• Journal of Environmental Health Sciences
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• v.28 no.4
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• pp.17-22
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• 2002

In crustaceans, as in other arthropods, the molt cycle and the physiological process of growth are controlled by molting hormones (MH) which are steroid hormones, the ecdysteroids. Ecdysteroids are major arthropod hormones which control both development (embryonic and larval molts, metamorphosis) and reproduction. The purpose of the present study was to evaluate both fenarimol and methoprene for embryotoxicity to daphnids. The embryotoxicity associated with each compound was assessed to discern whether the embryotoxicity of methoprene might be due to ecdysone agonist and the ecdysone antagonistic effects of fenarimol on Daphnia embryo. Exposure of daphnids for three weeks to 50 M methoprene resulted in a significantly high incidence of offspring that exhibited general toxicity. This exposure concentration had significant effects on the overall number of embryo death. However, exposure to 3 or 1 $\mu$M fenarimol were no significant effects on the embryo toxicity. The incidence of both of these toxicity increased with methoprene exposure. This observation suggest that methoprene showed embryonic general toxicity during embryo development, while, only fenarimol showed weak general toxicity with early stages of embryonic development.

• Journal of Embryo Transfer
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• v.24 no.4
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• pp.249-251
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• 2009

Polar body was usually used as a determinant of oocyte's maturation. Polar body morphology could reflect the embryo quality and implantation competence. This review only focuses on morphology of the first polar body and embryo developmental rate in the presence or absence of polar body. However, it is very difficult to describe whether polar body has any effects on embryo development in vitro or in vivo. Further intensive research is needed to determine its function on embryo development.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.389-396
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• 1997

Arrest in embryo development during in vitro culture has been reported in various mammals. Although some cause of the arrest have been suggested, little is known of the way that can overcome the arrest using in vitro culture system. The antioxidant, $\beta$-mercaptoethanol($\beta$-ME), has been shown to play an important role in embryo development. This study was designed to examine the effect of $\beta$-ME on the developing boving embryos produced in vitro by IVM and IVF. To select a, pp.opriate concentration of $\beta$-ME during whole culture period (7 days), various concentrations (10, 50 and 100$\mu$M) of $\beta$-ME were added to the CZB medium and their effects was significantly higher in 100$\mu$M of $\beta$-ME. The effects on development of embryos cultured with and without somatic cells to blastocyst stage were greater in FCS treatment (56.6 and 29.3%) than in BSA treatment(25.5 and 12.8%). We also evaluated the effects of $\beta$-ME addition on the blastocyst formation when embryos at different stages were exposed to 100$\mu$M $\beta$-ME. $\beta$-ME promoted increased development of embryo to blastocyst stage and the effect was greater in 6-cell to morula embryos than in embryos fewer than 4-cells at the initiation of treatment. The results suggested that $\beta$-ME can improve bovine embryo development by overcoming the arrest in early development.

• Reproductive and Developmental Biology
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• v.29 no.3
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• pp.145-147
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• 2005

Autocrine or paracrine mediators released by the early embryo are implicated in the support of embryonic development. Their mechanisms and optimal embryo density in the medium, however, are uncertain. This study was conducted to establish the optimal embryo density and culture medium volume in mouse parthenogenetic embryo culture. In experiment 1, culture of parthenogenetirally activated oocytes at a concentration of $2{\~}4$ embryos/${\mu}L$ significantly improved development to the blastoryst stage ($72{\%}{\leq}$) compared with culture at the lower ($0.2{\~}1$e mbryos/${\mu}L,\;0\~37.5\%$) and the higher ($5{\~}6$ embryos/${\mu}L,\;30\~53\%$) concentration for 120 h when the oocytes were cultured in a 5 ${\mu}L$ drop under mineral oil In experiment 2, the embryos cultured at a concentration of $2{\~}4$ embryos/${\mu}L$ in a 10 ${\mu}L$ drop ($81.1{\%}$) showed significantly higher blastocyst rates than those in a 5 ${\mu}L$ drop ($68.5{\%}$). This study optimizes in vitro culture condition by modifying embryo density and the volume of culture medium It may give appropriate level of autocrine and/or paracrine factors to enhance viability and subsequent normal development of mouse parthenogenetic embryos in vitro.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.207-213
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• 2016

The objective of this study was to investigate to influence of glutathione (GSH) on development and antioxidant enzyme activity in tetraploid porcine embryos. Tetraploid embryos were produced using parthenogenetic 2-cell embryo by electrofusion method. Tetraploid embryo development was observed every 24 hours and intracellular antioxidant enzyme activity was measured at 120 hours after electrofusion. The 4-cell to 16-cell stage tetraploid embryos was increased in 100 and $500{\mu}M$ GSH-treated groups compared control group at 48 hours (P < 0.05) but cleavage rates were not significantly different among the GSH treatment groups at 48, 72, 96, and 120 hours. Blastocyst formation was significantly increased by 300 and $500{\mu}M$ GSH at 120 hours in tetraploid embryos (P < 0.05). But blastocyst cell number were not significantly different among the GSH treatment groups ($16.4{\pm}0.8$, $16.8{\pm}2.6$, $18.5{\pm}2.8$ and $17.5{\pm}1.8$). The intracellular antioxidant enzyme level was increased in $500{\mu}M$ GSH compared to 0 and $100{\mu}M$ GSH (P < 0.05). We suggest that GSH may be improve development of tetraploid embryo in pigs.

• Journal of Forest and Environmental Science
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• v.33 no.3
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• pp.197-201
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• 2017

Populus. caspica L. is an Iranian indigenous poplar species which naturally distributed in the northern part of country. Unfortunately, overuse has removed many of the stems of better form, so that natural stands now usually appear small and crook. Therefore genetic variation for selection of new superior clone of this species is needed. Conventional hybridization system is currently used to induce genetic variation in poplar species but incompatibility barriers have been observed between them. In vitro ovule embryo culture was used to overcome incompatibility obstacle for interspecific hybridization between Populus caspica L. with Populus deltoids L.62/75. Female flowers of Populus caspica L. have artificially been pollinated with pollen grain of P. deltoides 62/75 in one direction using twig and pot crossing system. Ovaries at different ages (7, 14 and 21 days after pollination) were disinfected through 70% ethanol for 1 minute, 5% of sodium-hypochlorite solution for fifteen min followed by three time rising with sterile distil-water. Isolated ovaries were then transferred to MS hormone free medium containing 30 and 60 g/L sucrose for embryo development and germination. Collected data have been analyzed by two factorial experimental designs. The results indicated that there were significant differences between age of embryos for development and germination at ${\alpha}=0.01%$. Highest embryo germination (45%) was observed from 21 days old ovaries. No significant differences were observed between MS culture media containing 30 and 60 g/L for percentages of ovary-embryo germination and number of germinated embryo per ovary at ${\alpha}=0.05%$. Fourteen percentage of embryo germination obtained in MS medium supplemented with 60 g/L sucrose, while only 35% of isolated ovaries were able to germinate in MS containing 30 g/L sucrose. Induced plantlets in 4 cm height were transferred into pots containing soilless (1:1:1 peat, per lit and vermiculite) medium for acclimatization. After successful acclimatization, plants were delivered to nursery.

• Korean Journal of Animal Reproduction
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• v.22 no.1
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• pp.35-42
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• 1998

This experiment was carried out to improve in vitro development of rabbit one-cell embryos to the blastocyst stage. One-cell rabbit embryos were collected at 19\ulcorner20hr after superovulation induction and incubated at 39\ulcorner in 5% CO2 for 72hr. In order to find optimum conditions in medium that affects the rabbit embryo's development in vitro, RDH medium which mixed with RPMI1640, DMEM and Ham's F10 was compared with the previously reported mediums (Ham's F10 and RD) for embryo development and cell numbers. Three additives (BSA, taurine and glucose) were tested for the development of rabbit one-cell embryos in vitro. When the embryos were cultured in RDH medium, their development was markedly promoted as compared with Ham's F-10 or RD alone. Glucose exhibited no significant effects on embryo development and cell numbers. BSA a, pp.ared to promote transition from morula to blastocyst stage and taurine increased cell numbers of cultured embryos markedly regardless of medium. BSA and taurine together in RDH medium showed the additive effects on embryos development and cell number.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.1
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• pp.12-20
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• 2020

Cell adhesion plays an important role in the differentiation of the morphogenesis and the trophectoderm epithelium of the blastocyst. In the porcine embryo, CDH1 mediated adhesion initiates at compaction before blastocyst formation, regulated post-translationally via protein kinase C and other signaling molecules. Here we focus on muscle RAS oncogene homolog (M-RAS), which is the closest relative to the RAS related proteins and shares most regulatory and effector interactions. To characterize the effects of M-RAS on embryo compaction, we used gain- and loss-of-function strategies in porcine embryos, in which M-RAS gene structure and protein sequence are conserved. We showed that knockdown of M-RAS in zygotes reduced embryo development abilities and CDH1 expression. Moreover, the phosphorylation of ERK was also decreased in M-RAS KD embryos. Overexpression of M-RAS allows M-RAS KD embryos to rescue the embryo compaction and blastocyst formation. Collectively, these results highlight novel conserved and multiple effects of M-RAS during porcine embryo development.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.215-219
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• 2016

Value of excellent breeding animals is important in livestock industry, but their economic life time is limited. And, many countries have been trying procuration of genetic resource in good animals. Therefore, this study was conducted to determine embryo production and to test efficiency of embryo transfer via non-surgical artificial insemination (AI) in different breed of superior sows. A total of 17 sows were used in this experiment (Duroc, n=10; Landrace, n=4; Yorkshire, n=3). The sows were artificially inseminated by semen of same breed boars. After 4 or 5 days following the AI, the embryos were obtained from the sows and then transferred to Landrace and Yorkshire recipients (n=3, respectively) by non-surgical method. The corpora lutea tended to be increased in Yorkshire and Landrace than Duroc(28 and 26 vs. 17, respectively). The recovery of embryo was 78.8% in Landrace, 65.4% in Duroc and 51.4% in Yorkshire. Duroc showed lower morulaes and early blastocyst embryos than 2, 4, 8 and 16 cell. The morula in Yorkshire was higher (P<0.05) than that of Duroc (4.7 vs. 3.4). Similarly, the morulaes and early blastocyst embryos presented greater (P<0.05) in Landrace compared with other breed sows. The recipient sows were pregnant in a Landrace only. This reason may be due to little embryos inserted in the recipients. In addition, pregnancy results were limited because of the little sows. In conclusion, ovulated ovum in sows can be affected by different breed. Also, further study needed pregnant test by using the many embryo in each breed.

• Korean Journal of Veterinary Service
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• v.44 no.4
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• pp.227-237
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• 2021

Artificial insemination of Korean native cattle (KNC) is the predominant method for breed improvement. However, industrialization of embryo production and transfer is necessary to utilize the genetic potential of KNC. The aim of this study was to examine associations between KNC donor cows and ovum pick-up (OPU) conditions, in-vivo oocyte recovery, and embryo development. Oocyte recovery and blastocyst development rates were higher at 50 and 60 mmHg OPU vacuum pressure than at 40 mmHg, which was, however, not significant. Regarding follicle growth, injection of 500 ㎍ GnRH 36 hours before OPU significantly increased the number of OPU oocytes from an average of 4.6 to 7.6 (P<0.05); no significant difference in embryo development rates was observed. Significant differences were observed in the numbers of OPU oocytes, embryo development rates, and transplantable blastocysts per individual among nine KNC donors (P<0.05). Furthermore, although there was no difference in OPU oocyte recovery intervals in approximately 2~8 weeks, the number of recovered oocytes significantly decreased at the 12-week interval (P<0.05); there was no difference in embryo development rates. The number of oocytes and embryonic development rates only tended to decrease until the seventh OPU session, but decreased significantly until the eighth session (P<0.05). The average pregnancy rate after transfer of OPU-derived in-vitro embryos into recipient cows was 41.8%. To improve the efficiency of OPU egg recovery and in-vitro embryo production, considering KNC donor characteristics, vacuum pressure of 60 mmHg, GnRH pretreatment to induce follicle growth, and effective OPU egg recovery up to seven times at intervals of 2~4 weeks appears to be most suitable. This study may facilitate the industrialization of KNC embryo production and transfer using high-quality cows.