• 한국약용작물학회지
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• 제15권5호
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• pp.346-351
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• 2007

An efficient somatic embryogenesis and plant regeneration protocol was developed for Schisandra chinensis Baill, using embryogenic cell suspensions and optimized media conditions. Friable embryogenic callus was induced from cotyledonary leaf and hypocotyl explants of 7 days old seedlings on MS agar medium supplemented with 1.0 to $4.0\;mg\;l^{-1}$ of 2,4-dichlorophenoxyacetic acid (2,4-D). Fast growing and well dispersed embryogenic cell suspensions were developed within two months when embryogenic calli were transferred to MS liquid medium containing $1.0\;mg\;l^{-1}\;2,4-D$. One third strength of MS medium was the best for both overall growth and development of somatic embryos in liquid culture. Over 3400 viable somatic embryos were produced from each 150 ml flask with an initial cell density of 30 mg in 30 ml medium. Germinated somatic embryos developed in liquid medium converted into plantlets after transferred to half-strength MS semi-solid medium. Approximately 90% of the converted plantlets were successfully transplanted to soil and grew into fertile plants.

• Journal of Plant Biotechnology
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• 제32권2호
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• pp.135-138
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• 2005

더덕 자엽절편을 1 mg/L 2,4-D가 첨가된 MS기본배지에 배양하여 배발생캘러스를 얻었고, 호르몬이 첨가되지 않은 MS액체배지에서 구형기의 체세포배를 얻었다. 구형기에서 초기 심장형기로 발달할 때 자엽의 시원세포는 전형성층조직으로부터 분화되기 시작 하였으며, 하배축에서 관찰되는 원통형 전형성층대는 2개의 자엽을 형성할 경우 2개의 전형성층대가, 3개의 자엽은 3개의 전형성층대가, 4개의 자엽은 4개의 전형층대가 각각 독립적으로 분화되어 자엽절과 자엽부위까지 연결되어 있었다. 만약 구형기 체세포배에서 자엽시원세포가 원통형으로 분화될 경우 합생자엽을 갖는 체세포배가 형성되었다.

• 식물조직배양학회지
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• 제24권5호
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• pp.291-294
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• 1997

작약의 체세포 조직배양에 의한 기내증식방법을 확립하기 위하여 완숙종자의 접합자배를 배양하여 얻어진 유묘의 자엽으로부터 체세포 배발생에 영향을 미치는 몇 가지 요인에 대해 실험한 결과는 다음과 같다. 배양부위에 관계없이 2,4-D가 첨가된 배지에서는 높은 캘러스 형성률을 나타내었지만 체세포배는 발생되지 않았다. 그러나 2,4-D를 첨가하지 않은 배지에 자엽을 배양했을 때는 경우는 27.2%의 체세포배발생률을 나타내었다. NH$_4$NO$_3$가 3.3g/L첨가된 배지에서 접합자배배양으로 얻은 자엽을 NH$_4$NO$_3$1.65 g/L 첨가된 배지에서 배양한 경우 체세포배발생률이 80.0%로 가장 높았다. 탄소원의 경우, 30~40 g/L의 sucrose나 40 g/L의 fructose가 참가된 배지에서 체세포배발생률이 높았다. 자엽은 15～30일 간격으로 3~9회 새배지로 이식한 것이 39.6~41.4%의 높은 체세포배발생률을 나타내었으며, 자엽에서 얻어진 체세포배는 0.3 mg/L의 GA$_3$가 첨가된 배지에서 배양할 경우 39%의 상배축신장율을 나타내었다. 체세포배에서 발아한 유묘의 상배축휴면 타파를 위해서는 4$^{\circ}C$에서 3주 이상 처리하는 것이 효과적이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.483-491
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• 2009

In vitro produced porcine embryos have potential application in reproductive biotechnology. However, their development potential has been very low. This study evaluated the in vitro developmental ability and quality of cloned and parthenogenetic porcine embryos having 2-4 cells or 5-8 cells on Day 2 of in vitro culture. Analysis of results showed that 2 to 4 cell embryos had higher ability to form blastocysts than 5 to 8 cell embryos (p<0.05). Blastocysts produced from culture of 2 to 4 cell embryos also contained higher cell numbers and had lower BAX:BCLxL transcript ratio than those produced from 5 to 8 cell embryos (p<0.05), thereby suggesting 2 to 4 cell embryos have higher development potential. Further investigation revealed that 5 to 8 cell embryos had higher incidence (100${\pm}$0.0%) of blastomeric fragmentation than 2 to 4 cell embryos (15.2${\pm}$5.5% for parthenogenetic and 27.7${\pm}$7.1% for cloned embryos). This suggests that low development potential of 5 to 8 cell embryos was associated with blastomeric fragmentation. In conclusion, we have shown that morphological selection of embryos based on cell number on Day 2 of in vitro culture could offer a practical and valuable non-invasive means to select good quality porcine embryos.

• 한국동물생명공학회지
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• 제37권4호
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• pp.213-217
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• 2022

Haploidization in somatic cells is the process of reducing the diploid somatic chromosomes to haploid. Several studies have attempted somatic haploidization using oocytes in mice and humans. Some researchers showed partial somatic haploidization, but none observed embryo development. Our study attempted somatic haploidization using the modified somatic nuclear transfer (SCNT) protocol with various combinations of chemicals or proteins in mice. This study induced the proper segregation of somatic homologous chromosomes and full embryo development in vitro. Furthermore, somatic haploid embryos established embryonic stem cells and produced live births. The current review summarizes this recent study on the success of somatic haploidization and provides an overview of other related studies on somatic haploidization.

• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.43-53
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• 2021

We examine the effect of endoplasmic reticulum (ER) stress inhibitor treatment time on the in vitro development of porcine somatic cell nuclear transfer (SCNT) embryos. Porcine SCNT embryos were classified by four groups following treatment time of ER stress inhibitor, tauroursodeoxycholic acid (TUDCA; 100 µM); 1) non-treatment group (control), 2) treatment during micromanipulation process and for 3 h after fusion (NT+3 h group), 3) treatment only during in vitro culture after fusion (IVC group), and 4) treatment during micromanipulation process and in vitro culture (NT+IVC group). SCNT embryos were cultured for six days to examine the X-box binding protein 1 (Xbp1) splicing levels, the expression levels of ER stress-associated genes, oxidative stress-related genes, and apoptosis-related genes in blastocysts, and in vitro development. There was no significant difference in Xbp1 splicing level among all groups. Reduced expression of some ER stress-associated genes was observed in the treatment groups. The oxidative stress and apoptosis-related genes were significantly lower in all treatment groups than control (p<0.05). Although blastocyst development rates were not different among all groups (17.5% to 21.7%), the average cell number in blastocysts increased significantly in NT+3 h (48.5±2.3) and NT+IVC (47.7±2.4) groups compared to those of control and IVC groups (p<0.05). The result of this study suggests that the treatment of ER stress inhibitor on SCNT embryos from the micromanipulation process can improve the reprogramming efficiency of SCNT embryos by inhibiting the ER and oxidative stresses that may occur early in the SCNT process.

• Reproductive and Developmental Biology
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• 제29권4호
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• pp.229-234
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• 2005

Methods for activation of reconstructed oocytes were examined for the production of nuclear transfer (NT) rat embryos using fetal neural stem cells as donor. Neural stem cells were isolated from Day 14.5 rat fetuses, and the oocytes for recipient cytoplasm were recovered from 4-week old Sprague Dawley rats. After enucleation and nuclear injection, the reconstructed oocytes were immediately exposed to activation medium consisting of 10 mM $SrCl_2$ for 4 h (immediate activation after injection; IAI), or cultured in vitro for $2\~3$ h before activation treatment (injection before activation; IBA). Pre-activated oocytes were also used for NT to test reprogramming potential of artificially activated oocytes. The oocytes were grouped as IIA (immediate injection after activation) and ABI (activation $2\~3$ h before injection). Following NT, the oocytes were cultured in vitro. Development of the NT embryos was monitored at 44 and 119 h after activation. The embryos in groups IAI, mA, and IIA were cleaved to the 2-cell stage at the rates of $36.6\%\;(15/41),\;39.5\%\;(17/43)\;and\;46.3\%$ (25/54), respectively. However, in the ABI group, only one embryo ($1.8\%$, 1/55) was cleaved after activation. After in vitro culture, two NT embryos from IAI group had developed to the morula stage $(4.9\%\cdot2/41)$. However, no morula or blastocyst was obtained in the other groups. These results suggest that immediate activation after injection (IAI) method may be used for the production of rat somatic cell NT embryos.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2002년도 제42차 춘계학술대회
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• pp.11-17
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• 2002

Animal clones derived from somatic cells have been successfully produced in a variety of mammalian species such as sheep, cattle, mice, goats, pigs, cat and rabbits. However, there are still many unsolved problems in the present cloning technology. Somatic cell nuclear transfer has shown several developmental aberrancies including high rate of abortion in early gestation and increased perinatal death. These developmental failures of cloned embryos may arise from abnormal reprogramming of donor genome and/or incomplete cloning procedure. We have found that overall genomic methylation status of cloned bovine embryos is quite different from that of normal embryos in various genomic regions, suggesting that the developmental failures of cloned embryos may be due to incomplete reprogramming of donor genomic DNA. Many of the advances in understanding the molecular events for reprogramming of donor genome will more clarify the developmental defects of cloned embryos.

• 한국약용작물학회지
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• 제2권3호
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• pp.241-245
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• 1994

조직배양에 의한 두릅나무 종묘의 대량생산을 목적으로 체세포배의 발아에 효과적인 배지 및 생장조철제의 적정조건을 검토한 결과는 다음과 같다. 1. 배지는 MS매지가 채세포배의 발아에 가장 효과적이었으며(65%) 그 중애서도 무기염류의 농도를 1/4로 감소하고 당농도도 1%로 줄인 MS배지에서 발아 및 기관생장인 양호하였다. 2. Gelling agent는 gelrite $0.2{\sim}0.3%$ 처리에서 발아가 촉진되었으며 $(65{\sim}70%)$ shoot 및 root의 생장도 양호하였다. 3. Cytokinin은 $0.1mg/{\ell}$의 BA와 kinetin처리에서 발아율$(65{\sim}70%)$과 신초 및 뿌리 의 길이 및 건물중이 높게 나타났다. 4. Polyamine의 효과에 대한 실험결과 putrescine $1mg/{\ell}$과 5$mg/{\ell},\;spermidine\;10mg/{\ell}$ 처리에서 체세포배의 발아(90%) 및 기관생장이 양호하였으며 분화식물의 투명화도 억제되었다.

• 한국동물생명공학회지
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• 제35권3호
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• pp.258-264
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• 2020

This study investigated the effect of variation in the number of somatic-cell-cloned embryos and their developmental stage at transfer on pregnancy, as well as the influence of the estrus status of recipient pigs on in vivo development of cloned porcine embryos after embryo transfer. For somatic cell nuclear transfer (SCNT), fibroblast cells were obtained from a male porcine fetus. Recipient oocytes were collected from prepubertal gilts at a local abattoir and then cultured. After SCNT, reconstructed embryos of different numbers and developmental stages were transferred into recipient pigs. The developmental stage of the cloned embryos and the number of transferred embryos per surrogate showed no significant differences in terms of the resulting cloning efficiency. However, the pregnancy rate improved gradually as the number of transferred cloned embryos was increased from 100-150 or 151-200 to 201-300 per recipient. In pre-, peri-, and post-ovulation stages, pregnancy rates of 28.6%, 41.8%, and 67.6% and 16, 52, and 74 offspring were recorded, respectively. The number of cloned embryos and estrus status of the recipient pig at the time of transfer of the cloned embryo affect the efficiency of pig production; therefore, these variables should be particularly considered in order to increase the efficiency of somatic cell pig cloning.