精子磷酸化蛋白质组学研究应用

蛋白质磷酸化是生物体中广泛存在的翻译后修饰方式,参与多种过程的调节。精子是高度分化的特殊细胞,不具有转录活性,主要依赖于蛋白质的磷酸化完成精子成熟、分化和受精等过程。因此,对于精子磷酸化蛋白质组学的研究有助于进一步了解精子发生、精子获能、超激活以及精卵识别等过程的调控机制。本文简要综述了精子磷酸化蛋白质组学的研究方法及磷酸化蛋白质组学在精子中的应用,为精子磷酸化蛋白质组学在实际科研应用中提供了理论参考。     

糖在猕猴精子低温冷冻保存过程中的作用

TTE或TEST防冻液在冻存猕猴精子时产生不同结果,其主要不同在于防冻液中糖成分的不同。本实验利用透射电镜技术检测这2种防冻液冻存的猕猴精子冷冻前后超微结构的变化,以说明糖在低温冻存过程中的作用。结果表明,冷冻复苏过程对精子结构产生了影响。TTE法低浊保存的猕猴精子的头部的质膜出现少许皱褶或泡化现象,但精子的顶体、核或是精子尾部的结构与鲜精的结构基本相似。猕猴精子经TEST法低温保存后,大部分精子结构则发生了明显的变化。精子膜、顶体和精子核明显泡化、损伤或破裂,精子尾部不能分辨出正常的超微结构。这提示,可能由于TTE防冻液中复杂的糖成分在降温／复苏过程对精子起到了较好的协同冷冻保护作用;而TEST防冻液中单一的糖成分不能完全保护精子避免低温损伤,低温保存过程破坏了精子的结构,并影响了复苏后精子体外存活能力与受精能力。     

蜂王体内的精子贮存

蜜蜂最重要的生殖特征是一雌多雄交配,蜂王交配后将精子贮存于受精囊中长达数年之久,并仍能保持活力。这些特征使蜜蜂成为研究精子长期贮存的模式动物。文章介绍蜂王的交配和精子贮存过程,精子贮存器官,贮存过程中的精子竞争和隐秘雌性选择,以及蜂王精子的长期贮存机制,并对将来的研究方向进行了展望。     

精子胞浆小滴的发现及研究进展

精子成熟是一个复杂的过程,精子从睾丸向附睾运行过程当中,精子表面的胞浆逐渐脱落,最终精子成熟。各种原因引起的精子表面胞浆滞留最终形成胞浆小滴。胞浆小滴在多种物种中均有发现,与男性不育相关。     

精子胞浆小滴的发现及研究进展

精子成熟是一个复杂的过程,精子从睾丸向附睾运行过程当中,精子表面的胞浆逐渐脱落,最终精子成熟。各种原因引起的精子表面胞浆滞留最终形成胞浆小滴。胞浆小滴在多种物种中均有发现,与男性不育相关。     

精子的运动特性

精子的运动特性与生育力有密切关系。本文从超微结构水平和分子生物学基础出发,阐述精子运动机制的微管滑动学说;介绍了精子在液体介质中的运动形式、检测精子活动力的主要技术、影响精子活动力的因素、从异常精液中选择正常精子的技术,以及精子活动力在雄性和雌性生殖道中的演变过程。     

精子功能相关的蛋白质调控受精过程的研究进展

哺乳动物的受精过程涉及到精子一系列的功能活动,如精子在雌性生殖道的运行、精子的超活化与获能、顶体反应以及精卵融合等。在精子经历的这一系列过程中,精子功能相关的蛋白质发挥着不可或缺的作用,这些蛋白分子的正常与否与雄性个体的繁殖力高低密切相关,因此精子功能相关的蛋白质能够作为评定哺乳动物精液受精能力的生物标记。文章主要对哺乳动物精子功能相关的蛋白质进行了综述,以阐述相关蛋白分子对精子运动活力、精子获能、顶体反应、透明带穿入和精卵融合等方面的重要作用以及这些蛋白分子在家畜遗传改良上的潜在应用。     

山羊精子发生不同阶段的显微与超微结构观察

应用光镜和透射电镜技术研究山羊精子发生不同阶段各级生精细胞显微、超微结构及山羊精子分化成熟过程。结果表明：山羊精子发生经历了精原细胞、初级精母细胞、次级精母细胞、精子细胞及变态精子阶段发育成成熟的精子。精原细胞期核呈椭圆形,染色质凝集成团分布于核质中,线粒体开始出现;精母细胞期有高尔基体分布;精子细胞经过核质浓缩、线粒体迁移等过程发育成成熟精子,成熟的山羊精子头部细长,核质高度浓缩,中段膨大,线粒体丰富。线粒体、中心粒对精子变态发生起重要作用,同时观察到头部与中段脱落的畸形精子。     

日本鳗鲡精卵的超微结构以及受精过程观察

通过扫描电镜和透射电镜对经人工催产获得的日本鳗鲡(Anguilla japonica)精子、卵膜的超微结构以及受精过程进行了观察。实验观察到,除一般硬骨鱼类的精子特性外,日本鳗鲡精子有其独特的结构。精子头部为不规则的梨形,有背腹面之分。一个巨大的球形线粒体位于头部顶端。精子中段向后伸出一支根,支根位于袖套腔外精子的背侧,前端向精子头部线粒体方向延伸,支根的微管结构为"8+2"结构,并在精子入卵过程中起到切断鞭毛的作用。精子的尾部由鞭毛和鞭毛末端的结组成。鞭毛横切面呈圆形,无侧鳍,鞭毛微管结构为"9+0"结构。受精卵的整个表面密布着无规律延伸的脊、脊包围形成的窝和窝中的孔所组成的脊孔复合体,但无典型特征的受精孔。受精卵超薄切片观察发现,日本鳗鲡卵膜分为外层壳膜和内层卵黄膜。壳膜与卵黄膜间为卵周隙。壳膜只观察到放射带,未见透明带。放射带可分为三个亚层:最外层为脊孔复合体的脊,中间层为皱纹层,最内层为致密的平滑层。脊孔复合体的孔横穿整个放射带,在放射带内层形成一个乳突状结构。日本鳗鲡的卵膜不仅具有保护卵子的作用,而且还参与了受精。实验还通过扫描电镜观察了日本鳗鲡精子的入卵过程。观察结果认为:日本鳗鲡精子入卵过程可分为卵膜对精子的吸引、精子对卵膜的锚定、精核的进入和孔封闭等4个阶段。但由于研究只观察到受精过程中日本鳗鲡精子和卵膜的形态变化,因此对精子穿过卵膜的方式和特征等尚需做进一步的研究。整个受精过程为1min30s左右。此外,研究还探讨了日本鳗鲡精子结构的特殊性和受精过程的特殊性,为进一步突破日本鳗鲡人工育苗技术提供了理论依据。       

革胡子鲶受精过程的扫描电镜观察

应用扫描电镜观察和描述了革胡子鲶成熟卵和精子的形态、卵壳膜的表面结构和形态、受精孔的位置和结构、精子入卵过程的程序和变化。讨论了精子入卵过程及精孔细胞在解体之后可能转变为一种能够吸引精子在精孔区聚集的“受精素”物质等问题。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.