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1.
The aim of the present study was to clarify the overall efficiency of porcine somatic cell nuclear transfer (SCNT) by incorporating cryopreservation of the cloned embryos before transfer. The SCNT embryos reconstructed with preadipocytes and in vitro-matured (IVM) oocytes were cultured to harvest morula stage embryos; they were then subjected to delipation (removal of cytoplasmic lipid droplets) and vitrification. After warming and culture, the embryos developing to blastocysts were transferred to recipients to obtain cloned piglets. From 372 reconstructed embryos, 188 (50.5%) reached the morula stage and 117 (31.5%) developed to blastocysts after vitrification. Transfer of 98 (26.3%) morphologically normal blastocysts gave rise to 6 (1.6%) piglets, including 1 stillborn. The efficiency of the cloned piglet production was comparable with that obtained using SCNT embryos without cryopreservation (2.7%, 17/635). Here, we demonstrate that porcine somatic cell cloning can be performed without a significant reduction in efficiency even when the SCNT embryos are cryopreserved before transfer.  相似文献   

2.
In this study, we compared the developmental ability of somatic cell nuclear transfer (SCNT) embryos reconstructed with three bovine somatic cells that had been synchronized in G0‐phase (G0‐SCNT group) or early G1‐phase (eG1‐SCNT group). Furthermore, we investigated the production efficiency of cloned offspring for NT embryos derived from these donor cells. The G0‐phase and eG1‐phase cells were synchronized, respectively, using serum starvation and antimitotic reagent treatment combined with shaking of the plate containing the cells (shake‐off method). The fusion rate in the G0‐SCNT groups (64.2 ± 1.8%) was significantly higher than that of eG1‐SCNT groups (39.2 ± 1.9%) (P < 0.05), but the developmental rates to the blastocyst stage of SCNT embryos per fused oocytes were similar for all groups. The overall production efficiency of the clone offspring in eG1‐SCNT groups (12.7%) per recipient cow was higher than that in G0‐SCNT groups (3%) (P < 0.05). The mean birth weight of cloned calves and the average calving score in the G0‐SCNT groups (48.1 ± 3.4 kg and 3.3 ± 0.3, respectively) was significantly higher (P < 0.05) than those of eG1‐SCNT groups (37.2 ± 2.1 kg and 2.3 ± 0.2, respectively). Results of this study indicate that synchronization of donor cells in eG1‐phase using the shake‐off method improved the overall production efficiency of the clone offspring per transferred embryo.  相似文献   

3.
The objective of the present study was to examine the feasibility of the production of autologous porcine somatic cell nuclear transfer (SCNT) blastocysts using oocytes and donor cells from slaughtered ovaries. Therefore, we attempted to optimize autologous SCNT by examining the effects of electrical fusion conditions and donor cell type on cell fusion and the development of SCNT embryos. Four types of donor cells were used: 1) denuded cumulus cells (DCCs) collected from in vitro-matured (IVM) oocytes; 2) cumulus cells collected from oocytes after 22 h of IVM and cultured for 18 h (CCCs); 3) follicular cells obtained from follicular contents and cultured for 40 h (CFCs); and 4) adult skin fibroblasts. The DCCs showed a significantly (p < 0.01) lower rate of fusion than the CCCs when two pulses of 170 V/mm DC were applied for 50 µsec (19 ± 2% vs. 77 ± 3%). The rate of DCC fusion with oocytes was increased by the application of two DC pulses of 190 V/mm for 30 µsec, although this was still lower than the rate of fusion in the CCCs (33 ± 1% vs. 80 ± 2%). The rates of cleavage (57 ± 5%) and blastocyst formation (1 ± 1%) in the DCC-derived embryos did not differ from those (55 ± 6% and 3 ± 1%, respectively) in the CCC-derived SCNT embryos. Autologous SCNT embryos derived from CFCs (5 ± 2%) showed higher levels of blastocyst formation (p < 0.01) than CCC-derived autologous SCNT embryos (1 ± 0%). In conclusion, the results of the present study show that culturing cumulus and follicular cells before SCNT enhances cell fusion with oocytes and that CFCs are superior to CCCs in the production of higher numbers of autologous SCNT blastocysts.  相似文献   

4.
Many observations have been made on cloned embryos and on adult clones by somatic cell nuclear transfer (SCNT), but it is still unclear whether the progeny of cloned animals is presenting normal epigenetic status. Here, in order to accumulate the information for evaluating the normality of cloned cattle, we analyzed the DNA methylation status on satellite I region in blastocysts obtained from cloned cattle. Embryos were produced by artificial insemination (AI) to non‐cloned or cloned dams using semen from non‐cloned or cloned sires. After 7 days of AI, embryos at blastocyst stage were collected by uterine flushing. The DNA methylation levels in embryos obtained by using semen and/or oocytes from cloned cattle were similar to those in in vivo embryos from non‐cloned cattle. In contrast, the DNA methylation levels in SCNT embryos were significantly higher (P < 0.01) than those in in vivo embryos from non‐cloned and cloned cattle, approximately similar to those in somatic cells used as donor cells. Thus, this study provides useful information that epigenetic status may be normal in the progeny of cloned cattle, suggesting the normality of germline cells in cloned cattle.  相似文献   

5.
Interspecies cloning may be a useful method to help conserve endangered species and to study nuclear-cytoplasm interaction. The present study investigated in vitro development of goral (Naemorhedus goral) intergeneric nuclear transfer embryos produced by fusing goral fibroblasts with enucleated metaphase II (MII) bovine oocytes. After two to five passages, serum-starved or non-starved goral skin fibroblast cells were transferred into enucleated MII bovine oocytes. Couplets were electrically fused and chemically activated, and then cultured in either modified synthetic oviduct fluid (mSOF) or tissue culture medium-199 (TCM-199) supplemented with 10% FBS. Serum starvation of donor cells did not affect the fusion rate and or development to of cells to the two-cell stage, to more than 9-cells, or to morulae, regardless of culture medium. Three blastocysts from 202 fused embryos were obtained when embryos reconstructed with non- serum- starved donor cells were cultured in mSOF. However, no blastocysts were obtained when the embryos reconstructed with serum-starved donor cells were cultured in mSOF. The total cell number of goral intergeneric embryos averaged 130.3 (range 105-180). In conclusion, this study demonstrated that bovine oocytes can support blastocyst development after intergeneric SCNT with goral fibroblasts.  相似文献   

6.
Retrovirus-mediated exogenous gene transfection of somatic cells is an efficient method to produce transgenic embryos by somatic cell nuclear transfer (SCNT). This study evaluated whether efficiency of transgenic embryos production, by SCNT using fibroblast cells transfected by retrovirus vector, is influenced by the introduced transgene and whether recloning could further improve its efficiency. Transgenic cloned embryos were produced by SCNT of porcine foetal fibroblast cells transfected by either LNβ-Z or LNβ-enhanced green fluorescent protein (EGFP) retrovirus vector and evaluated for their developmental ability in vitro . Blastomeres from four-cell stage porcine embryos, produced by SCNT of foetal fibroblast cells transfected with LNβ-EGFP retroviral vector, were subsequently recloned into enucleated metaphase II oocytes and evaluated for changes in chromatin configuration, in vitro embryo development and gene expression. Analysis of results showed that cleavage and blastocyst rates of porcine SCNT embryos, using LacZ (53.6 ± 6.4%; 12.0 ± 5.7%) or EGFP (57.5 ± 6.3%; 10.1 ± 4.1%) transfected fibroblasts, did not differ (p > 0.05) from those of non-transfected controls (60.9 ± 8.2%; 12.3 ± 4.0%). Recloning of blastomeres did not further improve the in vitro development rate. Interestingly, the nuclei of blastomere underwent slower remodelling process than somatic cell nuclei. Both cloned and recloned embryos showed 100% transgene expression and there were no evidence of mosaicism. In conclusion, our data shows that the efficiency of transgenic cloned embryos production by SCNT of somatic cells transfected with replication-defective retrovirus vector is not influenced by the transgene introduction into donor cells and recloning of four-cell stage blastomere could not further improve its efficiency.  相似文献   

7.
The purpose of this study was to investigate the role of porcine cumulus cells (CC) in oocyte maturation and somatic cell nuclear transfer (SCNT) embryo development in vitro. Denuded pig oocytes were co-cultured with CC or routinely cultured in maturation medium without a feeder layer. Porcine CC inactivated with mitomycin C or non-inactivated were used for the feeder layer in co-culture with porcine SCNT embryos to investigate comparatively the developmental competence of cloned embryos. The DNA damage aspects of apoptosis and expression pattern of genes implicated in apoptosis (Fas/FasL) as well as the mRNA expression of DNA methyltransferase (Dnmt1, Dnmt3a) of porcine SCNT embryos were also evaluated by comet assay or real-time RT-PCR, respectively. The results showed that co-culture with CC improved the extrusion rate of pbI (49.3% vs 31.5%, p<0.05) and survival rate (75.7% vs 53.3%, p<0.05) of denuded oocytes, but had no effects on blastocyst developmental rate or 2-cell-stage survival rate of in vitro fertilization embryos. Co-culture with CC inactivated by mitomycin C improved the blastocyst developmental rate (26.6% vs 13.0%, p<0.05) and decreased the apoptotic incidence (27.6% vs 46.2%, p<0.05) of porcine cloned embryos. Co-culture with inactivated CC reduced Fas and FasL mRNA expression of cloned embryos at the blastocyst stage compared with NT controls (p<0.05), but there were no differences in Dnmt1 and Dnmt3a mRNA expression among groups. Co-culture with inactivated cumulus cell monolayer significantly increased blastocyst formation and decreased the apoptotic incidence in porcine cloned embryos during in vitro development.  相似文献   

8.
In this study the efficacy of the combination of glycerol (GLY) and ethylene glycol (EG) as cryoprotectants in a vitrification method developed for direct embryo transfer was evaluated by in vitro development of in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos after vitrification. The IVF and SCNT blastocysts were vitrified in either 40% GLY, 30% GLY + 10% EG, or 20% GLY + 20% EG using French straws. After warming, the straws were held vertically for 1 min without shaking and were then placed horizontally for 5 min to dilute the cryoprotectants. After washing, the vitrified-warmed embryos were cultured in vitro for 72 h. There were no differences among the vitrification solutions with respect to the rates of vitrified-warmed IVF and SCNT embryos surviving and developing to the hatched blastocyst stage. However, the rates of development to the hatched blastocyst stage of the SCNT embryos vitrified with 40% GLY tended to be higher than those vitrified with 30% GLY + 10% EG or 20% GLY + 20% EG (26% vs. 7-8%, respectively). The development rates to the hatched blastocyst stage of the IVF and SCNT embryos vitrified with solution containing EG were significantly lower (P<0.05) than those of non-vitrified embryos. These results suggest that use of the combination of GLY and EG as cryoprotectants had no beneficial effect on the viability of embryos after in-straw dilution. However, this method is so simple that it can be used for practical direct transfer of vitrified embryos in the field.  相似文献   

9.
The present study compared the efficiency of transgenic (TG) cloned embryo production by somatic cell nuclear transfer (SCNT) with fetal-derived fibroblast cells (FFCs) which were transfected with pEGFP-N1 to in vitro-fertilized (IVF), parthenogenetic and SCNT counterparts by evaluating the rates of cleavage and blastocyst formation, apoptosis rate at different developmental stages, cell number, ploidy and gene expression in blastocysts. In SCNT and TG embryos, the rates of cleavage and blastocyst formation were significantly lower (p < 0.05) than those of IVF controls, but it did not differ between SCNT and TG embryos. In IVF control, 86.7% embryos displayed diploid chromosomal complements and the rates were significantly (p < 0.05) higher than those of SCNT and TG embryos. Most TG embryos (79%) with FFCs expressed the gene by both PCR and under fluorescence microscopy. The expression of apoptosis by TUNEL was first detected at six to eight cell stages in all embryos of IVF, SCNT and TG groups, but the expression rate at each developmental stages was significantly higher (p < 0.05) in SCNT and TG embryos than in IVF counterparts. The expression rate in inner cell mass (ICM) of TG embryos was significantly higher (p < 0.05) than in SCNT and IVF embryos. These results indicate that the high occurrence of apoptosis observed in SCNT and TG embryos compared with IVF counterparts might influence the developmental competence. Moreover, the SCNT embryos derived using non-transfected donor cells exhibited a lower apoptosis expression in ICM cells than in TG embryos derived using pEGP-N1-transfected donor cells suggesting a possible role of negative gene effect in TG embryos.  相似文献   

10.
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11.
This study was carried out to determine whether culture media reconstructed with bovine enucleated oocytes and the expression pattern of Oct-4 could support dedifferentiaton of monkey fibroblasts in interspecies cloned monkey embryos. In this study, monkey and bovine skin fibroblasts were used as donor cells for reconstruction with bovine enucleated oocytes. The reconstructed monkey interspecies somatic cell nuclear transfer (iSCNT) embryos were then cultured under six different culture conditions with modifications of the embryo culture media and normal bovine and monkey specifications. The Oct-4 expression patterns of the embryos were examined at the two-cell to blastocyst stages using immunocytochemistry. The monkey iSCNT embryos showed similar cleavage rates to those of bovine SCNT and bovine parthenogenetic activation (PA). However, the monkey iSCNT embryos were not able to develop beyond the 16-cell stage under any of the culture conditions. In monkey and bovine SCNT embryos, Oct-4 could be detected from the two-cell to blastocyst stage, and in bovine PA embryos, Oct-4 was detectable from the morula to blastocyst stage. These results suggested that bovine ooplasm could support dedifferentiation of monkey somatic cell nuclei but could not support embryo development to either the compact morula or blastocyst stage. In conclusion, we found that the culture conditions that tend to enhance monkey iSCNT embryo development and the expression pattern of Oct-4 in cloned embryos (monkey iSCNT and bovine SCNT) are different than in bovine PA embryos.  相似文献   

12.
To optimize somatic cell nuclear transfer (SCNT) procedures in mini-pigs, the present study was designed to examine the effects of donor cell types and aphidicolin (APC) treatment on in vitro development of reconstructed embryos. Oviduct epithelial cells (OEC), ear fibroblast cells (EFC) and cumulus cells (CC) derived from mini-pigs were treated with serum starvation only or serum starvation followed by treatment of 0.1 µg/mL APC. The reconstructed embryos were cultured for 7 days to evaluate their developmental competency. Cleavage and blastocyst formation rates of reconstructed embryos derived from the OEC by APC treatment were significantly higher than the serum starvation (61.82% vs. 56.25%, 24.55% vs. 17.86%; P < 0.05). The cleavage rate from the EFC was significantly increased by APC treatment compared to serum starvation only (63.36% vs. 57.01%; P < 0.05). In the ooctyes with the CC, the reconstructed embryos could yield high blastocyst formation rate by APC treatment (29.63%; P < 0.05). In the presence of APC, CC gave rise to the highest cleavage and blastocyst formation rates among the three cell types. Therefore, our results suggest that treatment of CC with serum starvation plus APC prior to nuclear transfer is more suitable in SCNT of mini-pigs.  相似文献   

13.
The relationship between donor cell cycle and the developmental ability of somatic cell nuclear transfer (SCNT) embryos has not fully been elucidated. Donor cells that are usually prepared by serum starvation or confluent-cell culture for SCNT represent a heterogeneous population that includes mainly G0 phase cells, other cells in different phases of the cell cycle and apoptotic cells. In this study, we compared the developmental ability of porcine SCNT embryos reconstructed from G0 phase cells (G0-SCNT embryos) and strictly synchronized-G1 phase cells (G1-SCNT embryos), and examined the developmental rates and timing of first DNA synthesis. The G0 phase cells were synchronized by confluent culture, and the G1 phase cells were prepared from actively dividing M phase cells. The G1-SCNT embryos showed a significantly higher (P<0.05) developmental rate to the blastocyst stage per cleaved embryo (59%) than the G0-SCNT embryos (43%). Moreover, initiation of first DNA synthesis and cleavage occurred significantly earlier in the G1-SCNT embryos than in the G0-SCNT embryos. Delay of initiation of first DNA synthesis in the SCNT embryos by aphidicolin resulted in decreased developmental rates to the blastocyst stage without any effect on cleavage rates. Our data demonstrates that synchronized-G1 phase cells can be used as donor cells for SCNT embryos and that earlier initiation of first DNA synthesis may be important for subsequent development of SCNT embryos. The SCNT system using G1-synchronized cells, in terms of their highly uniform and viable cell states, can be useful for studying the reprogramming processes and embryonic development of SCNT embryos.  相似文献   

14.
The aim of this study was to reconstruct and cryopreserve somatic cell nuclear transferred (SCNT) ovine embryos and evaluate the effect of alpha-tocopherol on blastocyst development and subsequent cryosurvival of the SCNT embryos. The alpha-tocopherol (100 microg/ml) was added into culture medium for the SCNT embryos, the yield and total cell numbers of blastocysts were determined and the apoptosis incidences of the blastocysts were evaluated using the TUNEL assay. The blastocysts from the alpha-tocopherol and untreated groups were then frozen-thawed, and their cryosurvival was assessed by in vitro culture for 48 h. The results showed that there were no significant differences in blastocyst yield (26.3 vs. 22.3%) and total cell number (68.2 vs. 64.3) between the alpha-tocopherol and untreated groups. However, addition of alpha-tocopherol to the culture medium significantly decreased the apoptotic cell number (3.4 vs. 5.5) and significantly increased the cryosurvival of SCNT blastocysts (66.8 vs. 50.7%). In conclusion, addition of alpha-tocopherol to SCNT embryo culture medium was beneficial for improving embryo quality by decreasing the apoptotic blastocyst cell number and improving the tolerance of the embryos to cryopreservation.  相似文献   

15.
In mouse somatic cell nuclear transfer (SCNT), polyvinylpyrrolidone (PVP) is typically included in the nuclear donor injection medium. However, the cytotoxicity of PVP, which is injected into the cytoplasm of oocytes, has recently become a cause of concern. In the present study, we determined whether bovine serum albumin deionized with an ion-exchange resin treatment (d-BSA) was applicable to the nuclear donor injection medium in SCNT as an alternative to PVP. The results obtained showed that d-BSA introduced into the cytoplasm of an enucleated oocyte together with a donor nucleus significantly enhanced the rate of in vitro development of cloned embryos to the blastocyst stage compared with that of a conventional nuclear injection with PVP in SCNT. We also defined the enhancing effects of d-BSA on the blastocyst formation rate when d-BSA was injected into the cytoplasm of oocytes reconstructed using the fusion method with a hemagglutinating virus of Japan envelope before oocyte activation. Furthermore, immunofluorescence experiments revealed that the injected d-BSA increased the acetylation levels of histone H3 lysine 9 and histone H4 lysine 12 in cloned pronuclear (PN) and 2-cell embryos. The injection of d-BSA before oocyte activation also increased the production of cloned mouse offspring. These results suggested that intracytoplasmic injection of d-BSA into SCNT oocytes before oocyte activation was beneficial for enhancing the in vitro and in vivo development of mouse cloned embryos through epigenetic modifications to nuclear reprogramming.  相似文献   

16.
供体细胞培养处理方法对水牛核移植效果的影响   总被引：4，自引：1，他引：4  
以经常规培养法 (DMEM 10 % FCS)、血清饥饿法 (DMEM 0 .5 % FCS培养 5～ 10 d)和 Apidicolin- APD结合血清饥饿法 (0 .1mg/ L APD培养 2 4 h,DMEM 0 .5 % FCS培养 1～ 18d)培养处理的水牛卵巢颗粒细胞和水牛成体耳部成纤维细胞作供核 ,分别采取带下注核法和胞质内注核法进行核移植。同一供核细胞各处理组间的核移植胚融合率 (以颗粒细胞作供核 )以及重组胚的囊胚发育率无明显差异 (P>0 .0 5 ) ,但经 APD 0 .5 % FCS培养处理供体细胞核移植后的分裂率显著高于其他组 (P<0 .0 5 )。用 7%乙醇处理的成体耳部成纤维细胞进行核移植 ,其重组胚的分裂率和囊胚发育率与对照组 (不含乙醇 )均无明显差异 (P>0 .0 5 )。结果表明 ,(1)血清饥饿处理水牛供体细胞对其核移植效果没有影响 ;(2 ) DNA合成抑制剂 APD结合血清饥饿培养处理水牛颗粒细胞和成体耳部成纤维细胞 ,可提高其核移植效果 ;(3)乙醇预激活处理水牛成体耳部成纤维细胞 ,对其核移植效果没有影响  相似文献   

17.
[目的] 探索不同来源卵母细胞对体细胞核移植（SCNT）重构胚的发育能力及发育潜能关键蛋白表达水平的影响。[方法] 试验分为活体采卵（OPU）和屠宰场（SLH）卵巢2组,OPU组用超声波活体采卵仪穿刺抽吸10头非泌乳期经产水牛卵巢的卵泡采卵,SLH组从屠宰场卵巢抽吸卵泡采卵。获得的卵母细胞分别进行体外成熟,体外成熟22~24 h后,吹打去除卵丘细胞,挑选具有第一极体的卵母细胞,去核后与水牛耳部成纤维细胞进行SCNT,分别统计SCNT重构胚的融合率、分裂率和囊胚率,用免疫荧光检测2种SCNT重构胚的E-钙黏蛋白（E-cadherin）和转录因子Sox2蛋白的表达水平。[结果] OPU组卵母细胞成熟率及其SCNT重构胚的囊胚率均显著高于SLH组（P<0.05）,但2组SCNT重构胚的融合率和分裂率均无显著差异（P>0.05）;免疫荧光结果显示,E-cadherin蛋白定位于细胞膜上,Sox2蛋白分布在细胞核膜及细胞质中,OPU组SCNT重构胚中E-cadherin和Sox2的表达水平均显著高于SLH组（P<0.05）。[结论] 活体采集的水牛卵母细胞更适合用于SCNT重构胚的构建。  相似文献   

18.
The present study explored a suitable parthenogenetic activation (PA) procedure for rabbit oocytes and investigated the developmental potential of somatic cell nuclear transfer (SCNT) embryos using rabbit foetal fibroblasts (RFFs). The electrical activation had the optimal rate of blastocyst (14.06%) when oocytes were activated by three direct current (DC) pulses (40 V/mm, 20 μs each) followed by 6‐dimethylaminopurine (6‐DMAP) and cycloheximide (CHX) treatment; the blastocyst rate of ionomycin (ION) + 6‐DMAP + CHX (12.07%) activation was higher than that of ION + 6‐DMAP (8.6%) activation or ION + CHX (1.24%) activation; there was no significant difference in blastocyst rate between ION + 6‐DMAP + CHX and DC + 6‐DMAP + CHX groups. The blastocyst rate of ION + 6‐DMAP + CHX‐activated oocytes in the basic rabbit culture medium (M‐199) + 10% foetal bovine serum (FBS; 14.28%) was higher than that in buffalo conditioned medium (5.75%) or G1/G2 medium (0), and the blastocyst rate was increased when M‐199 + 10% FBS was supplemented with amino acids. Refreshing culture medium every day or every other day significantly increased the blastocyst rate. Treatment of donor cells with 0.5% FBS for 3–5 days increased blastocyst rate of SCNT embryos (33.33%) than no serum starvation (22.47%) or 0.5% FBS treatment for 6–9 days (23.61%); the blastocyst rate of SCNT embryos derived from nontransgenic RFFs was higher than that derived from transgenic RFFs by electroporation. The blastocyst development ability of SCNT embryos derived from RFFs by electroporation (32.22%) was higher than that of liposome (19.11%) or calcium phosphate (20.00%) transfection, and only the embryos from electroporation group have the EGFP expression (24.44%). In conclusion, this study for the first time systematically optimized the conditions for yield of rabbit embryo by SCNT.  相似文献   

19.
Cilostazol (CLZ) is a cyclic adenosine monophosphate (cAMP) modulator that influences the steady state of the meiotic stage. This study was conducted to determine the effects of CLZ treatment during in vitro maturation (IVM) on developmental competence of pig oocytes. Immature oocytes were exposed to 0 (control), 0.5, 2 and 4 μm CLZ during the first 22 h of IVM. Nuclear maturation, intraoocyte glutathione content and embryo cleavage after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) were not influenced by CLZ at any concentrations. However, 4 μm CLZ significantly (p < 0.05) improved blastocyst formation after PA (52.1% vs 38.7–46.0%) and SCNT relative to other concentrations (40.8% vs 25.0–30.7%). The mean cell numbers of SCNT blastocysts were significantly increased by 4 μm CLZ compared to the control (42.6 cells vs 35.3 cells/blastocyst). CLZ treatment significantly increased the intraoocyte cAMP level and effectively arrested oocytes at the germinal vesicle (GV) and GV break down stages compared to the control (74.5% vs 45.4%). Our results demonstrated that improved developmental competence of PA and SCNT pig embryos occurred via better synchronization of nuclear and cytoplasmic maturation induced by increased cAMP and delayed meiotic resumption after CLZ treatment.  相似文献   

20.
The objective of the present study was to investigate the effects of three different culture media on the development of canine somatic cell nuclear transfer (SCNT) embryos. Canine cloned embryos were cultured in modified synthetic oviductal fluid (mSOF), porcine zygote medium-3 (PZM-3), or G1/G2 sequential media. Our results showed that the G1/G2 media yielded significantly higher morula and blastocyst development in canine SCNT embryos (26.1% and 7.8%, respectively) compared to PZM-3 (8.5% and 0%) or mSOF (2.3% and 0%) media. In conclusion, this study suggests that blastocysts can be produced more efficiently using G1/G2 media to culture canine SCNT embryos.  相似文献   

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