• Journal of Life Science
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• v.24 no.8
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• pp.915-926
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• 2014

The ribosome is a protein synthesizing machinery and a ribonucleoprotein complex that consists of three ribosomal RNAs (23S, 16S and 5S) and 54 ribosomal proteins in bacteria. In the course of ribosome assembly, ribosomal proteins (r-protein) and rRNAs are modified, the r-proteins bind to rRNAs to form ribonucleoprotein complexes which are folded into mature ribosomal subunits. In this process, a number of non-ribosomal trans-acting factors organize the assembly process of the components. Those factors include GTP- and ATP-binding proteins, rRNA and r-protein modification enzymes, chaperones, and RNA helicases. During ribosome biogenesis, they participate in the modifications of ribosomal proteins and RNAs, and the assemblies of ribosomal proteins with rRNAs. Ribosomes can be assembled from a discrete set of components in vitro, and it is notable that in vivo ribosome assembly is much faster than in vitro ribosome assembly. This suggests that non-ribosomal ribosome assembly factors help to overcome several kinetic traps in ribosome biogenesis process. In spite of accumulation of genetic, structural, and biochemical data, not only the entire procedure of bacterial ribosome synthesis but also most of roles of ribosome assembly factors remain elusive. Here, we review ribosome assembly factors involved in the ribosome maturation of Escherichia coli, and summarize the contributions of several ribosome assembly factors which associate with 50S and 30S ribosomal subunits, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.1
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• pp.69-79
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• 1989

Steroid hormone profiles during luteal phase of clomiphene citrate(CC)/human menopausal gonadotropin(hMG)/human chorionic gonadotropin(hCG)-stimulated in vitro fertilization (IVF) cycles and of follicle-stimulating hormone(FSH)/hMG/hCG-stimulated IVF cycles were compared. In seventy three cycles stimulated with CC/hMG/hCG regimen, follicles were aspirated during exploratory laparotomy and yielded 7 pregnancies, and in 83 cycles stimulated with FSH/hMG/hCG regimen, follicles were aspirated by laparoscope and made 13 pregnancies. Serum estradiol($E_2$) and progesterone($P_4$) levels were determined on days 2, 5, 7, and 9 after follicle aspiration. The FSH/hMG/hCG regimen was more effective than the CC/hMG/hCG regimen in folliculogenesis, ie, ovarian stimulation, follicular phase $E_2$ peak levels, oocyte maturation, and the number of retrieved oocytes. There was no significant difference between luteal serum $P_4/E_2$ ratio of the two regimens, suggesting that secretory endometrial build-up ability for implantation may not differ each other. Several significant correlations were observed between follicular phase seum $E_2$ peak levels and luteal phase serum $E_2$ and $P_4$ levels in the FSH/hMG/hCG-stimulated cycles but any correlation was not significant in the CC/hMG/hCG-stimulated cycles, suggesting that somewhat more follicles may eventually fall in atresia even after attaining dominant stage in the CC/hMG/hCG-stimulated cycles than the FSH/hMG/hCG-stimulated cycles.

• Journal of Embryo Transfer
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• v.29 no.3
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• pp.273-281
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• 2014

This study was carried out to establish the system of OPU derived embryo production, management of recipients as well as offspring production. OPU derived embryo production system was carried out of aspiration of immature oocytes 2 times per week, total 24 times for 3 months by an ultrasonographic guided follicular aspiration system and then produced in vitro-produced blastocysts by in vitro maturation, fertilization and culture system. This work was collected total 13,866 oocytes, average $8.2{\pm}4.5$ oocytes per session and 8,170 G1 + G2 grade oocytes, average 4.8 oocytes per session by 1,692 times session of total 71 donors for 4 years from 2010 to 2013. The rate of cleavage and blastocyst developmental competence were obtained 11,825 (85.3%) and 5,032 (36.3%) that was $7.0{\pm}3.8$ cleaved embryos and $3.0{\pm}2.5$ blastocysts per session. OPU derived embryo transfer were taken place in 2, 4, 6 and 7 local governments at 2010, 2011, 2012 and 2013 for 4 years and pregnancy rate were obtained 41.2, 43.9, 46.5 and 49.7% in each years. It means that pregnancy rate was continuously improved according of every year for 4 years. Pregnancy rate was significantly different according to individual local government in which was 62.7% in B, but 24.2% in F at 2012. Paternity identification was carried out total 26 offspring in C local government of 2012 and then confirmed 100% agreement of its analysis. In conclusion, the results obtained the possibility of mass production of elite cow embryos as well as offspring by OPU derived embryo production system, of which could be decreased the required time of genetic improvement.

• Reproductive and Developmental Biology
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• v.36 no.2
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• pp.115-120
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• 2012

This study was conducted to examine the optimal concentration and treatment time of antioxidants for inhibition of the ROS generation in bovine somatic cell nuclear transfer (SCNT) embryos. Bovine oocytes were activated parthenogenetically, during which oocytes were treated with various antioxidants to determine the optimal concentrations and kind of antioxidants. Determined antioxidants were applied to oocytes during in vitro maturation (IVM) and/or SCNT procedures. Finally, antioxidant-treated SCNT embryos were compared with in vitro fertilized (IVF) embryos. $H_2O_2$ levels were analyzed in embryos at 20 h of activation, fusion or insemination by staining of embryos in $10{\mu}M$ 2'7'-dichlorodihydrofluorescein diacetate (H2DCFDA) dye, followed by fluorescence microscopy. $H_2O_2$ levels of parthenogenetic embryos were significantly lower in $25{\mu}M$ ${\beta}$-mercaptoethanol (${\beta}$-ME), $50{\mu}M$ L-ascorbic acid (Vit. C), and $50{\mu}M$ L-glutathione (GSH) treatment groups than each control group ($24.0{\pm}1.5$ vs $39.0{\pm}1.1$, $29.7{\pm}1.0$ vs $37.0{\pm}1.2$, and $32.9{\pm}0.8$ vs $36.3{\pm}0.8$ pixels/embryo, p<0.05). There were no differences among above concentration of antioxidants in direct comparison ($33.6{\pm}0.9{\sim}35.2{\pm}1.1$ pixels/embryo). Thus, an antioxidant of $50{\mu}M$ Vit. C was selected for SCNT. $H_2O_2$ levels of bovine SCNT embryos were significantly lower in embryos treated with Vit. C during only SCNT procedure ($26.4{\pm}1.1$ pixels/embryo, p<0.05) than the treatment group during IVM ($29.9{\pm}1.1$ pixels/embryo) and non-treated control ($34.3{\pm}1.0$ pixels/embryo). Moreover, $H_2O_2$ level of SCNT embryos treated with Vit. C during SCNT procedure was similar to that of IVF embryos. These results suggest that the antioxidant treatment during SCNT procedures can reduce the ROS generation level of SCNT bovine embryos.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.19-25
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• 2016

This study was conducted to evaluate the effects of type of culture media (BM, G2, OS, TCM, and MEM) on B6D2F1 mice oogenesis. In the present study, B6D2F1/CrljOri $F_1$ mice were utilized in order to maximize oogenesis. Also we used TCM-199, Dulbecco's medified Eagle's medium (DMEM), embryo culture medium (Fertilization medium, Cleavage medium, Blastocyst medium), G series medium and One step medium. In vitro maturation was highest in BM followed by the order of OS, MEM, TCM and G2 ($90{\pm}2.8%>88{\pm}3.2%>85{\pm}4.9%>78{\pm}10.2%>64{\pm}7.7%$, respectively). To note, the G2 group was statistically different compared to other groups (p<0.05). On the other hand the fertilization rate was highest in the G2 group followed by BM, OS, TCM, and MEM ($87{\pm}7.2%>85{\pm}6.9%>74{\pm}14.0%>71{\pm}13.8%>2{\pm}1.4%$, respectively). The MEM group was significantly lower compared to other groups (p<0.05). The developmental rate was highest in the OS group followed by the G2 group and the BM group albeit no statistical significance was noted ($73{\pm}11.6%>71{\pm}9.2%>66{\pm}10.4%$). Of note, all cells of the TCM and MEM groups were died during embryonic development. The zona hatched rate ($51{\pm}9.8%$ vs. $50{\pm}9.1%$ vs. $47{\pm}7.2%$ for BM, G2, and OS respectively) and attached rate ($45{\pm}12.3%$ vs. $38{\pm}16.1%$ vs. $37{\pm}11.5%$ for BM, G2, and OS respectively) were not different amongst groups. No difference was found in total cell numbers ($74{\pm}13.9$ vs. $64{\pm}9.2$ vs. $76{\pm}6.7$ for BM, G2, and OS respectively), ICM cell numbers ($20{\pm}1.9$ vs. $14{\pm}1.8$ vs. $15{\pm}2.1$), TE cell numbers ($55{\pm}12.5$ vs. $49{\pm}10.7$ vs. $61{\pm}5.9$), % ICM ($30{\pm}2.8%$ vs. $24{\pm}7.0%$ vs. $22.8{\pm}2.2%$) and ICM:TE ratio ($1:2{\pm}0.5$ vs. $1:3.1{\pm}0.8$ vs. $1:3.1{\pm}0.5$) amongst groups. In summary, these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice.

• Journal of Plant Biotechnology
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• v.7 no.4
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• pp.259-265
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• 2005

Indian citrus ringspot virus (ICRSV)-free plants of Kinnow mandarin (Citrus nobilis Lour x C. deliciosa Tenora) were raised from virus-infected plants using unfertilised ovules as explants. Plants were tested by indirect ELISA and RT-PCR before using their explant. An amplified product of 539 bp was obtained by RT- PCR in ICRSV infected plants. Unfertilized ovules were excised from unopened flower buds of plants tested postive for virus and were cultured on Murashige and Skoog's (MS) basal medium supplemented with various concentrations of kinetin (KN) or malt extract (ME). Maximum induction (31.94%) of embryogenic callus was observed on MS medium supplemented with KN ($9.29\;{\mu}M$). Transfer of embryogenic calli to similar media composition resulted in somatic embryogenesis in all cultures, with an average number of 60.36 globular, 17.39 heart and 7.71 cotyledonary-shaped somatic embryos per culture. All cotyledonary shaped embryos developed into complete plantlets within 60 days on transfer to similar medium. Embryogenic callus induction, somatic embryo formation, maturation, germination and plantlet formation were achieved on MS medium supplemented with KN ($9.29\;{\mu}M$) alone. The plantlets derived from somatic embryos were transferred to sterilized soil, sand and vermiculite (3:1:1) mixture. After acclimatization, the plantlets were transferred to screen house and were indexed for ICRSV employing indirect ELISA and RT-PCR and found free of virus. A distinct feature of this study is the induction of somatic embryogenesis from unfertilised ovules to produce virus-free plants.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.2
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• pp.82-86
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• 2011

Objective: To evaluate sperm nuclear DNA fragmentation and chromatin structure after 18 hours' incubation at room temperature. Methods: Twenty-eight male partners who participating IVF treatment were prospectively included in this study. Ejaculated sperm count and motility were assessed. The sperm was then immediately processed by the conventional swim-up method. After utilization of some of the sample for routine clinical use, the remainder of each of the samples was divided into two aliquots. One aliquot was immediately assessed for sperm nuclear DNA fragmentation (TUNEL assay) and chromatin structure (toluidine blue [TB] staining). The other aliquot was incubated at room temperature for 18 hours and then assessed by two methods. Only dark-TB sperms were considered as having abnormal chromatin structure. Data before and after extended incubation were compared using a paired Student's $t$-test. Results: Before and after extended culture, nuclear DNA fragmentation assessed by TUNEL was $4.9{\pm}4.7%$ and $7.0{\pm}6.4%$, respectively ($p$=0.008). The proportion of abnormal chromatin structure (dark-TB sperm) was $8.2{\pm}5.6%$ and $10.3{\pm}6.5%$ ($p$ <0.001), before and after incubation, respectively. Conclusion: After 18 hours' incubation at room temperature, sperm nuclear DNA and chromatin structure were significantly affected. The IVF practitioner should bear this information in mind when performing delayed insemination, especially for $in$ $vitro$ maturation cycles.

• The Korean Journal of Zoology
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• v.34 no.2
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• pp.181-187
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• 1991

We previously showed that transient exposure of Rana dybowskii follicles to exogenous cAMP in vitro could induce meiotic maturation. The present experiments were carried out to acertain whether the exogenous cAMP penetrate into the follicles. Isolated follicles were precultured in the medium containing cAMP (2.5 mM) for 6 hours and then cultured further in plain medium for 18 hours. The change of intrafollicular cAMP levels during the culture period were examined by utilizing cAMP radioimmunoassay (RIA). The intrafollicular levels of cAMP increased about thirty times of the basal level (about 3 p mole/follicle) in two hours and reached a peak in six hours (170 p mole/follicle) during the preculture period. However, when the follicles were transferred to plain medium, the levels decreased markedly in six hours to very low levels (about 10 p mole/ follicle), and kept the same levels thereafter. But the levels did not decrease to the basal levels. The increase and decrease of the intrafollicular cAMP was not affected by the presence of isobutyl methylxanthine (IBMX) or progesterone. The data suggest that exogenous cAMP pene-trate into the follicles and the cAMP accumulated by the follicles are degraded very rapidly.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.223-228
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• 2002

This study was carried out to examine the effects of antioxidants and buthionine sulfoximide(BSO) on the development of porcine in vitro maturation(IVM) and in vitro fertilization(IVF) oocytes. Cumulus cell free embryos derived from porcine IVM/IVF oocytes were cultured NCSU23 medium with antioxidants or BSO under an atmosphere of 5% $CO_2$ and 5% $O_2$at 38.5$^{\circ}C$ for 5~6 days. The embryos cultured in medium with BSO showed a significanthy(P<0.05) lower rates(8.4~15.7%) of the development to the morulae and blastocyst stage than control group(35.9%). When the embryos were cultured with NAC, ebselen, glutathione and BSO, the proportions of embryos beyond morulae and blastocysts were significantly(P<0.05) higher in medium with NAC(40.5%), ebselen(44.2%) and glutathione(36.0%) than BSO(10.9%). In conclusions, these results indicate that NAC, ebselen and glutathione as a antioxidants can increase the proportion of embryos that develop beyond morulae stage. BSO, intracellular glutathione inhibitors, is suppressed the development of porcine embryos derived from IVM/IVF.

• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.303-310
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• 1997

소 난포란의 체외성숙시 성숙배지에 FSH 및 LH의 첨가가 체외성숙난자의 calcium 반응과 체외수정란의 발달에 미치는 영향을 조사하였다. 난포란의 체외성숙은 TCM199을 기초로 한 4가지의 배양조건 하에서 : 1) 0.5$\mu\textrm{g}$/ml FSH＋5$\mu\textrm{g}$/ml LH, 2) 0.5$\mu\textrm{g}$/ml FSH, 3) 5$\mu\textrm{g}$/ml LH 및 4) 무 호르몬 첨가구로서 5% CO2에 24시간 동안 체외성숙을 유도하였다. 체외성숙 24기간째에 난포란의 과립막세포는 1ml PB1＋에서 4분 동안 vortexing을 하여 완전히 제거하였다. 세포 내 calcium 반응을 측정하기 위하여 2mM Fura-2 AM ester 및 0.02% Pluronic F-127가 첨가된 PB1-용액에 39$^{\circ}C$ in cubator에서 40분 동안 배양하였다. 30${\mu}\ell$ M2 medium drop을 30mm plastic dish에 만들어 20$\times$ 형광대물렌즈가 장착된 Nikon Diaphot 현미경의 장착된 Nikon Diaphot 현미경의 warm stage에 설치하였다. 세포 내 calcium 방출을 자극하기 위하여 난자에 25mM inositol 1, 4, 5-trasphophate(IP3)로 1.21kV/cm의 전기자극 또는 20mM ryanodine으로 미세주입을 실시하였다. 이러한 처리를 하지 않은 난자는 체외수정 후 CR1aa와 BRL monolayers의 공배양조건 하에서 체외발달을 유도하였다. 분할율(Day 2)과 배반포기발달율(Day 9)을 조사하였다. FSH와 LH의 처리구에서 IP3 또는 ryanodine으로 자극된 난자(1.79$\pm$0.05, 1.66$\pm$0.06)는 FSH, LH 및 무 호르몬처리구에 비하여 유의적으로 높은 calcium 반응을 보였다(1.00$\pm$0.03, 1.28$\pm$0.04, and 0.53$\pm$0.02 in IP3 elctroporation; 0.68$\pm$0.05, 1.03$\pm$0.05, and 0.47$\pm$0.04 in ryanodine microinjection). FSH와 LH, FSH, LH처리구에서 분할율(87.9, 71.5 및 75.6%)은 무 호르몬처리구(60.7%)(P<0.05)에 비하여 유의적으로 높았으며, FSH와 LH처리구(29.3%)에서의 배반포기 발달율은 FSH, LH 처리구뿐만 아니라 무 호르몬처리구보다 유의적으로 높았다(16.5, 19.0 and 9.8%)(P<0.05). Bovine FSH 및 Ovine FSH의 처리구에서의 calcium 반응은 유의적인 차이가 없었다(1.72$\pm$0.05, 1.61$\pm$0.06). 또한 분할율(82.2 and 84.0%) 및 배반포기(27.8 and 27.1%) 발달율도 bovine 및 ovine FSH처리구간에는 유의적인 차이가 없었다. 이상의 결과에서 전기자극에 의한 세포 내 calcium 반응은 체외성숙배지에 첨가하는 호르몬의 처리에 따라서 유의적인 변화를 보였다. 비록 분할율은 처리구간에 유의적인 차이가 없었지만 배반포기 발달율은 FSH와 LH 공동처리구에서 FSH, LH 단독처리구 및 무 호르몬처리구에 비하여 유의적으로 높은 발달율을 보였다. 체외성숙기간에 FSH와 LH의 공동첨가는 체외성숙 및 체외발달의 생리적인 교정을 위하여 요구되는 것으로 사려된다.