牛羊精子体外获能最新研究进展

获能是精子获得与卵母细胞识别、融合与实现受精的前提条件.在获能期间,精子发生了包括质膜通透性与流动性变化、膜内外离子动态变化、蛋白酪氨酸磷酸化与多级信号传导等极为复杂的生理生化反应.虽然已经成功获得多种体外受精动物,但体外受精胚胎的质量与效率远未达到预期.精子的体外获能是关键技术环节.本文仅就牛和羊精子体外获能研究相关最新进展进行介绍.     

超低温保存存前后太平洋牡蛎精子（Crassostrea gigas（Thunberg）超微结构观察

应用扫描电镜和透射电镜技术，研究超低温冷冻前后太平洋牡蛎精子形态与超微结构。结果发现，受伤精子被膜肿胀、皱褶、破裂；顶体变形、囊泡化、顶体膜肿胀，局部断裂；核膜肿胀，破裂，核空泡化；线粒体嵴变形、消失，基质电子密度降低，结构模糊；精子鞭毛被膜膨胀，鞭毛自精子基部或主、末段断裂。结果表明，超低浊冷冻和升温解冻，对牡蛎精子的膜结构损伤严重，导致精子活力和受精能力下降。     

精子获能过程中Zn~(2+)与Mg~(2+)的作用及蛋白质谱变化

获能是受精的前提条件,只有获能精子才具有超激活运动、发生顶体反应与受精能力.获能期间,精子发生了极为复杂的生理生化反应:质膜通透性与流动性变化、膜内外离子动态变化、蛋白酪氨酸磷酸化与多级信号传导等.尽管发现精子获能现象已近70年,但对其机制的了解远未完成.本文重点介绍Zn~(2+)与Mg~(2+)在精子获能中的作用及精子获能前后的蛋白质谱变化.     

入卵过程中太平洋牡蛎精子超微结构的变化

本文研究了精子入卵过程中太平洋牡蛎精子超微结构的变化规律。研究表明，精子入卵过程分为4个时期：顶体反应期、穿卵前期、穿卵期和融合期。顶体反应期，精子顶体物质释放，顶体致密部分向外延伸，形成1层保护膜，亚顶体腔开始向顶端突起；穿卵前期，亚顶体腔前突形成顶体锥，并向卵膜释放亚顶体物质，精子外膜后移；穿卵期，精子核及线粒体进入卵膜形成的受精锥，线粒体数量减少，顶体突消失，精子外膜和尾部脱落；融合期，精子核进入卵内与质膜融合，核解体。     

长江华溪蟹（SInopotamonyangtsekiense）精子的形成

透射电镜下观察长江华溪蟹精子形成的过程。早期精细胞中发现有典型的高尔基体形成前顶囊泡，前顶体囊泡融合形成ＰＡＳ阳性顶体囊泡；后期精细胞在头帽相对一端的顶体囊泡中央发生凹陷形成ＰＡＳ阴性的中央管；成熟精子的染色质呈出现网结纤丝状和致密块状。     

吐温-80与脂质体膜相互作用机理的研究

研究了表面活性剂吐温-80(聚氧乙烯山梨醇脂肪酸酯)与脂质膜间的相互作用机理,运用浊度测定、DSC1、H—NMR等分析手段验证了脂质膜的立体稳定结构.结果表明:吐温-80在水相与脂质相间分配达到饱和时的质量浓度为1.3%,与脂质膜开始增溶成混合胶团时的质量浓度为2.6%.当Re<0.5时,表面活性剂单体在溶液和脂质双层膜中分配,溶液中表面活性剂单体和囊泡并存,脂质双层囊泡膨胀,粒径逐渐增大,形成一个肿胀的脂质囊泡.当0.5相似文献   

玉米根细胞正面向外和内翻外质膜囊泡的分离

利用水双相分配分离法从玉米根细胞提取原生质膜囊泡。其质膜成分特异的K~+,Mg~(2+)—ATP酶活性比膜粗提液高1.67倍。其他细胞器标记酶活性在质膜组分中很低或没有。特异染色电镜形态学定量统计表明质膜组分中90％以上是质膜囊泡。去污剂刺激ATP酶活性实验证明,约92％囊泡是正面向外的。应用此法也证明NAD(P)H—氧化酶可能是跨膜存在的,其催化Fe~(3+)还原的位点可能在膜的内侧。应用高盐冻—融法并结合水双相分配分离法处理正面向外囊泡,可获得内翻外质膜囊泡,实验证明它不仅纯度高而且封闭。     

人老化红细胞囊泡的分离及其特性研究

本文报道了人红细胞在体外老化(37℃。48h)过程中会自然形成并释放的囊泡为不均一的群体,经 Dextran-T70不连续密度梯度离心后可明显分成三种组分。囊泡主要集中在组分Ⅱ和Ⅲ中,而组分Ⅰ除了囊泡外还含有膜和膜碎片。这三种囊泡组分在流动性、封闭度等性质上有明显差异。值得引起注意的是,囊泡的荧光光谱与正常红细胞膜相比变化较大,红移22nm 左右,这提示了囊泡膜脂的结构和组分与红细胞有较大差异。     

人老化红细胞囊泡的分离及其特性研究

本文报道了人红细胞在体外老化(37℃.48h)过程中会自然形成并释放的囊泡为不均一的群体,经Dextran-T70不连续密度梯度离心后可明显分成三种组分.囊泡主要集中在组分Ⅱ和Ⅲ中,而组分Ⅰ除了囊泡外还含有膜和膜碎片.这三种囊泡组分在流动性、封闭度等性质上有明显差异.值得引起注意的是,囊泡的荧光光谱与正常红细胞膜相比变化较大,红移22nm左右,这提示了囊泡膜脂的结构和组分与红细胞有较大差异.     

中国对虾精子发生过程内质网的变化

利用透射电镜观察了中国对虾精子发生过程及纳精囊中的精子内质网变化特征,精原细胞内质网囊泡较多,内质网较少,初级精母细胞内质网囊泡较多,在细胞核一侧有１－３个内质网囊泡团,粗面内质网折叠于细胞核的一侧,环状片层体２个,次级精母细胞内质网囊泡较少,早期的精细胞细胞核周期出现与核膜平行的环核内质网,中期的精细粗面内质网形成光滑内质网。后期精细胞光滑内质网折叠或盘曲,雄虾体内的精子主体部上方内质网发达。而雌性纳精囊中精子的内质网浓缩为团块状或颗粒状。     

Effects of ubiquitin-protea-some pathway on mouse sperm capacitation, acrosome reaction and in vitro fertilization

Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation with reagents that would block the UPP. They were the monoclonal antibody against ubiquitinated proteins-UCP1; the polyclonal antibody against ubiquitin anti-Ub, and a special inhibitor against proteasome ALLN. Furthermore, we treated the capacitated sperm or the eggs with these reagents separately and tested whether the normal in vitro fertilization was blocked or not. Results illustrate that UCP1, anti-Ub, and ALLN have little effects on sperm capacitation and acrosome reaction,but they do inhibit fusion of mouse sperm with eggs, which suggests that UPP play an important role in mouse in vitro fertilization.``     

Effects of ubiquitin-proteasome pathway on mouse sperm capacitation, acrosome reaction and in vitro fertilization

Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation with reagents that would block the UPP. They were the monoclonal antibody against ubiquitinated proteins—UCP1; the polyclonal antibody against ubiquitin—anti-Ub, and a special inhibitor against proteasome—ALLN. Furthermore, we treated the capacitated sperm or the eggs with these reagents separately and tested whether the normal in vitro fertilization was blocked or not. Results illustrate that UCP1, anti-Ub, and ALLN have little effects on sperm capacitation and acrosome reaction, but they do inhibit fusion of mouse sperm with eggs, which suggests that UPP play an important role in mouse in vitro fertilization.     

Sperm antigen MSH27 participates in sperm-egg membrane fusion

A monoclonal antibody (mAb), MSH27 has been selected from an mAb library which has been prepared with separated mouse sperm heads as antigens. Three aspects of evidence indicated that the MSH27 antigen was involved in the process of sperm-egg membrane fusion. After the acrosome reaction, the antigen was located at sperm equatorial segment and in postacrosomal area, where, it was widely accepted, the sperm-egg membrane fusion initially occurred. In in vitro fertilization, the MSH27 antibody could decrease the index of sperm-egg membrane fusion, but made no effects on sperm approaching and binding to the plasma membrane of eggs. The inhibition showed an antibody concentration-dependent manner, with a rate decrease of 90% at 600 μg/mL immuno-globulin lgM. Furthermore, the antigen was able to affect the sperm-egg membrane fusion directly. The fusion index was obviously reduced after the zona-free eggs were exposed to the antigen purified by immuno-affinity chromatography. These, all together, demonstrated that the MSH27 antigen played an important role in sperm-egg membrane fusion.     

重组人卵透明带蛋白(rhZP3)对人精子顶体反应的诱导作用

目的：观察重组人卵透明带蛋白（rhZP3）对人精子顶体反应的诱导作用。方法：正常生育力人精子经过获能后,分别用BSA、孕酮和含不同浓度的重组人ZP3蛋白的培养液共孵育。诱导精子顶体反应,对实验组和对照组的精子的顶体发生状态用考马斯亮蓝染色法进行评价。结果：精子与培养液共孵育30min后,rhZP3组与BSA组之间差异有显著性（P〈0．05）,顶体反应率随rhZP3质量浓度增加而升高。结论：重组人ZP3蛋白对人精子顶体反应有显著的诱导效应,且在一定范围内与质量浓度成正相关,重组人ZP3蛋白具有发展精子顶体反应试剂盒的潜能。     

精子获能及顶体反应中与Ca~(2+)相关的变化

获能及顶体反应是受精过程中两个重要的步骤,也是受精所必需的.这两个过程可被胞内 信号调节,但具体过程还不很清楚.目前已经知道Ca2 在其中起了重要的作用.对Ca2 在获能和 顶体反应中所发挥的效应做了简要综述.     

人输卵管液和输卵管上皮细胞培养液诱发精子的顶体反应

目的：探讨人输卵管液和上皮细胞培养液对人精子顶体反应的诱发作用。方法：用Ｈａｍ′ｓＦ１０作对照组，输卵管液和上皮细胞培养液为实验组，分别与生育力组（ｎ＝２０）和不育组（ｎ＝２０）的精子进行共孵育，用精子顶体三色染色法对顶体状态进行评价。结果：共孵育３ｈ时与Ｈａｍ′ｓＦ１０对照组相比较，两种输卵管液均可显著提高生育力组和不育组的精子顶反应率（Ｐ〈０．０５），但这两种输卵管液处理的生育力组与不育组之间     

冷冻保存对人类精子顶体蛋白酶的影响

探讨了冷冻保存对人类精子顶体蛋白酶的影响,应用明胶薄层法检测,冷冻保存后精子顶体蛋白酶反应率和成环直径显著减少（ｎ＝３０,Ｐ＜０．０１）．透射电镜观察到冷冻保存后精子（ｎ＝３）头部结构完整性显著降低,提示浆膜、顶体膜超微结构的冷冻损伤与冷冻精子顶体蛋白酶活性丢失和降低有关．冷冻精子穿卵率与顶体蛋白酶反应率不呈相关性（ｎ＝２１,ｒ＝０．３４,Ｐ＞０．０５）,提示两项检测反映的是精子功能的不同方面．     

Crystal structure of the CusBA heavy-metal efflux complex of Escherichia coli

Gram-negative bacteria, such as Escherichia coli, expel toxic chemicals through tripartite efflux pumps that span both the inner and outer membrane. The three parts are an inner membrane, substrate-binding transporter; a membrane fusion protein; and an outer-membrane-anchored channel. The fusion protein connects the transporter to the channel within the periplasmic space. A crystallographic model of this tripartite efflux complex has been unavailable because co-crystallization of the various components of the system has proven to be extremely difficult. We previously described the crystal structures of both the inner membrane transporter CusA and the membrane fusion protein CusB of the CusCBA efflux system of E. coli. Here we report the co-crystal structure of the CusBA efflux complex, showing that the transporter (or pump) CusA, which is present as a trimer, interacts with six CusB protomers and that the periplasmic domain of CusA is involved in these interactions. The six CusB molecules seem to form a continuous channel. The affinity of the CusA and CusB interaction was found to be in the micromolar range. Finally, we have predicted a three-dimensional structure for the trimeric CusC outer membrane channel and developed a model of the tripartite efflux assemblage. This CusC(3)-CusB(6)-CusA(3) model shows a 750-kilodalton efflux complex that spans the entire bacterial cell envelope and exports Cu I and Ag I ions.     

花背蟾蜍变态前后眼各部位Con A受体的荧光显微镜观察

本文以花背蟾蜍变态前后的眼为材料,运用 Con A-FITC 在荧光显微镜下观察了眼变态前后 Con A 受体的变化.结果表明:变态前內处角膜愈合处的 Con A 受体较多;晶体上皮的外表面比内表面 Con A 受体多;视网膜各层扬构的 Con A 受体分布差异较大.变态后角膜上皮的细胞膜,角膜基质和角膜内皮中均有 Con A 受体分布;晶状体仅晶体上皮有 Con A受体分布;视网膜中内界膜,内网层,外网层,外界膜,视杆视锥细胞层和色素上皮层的内外表面 Con A 受体较多:节细胞层,内核层和外核层仅细胞表面有少量的 Con A 受体分布.推测眼在变态前后 Con A 受体数量和分布上的变化与眼各部位细胞的分化,结构的组建和视觉功能的完善有关.     

动物精子发生及成熟过程中凝集素受体的分布与变化

对各种动物精子发生与成熟过程中生精细胞表面凝集素受体的变化做了综述 .精子发生过程伴随着不同凝集素受体的出现和变化 ,这些受体是由生精细胞自身合成的 ;精子在成熟过程中 ,质膜凝集素受体的合成、修饰及分布会进一步发生变化 ,这些变化与精子获得与卵子进行识别、粘附、结合等受精能力密切相关 .