Energy Status Characteristics of Porcine Oocytes During In Vitro Maturation is Influenced by Their Meiotic Competence

The characteristics of energy status in porcine oocytes as related to their meiotic competence and in vitro maturation were studied. Cycling pubertal gilts in the early luteal to early follicular phases of the ovarian cycle were used as oocyte donors. The oocytes recovered from medium (MF) or small follicles (SF) were considered meiotically more or less competent, respectively. A half of oocytes from each category was matured by the standard protocol. The oocytes were examined before or after maturation by confocal microscopy, a bioluminescent cell assay and Western blotting. Four experiments, each in triplicate, were performed to assess both SF and MF oocytes in terms of metabolic units formed by mitochondria and lipids, ATP and lipid consumption and lipid droplets with adipose differentiation‐related protein (ADRP) expression. The proportion of oocytes with metabolic units, the mean ATP content and the number of lipid droplets per oocyte, and the relative number of lipid droplets with ADRP expression were significantly higher in the MF compared to SF oocytes before maturation. On the other hand, after maturation, there was an increase in the proportion of oocytes with metabolic units and the relative number of lipid droplets with ADRP expression in the SF compared to MF oocytes. In conclusion, specific differences in energy characteristics between porcine oocytes with different meiotic competence were found. Meiotically more competent oocytes are more advanced in terms of energy reserves before maturation, while meiotically less competent oocytes are more active in replenishing energy stores during maturation.     

虎杖苷对牛卵母细胞体外成熟的影响

为研究虎杖苷(PD)对牛卵母细胞体外成熟的影响,本实验在体外成熟液中添加不同浓度(0、0.5、1.0、2.0μmol/L)PD,对牛卵母细胞体外培养22～24 h,统计第一极体排出率,然后对各组卵母细胞进行体外受精并统计胚胎的发育情况;最后分析PD对牛卵母细胞体外成熟作用机制。结果表明:与对照组(0μmol/L)相比,PD各处理组的第一极体排出率显著提高,体外受精后的胚胎分裂率无差异,而1.0μmol/L PD处理组囊胚率较对照组显著提高,1.0、2.0μmol/L PD处理组囊胚期细胞数较对照组显著提高;进一步分析发现,与对照组相比,1.0μmol/L PD可显著降低细胞内活性氧水平,提高抗氧化基因GPX4、SOD1表达水平,显著提高细胞内总谷胱甘肽含量。综上,成熟液中添加1.0μmol/L PD可提高细胞内抗氧化基因的表达以及提高谷胱甘肽含量,降低细胞内的活性氧含量,从而有利于牛卵母细胞的成熟以及早期胚胎发育。     

牛卵泡卵母细胞体外成熟的研究

研究了卵泡大小、卵泡液和卵丘细胞对牛卵泡卵母细胞体外成熟的影响。结果表明 :直径 2～ 6mm卵泡中的卵母细胞成熟率 ( 72 1%)最高 ,与直径小于 2mm( 5 8 4%)、6～ 8mm( 5 6 4%)及大于 8mm ( 3 5 0 %)卵泡中的卵母细胞组差异显著 ;成熟培养基中添加 10 %的新鲜牛卵泡液 (bFF)对牛卵母细胞的体外成熟有促进作用 ,但高浓度的bFF( 2 0 %、3 0 %)则抑制牛卵母细胞的体外成熟 ;卵丘 -卵母细胞复合体的质量影响卵母细胞的体外成熟 ,A、B、C三级卵母细胞成熟率分别为 86 1%、66 3 %、3 5 6%,卵裂率分别为 42 8%、3 1 9%、10 5 %,差异均显著 (P <0 0 5 )。     

没食子酸对黄牛卵母细胞体外成熟的影响

试验旨在研究没食子酸（gallic acid,GA）对黄牛卵母细胞体外成熟及早期胚胎发育的影响,进一步优化黄牛卵母细胞体外成熟体系。在卵母细胞体外成熟液（M液）中添加不同浓度没食子酸（0、10、30、50、100 μmol/L）,成熟22~24 h后,统计卵丘扩展情况及卵母细胞成熟率;同时,对成熟的卵母细胞进行正常体外受精（IVF）,统计早期胚胎的分裂率、囊胚率、囊胚卵裂球数及卵裂球细胞凋亡率。根据试验结果,选择最优浓度,使卵母细胞在含该浓度没食子酸的成熟液中成熟24 h后,检测其细胞内的活性氧水平（ROS）和总谷胱甘肽（TGSH）含量。结果显示,M液中添加30 μmol/L没食子酸组卵丘扩展分值和成熟率显著高于对照组（0 μmol/L）（P<0.05）,其他处理组与对照组无显著差异（P>0.05）;成熟的卵母细胞体外受精后进行后续胚胎培养,其中10和30 μmol/L组的分裂率均显著高于对照组和100 μmol/L组（P<0.05）,50和100 μmol/L组分裂率较对照组也有所提高,但差异不显著（P>0.05）;早期囊胚率统计发现,与对照组相比,30和100 μmol/L能够显著提高囊胚发育率（P<0.05）,10和50 μmol/L浓度组则无显著差异（P>0.05）;与对照组相比,30、100 μmol/L没食子酸均能显著提高IVF胚胎的早期囊胚卵裂球数（P<0.05）;但囊胚卵裂球凋亡率与对照组无显著差异（P>0.05）;对卵母细胞内活性氧和总谷胱甘肽含量检测时,发现30 μmol/L没食子酸可显著降低细胞内活性氧水平（P<0.05）,且显著提高总谷胱甘肽含量（P<0.05）。综上所述,在黄牛卵母细胞体外成熟液中添加适量的没食子酸能有效降低卵母细胞内活性氧水平,提高总谷胱甘肽含量,进而提高卵母细胞成熟的质量及其后续IVF胚胎发育能力。     

猪不同直径卵泡中卵母细胞体外培养的成熟潜力

比较研究了猪卵巢表面直径０．５～１ｍｍ、１～２ｍｍ、２～６ｍｍ、〉６ｍｍ卵泡中卵母细胞所处的发生泡阶段。结果表明,０．５～１ｍｍ卵泡中卵母细胞主要处于ＧＶ－Ｉ用ＧＶ－Ⅱ期２个阶段,比例分别为６７．２％和２０．６％;而１～２ｍｍ和２～６ｍｍ直径卵泡中,卵母细胞大部分则处于ＧＶ－Ⅱ期,比例分别为９１．９％和８９．６％;〉６ｍｍ直径卵泡中,卵母细胞逐渐发生老化,ＧＶ－Ⅱ期比例仅为５３．２％,一部分处于Ｖ     

O-GlcNAc修饰水平变化对牛卵母细胞体外成熟的影响

旨在探究O-β-N-乙酰葡糖胺(O-linked beta-N-acetylglucosamine, O-GlcNAc)修饰水平变化对牛卵母细胞体外成熟的影响。本研究以牛卵母细胞为研究对象,检测O-GlcNAc转移酶(O-GlcNAc transferase, OGT)、O-GlcNAc糖苷酶(O-GlcNAcase, OGA)及O-GlcNAc蛋白在牛体外成熟卵母细胞中的分布;将卵丘-卵母细胞复合体分别在添加4 mmol·L^-1 OGT抑制剂BADGP和100μmol·L^-1 OGA抑制剂PUGNAc的体外成熟液中进行体外成熟,将未添加组作为对照组,分别统计各组卵母细胞第一极体排出率和体外受精胚胎发育率,并采用荧光定量PCR和Western blot检测O-GlcNAc蛋白、OGT、OGA、GFAT和TXNIP的mRNA和蛋白表达。结果表明,OGT和O-GlcNAc蛋白共定位于牛体外成熟卵母细胞的细胞质和细胞核中,而OGA和O-GlcNAc蛋白共定位于体外成熟卵母细胞的细胞质中,且相对集中在卵母细胞的皮质区。与对照组相比,BADGP处理组和...     

绵羊卵母细胞体外成熟过程中的线粒体分布变化

为了检测绵羊卵母细体外成熟前后的线粒体分布变化,将成熟过程不同阶段的卵母细胞用活体细胞线粒体跟踪试剂盒(GENMED kit)对线粒体进行染色,之后用碘化丙啶(Propidium Iodide,PI)对细胞核进行染色,最后用激光共聚焦显微镜观察线粒体分布情况以及相应的细胞核所处的发育时期.结果:生发泡期(Germinal Vesicle,GV)的卵母细胞线粒体呈周边分布;生发泡破裂期(Germinal Vesicle Breakdown,GVBD)、第一次减数分裂中期(Metaphase Ⅰ,MⅠ中期)的卵母细胞呈半周边分布;第一次减数分裂末期(M Ⅰ Anaphase,MⅠ后期)的卵母细胞线粒体基本呈均匀分布,但是线粒体簇较小,着色较浅;第二次减数分裂中期(Metaphase Ⅱ,MⅡ期)的卵母细胞线粒体呈均匀分布,而且细胞质中央的线粒体簇变大,着色变深.结论:线粒体分布随着绵羊卵母细胞体外成熟阶段的进展,由细胞周边向均匀、由疏松向致密呈波动变化,这种变化有可能作为一种判定绵羊卵母细胞胞质成熟的有效参考指标.     

Meiotic Competence of Canine Oocytes Embedded in Collagen Gel

The present study was conducted to examine the meiotic competence of canine oocytes embedded in collagen gel, and to investigate the effects of timed exposure of the oocytes embedded in collagen gel to gonadotrophins during maturation culture, on their nuclear maturation. Cumulus-oocyte complexes (COCs) were collected from bitches at the anoestrous and dioestrous stages of the reproductive cycle. In the first experiment, half of the COCs were embedded in collagen gels. The COCs with or without collagen-gel embedding were cultured in a TCM-199 medium supplemented with 0.1 IU/ml human menopausal gonadotropin (hMG) and 10 IU/ml human chorionic gonadotropin (hCG) for 72 h. In the second experiment, the COCs embedded in collagen gels were cultured in TCM-199 medium with gonadotrophins (hMG and hCG) for various periods (0, 24, 48 and 72 h) and then cultured in the medium without gonadotrophins until reaching total culture period (72 h). The percentage of the oocytes reaching metaphase I and metaphase II (MI/MII) was significantly higher (p < 0.05) in COCs with collagen-gel embedding than in COCs without collagen-gel embedding. The percentage of oocytes that were arrested at the germinal vesicle stage was significantly lower (p < 0.05) in oocytes cultured with gonadotrophins than in oocytes cultured without gonadotrophins. However, there were no significant differences in the percentages of oocytes that reached each stage of meiosis among the groups, irrespective of the duration of exposure to gonadotrophins. These observations indicate that embedding of COCs by collagen gel enhances the meiotic competence of canine oocytes, but removal of hormone supplement from maturation medium does not improve the ability of the oocytes to reach MII stage.     

Effect of Sugar on in vitro Maturation and Developmental Competence of Yak Oocytes

This study was designed to investigate the effect of different types and different concentrations of sugar on in vitro maturation(IVM) and developmental competence of yak oocytes, for being further research and optimization culture system of yak oocytes for efficient maturity yak oocytes and productivity of embryos. Immature yak oocytes were matured in vitro on culture medium with different concentrations (0,5 and 10 mmol/L) of glucose and sucrose in incubator for 24 h or 2 h pretreament with sugar and 22 h without sugar. Subsequently, then the maturation of oocytes,the cleavage rates and blastocyst formation rates after in vitro fertilization(IVF) were evaluated. The results showed that a medium with 5 and 10 mmol/L glucose IVM could significantly increase the yak oocytes maturation and cleavage (P<0.05), and the highest blastocyst formation rates in 10 mmol/L glucose group was significantly higher than 0 mmol/L glucose (P<0.05).10 mmol/L sucrose could increase significantly the nucleus maturation rates (P<0.05),and there was no significant difference of the blastocyst formation rates after IVF between 0 and 10 mmol/L sucrose (P>0.05). Furthermore, the nucleus maturation rates,IVF cleavage rates and blastocyst formation rates of yak oocytes which pretreated with 10 mmol/L glucose were the highest in these groups, and were higher than 0 mmol/L glucose (P<0.05). It manifested that the appropriate concentration of sugar could improve the quality of yak oocytes and embryos in vitro developmental competence, so it influenced in vitro development of yak oocytes indirectly.     

糖对牦牛卵母细胞体外成熟及其发育能力的影响

试验旨在研究不同种类、不同浓度的糖对牦牛卵母细胞体外成熟和发育能力的影响,进一步探索和优化牦牛卵母细胞培养体系,提高卵母细胞体外成熟和胚胎生产效率。在牦牛卵母细胞成熟液中添加不同浓度（0、5和10 mmol/L）的葡萄糖或蔗糖,培养24 h或预培养2 h后移入无糖培养基中继续培养22 h,统计卵母细胞体外成熟率及体外受精（IVF）后的胚胎卵裂率和囊胚率。结果显示,与对照组（0 mmol/L）相比,5和10 mmol/L葡萄糖组牦牛卵母细胞核成熟率和体外受精胚胎卵裂率均显著提高（P<0.05）,10 mmol/L葡萄糖组的囊胚率最高,且与对照组相比差异显著（P<0.05）。添加10 mmol/L蔗糖可以显著提高牦牛卵母细胞核成熟率（P<0.05）,但胚胎囊胚率与对照组相比差异不显著（P>0.05）。此外,用10 mmol/L葡萄糖预处理牦牛卵母细胞后其核成熟率、胚胎卵裂率和囊胚率最高,且均显著高于对照组（P<0.05）。由此可见,糖对牦牛卵母细胞体外成熟和发育有一定的影响,在成熟过程中添加适当浓度的糖能提高卵母细胞成熟率及体外受精胚胎发育能力。     

牛卵泡卵体外成熟及其受精能力的研究

本试验主要研究了牛卵泡卵体外成熟、体外受精及其受精过程的发生。从屠宰场收集800枚牛卵泡卵进行体外成熟培养,并用体外获能的精子体外受精。在用m-TCM199培养21、22、24、26、28h后,达到中期Ⅱ的卵母细胞比例分别为33.89％、74.16％、77.78％、86.67％、85.71％;25h后,如果继续培养,成熟的卵母细胞比例不再显著增加。卵母细胞的自身形态显著地影响其成熟效果,A、B、C级卵培养24h后分别有94.60％、55.43％、31.25％的卵母细胞达到中期Ⅱ。卵泡卵在体外滞留8h后,其成熟率(47.11％)明显地低于45min(77.92％)或4h(74.60％)。肝素和钙离子载体A 23187都能诱发牛精子获能,二者在受精效报上差异不显著(P>0.05),并且都有多精入卵现象发生。授精后6h精子进入卵内,精子入卵后2～3h头部膨大,6h后出现早期原核,最早发生卵裂是在授精后30h。     

不同因素对牛卵母细胞体外成熟培养效果的影响

文章主要从采集方法、性周期阶段以及培养液中FBS浓度3个方面对牛卵母细胞体外成熟的影响进行了分析。结果表明：①不同采卵方法的采卵效果存在差异,但成熟培养和体外受精情况差异不显著（P〉0．05）;②从卵泡期和黄体期卵巢采集到的卵母细胞的体外成熟率和卵裂率分别,为59.7%,56．6％和39．5％、36．6％,没有显著差异（P〉0．05）;③培养液中添加20％FBS组的卵母细胞成熟率和卵裂率显著高于10%FBS和30%FBS组（P〈0．05）.     

微量元素锌对牛卵母细胞体外成熟及其体外受精胚胎发育的影响

本研究旨在探讨锌对牛卵母细胞体外成熟及体外受精胚胎发育的影响。首先使用锌螯合剂TPEN去除锌,并检测缺锌对牛卵母细胞体外成熟的影响;然后在体外成熟液中分别添加0(对照组)、0.4、0.8、1.2、1.6μg/mL硫酸锌,探索不同浓度硫酸锌对体外成熟及后续胚胎发育的影响。结果表明:锌元素在体外成熟液中的含量低于牛卵泡液和颈静脉血清(P<0.05);去除体外成熟液中的锌后牛卵母细胞的体外成熟效率下降(P<0.05),且具有时间依赖性,补充适宜浓度硫酸锌后成熟效率恢复;向体外成熟液中添加硫酸锌并未对卵母细胞体外成熟效率产生显著影响,但添加0.8μg/mL硫酸锌成熟后的卵母细胞中活性氧含量显著降低,后续体外受精胚胎的囊胚发育效率显著提高;RT-qPCR分析结果显示,与对照组相比,添加0.8μg/mL硫酸锌成熟后的卵母细胞中抗氧化基因SOD1、CAT、TXN1、PRD1和卵丘扩展基因PTX3、TSG6的表达水平均提高(P<0.05)。研究表明,添加0.8μg/mL硫酸锌可以通过提高卵母细胞内抗氧化酶基因的表达水平,降低卵母细胞内活性氧含量,促进卵丘扩展,从而提高卵母细胞成熟质量和体外受精胚胎的发育效率。     

开放式拉长细管冷冻法对牛卵母细胞体外受精后发育的影响

在常规牛体外受精(IVF)技术的基础上,分别采用开放式拉长细管 (OPS,open pulled straw)法和细管法对未经成熟培养的卵丘卵母细胞(COCs)进行玻璃化冷冻,解冻后再进行体外成熟(IVM)、IVF和早期胚胎的体外培养(IVC)。结果表明,细管组和 OPS组的解冻后 COCs正常率分别为 59.4%±4.3%和 77.9%±4.1%(P<0 01);成熟率分别为48.2%±5.3%和66.0%±5.8%(P<0 01);卵裂率分别为18.5%±2.0%和32.8%±1.4%(P<0 01);8 细胞阶段的成功率分别为14.8%±2.5%和 24.8%±1.5%(P<0 01);桑椹胚发育率分别为 0 和5 3%±1.1%,明显低于未经冷冻的鲜卵组(21.0%±3.8%;P<0 01);囊胚发育率分别为0和4.0%,明显低于鲜卵组(P<0 01)。说明OPS玻璃化冷冻法可以使未经成熟培养的牛 COCs冷冻后获得桑椹胚和囊胚,但桑囊胚发育率仍较低,方法有待改进。     

犬卵母细胞体外成熟的影响因素

采集发情期和间情期犬卵巢,回收大腔（直径大于１ｍｍ）卵泡和不可见卵泡的卵母细胞,在４种成熟液（ＴＣＭ１９９＋２０％ＦＣＳ,ＴＣＭ１９９＋２０％ＦＣＳ＋１０ＩＵ／ｍＬＦＳＨ,ＴＣＭ１９９＋２０％ＥＤＳ和ＴＣＭ１９９＋２０％ＥＤＳ＋１０ＩＵ／ｍＬＦＳＨ）中成熟后进行了受精试验。结果：（１）发情期大于２ｍｍ和１～２ｍｍ的大腔卵泡卵母细胞的体外成熟率（４２．５％,３２．５％）显著高于间情期卵母细胞（２０．４％）,但发情犬不可见卵泡卵母细胞的体外成熟率（２８．９％）与间情期卵母细胞差异不显著;（２）在成熟液中添加促性腺激素,能有效地提高卵母细胞成熟率,不可见卵泡的卵母细胞对促性腺激素的依赖性（３０．０％比７．８％）大于大腔卵泡的卵母细胞（４２．５％比２９．０％）;（３）卵丘扩散与卵母细胞成熟存在相关性;（４）ＥＤＳ可诱导卵丘扩散,但不能有效提高卵母细胞的成熟率;（５）发情期卵巢上的大腔卵泡和不可见卵泡的卵母细胞以及间情期卵巢不可见卵泡的卵母细胞体外培养后,与体外获能的精子进行体外受精,其卵裂率分别为１６．０％（４／２５）,０％（０／４０）和２．５％（１／４０）。     

牛体外成熟卵母细胞染色体形态学研究

[目的]为了给牛体细胞克隆和转基因克隆工作提供基础性材料.[方法]在显微镜下,从卵液中捡出卵丘-卵母细胞复合体,置入成熟培养液中进行成熟培养,处理培养不同时期的卵母细胞,所得的去掉卵丘的卵母细胞固定在载玻片上,染色、冲洗、晾干,在显微镜下观察.[结果]表明:成熟培养0 h到4 h大多数卵母细胞处于GV期(97.5%～87.8%),培养6 h以后GVBD发生了卵母细胞数量明显增多(51.6%),成熟培养8 h～12 h处于Pre-MI的卵母细胞逐渐减少(76.7%～43.2%),MI期卵母细胞逐渐增多(13.3%～50.0%).成熟培养16 h有17.8%的卵母细胞处于MII期,大部分细胞仍处于MI期(40.0%)和AI/TI期(42.2%).从16 h～24 h,MII期卵逐渐增多,培养24 h后大多数卵母细胞排出第一极体到达MII期(86.5%).[结论]在减数分裂过程中,染色体也发生了显著的形态变化.第一次减数分裂中期时的染色体清晰可数,进入后期时,分开的两团染色体各自凝集成染色质团,并且一直持续到末期,到达第二次减数分裂中期时又成为清晰可数的染色体状态.     

丁内酯-Ⅰ对绵羊卵母细胞体外成熟及发育能力的影响

研究从丁内酯-Ⅰ(BL-Ⅰ)的浓度筛选、作用时间以及作用解除后的成熟培养时间等方面分别进行了试验,以观察其对绵羊卵母细胞核成熟的抑制程度以及对卵母细胞体外成熟及发育能力的影响.结果表明:150μmol/L的BL-Ⅰ能将62.9%的卵母细胞抑制在GV期.BL-Ⅰ抑制8、16 h和24 h后绵羊卵母细胞停滞在GV期的比率差异不显著(P＞0.05);抑制24 h时卵裂率和囊胚率低于对照组,16 h的囊胚率也低于对照组,抑制8 h的卵裂率和囊胚率与对照组差异不显著(P＞0.05).去除抑制后卵母细胞的成熟能力不受影响.由此可得出,丁内酯-Ⅰ能可逆性抑制绵羊卵母细胞的核成熟,但未能提高其发育潜力.     

丁内酯-I对绵羊卵母细胞体外成熟及发育能力的影响

研究从丁内酯-I(BL-I)的浓度筛选、作用时间以及作用解除后的成熟培养时间等方面分别进行了试验,以观察其对绵羊卵母细胞核成熟的抑制程度以及对卵母细胞体外成熟及发育能力的影响。结果表明:150μmol/L的BL-I能将62.9%的卵母细胞抑制在GV期。BL-I抑制8、16 h和24 h后绵羊卵母细胞停滞在GV期的比率差异不显著(P>0.05);抑制24 h时卵裂率和囊胚率低于对照组,16 h的囊胚率也低于对照组,抑制8 h的卵裂率和囊胚率与对照组差异不显著(P>0.05)。去除抑制后卵母细胞的成熟能力不受影响。由此可得出,丁内酯-I能可逆性抑制绵羊卵母细胞的核成熟,但未能提高其发育潜力。     

牛卵丘细胞对卵母细胞体外成熟与孤雌发育的影响

试验以牛卵泡内卵丘-卵母细胞复合体(COCs)为材料,探讨了牛卵丘细胞包裹程度对卵母细胞体外成熟(IVM)和孤雌胚胎(PAEs)发育的影响。试验1,将COCs随机分为2组,在开展IVM前,将其中一组COCs的卵丘细胞机械吹打去除成为机械裸卵(DOs),研究卵丘细胞层存在与否对卵母细胞体外核成熟(排出第一极体)和孤雌激活后发育能力的影响;试验2,根据COCs卵丘细胞包裹层数将COCs分为3组,即卵丘细胞层少(1～4层)的COCs为A组、卵丘细胞层多(5层以上)的COCs为B组及包裹5层以上卵丘细胞且附带卵泡壁颗粒细胞层(FSP)的COCs为C组,研究卵丘细胞层包裹程度对卵母细胞的体外核成熟和孤雌激活后胚胎发育能力的影响。结果表明:卵丘细胞的存在更有利于卵母细胞体外成熟和孤雌胚胎发育;COCs中卵丘细胞包裹层数对卵母细胞体外核成熟率没有显著影响,但包裹卵丘细胞层数多且附带FSP的卵母细胞,其PAEs的囊胚率显著高于包裹卵丘细胞少的卵母细胞PAEs。