Effect of Lycopene on Cytoplasmic Maturation of Porcine Oocytes In Vitro

The aim of the present study was to improve cytoplasmic maturation of porcine oocytes by the addition of lycopene into in vitro maturation (IVM) media. We designed six experimental groups; IVM medium was supplemented with 10 IU/ml FSH, FSH and 10 IU/ml human chorionic gonadotrophin (hCG), or FSH and 7 μm lycopene in the first half of the IVM culture (0–22 h) followed by further culture (22–44 h) with or without hCG. The addition of lycopene into IVM media delayed the interruption of communication between an oocyte and the cumulus cells. Although meiotic competence was similar among the six groups, the glutathione level of matured oocytes was significantly higher in the lycopene‐supplemented group (9.89 pmol per oocyte) than that in other groups (7.25 and 7.81 pmol per oocyte). Fertilization rate was significantly improved in lycopene‐supplemented groups (58.3%) more than that in the group supplemented with FSH only (43.1%), whereas there were no differences in developmental competence among the groups (blastocyst rate: 20.1–29.5%). These results indicate that insufficient cytoplasmic maturation during conventional IVM resulted by disconnection of the gap junction between an oocyte and the cumulus cells in the early phase during IVM culture. We concluded that lycopene induced a prolonged sustainment of gap junctional communication between an oocyte and the cumulus cells during porcine IVM culture, which was an effective cytoplasmic maturation of porcine IVM oocytes.     

山羊卵母细胞体外成熟的研究

在38℃和39℃不同温度条件下培养山羊卵母细胞,结果表明:在38℃和39℃下成熟率分别为63.6%和57.3%,二者之间差异不显著,说明只要培养温度在山羊正常体温的变动范围内,对其卵母细胞的成熟率没有影响;在38℃温度条件下用10?S的M199培养液成熟率为62.5%,而10 mg/ml BSA的M199培养液成熟率为58.7%,二者之间差异不显著,说明无血清培养可以代替血清培养.     

Effect of Sericin Supplementation During In Vitro Maturation on the Maturation,Fertilization and Development of Porcine Oocytes

This study aimed to examine the effects of sericin supplementation during in vitro oocyte maturation on the nuclear maturation, fertilization and development of porcine oocytes. Cumulus‐oocyte complexes (COCs) were cultured in maturation medium supplemented with 0 (control), 0.1, 0.5, 1.0, 2.5 or 5.0% sericin and were then subjected to in vitro fertilization and embryo culture. More COCs matured with 1.0% sericin underwent germinal vesicle breakdown and reached metaphase II compared with the control COCs matured without sericin (p < 0.01). The proportions of oocytes with DNA‐fragmented nuclei did not differ between the groups, regardless of the sericin level. The total fertilization rate of oocytes matured with 1.0% sericin was higher (p < 0.05) than that of oocytes matured with 0.1%, 2.5% and 5.0% sericin. Supplementation with more than 1.0% sericin decreased the DNA fragmentation index of the blastocysts compared with the control group (p < 0.05). However, the supplementation of the maturation medium with sericin had no beneficial effects on the cleavage, development to the blastocyst stage and the total cell number of the embryos. Our findings indicate that supplementation with 1.0% sericin during maturation culture may improve the nuclear maturation and the quality of the embryos but does not affect blastocyst formation.     

Effect of Porcine and Ovine FSH on Nuclear Maturation of Pig Oocytes In Vitro

The effect of porcine or ovine FSH on the maturation rate of porcine oocytes and on the time course of meiotic progression was studied. Groups of 20 grade‐A cumulus oocyte complexes, aspirated from slaughterhouse cycling‐gilt ovaries, were cultured in vitro in 400 μl of Modified Parker's Medium supplemented with oestrous cow serum and porcine FSH (Folltropin®‐V, 0.50 mg/ml) or ovine FSH (Ovagen^TM, 0.44 iu/ml), in four‐well dishes under mineral oil, at 38.5°C, 5% CO₂ in humidified air. At the end of each 3‐h interval, from 3 to 42 h of culture, the nuclear status of oocytes was assessed microscopically (1000×), after fixation (methanol/acetic acid: 3/1) and orcein (2%) staining. Oocytes were classified as (i) immature (IMM), i.e. oocytes at germinal vesicle stage, germinal vesicle break down and prophase I, (ii) metaphase I (MI) and (iii) metaphase II (MII), i.e. oocytes at anaphase I, telophase I and metaphase II. Data were analysed using regression analysis, chi‐square and t‐test. Nuclear status was assessed in 1610 oocytes (porcine FSH: 787, ovine FSH: 823). Most of the oocytes were at MI from 24 to 33 h (porcine FSH 60.27%, ovine FSH 42.80%, p < 0.001) and at MII from 36 to 42 h (porcine FSH 80.38%, ovine FSH 67.45%, p < 0.01) of culture. Significantly higher maturation rate was observed in porcine FSH than in ovine FSH treated oocytes (86.69 ± 12.97%, 71.34 ± 9.86%, mean ± SD, p < 0.05), after 42 h of culture. In conclusion, under the specific culture conditions, porcine FSH seems to support pig oocyte maturation better than ovine FSH.     

促卵泡素与促黄体素对猪卵母细胞体外成熟的影响

本试验探讨了促性腺激素（FSH、LH）对猪卵母细胞体外成熟的影响,最终找到了其合理的使用剂量。在成熟液中添加LH浓度分别为1、5、10IU／mL时,与没有添加FSH与LH的对照组（15．9％）相比,成熟率有显著提高,成熟率分别为49．1％、30．0％、36．3％。LH浓度为1IU,mL的实验组成熟率最高,显著高于对照组（P〈0．05）;然后以成熟液中只添加1IU/mLLH为对照组,试验组分别添加1、5、10IU/mLPSH。试验结果表明：添加FSH浓度为5和10IU/ml时其成熟率分别为40．1％、27．6％,低于对照组（49．0％）。添加FSH浓度为1IU／mL时其成熟率（49．1％）高于对照组（49．0％）,但差异不显著（P〉0．05）。两组试验同时得出,随着LH与FSH添加浓度的增加,成熟率呈下降趋势。通过本试验结果得出,在体外成熟培养猪卵母细胞时,各添加1IU／mL LH与FSH时,得到最佳的成熟效果。     

促卵泡素与促黄体素对猪卵母细胞体外成熟的影响

本试验探讨了促性腺激素(FSH、LH)对猪卵母细胞体外成熟的影响,最终找到了其合理的使用剂量。在成熟液中添加LH浓度分别为1、5、10 IU/mL时,与没有添加FSH与LH的对照组(15.9%)相比,成熟率有显著提高,成熟率分别为49.1%、30.0%、36.3%。LH浓度为1 IU/mL的实验组成熟率最高,显著高于对照组(p<0.05);然后以成熟液中只添加1 IU/mLLH为对照组,试验组分别添加1、5、10 IU/mLFSH。试验结果表明:添加FSH浓度为5和10 IU/ml时其成熟率分别为40.1%、27.6%,低于对照组(49.0%)。添加FSH浓度为1 IU/mL时其成熟率(49.1%)高于对照组(49.0%),但差异不显著(p>0.05)。两组试验同时得出,随着LH与FSH添加浓度的增加,成熟率呈下降趋势。通过本试验结果得出,在体外成熟培养猪卵母细胞时,各添加1 IU/mL LH与FSH时,得到最佳的成熟效果。     

猪卵泡卵母细胞的体外成熟与体外受精

本试验对猪卵泡卵母细胞不同体外成熟培养时间、不同精子获能时间、不同精卵共孵育时间对体外受精的影响进行了研究。结果表明,体外成熟培养44 h左右,精子获能时间在1～2 h之间,精卵共孵育时间在6～8 h之间,受精后卵裂率最高。     

Ghrelin and Leptin Did Not Improve Meiotic Maturation of Porcine Oocytes Cultured In Vitro

To improve culture system for in vitro maturation (IVM) of porcine oocytes, ghrelin, leptin or growth hormone (GH), at concentration of 0, 0.5, 5, 50 and 500 ng/ml were added to the porcine follicular fluid (pFF)‐supplemented medium NCSU23, and their effects on the maturation and cytoskeletal distribution of the oocytes with or without cumulus cells were compared. In the cumulus‐denuded oocytes, no significant changes were noted in the maturation rate by different hormone treatments due to a marked decline in the controls. Maturation of the cumulus intact oocytes was moderately interfered by ghrelin (0.5–50 ng/ml, p < 0.01), but not significantly affected by leptin and GH. Distribution density of the cytoplasmic microtubules was decreased significantly by addition of ghrelin (by approximately 30% in 50–500 ng/ml, p < 0.01), whereas no remarkable effect was noted by leptin supplementation. High concentration (500 ng/ml) of ghrelin or leptin decreased significantly the cytoplasmic microfilaments in density (by 43% and 38%, p < 0.01, respectively). GH did not affect cytoskeletal distribution. The results suggest, in the culture system using pFF‐supplemented medium that (i) ghrelin may have some inhibitory effect on the organization of microtubules and microfilaments, probably being a factor in lowered maturation rate and (ii) the addition of higher concentration of leptin may decrease microfilaments in density with no effect on meiotic maturation of the porcine oocytes.     

半胱氨酸对猪卵母细胞体外成熟、体外受精及GSH水平的影响

体外受精技术也称胚胎生产技术（invitro production,IVP）,包括卵母细胞的体外成熟、精子的获能、卵子的体外受精和受精卵的体外培养等几个连续的过程。半胱氨酸是GSH的前体物质,在牛体外胚胎生产过程中疏基复合物能增加细胞内GSH的合成,在受精和胚胎的开始阶段保持高浓度GSH可以增加发育率。试验的目的是评价半胱氨酸对猪卵母细胞的成熟率、受精率及成熟培养时期卵母细胞内GSH水平的影响,现报道如下。     

猪卵泡卵母细胞体外成熟与冷冻保存

研究了激素、猪卵泡液、不同类型血清对猪卵泡卵母细胞体外成熟的影响 ;比较了卵泡直径小于 2 mm、2～ 5 mm和大于 5 mm的卵母细胞体外成熟能力的差异 ,并对不同发育阶段猪卵母细胞的冷冻保存进行了研究。结果表明 :猪卵母细胞体外培养 4 8h时 ,培养的前 2 4 h培养液中加入激素 ,后 2 4 h去掉激素 ,卵母细胞的 A级成熟率 (5 1.73% )和总成熟率 (83.2 5 % )最高 ,极显著高于前 2 4 h不加激素 ,后 2 4 h添加激素培养的成熟率 (P<0 .0 1) ;也显著高于不含激素的培养液连续培养 4 8h的成熟率 (P<0 .0 5 ) ;但与添加激素连续培养 4 8h的成熟率差异不显著 (P>0 .0 5 )。在体外成熟培养液中 ,添加 10 % (体积分数 ) ECS的成熟率 (72 .86 % )显著高于添加 10 % (体积分数 ) NCS的成熟率(6 2 .2 1% ) (P<0 .0 5 ) ,而添加 10 % p FF则抑制卵母细胞的体外成熟。随着卵泡直径的增大 ,卵母细胞体外成熟能力逐渐增强。采用程序冷冻保存方法 ,成熟卵母细胞的成活率 (35 .5 9% )显著高于培养前 (2 4 .6 4 % )和培养 2 4 h(2 3.36 % ) (P<0 .0 5 )。培养 2 4 h(77.2 2 % )和培养成熟 (72 .81% )的卵母细胞解冻后的形态完整率均显著高于培养前(5 3.2 4 % ) (P<0 .0 5 )     

RFRP-3对猪卵母细胞体外成熟的影响

旨在研究RFRP-3对猪卵母细胞体外成熟的影响。本研究采用从屠宰场收集健康母猪的卵巢中挑取的GV期卵母细胞,随机分为3组,在培养基中分别添加0、10^-6和10^-8mol·L^-1 RFRP-3培养猪卵母细胞44 h后统计各组卵母细胞的成熟率;在后续试验中将收集到的卵母细胞随机分为2组,在培养基中分别添加0和10^-8 mol·L^-1 RFRP-3培养猪卵母细胞44 h,观察猪卵母细胞的卵丘扩展情况并计算各组的卵丘扩展指数和各组卵母细胞的成熟率;利用qRT-PCR检测卵丘扩展因子(PTGS2、HAS2、PTX3)、卵母细胞分泌因子(GDF9、BMP15)和周期蛋白相关基因(CCNB1和CDK1)的表达变化;利用ELISA试剂盒检测MPF和cAMP的含量;采用放射免疫法检测孕酮和雌激素的浓度,每组卵母细胞量不少于100枚,每个试验重复3次。结果表明,与对照组相比,添加10^-8mol·L^-1 RFRP-3培养猪卵母细胞可极显著降低卵母细胞的成熟率(P<0.01);通过显微镜观察并计算卵丘扩展指数发现,试验组中卵丘扩展无明显变化(P>0.05),但卵丘扩展因子(PTGS2、HAS2、PTX3)的表达极显著下降(P<0.01);RFRP-3可以极显著降低猪卵母细胞MPF的含量(P<0.01),对cAMP的含量无显著影响(P>0.05);添加RFRP-3可促进GDF9(P<0.01)和BMP15(P<0.05)的表达,抑制CCNB1(P<0.05)和CDK1(P<0.05)的表达;同时试验组培养基中孕酮、雌激素的浓度也极显著下降(P<0.01)。综上,RFRP-3通过调控猪卵母细胞成熟相关因子和卵丘扩展因子的表达以及类固醇激素的分泌,从而抑制卵母细胞的体外成熟。本研究为阐明RFRP-3对哺乳动物卵母细胞的调控作用奠定理论基础。     

FSH 、LH对猪卵母细胞核成熟及体外成熟时间对去核效率的影响

克隆动物(核移植)的原理就是将卵裂球或体细胞核移人去核的卵母细胞或受精卵中,采用各种激活方法使之激活,发生卵裂,移植受体后产生个体。猪的体细胞克隆效率与其他动物(牛、羊)相比较低,需     

不同因素对猪卵母细胞体外成熟培养的影响

本试验旨在探讨不同外源激素组合的添加、胰岛素—转铁蛋白—亚硒酸钠(ITS)的添加、不同培养皿、石蜡油的添加对卵母细胞体外成熟培养(IVM)的影响。结果显示:①孕马血清促性腺激素+人绒毛膜促性腺激素+促卵泡素(PMSG+HCG+FSH)组高于促卵泡素+促黄体素(FSH+LH)组和尿促性腺激素(hMG)组,相互之间差异显著(80.1%、68.3%、53.3%,P<0.05);②添加1% ITS到猪卵母细胞培养液中对卵母细胞成熟率无显著提高(P>0.05),但显著提高了孤雌激活后孤雌胚胎的卵裂率和囊胚率(63.3%、55.1%,18.7%、12.1%,P<0.05);③凹槽皿组猪卵母细胞成熟率显著高于四孔板和30 mm塑料皿组(73.3%、68.0%、68.3%,P<0.05);④石蜡油的添加对卵丘细胞扩展和卵母细胞体外成熟率均有显著提高(84.8%、69.9%,P<0.05)。结果表明培养液中添加PMSG+HCG+FSH和ITS及选用凹槽皿、成熟培养液上覆石蜡油可提高猪卵母细胞IVM效果。     

海狸鼠卵母细胞体外成熟培养初探

实验用ＰＭＳＧ或ＰＭＳＧ＋ＨＣＧ处理或未经激素处理的海狸鼠８只，共获卵巢卵母细胞１３８枚。激素处理对获取卵巢卵母细胞的数量没有影响，而对体外成熟发育至卵丘扩展和半成熟阶段有促进作用。三种不同培养液（Ｗｈｉｔｅｎ＋ＦＣＳ；ＴＣＭ１９９＋ＰＭＳＧ＋ＦＣＳ；ＴＣＭ１９９＋ＨＣＧ＋ＦＣＳ）共培养１２５枚卵母细胞，培养后卵丘扩展率及半成熟率分别为５６．５％，４５．７％，４７．６％和２１．７％，１２．３％，９．５％，以Ｗｈｉｔｅｎ液较高（分别为５６．５％和２１．７％），但只有ＴＣＭ１９９＋ＰＭＳＧ＋ＦＣＳ组有２枚卵母细胞出现第一极体。结果表明海狸鼠卵母细胞与其它啮齿动物的卵母细胞一样，能够在体外培养成熟，完成第一次减数分裂，排出第一极体     

Ghrelin Accelerates In Vitro Maturation of Bovine Oocytes

Ghrelin, apart from its metabolic role, is nowadays considered as a basic regulator of reproductive functions of mammals, acting at central and gonadal levels. Here, we investigated for possible direct actions of ghrelin on in vitro maturation of bovine oocytes and for its effects on blastocyst yield and quality. In experiment 1, cumulus oocyte complexes (COCs) were matured in the presence of four different concentrations of ghrelin (0, 200, 800 and 2000 pg/ml). In vitro fertilization and embryo culture were carried out in the absence of ghrelin, and blastocyst formation rates were examined on days 7, 8 and 9. In experiment 2, only the 800 pg/ml dose of ghrelin was used. Four groups of COCs were matured for 18 or 24 h (C18, Ghr18, C24 and Ghr24), and subsequently, they were examined for oocyte nuclear maturation and cumulus layer expansion; blastocysts were produced as in experiment 1. The relative mRNA abundance of various genes related to metabolism, oxidation, developmental competence and apoptosis was examined in snap‐frozen cumulus cells, oocytes and day‐7 blastocysts. In experiment 1, ghrelin significantly suppressed blastocyst formation rates. In experiment 2, more ghrelin‐treated oocytes matured for 18 h reached MII compared with controls, while no difference was observed when maturation lasted for 24 h. At 18 and 24 h, the cumulus layer was more expanded in ghrelin‐treated COCs than in the controls. The blastocyst formation rate was higher in Ghr18 (27.7 ± 2.4%) compared with Ghr24 (17.5 ± 2.4%). Differences were detected in various genes’ expression, indicating that in the presence of ghrelin, incubation of COCs for 24 h caused over‐maturation (induced ageing) of oocytes, but formed blastocysts had a higher hatching rate compared with the controls. We infer that ghrelin exerts a specific and direct role on the oocyte, accelerating its maturational process.     

Hanging Drop Monoculture for Selection of Optimal Antioxidants During In Vitro Maturation of Porcine Oocytes

We analysed the effect of three antioxidants that have different functional mechanisms on the in vitro maturation (IVM) of porcine oocytes. Single oocyte monoculture using the hanging drop (HD) system has some advantages such as improving analysis efficiency brought by the smaller number of samples than the number of oocytes cultured in one drop. Direct effects of ligands on single oocytes could also be detected without considering the effects of paracrine factors from other oocytes. After 22 h of pre‐culture, denuded oocytes were cultured for 22 h with 0.01 and 0.1 μg/ml of L‐carnitine (LC), lactoferrin (LF) or sulforaphane (SF) in the presence/non‐presence of oxidant stress induced by H₂O₂ supplementation to evaluate the reducing effects against oxidative stress on nuclear maturation. As a result, compared with LC and SF, LF showed effective reduction in oxidative stress at a lower concentration (0.01 μg/ml), suggesting that LF is a more effective antioxidant in porcine oocyte IVM. Additionally, LF also increased maturation rate even in culture without H₂O₂. Our results clearly suggest that the HD monoculture system is useful for screening the substances that affect porcine oocyte culture.     

马卵母细胞体外成熟的研究进展

随着全球马产业的发展,马发挥的经济价值越来越大。辅助生殖技术有利于发挥优良马匹的潜在价值。马卵母细胞体外成熟(IVM)是辅助生殖技术重要的组成部分,卵母细胞的获取是体外成熟的前提,切刮法能从离体卵巢中获得较多的马卵母细胞,而活体采卵技术(OPU)则能持续地获得卵母细胞,并能较好的保存马卵母细胞的发育能力。扩张型卵母细胞的成熟率高于紧密型卵母细胞,母马的年龄会影响到其卵母细胞的质量。马卵母细胞体外存放较长时间不会影响其发育能力,现在已有较为成熟的体系能使马卵母细胞在体外保存24 h以上而不影响其成熟率。在马卵母细胞成熟体系中常用的基础培养液是M199,添加胎牛血清(FBS)、促卵泡素(FSH)、促黄体生成素(LH)、胰岛素样生长因子-1(IGF-1)等物质能显著提高成熟率,常用培养环境为38~39℃,5%CO2饱和湿度下培养,培养时间30 h。成熟的卵母细胞有扩张的卵丘细胞和极体,且成熟的卵母细胞的细胞骨架及微管结构也会发生变化。本文针对马卵母细胞的采集和体外成熟培养的相关研究进行总结,重点阐述了不同采集技术的回收率以及影响马卵母细胞体外成熟率的关键因素,以期对今后马卵母细胞体外成熟的进一步研究及后期体外受精技术的发展提供借鉴与参考。     

卵泡FSH受体mRNA的表达及其对卵母细胞体外培养成熟率的影响

本研究采用RT-PCR技术检测了猪大、中、小卵泡颗粒细胞中FSH受体(FSHR)mRNA的表达差异,比较和分析了受体表达差异及其对卵母细胞体外成熟培养的影响。结果表明大、中、小卵泡中颗粒细胞都有FSHR mRNA表达,大卵泡的颗粒细胞与小、中卵泡的颗粒细胞FSHR mRNA相对表达量有显著差异(P<0.05),中、小卵泡的颗粒细胞FSHR mRNA相对表达量之间无显著差异(P>0.05)。不同大小卵泡卵母细胞体外成熟培养结果表明,小卵泡与大、中卵泡比较,卵丘细胞扩展率和第一极体排出率差异显著(P<0.05)。这表明猪不同大小卵泡颗粒细胞FSHR mRNA的表达量与其卵母细胞体外培养成熟率呈相关性,进一步证实FSHR在猪卵泡及卵母细胞发育中起着重要作用。     

影响动物卵母细胞体外成熟的因素

文章就卵母细胞体外成熟的影响因素做了简要的论述。主要介绍了卵母细胞来源、培养系统、激素和生长因子等因素对卵母细胞体外成熟的影响。