小鼠电融合四倍体胚胎早期发育的研究

多倍体发育现象在低等动物,尤其是在无脊椎动物中比较普遍,在哺乳动物中多倍体往往发育到胚胎早期就死亡,因而在自然界中不能存活。探讨哺乳类四倍体不能存活的原因是当今生物学研究的热点问题之一。目前,电融合技术是大量获得四倍体胚胎的主要手段。本以8－12周龄昆明小白鼠为实验对象,取其2－细胞胚胎于Whitten氏液中进行电融合,再移入CZB液中培养。电刺激的条件分别为：1．0kv/cm,40μs,和0．8kv/cm,80μs。对融合胚发育的状态、细胞数目及染色体组成等进行观察的结果表明,融合胚培养24小时后发育到4－细胞期,并发生致密化（Tab.1)。融合胚的囊胚形成时间与体内发育的同期胚胎及体外培养的同期二倍体胚胎基本一致（Tab,2;Fig.1)。融合囊胚的细胞数平均为13．0±4．95,显（P＜0．01）少于体外发育囊胚（37．0±5．92）和体内发育囊胚（41．6±2．4）的细胞数（Tab.3)。融合胚各个分裂相的染色体数目分布情况见Fig.2,其四倍体（4n＝80）率为42．86％,非整倍体率达57．14％。而对照组的体内发育囊胚的非整倍体率仅为11．54％;（Tab.4),与Kaufman的结果（12．4％）很接近,说明本实验中的染色体制备技术和分析方法是可行的。融合囊胚的细胞数目减少和高发的非整倍体率可能是四倍体胚胎发育能力差的原因。     

小鼠2—细胞期经电融合后的早期胚胎发育

小鼠２－细胞期经电融合后的早期胚胎发育小鼠,电融合,细胞数,核型,四倍体胚胎小鼠２细胞期经电融合后的早期胚胎发育ＥＡＲＬＹＤＥＶＥＬＯＰＭＥＮＴＯＦＭＯＵＳＥＥＭＢＲＹＯＳＰＲＯＤＵＣＥＤＢＹＥＬＥＣＴＲＯＦＵＳＩＯＮＡＴ２ＣＥＬＬＳＴＡＧＥ关键...     

兔2—细胞胚胎电融合及其融合胚体外发育的研究

本文对兔２－细胞胚胎卵裂球电融合制作四倍体胚胎的适宜条件进行了研究。电场强度为２．０千伏／厘米,脉冲时程为４０微秒时,可获得最好的融合率（６８．９－１００％,平均为７７．３％）及融合胚发育率（７４．５％）,该发育率与受精卵体外囊胚发育率（７９．３％）相似。对于电融合及融合胚发育,非电解质溶液（０．３ｍｏｌ／Ｌ甘露醇＋０．１ｍｍｏｌ／Ｌ氯化钙＋０．１ｍｍｏｌ／Ｌ硫酸镁）优于电解质溶液。融合后,７２．     

褪黑素对小鼠2-细胞期胚胎发育的影响

目的：研究褪黑素对小鼠2-细胞期胚胎发育的影响。方法：在培养液中添加不同浓度褪黑素,在不同的作用时间点,观察并记录小鼠胚胎囊胚率、孵出率,研究其变化情况。结果：不同浓度褪黑素对小鼠2-细胞期胚胎存在双向作用,在10-13-10-5M之间促进细胞囊胚形成和孵出,在10-9M时促进效应达到最高,而在10-3M时则呈现出一定的毒性作用。结论：褪黑素对小鼠胚胎发育影响与褪黑素浓度密切相关。     

褪黑素对小鼠2- 细胞期胚胎发育的影响

目的:研究褪黑素对小鼠2-细胞期胚胎发育的影响。方法:在培养液中添加不同浓度褪黑素,在不同的作用时间点,观察并记录小鼠胚胎囊胚率、孵出率,研究其变化情况。结果:不同浓度褪黑素对小鼠2-细胞期胚胎存在双向作用,在10-13-10-5M之间促进细胞囊胚形成和孵出,在10-9M时促进效应达到最高,而在10-3M时则呈现出一定的毒性作用。结论:褪黑素对小鼠胚胎发育影响与褪黑素浓度密切相关。     

PGE2、PGF2α和Iloprost对小鼠2-细胞胚胎体外发育的影响

目的研究PGE2、PGF2。以及Hoprost（PGl2的稳定类似物）对小鼠2-细胞胚胎体外发育的影响。方法在含0．5％BSA的mCZB液中分别添加0、10^-4、10^-5和10^-6mol／L的PGE2,0、10^-4、10^-5和10^-6mol／L PGF2α以及0、1×10^-6、2×10^-6和4×10^-6mol/L Iloprost,观察小鼠2-细胞胚胎的体外发育,同时利用H33342染色进行囊胚和孵化囊胚的细胞核计数。结果添加PGE2、PGF2α以及Iloprost的各处理组2-细胞胚胎体外培养的囊胚率和孵化率均显著低于对照组（P〈0．05）,但各处理组与对照组之间在囊胚或孵化胚胎的细胞数上差异不显著（P〉0．05）。结论培养液中添加这三种前列腺素均不利于小鼠2-细胞胚胎的体外发育,但不影响囊胚或孵化胚胎的细胞数。     

四种冷冻保护剂对小鼠2-细胞胚胎渗透性和毒性作用的比较

作为胚胎冷冻保存的基础性研究,冷冻保护剂的渗透性和毒性研究非常重要.本试验选用1,2-丙二醇、甘油、乙二醇和二甲基亚砜4种常用冷冻保护剂,对小鼠2-细胞胚胎进行渗透性和毒性研究.结果显示:1.5 mol/L的1,2-丙二醇、乙二醇和二甲基亚砜冷冻保护剂对2-细胞胚胎的渗透性显著高于甘油保护剂;4种冷冻保护剂对细胞膜的完整性没有影响;1.5 mol/L的乙二醇、1,2-丙二醇和甘油保护剂处理后的2-细胞胚胎的囊胚发育率和孵化率与对照组胚胎比较差异不显著(P>0.05),但显著高于二甲基亚砜处理后的2-细胞囊胚发育率和孵化率(P<0.01).结果表明:在4种冷冻保护剂中,乙二醇和1,2-丙二醇适合于小鼠2-细胞胚胎冷冻保存     

葡萄糖对小鼠胚胎体外发育的影响

通过在CZB培养液中添加不同浓度葡萄糖及在胚胎发育的不同阶段加入葡萄糖,对小鼠胚胎进行体外培养,以探讨葡萄糖在小鼠早期胚胎体外发育中的作用。其结果表明,小鼠胚胎在含糖CZB与在无糖CZB中培养比较,4-细胞发育率无差异;各浓度葡萄糖组囊胚率显著高于无糖组,其中3.0mmol/L浓度组囊胚细胞数显著高于其余组;实验二：2-细胞至4-细胞、4-细胞至桑椹胚前添加葡萄糖囊胚率显著提高。上述结果证明,在小鼠胚胎体外培养中加入葡萄糖不会导致2-细胞阻滞;葡萄糖浓度增加至10mmol/L对小鼠胚胎无毒性作用,其最适浓度为3.0mmol/L;2-细胞至4-细胞、4-细胞至桑椹胚前添加葡萄糖是必要的。关键词 葡萄糖;小鼠;2-细胞阻滞;胚胎;体外发育     

两种冷冻保护剂对小鼠2-细胞胚冷冻效果的比较

乙二醇（ETG）和1,2-丙二醇（PROH）具有高细胞渗透性和低毒性特点,常被用于人及多种哺乳动物早期胚胎冷冻保存。为了比较ETG和PROH对小鼠2-细胞胚的冷冻保护效果,本试验分别采用这两种冷冻保护剂,对小鼠2-细胞胚进行冷冻保存,并采用冻后体外培养和囊胚移植进行冷冻效果检测。结果表明,PROH组胚胎解冻后胚胎存活率与ETG组无显著差异,但PROH组4-细胞胚发育率和囊胚发育率显著高于ETG组（82．7％vs．64．6％,61．2％vs．29．1％,P〈0．01）。囊胚移植结果表明,2-细胞胚胎冻存后能够发育为正常的后代,PROH组和ETG组的囊胚移植后妊娠产仔率无统计学差异（P〉0．05）,但均显著低于对照组（P〈0．05）。为了分析两组胚胎冻存后损伤情况,埘解冻后的胚胎细胞微丝进行检测,结果显示ETG组微丝受损的胚胎数高于PROH组。本研究结果证明采用PROH作为冷冻保护剂冷冻保存小鼠2-细胞胚的冻存效果优于ETG[动物学报54（6）：1098—1105,2008]。     

葡萄糖对ICR小鼠胚胎体外发育的影响

研究葡萄糖在小鼠早期胚胎体外发育中的作用。实验1将6—8周龄的ICR雌鼠超数排卵后与公鼠交配,收集1-细胞放入含0(对照组)、0.5、1、3、5、10mmol/L葡萄糖的CZB中培养;实验2将从超排的ICR雌鼠输卵管内收集的1-细胞放入无糖CZB中培养,分别于1细胞、2细胞、4细胞、桑椹胚阶段移入含3.0mmol/L葡萄糖(最适浓度)的CZB中,培养24h后又移回到无糖CZB中(桑椹胚阶段除外)继续培养以及整个胚胎培养过程均在含糖CZB中,对照组胚胎培养全程均在无糖CZB中。每组胚胎于37℃、5%CO2培养箱中培养120h,每24h在倒置显微镜下观察胚胎发育情况,分别计算2-细胞率、4-细胞率、桑椹胚率、囊胚率和孵化率,并进行囊胚细胞计数。结果显示,小鼠胚胎在含糖CZB中与在无糖CZB中4-细胞发育率无差异;含糖CZB中囊胚率显著高于对照组;3.0mmol/L浓度组囊胚细胞数显著高于其余组;2-细胞至4-细胞、4-细胞至桑椹胚前添加葡萄糖囊胚率显著高于对照组,1-细胞至2-细胞、桑椹胚及其以后阶段添加葡萄糖囊胚率与对照组无差异。实验证实,在ICR小鼠胚胎体外培养中加入葡萄糖不会导致2-细胞阻滞;葡萄糖浓度增至10mmol/L对ICR小鼠胚胎无毒性作用;ICR小鼠胚胎体外培养的最适葡萄糖浓度为3.0mmol/L;2-细胞至4-细胞、4-细胞至桑椹胚前添加葡萄糖是必要的。     

视黄酸对小鼠早期胚胎结构及0tx2基因表达的影响

以全反式视黄酸 ( all trans-retinoic acid,AT-RA)体外处理 EB( early allantoic bud)期和 LB( lateallantoic acid)期的小鼠胚胎 ,然后用洋地黄毒苷 ( digoxigenin)标记的 0 tx2反意义 RNA探针对整体胚胎进行原位杂交。以 4× 1 0 - 6 mol/ l的 AT— RA处理 ,抑制或减少了胚胎的前肠形成 ,经处理的胚胎的头褶没有对照的那样明显向腹部突出 ,其神经沟也不整齐 ;经处理的 EB期胚胎 ,其 0 tx2表达范围剧烈地向前退缩或只有很微弱的表达 ;但以同样浓度处理 LB期胚胎时 ,与对照相比 ,0 tx2的表达除了在极少数胚胎中变得弱一些以外 ,在绝大多数胚胎中其表达模式没有变化     

乙醇和液体石蜡对早期小鼠胚胎体外发育的影响

哺乳动物早期胚胎体外培养技术是研究早期胚胎发育和胚胎工程的基本手段。目前最常用的方法是采用液体石蜡覆盖的液滴培养法。该方法中所用液体石蜡和ＣＯ２质量的好坏对体外培养胚胎的发育有严重影响。本文就此对几种中国产液体石蜡和含气体乙醇的ＣＯ２作为胚胎体外培养条件对胚胎发育的影响进行了研究。取成熟小鼠受精后的２细胞和８细胞胚胎分别用于两组实验。一、不同品牌液体石蜡对胚胎发育的影响。体外培养采用液体石蜡覆盖液滴培养法。所用液体石蜡均经过水洗。ＣＯ２为经过一次水滤的工厂粗制品,其乙醇含量经气相色谱仪测定约为０．１８％。二、不同浓度乙醇对胚胎发育的影响。采用试管培养法,采用乙醇浓度不同的培养液。表１为五个不同厂家的液体石蜡对早期胚胎体外培养的影响。其中,Ⅰ、Ⅱ（上海、北京）号两种产品符合胚胎体外培养的要求,可使２细胞后期胚胎发育到囊胚的比率达到９２％以上,对细胞没有毒害作用（图１Ａ和图２Ａ、Ｂ）。其余,则不符合要求,对细胞有毒害作用（图１Ｂ）,甚至用无水乙醇和水先后各洗涤３至４遍,亦无改善。由于影响液体石蜡质量的硝基萘可溶于乙醇而被清除,说明这些不合格的液体石蜡中可能还含有其它对胚胎发育有毒害作用的未知因素,有待进一步查明     

Effects of Colchicine on Distribution of Mitochondria in 2-cell and Compacted 8-cell Mouse Embryos

The distribution of mitochondria during early development of mouse embryos was visualized bymitochondria-specific vital fluorescent dye, rhodamine 123(Rh 123). Mitochondrial clusters wasmarkedly conceotrated to perinuclear area in blastomere of normal 2-ccll embryos. In blastomere ofuncompacted 8-cell embryos, mitochondria were randomly distributed throughout the cytoplasm, butthey were reorganizcd to the cytocortices beneath the apposed surfaces of blastomere duringcompaction. As demonstrated in our study, colchicine (10 μg/ml) produced marked effect onmitochondrial distribution in blastomcre of 2-cell and compacted 8-cell embryos: mitochondriabecame scattered throughout the cytoplasm ofblastomere. It is suggested that the spatial distributionof mitochondria in early mouse embryo are maintained by microtubule.     

家兔胚胎细胞核移植的研究(英文)

本研究以兔为实验材料,对细胞核移植过程中显微操作、电融合、电活化以及移核胚的培养等基本问题进行了研究。对兔进行ＰＭＳＧｈＣＧ超数排卵,收集成熟卵母细胞和１６细胞胚;后者经胰蛋白酶消化,去除胶膜和透明带,在不含Ｃａ２＋、Ｍｇ２＋的分离液中分成单个卵裂球;然后,分别对两者做ＣＢ预处理;首次尝试采用Ｗｉｌａｄｓｅｎ法,去除卵母细胞核、并将单个卵裂球注入透明带,同时、与ＭｃＧｒａｔｈＳｏｌｔｅｒ法进行比较;通过电融合使供体核进入去核的卵母细胞内;将所得移核胚在体外或在中间受体内培养并观察。结果表明：一、Ｗｉｌａｄｓｅｎ法与ＭｃＧｒａｔｈＳｏｌｔｅｒ法比较,核移植操作的成功率及以后的电融合率均无明显差异（Ｔａｂ．１）。相对于后者,Ｗｉｌａｄｓｅｎ法更简便、易于掌握并提高去核率。二、ｈＣＧ超排注射后１３～１５ｈ,观察卵母细胞发现：其中,６７８％保留有第一极体。此时的卵子若去除１／３胞质量,去核率可以达到５８３％。若推迟去核时间,笫一极体退化,失去去核标志。三、比较不同电脉冲条件,发现强度为０６３ｋｖ／ｃｍ,持续１６０μｓ的一次电脉冲可获较高移核胚的融合率（７０．８％）（Ｔａｂ．２）;并可使６１１％的成熟     

卵裂球电脉冲融合制作昆明小鼠四倍体胚胎

为制作四倍体小鼠胚胎 ,用 4种脉冲电压强度 (6 0 0、 80 0、 10 0 0和 12 0 0V/cm )和 3种脉冲宽度(10、 30和 5 0 μs)组合 ,对 2 -细胞昆明小鼠胚胎做了融合实验。 6 0 0V/cm× 5 0 μs和 12 0 0V/cm× 30 μs两种组合融合率最高 ,分别为 91 6 %和 93 0 % ;而 6 0 0V/cm× 10 μs和 12 0 0V/cm× 5 0 μs时均显著低于其他各种组合 ,融合率分别为 5 8 9%和 6 0 2 %。以上结果表明 ,一定的脉冲电压强度是胚胎融合的必要条件 ,而脉冲宽度是影响胚胎融合及其后期发育的关键因素。激光共聚焦显微镜对融合后两细胞核的观察暗示 ,细胞核的迁移、靠近和融合是自发过程     

Birth of mice from vitrified/warmed 2-cell embryos transported at a cold temperature

Cryopreservation of 2-cell embryos is an effective technology for storage of genetically engineered mouse strains. Transport of genetically engineered mice between laboratories has frequently been performed using such cryopreserved 2-cell embryos. However, the receiving laboratory requires proficient skills and special instruments to obtain live young from cryopreserved and transported embryos. Therefore, in this study, we tried to address the storage and transport of vitrified/warmed 2-cell embryos at a cold temperature. In cold storage experiments, the development rates of 2-cell embryos stored in M2 medium for 24, 48 and 72 h into blastocysts were relatively high (83%, 63% and 43%, respectively). Although, 2-cell embryos stored in PB1 and mWM maintained the developmental potency for 24 h, the rates were markedly decreased to low levels after 48 h (PB1: 0%; mWM: 5%). In transport experiments, many pups were obtained from vitrified/warmed 2-cell embryos transported at a cold temperature in all receiving laboratories (incidence of successful development: 49%; 249/511). In summary, short-term storage and transport of vitrified/warmed 2-cell embryos in M2 medium at a cold temperature can maintain their ability to develop into live young.     

不同冷冻保护剂对早期卵裂期小鼠胚胎冷冻后成活率和发育的影响

为了评价利用不同冷冻保护剂冷冻早期卵裂期胚胎的效果,用小鼠为实验动物,采用慢速冷冻、快速融解的冷冻技术,比较丙二醇、二甲基亚砜和甘油作冷冻保护剂对小鼠2-细胞、4-细胞、8-细胞胚胎冷冻后胚胎存活率和囊胚形成率的影响。发现以丙二醇和蔗糖为冷冻保护剂冷冻4-细胞、8-细胞胚胎,解冻后胚胎成活率和囊胚形成率显著高于以二甲基亚砜或甘油为冷冻保护剂。结果表明,丙二醇是一种冷冻早期卵裂期小鼠胚胎有效的冷冻保护剂。     

Electrofusion parameters for nuclear transfer predicted using isofusion contours produced with bovine embryonic cells

Electrofusion is a valuable technique for the nuclear transfer procedure. An enucleated oocyte is electrofused with a blastomere to create a nuclear transfer embryo. The present study constructed isofusion contours after the electrofusion of identical coupled cells that characterized all the bovine embryonic cell types used in nuclear transfer. The intersection of isofusion contours for enucleated oocytes and blastomeres provided the parameters for electrofusion during nuclear transfer. Blastomeres isolated from in vitro produced embryos 3–6 days after (in vitro fertilization) were electrofused with oocytes enucleated by centrifugation (85, 87, 89, and 73% electrofusion, respectively). The cleavage (46, 40, 37, and 28%, respectively) of the nuclear transfer embryos produced a trend that decreased as the age of the blastomeres increased. The isofusion contours provided information about the interaction between different cell types in an electric field, and gave precise electrofusion parameters for a range of bovine embryonic cell types used in nuclear transfer. © 1996 Wiley-Liss, Inc.     

Cryopreservation of Mouse Embryos by Ethylene Glycol-Based Vitrification

Cryopreservation of mouse embryos is a technological basis that supports biomedical sciences, because many strains of mice have been produced by genetic modifications and the number is consistently increasing year by year. Its technical development started with slow freezing methods in the 1970s¹, then followed by vitrification methods developed in the late 1980s². Generally, the latter technique is advantageous in its quickness, simplicity, and high survivability of recovered embryos. However, the cryoprotectants contained are highly toxic and may affect subsequent embryo development. Therefore, the technique was not applicable to certain strains of mice, even when the solutions are cooled to 4°C to mitigate the toxic effect during embryo handling. At the RIKEN BioResource Center, more than 5000 mouse strains with different genetic backgrounds and phenotypes are maintained³, and therefore we have optimized a vitrification technique with which we can cryopreserve embryos from many different strains of mice, with the benefits of high embryo survival after vitrifying and thawing (or liquefying, more precisely) at the ambient temperature⁴.Here, we present a vitrification method for mouse embryos that has been successfully used at our center. The cryopreservation solution contains ethylene glycol instead of DMSO to minimize the toxicity to embryos⁵. It also contains Ficoll and sucrose for prevention of devitrification and osmotic adjustment, respectively. Embryos can be handled at room temperature and transferred into liquid nitrogen within 5 min. Because the original method was optimized for plastic straws as containers, we have slightly modified the protocol for cryotubes, which are more easily accessible in laboratories and more resistant to physical damages. We also describe the procedure of thawing vitrified embryos in detail because it is a critical step for efficient recovery of live mice. These methodologies would be helpful to researchers and technicians who need preservation of mouse strains for later use in a safe and cost-effective manner.