FSH和LH对延边黄牛卵母细胞体外成熟及重组胚发育的影响

实验主要研究促卵泡素(FSH)、促黄体素(LH)对延边黄牛卵母细胞体外成熟及重组胚发育的影响,从而提高延边黄牛体细胞克隆的效率。采集屠宰后延边黄牛卵巢,用抽吸法回收卵母细胞,然后在不同种类、浓度激素条件下进行卵母细胞的体外成熟培养,最后将成熟的卵母细胞进行核移植及重组胚的体外培养。实验分别比较了在0、5、10、15、20μg/mL条件下,单独使用FSH与LH和在15μg/mL的FSH与10μg/mL的LH共同作用下对延边黄牛卵母细胞体外成熟率、卵裂率和囊胚发育率的影响。结果表明:将卵母细胞单独置于加有浓度为15μg/mL的FSH和10μg/mL的LH的成熟液中培养,其成熟率及后期发育率优于其他浓度组(P<0.05);而2种最优浓度同时添加共同作用时要好于单独使用(P<0.05)。由试验可得出,成熟培养液中单独添加15μg/mL的FSH和单独添加10μg/mL的LH浓度对延边黄牛卵母细胞体外成熟及重组胚后期发育效果最好;使用最佳浓度进行协同作用时,其共同作用要好于单独使用的效果。     

不同浓度离子霉素对猪体外成熟卵母细胞孤雌发育的影响

试验探讨了不同浓度的离子霉素结合6-二甲氨基嘌呤激活猪体外成熟卵母细胞后对其孤雌发育的影响。体外成熟卵母细胞分别用10、15、20、25mol/L的离子霉素处理40min,再用2mmol/L的6-DMAP处理8h,各组的卵裂率分别是:(13.11±6.75)%,(22.31±14.18)%,(26.93±24.53)%和(26.72±19.75)%,囊胚率分别是2.26±1.03)%,(2.39±2.41)%,(3.32±3.95)%和(11.76±10.76)%,各组之间差异不显著(P>0.05)。结果表明:用10～25mol/L离子霉素和6-DMAP联合激活猪体外成熟卵母细胞,对其孤雌发育能力有一定影响,但效果不显著;猪卵母细胞采用离子霉素激活的最佳方案是用25mol/L处理40min,再用浓度为2mmol/L的6-DMAP处理8h。     

大鼠卵母细胞孤雌激活方法的研究

本试验以Wistar大鼠为动物模型,研究了单独应用乙醇、电刺激、 6-DMAP以及乙醇/6 DMAP、 电刺激/6-DMAP 对大鼠卵母细胞激活的影响。结果表明,单独应用电刺激、乙醇、6-DMAP均能激活大鼠卵母细胞,但激活率较低,卵母细胞的发育不能超过2-细胞阶段。单独应用电刺激时,相同的场强条件下,电刺激2次的激活效果明显优于电刺激1次的激活效果,并且电刺激场强在100 V/mm时卵母细胞的激活率最高。乙醇或电刺激联合6-DMAP激活大鼠卵母细胞,激活率和后期囊胚发育率都明显优于单独使用1种激活方法激活的效果。     

细胞松弛素B对水牛体细胞核移植效果的影响

以水牛耳皮成纤维细胞为供体细胞,采用电融合方法,探讨细胞松弛素B(CB)对水牛体细胞核移植效果的影响.体外成熟培养22～24 h的水牛卵母细胞去核后.将经0.1 mg/L Aphidicolin(APD)+0.5%FBS培养2～9 d的水牛耳皮成纤维细胞注射到卵周隙中再经电融合(100 V/mm,15μs,电脉冲3次)构建核移植重构胚.重构胚经化学激活后(5 μmol/L)离子霉素5 min,2 mmol/L 6-DMAP 3 h)培养,7～9 d评定其胚胎发育能力.结果显示,在含CB(3 mg/L)的融合液中进行电融合后,核移植的融合率、重组胚的存活率、卵裂率和囊胚率与对照组(不含CB)相比均无显著差异(P>0.05);核移植重组胚激活前用含CB(6 mg/L)的培养液培养1 h,其激活后的存活率(97.52%)和体外囊胚发育率(22.09%)均显著地高于未经CB处理的重组胚的存活率(93.87%)和囊胚率(13.25%,P<0.05);重组胚经离子霉素激活5 min后,在6-DMAP+CB中培养3 h的分裂率明显低于放在6-DMAP中培养3 h的分裂率(65.37% vs 78.92%,P<0.05),但囊胚发育率无显著差异(11.19% vs 10.96%,P>0.05).这表明水牛体细胞核移植电融合时,融合液中不添加CB,而核移植重组胚激活前经CB培养处理后,有利于胚胎的进一步发育,但激活后用CB培养处理会降低胚胎的发育率.     

氨基酸和半胱胺对绵羊胚胎体外发育的影响

将从绵羊卵巢采集的卵母细胞成熟培养22~24h;成熟卵母细胞去除颗粒细胞,选择排出第一极体的卵母细胞,用5μmol/L A23187(5min)联合2mmol/L 6-DMAP(4h)进行孤雌激活;激活后的卵母细胞在培养液中进行培养。研究氨基酸和半胱胺对绵羊胚胎早期体外发育的影响。结果显示:(1)氨基酸能促进胚胎体外发育,0~24h培养添加抑制卵母细胞的卵裂,24h后培养添加比全过程培养添加更能促进胚胎体外发育;(2)24~72h培养添加必需氨基酸(EAA),能促进胚胎体外发育;(3)半胱胺添加量0~100μmol/L,随浓度增高各项发育指标呈增高趋势,添加100~200μmol/L,随浓度增高各项发育指标呈下降趋势。     

不同方法对滩羊卵母细胞孤雌激活及重构胚发育影响的研究

旨在探索宁夏滩羊卵母细胞孤雌激活及胚胎培养条件,并建立转Cherry基因滩羊体细胞重构胚的融合与体外培养体系。试验分析了3种激活方法即电激活、Ionomycin结合6-DMAP与电激活结合6-DMAP对成熟的滩羊卵母细胞激活的影响,以及3种胚胎培养液mSOFaa、M16和KSOM的培养筛选,并优化了滩羊体细胞重构胚的融合与体外培养条件。结果表明:在卵母细胞孤雌激活中,最适电压为1 600V/cm,获得卵裂率和囊胚率分别为58.5%和19.5%;5μmol离子霉素结合2 mmol 6-DMAP能有效地激活成熟的滩羊卵母细胞,卵裂率为81.0%,囊胚率为26.2%;并发现mSOFaa胚胎培养液的卵裂率和囊胚显著优于M16和KSOM培养液;在转基因重构胚融合中发现在电压1 800V/cm、脉冲时间10μs、脉冲次数2次和间隔时间为1s的条件下,卵裂率和囊胚率为40.0%、21.4%。本试验建立的滩羊孤雌激活和转基因重构胚融合与体外培养体系为宁夏滩羊的分子育种奠定了基础。     

山羊卵母细胞孤雌激活及孤雌胚的体外培养

为了比较不同的激活方法对卵母细胞孤雌激活的影响,以及培养液(CR1aa)中添加不同类型的血清对孤雌激活胚体外发育的影响。采用Eth 6-DMAP、A23187 6-DMAP和Ion 6-DMAP三种方法激活山羊卵母细胞,Eth 6-DMAP组孤雌激活胚的卵裂率和囊胚率(35.2%和4.8%)显著低于A23187 6-DMAP组(68.9%和24.1%)和Ion 6-DMAP组(88.1%和48.0%),表明以Ion 6-DMAP激活最为理想。在培养液(CR1aa)与颗粒细胞共同培养条件下,分别添加100 mL/L的发情牛血清(OCS)、胎牛血清(FBS)和新生牛血清(NCS)。添加OCS和FBS后,孤雌胚囊胚率分别为48.1%和45.0%,显著高于添加NCS组(26.0%)。表明OCS、FBS和NCS能有效的提高孤雌胚的体外发育能力,尤其是对提高孤雌胚的囊胚发育能力更佳。     

供体细胞和去核卵母细胞的不同预激活对体细胞核移植胚胎体外发育的影响

研究用细胞质内注射法构建重组胚，比较了离子霉素和乙醇预激活供体细胞和去核卵母细胞对重组胚卵裂和体外发育的影响。结果表明：与未经处理的对照组相比，离子霉素预激活供体细胞对重组胚的卵裂率和囊胚发育率有所提高；而供体细胞和去核卵母细胞同时用离子霉素预激活，重组胚的卵裂率无明显提高，囊胚发育率下降；用离子霉素或乙醇预激活去核卵母细胞，对重组胚的卵裂和发育无明显影响。     

氨基酸和半胱胺对绵羊胚胎体外发育的影响

将从绵羊卵巢采集的卵母细胞成熟培养22-24h;成熟卵母细胞去除颗粒细胞,选择排出第一极体的卵母细胞,用5μmol／LA23187（5min）联合2mmol／L 6-DMAP（4h）进行孤雌激活;激活后的卵母细胞在培养液中进行培养。研究氨基酸和半胱胺对绵羊胚胎早期体外发育的影响。结果显示：（1）氨基酸能促进胚胎体外发育,0-24h培养添加抑制卵母细胞的卵裂,24h后培养添加比全过程培养添加更能促进胚胎体外发育;（2）24～72h培养添加必需氨基酸（EAA）,能促进胚胎体外发育;（3）半胱胺添加量0～100μmol／L,随浓度增高各项发育指标呈增高趋势,添加100～200μmol／L,随浓度增高各项发育指标呈下降趋势。     

不同化学激活剂对牛卵丘细胞重构胚发育的影响

本文主要研究了①离子霉素（Ion）＋6-二甲基氨基嘌呤（6-DMAP）、②Ion＋放线菌酮（CHX）、③体积分数7％乙醇＋6-DMAP、④体积分数7％乙醇＋CHX四种不同化学激活方法对牛胞质内卵丘细胞全细胞注射法所获得重构胚的激活及前期发育的影响。Ion和7％乙醇的处理时间为5min,6-DMAP的处理时间为4h．CHX的处理时间为5h。结果表明,重构胚与颗粒细胞单层细胞共培养2d后,各组卵裂率分别为52．7％、51．5％、53．2％和54．0％．差异不显著（P〉0．05）;培养8d后,①组激活的囊胚发育率（20．0％）极显著高于其他组（P〈0．01）,其他各组之间差异不显著．分别为8．5％、10．2％和6．1％;培养10d后,①组激活的囊胚孵化率（10．7％）极显著高于其他组（P〈0．01）．其他各组之间差异不显著,分别为2．3％、3．0％和1．8％。表明,4种激活方法均可以有效地激活重构胚,但Ion＋6-DMAP法激活重构胚的囊胚率和囊胚孵化率均极显著高于其他3组,说明Ion＋6-DMAP激活法有利于牛重构胚的发育．可以获得较理想的囊胚率．是胞质内全细胞注射法克隆的理想激活方法。     

不同化学激活剂对牛卵丘细胞重构胚发育的影响

本研究主要研究了Ⅰ:Ionomycin+6 甲氨基嘌呤（6DMAP）、Ⅱ:Ionomycin+放线菌酮（CHX）、Ⅲ:体积分数7%乙醇+6 DMAP、Ⅳ:体积分数7%乙醇+CHX 4种不同化学激活方法对牛胞质内卵丘细胞全细胞注射法所获得重构胚的激活及前期发育的影响。Ionomycin和7%乙醇的处理时间为5 min, 6DMAP的处理时间为4 h,CHX的处理时间为5 h。结果表明,重构胚与颗粒细胞单层细胞共培养2 d后,各组卵裂率分别为52.6%、52.8%、53.8%和54.2%,差异不显著（P＞0.05）;培养8 d后,Ⅰ组激活的囊胚发育率（20.0%）极显著高于其他组（P＜0.01）,其他各组之间差异不显著,分别为8.5%、10.2%和6.1%;培养10 d后,Ⅰ组激活的囊胚孵化率（10.7%）极显著高于其他组（P＜0.01）,其他各组之间差异不显著,分别为2.3%、3.0%和1.8%。结果提示,4种激活方法均可以有效的激活重构胚,但Ionomycin+6 DMAP法激活重构胚的囊胚率和囊胚孵化率均极显著高于其它3组,说明Ionomycin+6 DMAP激活法有利于牛重构胚的发育,可以获得较理想的囊胚率,是胞质内全细胞注射法克隆的理想激活方法。     

Heterospecific Nuclear-transferred Embryos Derived from Equine Fibroblast Cells and Enucleated Bovine Oocytes

This study was conducted to reconstruct heterogeneous embryos using equine skin fibroblast cells as donor karyoplasts and the bovine oocytes as recipient cytoplast for investigating the reprogramming of equine somatic cell nuclear in bovine oocyte cytoplasm and the developmental potential of the reconstructed embryos. Adult horse skin fibroblast cells serum-starved were used as donor somatic cells. Bovine oocytes matured in vitro were employed as recipient cytoplasts. The fusion of fibroblast cells into recipient cytoplasm was induced by electofusion. The fused eggs were activated by inomycin with 2 mm/ml 6-dimethylaminopurine (6-DMAP). The activated reconstructed embryos were co-cultured with bovine cumulus cells in synthetic oviduct fluid supplemented with amino acid (SOFaa) and 10% fetal calf serum (FCS) for 168 h. The results showed that the first completed cleavage of xenonuclear transfer equine embryos occurred between 30 and 48 h following activation. 52% of the injected oocytes were successfully fused, 72% of the fused eggs underwent the first egg cleavage and 17% of the heterospecific nuclear-transferred zygotes developed to 4- or 8-cell embryo stages. This study demonstrated that the reconstructed embryos have undergone the first embryonic division and the reprogramming of equine fibroblast nuclei can be initiated in bovine-enucleated oocytes.     

Spindle formation and microtubule organization during first division in reconstructed rat embryos produced by somatic cell nuclear transfer

The present study was conducted to demonstrate the spindle formation and behavior of chromosomes and microtubules during first division in reconstructed rat embryos produced by somatic cell nuclear transfer (SCNT) with cumulus cell nuclei. To demonstrate the effect of oocyte aging after ovulation on the cleavage of SCNT embryos, micromanipulation was carried out 11, 15 and 18 h after injection of hCG. SCNT oocytes were activated by incubation in culture medium supplemented with 5 microM ionomycin for 5 min followed by treatment with 2 mM 6-dimethylaminopurine (6-DMAP) in mR1ECM for 2-3 h. For immunocytochemical observation, the SCNT embryos were incubated with monoclonal anti-alpha-tubulin antibody and then fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG. Cleavage rates were significantly higher for oocytes collected after 15 and 18 h rather than for those collected 11 h after injection of hCG (56 and 53%, respectively vs. 28%; P<0.05). Premature chromosome condensation occurred before activation of the SCNT oocytes, but adequate spindle formation was only rarely observed. The distribution of microtubules in SCNT embryos after activation was different from those of fertilized and parthenogenic oocytes, i.e., a dense microtubule organization shaped like a ring was observed. Eighteen to 20 h post-activation, most SCNT embryos were in the 2-cell stage, but no nucleoli were clearly visible, which was quite different from the fertilized oocytes. In addition, first division with and without small cellular bodies containing DNA was observed in the rat SCNT embryos in some cases. The present study suggests that reorganization of transferred nuclei in rat SCNT embryos may be inadequate in terms of formation of the mitotic assembly and nucleolar reorganization.     

Effects of Donor Cells Treated with Egg Extracts on the Development Competence of Cloned Embryos

Japanese Balck cattle fetal fibroblasts (JBCFF) were induced with Xenopus leavis egg extracts and somatic cell nuclear transfer (SCNT) was carried out with the reprogrammed JBCFF as donor cells in order to investigate their effects on SCNT efficiency.Three samples of egg extracts were acquired from different Xenopus laevis.The protein contents and kinds in extracts were evaluated with BCA Protein Quantification Kit and SDS-PAGE.Concentration of Digitonin to permeabilize JBCFF was optimized and assessed with PI staining.Reprogrammed cells treated with egg extract were used as donor in SCNT.Additionally the reconstructed embryos were activated with ionomycin+6-DMAP and A23187+6-DMAP to compare their effects on the development competence.The protein contents of extracts samples were 56.2255,64.6570 and 71.2158 μg/mL,respectively,the each extract had the same composition about 40-55 and 70-100 ku.The optimal concentration of Digitonin was 7 μg/mL and the permeabilization rate was 55.44%.After extracts treatment and continuous culture for 6-7 d,JBCFF formed well-defined colony structures.No significant composition difference was found in rates of fusion (92.83% vs 96.04%),cleavage (89.64% vs 89.78%) and blastocyst formation (24.06% vs 23.12%) of cloned embryos when the colony cells and JBCFF without extracts treatment were used as donor cells (P>0.05).Similarly,the two activation methods had no significant effect on the developmental competence of cloned embryos (cleavage rate 92.16% vs 92.28%,blastocyst rate 23.21% vs 24.18%).Conclusively,Xenopus leavis,egg extracts could induce JBCFF reprogramming to a low differentiated state.However donor cells with reprogramming partially could not improve the development of cloned embryos and its mechanism requires further research.     

抽提物处理供体细胞对克隆胚胎发育的影响

本研究采用爪蟾卵母细胞抽提物处理和牛胎儿成纤维细胞(JBCFF),并以发生重编程的细胞为核供体进行体细胞核移植,研究其对克隆效率的影响.分别超排3只爪蟾,收集卵母细胞后提取其抽提物,用BCA蛋白浓度测定试剂盒确定其蛋白含量,SDS-PAGE分析其中所含蛋白的种类.应用细胞膜透化剂Digitonin对建立的JBCFF进行通透处理和PI染色,筛选最适浓度;并用获得的抽提物处理牛体细胞,获得重编程细胞.以发生重编程的体细胞为供体进行核移植,同时比较离子霉素+6-DMAP和A23187+6-DMAP两种组合激活后克隆胚的体外发育能力.结果,3个爪蟾卵母细胞抽提物样品的蛋白浓度分别为56.2255、64.6570和71.2158 μg/mL,其中所含蛋白种类一致,主要集中在40~55、70~100 ku之间.经过连续的筛选,透化剂Digitonin对JBCFF通透处理的最适浓度为7 μg/mL,PI染色显示透化效率为55.44%.爪蟾卵母细胞抽提物与体细胞共孵育后继续培养6~7 d,细胞聚集形成"克隆簇".分别以"克隆簇"细胞和未处理细胞为核供体,制备的重构胚在融合率(92.83%和96.04%)、卵裂率(89.64%和89.78%)和囊胚率(24.06%和23.12%)均无显著差异(P>0.05);离子霉素+6-DMAP和A23187+6-DMAP两种激活方式对克隆胚胎的分裂率(92.16%和92.28%)和囊胚率(23.21%和24.18%)均无显著影响(P>0.05).爪蟾卵母细胞抽提物诱导和牛体细胞发生重编程,并恢复到较低的分化状态,但没有显著促进克隆胚胎的体外发育,可见缺少对胚胎发育起重要作用的重编程过程,还需要继续深入研究.     

The effect of activation protocols on the development of cloned goat embryos

This study was conducted to compare the developmental competence of somatic nuclear transfer (NT) embryos, after either ionomycin or ethanol activation, in locally bred goats. Donor cells were prepared from the ear skin fibroblasts of a female goat. Cells, at passage 3-8, starved by culturing in 0.5% FCS for 4-8 d, were used for NT. Immature oocytes were obtained from FSH-stimulated goats and matured for 22 hr before enucleation and NT. After fusion, the reconstructed embryos were activated with either ionomycin or ethanol followed by culturing in 6-dimethylaminopurine (6-DMAP) and cytochalasin B (CB), for 3 hr. In experiment I, the fused NT embryos (n=63, ionomycin and n=68, ethanol treatments, respectively) were cultured in B2 with a Vero co-culture system and their developmental competence was evaluated through to Day 9. In experiment II, the NT embryos at the 2-4 cell stage on Day 2 derived from each treatment (ionomycin n=46, and ethanol n=37), were transferred into 10 synchronous recipients. There were no significant differences between the NT embryos derived from the ionomycin and ethanol groups, in fusion (86.3% versus 82.9%), cleavage (90.5% versus 82.4%) and for morula/blastocyst development rates (9.5% versus 5.9%). Sixty percent (3/5) of the recipients from ionomycin became pregnant by midterm (2.5 mts) while only 20% (1/5) from ethanol treatment was pregnant by Day 45. The results demonstrate that activation with either ionomycin or ethanol in combination with 6-DMAP-CB treatment does not affect the development of cloned goat embryos.     

Milrinone treatment of bovine oocytes during in vitro maturation benefits production of nuclear transfer embryos by improving enucleation rate and developmental competence

In the production of cattle nuclear transfer embryos, the production efficiency is affected by the oocyte developmental competence and successful enucleation rate. This study investigated the effect of treating oocytes with milrinone, a phosphodiesterase inhibitor, on these two characteristics. When cumulus-oocyte complexes (COCs) were cultured for 19 h with 0, 50 or 100 μM of milrinone, the enucleation rate was significantly improved by 100 μM milrinone. However, milrinone treatment during in vitro maturation (IVM) also delayed meiotic progression by at least 2 h, which would affect the examination of enucleation rate and developmental competence of oocytes. Thus, in the second experiment, meiotic resumption was temporarily inhibited with butyrolactone I (BL-I; 100 μM, 18 h) to decrease the delayed maturation caused by milrinone; this enabled a more accurate comparison of the effects of milrinone after oocyte maturation. In nuclear transfer embryo production, oocytes treated with milrinone (100 μM, 20 h) showed a significantly higher rate of enucleation compared with that of control oocytes. This improved enucleation rate was associated with a closer location of the metaphase plate to the first polar body in the treated oocytes compared with that in control oocytes. Furthermore, milrinone improved the frequency of development to the blastocyst stage in the resulting embryos. In conclusion, milrinone supplementation during IVM improved enucleation rates by rendering the metaphase plate in close proximity to the first polar body, and this treatment also improved oocyte developmental competence. These benefits additively improved the yield of cloned embryos that developed to the blastocyst stage.     

Determination of optimal conditions for parthenogenetic activation and subsequent development of rat oocytes in vitro

The present study was undertaken to determine optimal conditions for parthenogenetic activation and subsequent development of rat oocytes. Oocytes from immature Wistar-Imamichi (WI) and Sprague Dawley (SD) rats were activated by electrical stimulation in combination with 6-dimethylaminopurine (6-DMAP) to assess whether different rat strains display different responses to activation treatment. Since the cleavage rates of activated oocytes were significantly higher in WI than SD strain rats, WI rats were used for the subsequent experiments to determine the effects of post-hCG time, culture duration, different activation protocols (electrical stimulation with 6-DMAP or ionomycin with 6-DMAP) and osmolarity of the activation medium on the activation and subsequent development of WI rat oocytes. For oocytes activated by electrical stimulation combined with 6-DMAP, the percentages of oocytes that were activated and that developed to blastocysts were higher when oocytes were collected at 18-20 h than at any other time points after hCG injection (16, 22-24 h). Culturing for 2-6 h before activation treatment markedly decreased the percentage of activated oocytes that developed to beyond the four-cell stage. There were no differences in the percentages of oocytes with pronuclear formation and subsequent development to the two-cell and blastocyst stages between oocytes that were activated by electrical stimulation or ionomycin, both followed by 6-DMAP treatment. Activation of oocytes by ionomycin and 6-DMAP, both in low osmolarity media (246 mOsM), markedly increased the cleavage rates and percentages of high quality blastocysts (71%). The optimal conditions determined in the present study with simplified activation protocols and high efficiency of activation and subsequent development of WI rat oocytes will be helpful for further research involving nuclear transfer in the rat.     

影响猪ICSI转基因技术效率的主要因素研究

以猪体外成熟卵子和冷冻解冻的死精子为材料,以pEGFP-N1为模式基因,探讨注射台温度、激活后6-DMAP的处理和精子与PEGFP-N1孵育液添加BSA(牛血清白蛋白)对精子胞质内注射(ICSI)转基因效率的影响。结果表明:注射台温度为30℃时的阳性率为40.07%,而38.5℃时为20.97%,差异极显著(P<0.01)。添加BSA的囊胚转基因率为55.56%,对照组为33.33%,差异极显著(P<0.01)。6-DMAP处理组与对照组的转基因率分别为52.53%和26.25%,差异极显著(P<0.01);而且6-DMAP处理组的囊胚率(9.96%)显著高于(P<0.05)对照组(2.30%)。研究表明注射台温度对转基因效率有明显影响,温度高转基因率低;精子与PEGFP-N1孵育液添加BSA对转基因胚胎发育有一定促进和保护作用,有利于提高囊胚转基因率;激活后用6-DMAP处理能提高转基因率和囊胚率。