第十九期鸡胚原始生殖细胞的冷冻保存

采用Ficoll密度梯度离心,提取第 19期(孵化 72h)性腺中的PGCs,对其应用不同的冷冻保护液和不同的平衡方法进行冷冻保存,并于复苏后进行体外培养。复苏后的PGCS用台盼蓝染色检测其存活率,结果发现:从第 19期性腺中获取的PGCs在同一种冷冻保护液下,采用不同的平衡方法进行冷冻,对PGCs的存活率有显著影响(P<0.05)或极显著影响(P<0.01);平衡方法相同,在不同冷冻保护液之间存在显著(P<0.05)或极显著 (P<0.01)差异。PGCs经体外培养 24h后再进行冷冻保存,复苏后其存活率、体外培养存活时间均极显著(P<0.01)短于分离后直接冷冻的PGCs。     

表皮生长因子的作用机理及对体外受精的影响

表皮生长因子(EGF)是一种重要的多肽类生长因子,它对卵母细胞的体外成熟和早期胚胎的发育具有明显的促进作用。大量研究表明:EGF能够以旁分泌(Paracrine)或自分泌(Autocrine)的形式作用于胚胎组织中的EGFR,刺激内细胞团(ICM)和滋养外胚层的增殖,从而调节早期胚胎的发育。     

体外培育赤眼蜂研究进展

体外培育赤眼蜂的国内外研究已达到相当平：随着人工饲料配方的优化，选用的人工卵壳材料更适合于赤眼蜂的寄生与发，以及人工卵卡机的研制成功和性能不断改进，产业化体外培育赤眼蜂已成为可能。体外培育赤眼蜂的品质管理问题是实现产业化体外培育赤眼蜂的关键。然而，国内外对体外培育赤眼蜂的品质管理研究涉及甚少，有待进一步研究。本文指出应开展体外培育赤眼蜂生物学特性、行为学特性和分子生物学特性的研究，并应用于品质管理，建立体外培育赤眼蜂的品质管理体系，促进实现体外培育赤眼蜂产业化的进程，从而满足农业生产上对赤眼蜂种群的大量需要。另外，人工卵滞育贮存法的突破有助于实现体外培育赤眼蜂的产业化，也应加强研究，最后，本文对体外培育赤眼蜂的应用前景进行了展望。     

中链脂肪酸对体外发酵甲烷产量的影响

利用人工瘤胃体外产气法研究不同精粗比(0:1和1:1)日粮类型时中链脂肪酸对甲烷产量的影响。结果显示,体外培养24h,添加脂肪酸对甲烷产量的抑制作用不受日粮类型的影响(P>0.05);与不添加酸的对照相比,添加50mg未酯化月桂酸(C12:0)及月桂酸和肉豆蔻酸(C14:0)以3:2的比例组成的混合物(50mg)可分别抑制甲烷产量的22.2%(P<0.01)和11.8%(P<0.05);添加50 mg未酯化C14:0使甲烷产量降低3.4%(P>0.05);不同日粮类型上饲料产气量、瘤胃液pH值和氨氮浓度差异显著(P<0.01)。     

羊胚胎生物技术研究进展及应用

阐述了胚胎移植、胚胎冷冻、胚胎分割、胚胎性别控制及体外受精等胚胎生物技术在养羊业的研究进展及应用现状。     

白水生姜组培脱毒及离体快繁体系建立研究

以白水生姜茎尖为材料进行组培脱毒及离体快繁体系建立研究,结果表明,姜块催芽并在40～45℃光照箱中热处理30 d,再结合微茎尖（0.1～0.3 mm）分生组织培养,能有效脱除白水生姜烟草花叶病毒（TMV）和黄瓜花叶病毒（CMV）。以MS为基本培养基,添加6-BA 2.0 mg/L、NAA 0.1 mg/L有利于茎尖诱导分化;最适试管苗增殖培养基为MS＋6-BA 3.0 mg/L＋NAA 0.03 mg/L,增殖系数达7倍,丛芽叶绿、壮,长势好;生根培养基以MS＋NAA 0.5 mg/L＋IBA0.1 mg/L为宜,生根率达100%,纤维根多。     

苹果离体叶片培养直接体细胞胚胎发生研究

在ＭＳ＋ＢＡ１０ｍｇ／Ｌ＋ＮＡＡ５０ｍｇ／Ｌ＋２，４＿Ｄ０＼＾５ｍｇ／Ｌ＋蔗糖２０ｇ／Ｌ的固体培养基上，苹果品种嗄拉试管苗叶片经７天暗培养产生胚性细胞。将具有胚性细胞的叶片转入ＭＳ＋ＢＡ１０ｍｇ／Ｌ＋蔗糖２０ｇ／Ｌ的培养基上暗培养４０天，６５％的叶片直接发生体细胞胚，体细胞胚在同种培养基上萌发，长成小植株。     

Characterization of In Vitro Synthesized Equine Metabolites of the Selective Androgen Receptor Modulators S24 and S4

Several selective androgen receptor modulators (SARMs) have been synthesized and investigated in humans, rats, and dogs in the past, but no data are yet available concerning the metabolism of SARMs in horses. The aryl-propionamide-derived drug candidates S24 and S4 (andarine) have a strong androgen receptor binding affinity and show distinctive specific cell answers. Although no SARM drug candidate (aiming for testosterone replacement therapy) has completed clinical trials yet, S4 has been illicitly available via the Internet. These facts led to the prohibition of SARMs by the German equestrian federation, and the (mis)use of such compounds would further represent a doping rule violation in horse racing. In this study, the drug candidates S24 and S4 were subjected to in vitro metabolism experiments with equine liver microsomal preparations from a female Quarter Horse to obtain information about potential target analytes in equine doping control analysis. The enzymatically synthesized metabolites were characterized by liquid chromatography–tandem mass spectrometry and –high-resolution/high-accuracy mass spectrometry. All observed S24 and S4 equine metabolites are in agreement with earlier in vitro and in vivo studies in humans and dogs. Nevertheless, the relative percentage of generated equine metabolites (as determined from the analytes’ response in full-scan chromatography–tandem mass spectrometry and –high-resolution/high-accuracy mass spectrometry measurements) differs considerably from the reported profiles. Although the S24 metabolite pattern is comparably balanced concerning glucuronidated and sulfonated conjugates, the major S4 metabolite was found to be the unconjugated dephenylated compound, with a proportion of more than 90%.     

In Vitro Production of Equine Embryos

The development of methods to produce embryos in vitro in the horse has been delayed compared with other domestic species. Oocytes can be collected from excised ovaries or from the small or preovulatory follicles of live mares. Intracytoplasmic sperm injection is the only reliable method to fertilize equine oocytes in vitro. Intracytoplasmic sperm injection-produced embryos can be transferred into the oviducts of recipient mares or cultured to the morula or blastocyst stage of development for nonsurgical embryo transfers into recipients' uteri. Embryos cultured in vitro have some morphological differences compared with embryos collected from the mares' uteri. Most notably, the embryonic capsule does not form in culture, and the zona pellucida fails to expand completely. However, embryo produced in vitro can result in viable pregnancies and healthy offspring.