to epigenetic modification of somatic cell genome. The present study was to investigate the effects of applying histone deacetylation inhibitor, trichostatin A (TSA) to activated porcine embryos on subsequent development of porcine parthenogenetic and nuclear transfer embryos. Electrically activated oocytes were treated with 5 nM TSA for different exposure times (0, 1, 2 and 4 hr) and then the activated embryos were cultured for 7 days. The reconstructed embryos were treated with different concentrations of 0, 5, 10 and 25 nM TSA for 1 hr. Also 5 nM TSA was tested with different exposure times of 0, 0.5, 1, 2 and 4 hr. And fetal fibroblast cells were treated with 50 nM TSA for 1, 2 or 4 hr and with 5 nM TSA for 1 hr. Cumulus-free oocytes were enucleated and reconstructed by TSA-treated donor cells and electrically fused and cultured for 6 days. In parthenogenetic activation experiments, 5 nM TSA treatment for 1 hr significantly improved the percentage of blastocyst developmental rates than the other groups. Total cell number of blastocysts in 1 hr group was significantly higher than other groups or control. Similarly, blastocyst developmental rates of porcine NT embryos following 5 nM TSA treatment for 1 hr were highest. And the reconstructed embryos from donor cells treated by 50 nM TSA for 1 hr improved the percentage of blastocyst developmental rates than the control group. In conclusion, TSA treatment could improve the subsequent blastocyst development of porcine parthenogenetic and nuclear transfer embryos.

• Development and Reproduction
• /
• v.22 no.3
• /
• pp.235-244
• /
• 2018

We investigate the effect of endoplasmic reticulum (ER) stress inhibitor treatment during parthenogenetic activation of oocytes on the ER stress generation, apoptosis, and in vitro development of parthenogenetic porcine embryos. Porcine in vitro matured oocytes were activated by 1) electric stimulus (E) or 2) $E+10{\mu}M$ Ca-ionophore (A23187) treatment (EC). Oocytes were then treated by ER stress inhibitors such as salubrinal (200 nM) and tauroursodeoxychloic acid (TUDCA, $100{\mu}M$) for 3 h prior to in vitro culture. Parthenogenetic embryos were sampled to analyze ER stress and apoptosis at the 1-cell and blastocyst stages. The x-box binding protein 1 (Xbp1) mRNA and ER stress-associated genes were analyzed by RT-PCR or RT-qPCR. Apoptotic gene expression was analyzed by RT-PCR. At the 1-cell stage, although no difference was observed in Xbp1 splicing among treatments, BiP transcription level in the E group was significantly reduced by salubrinal treatment, and GRP94 and ATF4 transcription levels in EC group were significantly reduced by all treatments (p<0.05) compared to control. In the EC group, both apoptotic genes were reduced by ER stress inhibitor treatments compared to control (p<0.05) except Caspase-3 gene by TUDCA treatment. These results suggest that the treatment of ER stress inhibitor during parthenogenetic activation can reduce ER stress, and thereby reduce apoptosis and promote in vitro development of porcine parthenogenetic embryos.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.8
• /
• pp.1188-1195
• /
• 2001

A tetraparental chimeric bull was successfully produced by aggregating bovine IVF embryos of F1 (female Holstein${\times}$male Japanese Black) and F1(female Japanese Brown${\times}$male Limousin) and culturing in vitro without the zona pellucida at Yamaguchi Research Station in Japan. In the microsatellite genotyping, 12% (28/228) microsatellite primer sets ware potentially useful for this parentage analysis in the chimeric bull, 78.6% (22/28) of microsatellite present in the chimeric bull were uniquely contributed from the Japanese Black and 21.4% (6/28) from Limousin. This chimeric bull semen was used in producing IVF embryos. The chromosome preparations were made from peripheral lymphocytes. Based on chromosome analysis the Chimera had apparently normal chromosomes (29 acrocentric pairs, one large sub metacentric X chromosome and one small sub metacentric Y chromosome). The proportion of acrosome reacted spermatozoa after 1 h of incubation was higher (p<0.01) with the Chimera than with the Holstein and in Japanese Brown bulls. But did not differ from Japanese Black and Limousin bull sperm. Fertilization rates observed after 5 h of sperm-oocyte incubation with Chimera sperm were higher (p<0.05) than with Japanese Brown and (p<0.01) than with Holstein sperm, but did not differ from Japanese Black and Limousin sperm. The cleavage rates of IVF oocytes inseminated with Chimera sperm were also higher (p<0.001) compared with Holstein, (p<0.01) Japanese Brown and (p<0.05) Limousin, but did not differ from Japanese Black sperm. The blastocyst rates of IVM oocytes inseminated with sperm were higher (p<0.05) than in Limousin, Japanese Brown and Holstein, but did not differ from Japanese Black. Chimeric cattles were produced by aggregation of parthenogenetic (Japanese Brown) and in vitro fertilized (Holstein) bovine embryos at the Yamaguchi Research Station in Japan and by aggregation of parthenogenetic (Red Angus) and in vitro fertilized (Holstein) embryos at the St. Gabriel Research Station in Louisiana. The aggregation rate of the reconstructed demi-embryos cultured in vitro without agar embedding was significantly lower than with agar embedding. The aggregation was also lower when the aggregation resulted from a whole parthenogenetic and IVF-derieved embryos cultured without agar than when cultured with agar. The development rate to blastocysts, however, was not different among the treatment. To verify parthenogenetic and the cells derieved from the male IVF embryos in blastocyst formation, 51 embryos were karyotyped, resulting in 27 embryos having both XX and XY chromosome plates in the same sample, 14 embryos with XY and 10 embryos with XX. The viability and the percentage of zonafree chimeric embryos at 24 h following cryopreservation in EG plus T with 10% PVP were significantly greater than those cryopreserved without PVP. Pregnancies were diagnosed in both stations after the transfer of chimeric blastocysts. Twin male and single chimeric calves were delivered at the Yamaguchi station, with each having both XX and XY chromosomes detected. Three pregnancies resulted from the transfer of 40 chimeric embryos at the Louisiana station. Two pregnancies were Jost prior to 4 months and one phenotypically chimeric viable male born.

• Reproductive and Developmental Biology
• /
• v.31 no.4
• /
• pp.261-265
• /
• 2007

Insulin, transferrin and selenium (ITS) complex is reported to improve in vitro development of oocytes and embryos. This study was carried out to investigate the effects of ITS during in vitro culture (IVC) of porcine parthenogenetic and nuclear transfer (NT) embryos on subsequent developmental capacity in vitro. The electrically activated oocytes were cultured in Porcine Zygote Medium (PZM-3) with various concentrations (0, 0.1, 0.5, and 1.0%) of ITS for 7 days. Also, the electrically activated reconstructed embryos were cultured in PZM-3 with various concentrations (0, 0.1, 0.5, and 1.0%) of ITS for 6 days. Addition of ITS to culture medium did not affect development of porcine parthenogenetic embryos in vitro. To test the effect of ITS on the in vitro development of porcine NT embryos, factorial experiments were also performed for in vitro maturation (IVM) medium (TCM-199) with or without 1% ITS and culture medium (PZM-3) with or without 0.5% ITS. Addition of 0.5% ITS to culture medium increased (p<0.05) the proportion of NT blastocysts compared with non-treated group. In contrast, addition of 1% ITS to culture medium was ineffective or had a detrimental effect. Also, addition of ITS only to maturation medium increased (p<0.05) the percentage of NT blastocysts formation compared with the control group. In conclusion, addition of ITS to IVM or IVC medium could improve subsequent blastocyst development of porcine NT embryos.

• Reproductive and Developmental Biology
• /
• v.35 no.2
• /
• pp.191-195
• /
• 2011

The present study was conducted to examine the reactive oxygen species (ROS) generation levels in porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by the combination of electric stimulus and 6-DMAP before in vitro culture. Porcine oocytes and parthenogenetic embryos were stained in 10 ${\mu}M$ dichlorohydrofluorescein diacetate (DCF) or 10 ${\mu}M$ hydroxyphenyl fluorescein (HPF) dye each for 30 min at $39^{\circ}C$. The fluorescent emissions from the samples were recoded as JPEG file and the intensity of fluorescence in oocytes and embryos were analyzed. $H_2O_2$ and $^{\cdot}OH$ radical levels of porcine oocytes were reduced immediately after electric stimulation. However, $H_2O_2$ and $^{\cdot}OH$ radical levels of parthenogenetic embryos were increased with time elapsed after electric stimulation from 0 h to 3 h and after DMAP culture. During in vitro culture, $H_2O_2$ and $^{\cdot}OH$ radical levels were gradually increased from the one-cell stage to the two- and four-cell stages. The result of the present study suggests that the ROS was not increased by electric pulse in porcine embryos. Rather than it seems to be associated with the stage of development and the culture condition.