간행물
Reproductive & developmental biology
- 발행기관 한국동물번식학회
- 자료유형 학술지
- 간기 계간
- ISSN 1738-2432 (Print)2288-0151 (Online)
- 수록기간 1977 ~ 2018
- 주제분류 농수해양 > 축산학 농수해양 분류의 다른 간행물
- 십진분류KDC 527DDC 636
권호리스트/논문검색
Volume 35 No 1 (2011년 3월) 16건
1.
2011.03
구독 인증기관 무료, 개인회원 유료
Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.
4,000원
2.
2011.03
구독 인증기관 무료, 개인회원 유료
The functional cardiovascular system is comprised of distinct mesoderm-derived lineages including endothelial cells, vascular smooth muscle cells and other mesenchymal cells. Recent studies in the human embryonic stem cell differentiation model have provided evidence indicating that these cell lineages are developed from the common progenitors such as hemangioblasts and cardiovascular progenitor cells. Also, the studies have suggested that these progenitors have a common primordial progenitor, which expresses KDR (human Flk-1, also known as VEGFR2, CD309). We demonstrate here that sustained activation of BMP4 (bone morphogenetic protein 4) in hESC line, CHA15 hESC results in KDR+ mesoderm specific differentiation. To determine whether the KDR+ population derived from hESCs enhances potential to differentiate along multipotential mesodermal lineages than undifferentiated hESCs, we analyzed the development of the mesodermal cell types in human embryonic stem cell differentiation cultures. In embryoid body (EB) differentiation culture conditions, we identified an increased expression of KDR+ population from BMP4-stimulated hESC-derived EBs. After induction with additional growth factors, the KDR+ population sorted from hESCs-derived EBs displays mesenchymal, endothelial and vascular smooth muscle potential in matrix-coated monolayer culture systems. The populations plated in monolayer cultures expressed increased levels of related markers and exhibit a stable/homologous phenotype in culture terms. In conclusion, we demonstrate that the KDR+ population is stably isolated from CHA15 hESC-derived EBs using BMP4 and growth factors, and sorted KDR+ population can be utilized to generate multipotential mesodermal progenitors in vitro, which can be further differentiated into cardiovascular specific cells.
4,000원
3.
2011.03
구독 인증기관 무료, 개인회원 유료
This study was designed to determine the effect of electric field strength, duration and fusion buffer in fusion parameters on the rate of membrane fusion between the somatic cell and cytoplast for Korean cattle (HanWoo) somatic cell nuclear transfer (SCNT) procedure. Following electrofusion, effect of 5 or 10 μM Ca2+-ionophore of activation treatment on subsequent development was also evaluated. Cell fusion rates were significantly increased from 23.1% at 20 V/mm to 59.7% at 26 V/mm and 52.9% at 27 V/mm (p<0.05). Due to higher cytoplasmic membrane rupture or cellular lysis, overall efficiency was decreased when the strength was increased to 30 V/mm (18.5%) and 40 V/mm (6.3%) and the fusion rate was also decreased when the strength was at 25 V/mm or below. The optimal duration of electric stimulation was significantly higher in 25 μs than 20 and 30 μs (18.5% versus 9.3% and 6.3%, respectively, p<0.05). Two nonelectrolyte fusion buffers, Zimmermann’s (0.28 M sucrose) and 0.28 M mannitol solution for cell fusion, were used for donor cell and ooplast fusion and the fusion rate was significantly higher in Zimmermann’s cell fusion buffer than in 0.28 M mannitol (91.1% versus 48.4%, respectively, p<0.05). The cleavage and blastocyst formation rates of SCNT bovine embryos activated by 5 μM Ca2+-ionophore was significantly higher than the rates of the embryos activated with 10 μM of Ca2+-ionophore (70.0% versus 42.9% and 22.5% versus 14.3%, respectively; p<0.05). This result is the reverse to that of parthenotes which shows significantly higher cleavage and blastocyst rates in 10 μM Ca2+-ionophore than 5 μM counterpart (65.6% versus 40.3% and 19.5% versus 9.7%, respectively; p<0.05). In conclusion, SCNT couplet fusion by single pulse of 26 V/mm for 25 μs in Zimmermann’s fusion buffer followed by artificial activation with 5 μM Ca2+-ionophore are suggested as optimal fusion and activation methods in Korean cattle SCNT protocol.
4,000원
4.
2011.03
구독 인증기관 무료, 개인회원 유료
Two piglets and one juvenile pig were used to investigate closely what types of cells express green fluorescent protein (GFP) and if any, whether the GFP-tagged cells could be used for stem cell transplantation research as a middle-sized animal model in bone marrow cells of recloned GFP pigs. Bone marrow cells were recovered from the tibia, and further analyzed with various cell lineage markers to determine which cell lineage is concurrently expressing visible GFP in each individual animal. In the three animals, visible GFP were observed only in proportions of the plated cells immediately after collection, showing 41, 2 and 91% of bone marrow cells in clones #1, 2 and 3, respectively. The intensity of the visible GFP expression was variable even in an individual clone depending on cell sizes and types. The overall intensities of GFP expression were also different among the individual clones from very weak, weak to strong. Upon culture for 14 days in vitro (14DIV), some cell types showed intensive GFP expression throughout the cells; in particular, in cytoskeletons and the nucleus, on the other hand. Others are shown to be diffused GFP expression patterns only in the cytoplasm. Finally, characterization of stem cell lineage markers was carried out only in the clone #3 who showed intensive GFP expression. SSEA-1, SSEA-3, CD34, nestin and GFAP were expressed in proportions of the GFP expressing cells, but not all of them, suggesting that GFP expression occur in various cell lineages. These results indicate that targeted insertion of GFP gene should be pursued as in mouse approach to be useful for stem cell research. Furthermore, cell- or tissue-specific promoter should also be used if GFP pig is going to be meaningful for a model for stem cell transplantation.
4,000원
5.
2011.03
구독 인증기관 무료, 개인회원 유료
Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bcl-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MTT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG (2 μM) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.
4,500원
6.
2011.03
구독 인증기관 무료, 개인회원 유료
Endocrine disruptors bind to hormone receptors on sperm membrane, therefore spermatozoa are potentially a useful model for examining estrogenic activities of endocrine disruptors. The objective of this study was to compare the effects of two xenoestrogenic compounds [genistein (Gen) and 4-tert-octylphenol (OP)] to those of two steroids [estrogen (E2) and progesterone (P4)] on boar sperm % motility and motion kinematics of in vitro. Porcine spermatozoa were incubated with various concentrations (0.001～100 μM) of each chemical for 15 or 30 min, and then assessed % motility and sperm motion kinematics using computer assisted sperm analyzer (CASA). Each chemical decreased sperm % motility, and OP decreased VSL and VAP compared with untreated control(p<0.05). E2 stimulated the motion kinematic changes except VCL. Moreover, Gen had effects on VCL and VAP alterations after 30 min incubation. In summary, since all chemicals studied effectively altered sperm % motility and motion kinematics, it was concluded that porcine spermatozoa could be a useful model for in vitro screening of potential endocrine disruptors.
4,000원
7.
2011.03
구독 인증기관 무료, 개인회원 유료
The objective of this study was carried out to evaluate the efficiency of sperm collection methods on the post-thaw viability of cat semen. The cat semen was collected by artificial virginal (AV) and electronic ejaculate (EE) methods. The composition of semen extender was consisted of Tris-buffer supplemented with 20% egg yolk and 1% P/S antibiotics in Ext I, and more added 8% glycerol, 1.0% Equex STM paste of total volume in Ext II. The collected semen was adjusted the concentration and then diluted in Ext I for optimal concentration. The diluted semen was cooling to 5℃ temperature in refrigerator for at least 2 hrs and then diluted stepwise with Ext II for at least 1 hrs. After an equilibration for 1 hrs, the cooled semen was packaged in 0.5 ml straw and then freezing on the LN2 vapor over 5 cm above from LN2 and then immersed directly in LN2 for cryopreservation. The frozen semen was thawed in 38℃ water for 15 sec and then evaluated the motility, viability, and morphology. Post-thaw semen were calculated the motility by SMI (sperm motility index). The live-dead sperm was evaluated by Eosin-B and morphological evaluation was by Diff-quik kit staining. The post-thaw concentration (89×106 /ml vs. 128×106 /ml), viability (22.6±10.6% vs. 37.1±26.1%), morphological normality (27.0±50.2% vs. 45.6±123.0%) of EE and AV groups were not significant different, but the post-thaw motility was significant lower in EE than that in AV group (53.1±3.6 vs. 73.6±5.7) (p<0.05). In conclusion, semen collection methods did not significant different between EE and AV groups except of post-thaw motility and so both semen collection methods could be applied in feline semen collection methods.
4,000원
8.
2011.03
구독 인증기관 무료, 개인회원 유료
The objective of this study was to examine the effect of various discontinuous Percoll washing conditions on motile sperm recovery rate and motion kinematics. Frozen semen samples from 3 bulls (0.5 ml plastic straws, 6% glycerol in egg yolk-Tris-glycerol extender) were thawed in 37℃ water bath for 1 min. After thawing, the mixed semen samples were randomly allocated to 12 treatment groups. Briefly, the spermatozoa were centrifuged for three different time lengths (10, 20, and 30 min) at two gravities (300×g and 700×g) through two concentrations of discontinuous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll and 2 ml 90%: 2 ml 45% Percoll to remove extender, debris, and dead spermatozoa. Motile sperm recovery rate and motion kinematics were evaluated by computer assisted sperm analyzer using Makler counting chamber. Sperm motility (%) and motile sperm recovery rate showed similar pattern in all treatment groups. However, sperm motility (%) and motile sperm recovery rate were highest at 700×g for 30 min through a discontionous Percoll density gradient of 1 ml 90%: 1 ml 45% Percoll. There were no significant differences in motion kinematics after various Percoll washings. These results suggest that force of centrifugation, centrifugation time, and Percoll volume significantly affect motile sperm recovery rate.
4,000원
9.
2011.03
구독 인증기관 무료, 개인회원 유료
The faulty regulation of imprinting gene lead to the abnormal development of reconstructed embryo after nuclear transfer. However, the correlation between the imprinting status of donor cell and preimplantation stage of embryo development is not yet clear. In this study, to determine this correlation, we used the porcine spermatogonial stem cell (pSSC) and fetal fibroblast (pFF) as donor cells. As the results, the isolated cells with laminin matrix selection strongly expressed the GFRα-1 and PLZF genes of SSCs specific markers. The pSSCs were maintained to 12 passages and positive for the pluripotent marker including OCT4, SSEA1 and NANOG. The methylation analysis of H19 DMR of pSSCs revealed that the zinc finger protein binding sites CTCF3 of H19 DMRs displayed an androgenic imprinting pattern (92.7%). Also, to investigate the reprogramming potential of pSSCs as donor cell, we compared the development rate and methylation status of H19 gene between the reconstructed embryos from pFF and pSSC. This result showed no significant differences of the development rate between the pFFs (11.2±0.8%) and SSCs (13.3±1.1%). However, interestingly, while the CTCF3 methylation status of pFF-NT blastocyst was decreased (36.3%), and the CTCF3 methylation status of pSSC-NT blastocyst was maintained. Therefore, this result suggested that the genomic imprinting status of pSSCs is more effective than that of normal somatic cells for the normal development because the maintenance of imprinting pattern is very important in early embryo stage.
4,000원
10.
2011.03
구독 인증기관 무료, 개인회원 유료
One-step dilution and direct transfer would be a practical technique for the field application of frozen embryo. This study was to examine whether Jeju Black Cattle (JBC, Korean Cattle) can be successfully cloned from vitrified and one-tep diluted somatic cell nuclear transfer (SCNT) blastocyst after direct transfer. For vitrification, JBC-SCNT blastocysts were serially exposed in glycerol (G) and ethylene glycol (EG) mixtures〔10% (v/v) G for 5 min., 10% G plus 20% EG (v/v) for 5 min., and 25% G plus 25% EG (v/v) for 30 sec.〕which is diluted in 10% FBS added D-PBS. And then SCNT blastocysts were loaded in 0.25 ml mini straw, placed in cold nitrogen vapor for 3 min. and then plunged into LN2. One-step dilution in straw was done in 25℃ water for 1 min, by placing vertically in the state of plugged- end up and down for 0.5 min, respectively. When in vitro developmental capacity of vitrified SCNT blastocyst was examined at 48 h after one-step dilution, hatched rate (56.4%) was slightly lower than that of control group (62.5%). In field trial, when the vitrified-thawed SCNT blastocysts were transferred into uterus of synchronized 5 recipients, a cloned female JBC was delivered by natural birth on day 299 and healthy at present. In addition, when the short tandem repeat marker analysis of the cloned JBC was evaluated, microsatellite loci of 11 numbers was perfectly matched genotype with donor cell (BK94-14). This study suggested that our developed vitrification and one-step dilution technique can be applied effectively on field trial for cloned animal production, which is even no longer in existence.
4,000원
11.
2011.03
구독 인증기관 무료, 개인회원 유료
The objective of this study was to evaluated the efficiency on sperm cryosurvival and ability of in vitro fertilization using Triladyl and Lactose Egg-Yolk(LEY) as extenders for cryopreservation of separated sperm by 65% percoll in miniature pig. Sperm viability was measured with SYBR-14/PI double stained sperm by flow cytometry. Ability on embryo cleavage rate and blastocyst development were observed by in vitro fertilization after frozen-thawing of sperm separated by 65% percoll. The experimental groups were designed that separated sperm by 65% percoll with Triladyl (ST) or LEY(SL) and unseparated sperm with Triladyl(UT) or LEY(UL) for cryopreservation. As a results, the viability was significantly(p<0.05) higher in ST(55.1%), SL(63.1%), UL(58.8%) than UT(38.2%) group. Sperm viability in SL(63.1%) group was significantly(p<0.05) higher than other experimental groups. On the other hand, embryo cleavage rate was significantly(p<0.05) higher in ST(79.1%), SL(83.2) than UT(74.1%) and UL(75.7%) groups at 96h after in vitro fertilization. Blastocyst development was also significantly(p<0.05) higher in ST(21.5%), SL(20.9%) than UT(17.0%) and UL (18.8%) groups. In conclusion, cryopreservation of miniature boar sperm separated by 65% percoll were beneficial to viability and capacity on in vitro fertilization.
4,000원
12.
2011.03
구독 인증기관 무료, 개인회원 유료
Previously, we reported that the osmolarity conditions in the satellite region were affected CpG DNA methylation status while Pre-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. This study was conducted to investigate the DNA methylation status of repeat sequences in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05 M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. The DNA methylation status of the Pre-1 sequences in blastocysts was characterized using a bisulfite-sequencing method. Intriguingly, in the present study, we found the unique DNA methylation at several non-CpG sequences at the Pre-1 sequences in all groups. The non-CpG methylation was hypermethylated in all three groups, including in vivo group (86.90% of PZM- 3; 83.87% of NaCl; 84.82% of sucrose; 90.94% of in vivo embryos). To determine whether certain non-CpG methylated sites were preferentially methylated, we also investigated the methylation degree of CpA, CpT and CpC. Excepting in vivo group, preference of methylation was CpT>CpC>CpA in all three groups investigated. These results indicate that DNA methylation of Pre-1 sequences was hypermethylated in CpG as well as non-CpG site, regardless modification of osmolarity in a culture media.
4,000원
13.
2011.03
구독 인증기관 무료, 개인회원 유료
Transducin-like enhancer protein 1(TLE-1) is protein associated with cell proliferation. This study analyzed change of TLE-1 mRNA expression during in vivo and in vitro maturation in porcine oocytes. Oocytes and granulose cells were collected from follicles of <2 mm, 2～6 mm and >6 mm in diameter in slaughtered pig’s ovaries. Oocytes collected from follicles of 2～6 mm in diameter were used after in vitro maturation for 0, 10, 20 and 44 h. Cumulus cells and granulose cells were collected after treatment with hyaluronidase. In results, TLE-1 mRNA expression in oocytes collected from follicle >6 mm in diameter is increased, TLE-1 RNA expression in cumulus cells and granulosa cells from follicles <2 mm, 2 mm 6 mm and >6 mm in diameter. However, there is no significant difference. On the other hand, TLE-1 mRNA expression from oocytes cultured for 10 h and 44 h is increased, TLE-1 mRNA in cumulus cells cultured for 10 h is significant increased(p<0.05) than other culture periods. In conclusion, these results show that TLE-1 is expressed in all cell types of oocytes, cumulus cells and granulose cells, and associated with oocyte maturation.
4,000원
14.
2011.03
구독 인증기관 무료, 개인회원 유료
The present study investigated the nuclear remodeling, development potential with telomerase activity and transcription level of X-linked genes (ANT3, HPRT, MeCP2, RPS4X, XIAP, XIST and ZFX) in the bovine somatic cell nuclear transfer (SCNT) embryos using two different fusion and activation methods. Female adult fibroblasts were injected into perivitelline space of in vitro matured oocytes. The oocyte-nucleus complexes were fused and followed by immediately either activated (Group 1), or activated at 1 h post-fusion (hpf) (Group 2), respectively. The incidence of normal premature chromosome condensation (PCC) at 1 hpf was slightly increased in the Group 2, compared to those of Group 1, but there was no significant (p<0.05) difference. The incidence of normal pronucleus (PN) and chromosome spread at 5 and 18 hpf were significantly (p<0.05) higher in the Group 2 than those of Group 1. The cleavage rate to 2-cell stage, developmental rate to blastocyst stage, and the mean number of total and ICM cell numbers were significantly (p<0.05) higher in the Group 2, compared to those of Group 1. Level of telomerase activity was significantly (p<0.05) higher in the SCNT blastocysts of Group 2, compared to those of Group 1. Transcript levels of HPRT, MeCP2 and XIST were not significantly (p<0.05) different between blastocysts of Group 1 and 2. However, transcript level of ANT3, RPS4X, XIAP and ZFX were significantly (p<0.05) up-regulated in the SCNT blastocysts of Group 2, compared to those of Group 1. Taken together, it is concluded that oocyte activation at 1 hpf induces the enhanced developmental potential by efficient nuclear remodeling and subsequent facilitation of the nuclear reprogramming of bovine SCNT embryos.
4,000원
15.
2011.03
구독 인증기관 무료, 개인회원 유료
hFSH is a glycoprotein secreted from anterior pituitary and consists of α and β subunits. Because of its major biological functions including sperm formation in the male and for follicular growth, FSH is used to cure woman's sterility. In this study we tried to produce recombinant hFSH in vitro using a retrovirus expression vector. Two major components of the vector we constructed are: (ⅰ) a DNA fragment containing α and β genes fused by a DNA sequence coding carboxyl terminal peptide (CTP) of human chorionic gonadotropin, (ⅱ) a DNA fragment corresponding woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Evaluation of expression profile of the recombinant FSH using reverse transcription PCR and enzyme-linked immunosorbent assay (ELISA). Among three cell lines tested, HeLa cells were the best for hFSH expression (5,395 mIU/ml), then followed by chicken embryonic fibroblast (CEF) cells and Chinese hamster ovary (CHO) cells in the order of hFSH production. In addition to the amount, the FSH produced from HeLa cells was highest in terms of biological activity which was determined by measuring cAMP.
4,000원
16.
2011.03
구독 인증기관 무료, 개인회원 유료
The pig has been considered to serve as an appropriate model of human disease. Therefore, establishment of porcine embryonic stem cell lines is important. The purpose of the present study was to further work in this direction. We produced porcine parthenogenetic embryos, and separately aggregated two of each of two-cell (2×2), four-cell (2×4), and eight-cell (2×8) embryos derived by parthenogenesis. After culture for 4 days, the developmental ability of the aggregates and total blastocyst cell numbers were evaluated. The percentage of blastocysts was significantly higher in both 2×4- and 2×8-aggregated embryos (58.3±1.9% and 37.2±2.8%, respectively) than in the control or 2×2-aggregated embryos (23.6±1.1% and 12.5±2.4%, respectively). Total blastocyst cell numbers were increased in the 2×4- and 2×8-aggregated embryos (by 44±3.0% and 45±3.3%, respectively) compared with those of control or 2×2-aggregated embryos (30.5±2.1% and 30.7±2.6%, respectively; p<0.05). The levels of mRNA encoding Oct-4 were higher in both the 2×4- and 2×8-aggregated embryos than in the control. When blastocysts derived from 2×4- aggregated embryos or intact normal embryos were cultured on mouse embryonic fibroblast feeder cells to obtain porcine stem cells, blastocysts from aggregated embryos formed colonies that were better in shape compared with those derived from intact blastocysts. Together, the data show that aggregation of porcine embryos not only improves blastocyst quality but also serves as an efficient procedure by which porcine embryonic stem cells can become established.
4,000원
