蟋蟀精子顶体复合体形成的超微结构

顶体复合体是昆虫精子进行穿卵受精的重要细胞器,它位于精子的最前端.1997年我们对蟋蟀科一种类昆虫北京油葫芦(Gryllus mitratusburmeister)精子顶体复合体形成过程进行了超微结构的观察,发现与前人描述的蟋蟀科精子顶体复合体超微结构特征在某些方面有所不同,从而为准确认识和掌握该结构的特点提供一定的理论依据.     

暗褐蝈螽与优雅蝈螽精子超微结构的比较研究(直翅目,螽斯科)

研究了暗褐蝈螽Gampsocleis sedakovii(Fischer von Waldheim)和优雅蝈螽G.gratiosa Brunner von Wattenwyl精子的超微结构。这两种蝈螽精子头部的顶体复合体由顶体外层、顶体本体和顶体组成,顶体复合体位于细胞核前端,并包裹部分细胞核;颈部具5纵层细胞器;尾部鞭毛轴丝为典型的9+9+2型,线粒体衍生体部分晶状化。暗褐蝈螽精子较短,顶体复合体夹角较大,精子鞭毛横切面直径稍大;优雅蝈螽精子稍长,顶体复合体夹角较小,精子鞭毛横切面直径较小,两种精子超微结构差异不显著,其生殖隔离机制有待进一步研究。     

TELEOGRYLUS EMMA精子体外顶体反应的超微结构比较研究

采用相同种类卵水诱导的方法对直翅目,蟋蟀科,黄脸油葫芦的受精囊精子的顶体反应过程进行系统观察.发现黄脸油葫芦精子顶体反应可划分为3个阶段,第1阶段,精子质膜膨胀、断裂或丢失;第2阶段,顶体复合体的顶体外层与顶体本体外膜发生融合,囊泡化;第3阶段,顶体复合体大部分脱落,只留有短锥状的顶体位于核前端.据观察,蟋蟀精子质膜不参与囊泡形成,此结果与家蝇及哺乳类的猪、牛、绵羊、猕猴精子的顶体反应结果很相似.经过比较发现卵水对受精囊内精子的诱导率明显高于精巢内,据分析,可能与精子的生理成熟有关,即便受精囊内精子比精巢内精子更趋于成熟.与其他学者的实验结果相比,蟋蟀精子顶体反应率与家蝇的相似,但明显低于其他动物.这可能与动物的授精方式有关.     

中国雨蛙精子结构及其在系统发育上的意义

研究了中国雨蛙（Ｈｙｌａｃｈｉｎｅｎｓｉｓ）精子的超微结构,并初步探讨其在系统发育上的意义,中国雨蛙精子由头部和尾部两部分组成,头部一有棒状的细胞核,核内染色质高度浓缩,细胞核前方有顶体。顶体圆锥状,顶体下腔之中一圆锥状的顶体下锥和细小的囊泡,精子尾部细长,主要由轴丝,致密纤维和线粒体组成,尾部没有波动膜。从蟾蜍科,雨蛙科和蛙科的精子结构看,无尾两栖类在进化过程中,精子结构趋向简单,雨蛙科精子的结     

Dynamics of F-actin during spermiogenesis in Gampsocleis gratiosa ( Orthoptera: Tettigoniidae)

为阐明F-肌动蛋白在优雅蝈螽Gampsocleis gratiosa Brunner von Wattenwyl精子形成过程中的动态变化,本研究利用微分干涉相衬技术和免疫荧光技术首次对优雅蝈螽精子形成过程中的F-肌动蛋白进行了细胞定位,利用透射电镜技术从超微水平观察了优雅蝈螽精子顶体复合体的结构.结果显示:精子形成早期,F-肌动蛋白富集于亚顶体区域,形态由“球状”转变为“棒锥状”;精子形成中期,F-肌动蛋白呈“倒Y型”分布于亚顶体区域和细胞核前端两侧;精子形成后期,亚顶体区域的F-肌动蛋白解聚消失,F-肌动蛋白呈“箭头状”,仅分布于顶体复合体扩张的两翼中.F-肌动蛋白动态变化伴随着细胞核和精子头部的形态改变,F-肌动蛋白的动态装配在精子顶体复合体形态构建和细胞核的形变中起着重要的作用.本研究还发现未成熟的精子尾部有一些富含F-肌动蛋白的细胞质微滴,与精子形成过程中多余细胞质和细胞器的外排有关.F-肌动蛋白的动态变化研究为进一步阐明细胞骨架蛋白在昆虫精子形成过程中的功能和作用机制奠定了基础.     

优雅蝈螽精子形成过程中F-肌动蛋白的动态变化

为阐明F-肌动蛋白在优雅蝈螽Gampsocleis gratiosa Brunner von Wattenwyl精子形成过程中的动态变化, 本研究利用微分干涉相衬技术和免疫荧光技术首次对优雅蝈螽精子形成过程中的F-肌动蛋白进行了细胞定位, 利用透射电镜技术从超微水平观察了优雅蝈螽精子顶体复合体的结构。结果显示： 精子形成早期, F-肌动蛋白富集于亚顶体区域, 形态由“球状”转变为“棒锥状”; 精子形成中期, F-肌动蛋白呈“倒Y型”分布于亚顶体区域和细胞核前端两侧; 精子形成后期, 亚顶体区域的F 肌动蛋白解聚消失, F-肌动蛋白呈“箭头状”, 仅分布于顶体复合体扩张的两翼中。F-肌动蛋白动态变化伴随着细胞核和精子头部的形态改变, F-肌动蛋白的动态装配在精子顶体复合体形态构建和细胞核的形变中起着重要的作用。本研究还发现未成熟的精子尾部有一些富含F-肌动蛋白的细胞质微滴, 与精子形成过程中多余细胞质和细胞器的外排有关。F-肌动蛋白的动态变化研究为进一步阐明细胞骨架蛋白在昆虫精子形成过程中的功能和作用机制奠定了基础。     

中华蝈螽与中华螽斯精子超微结构研究(直翅目,螽斯总科)

研究了中华蝈螽Gampsocleis sinensis与中华螽斯Tettigonia chinensis精子的超微结构.两种精子的顶体复合体侧生于核上且包裹了核的一部分,顶体复合体横切面两侧角分离或两侧角与细胞核远离,或仅见其一侧角;中华蝈螽顶体外层在顶体本体两侧角外多呈晕圈状;轴丝为典型的9 9 2型;轴丝两侧的副纤维结构为2副微管;轴丝与线粒体衍生体之间的连接带3条;中华蝈螽有的横切面中两扁平膜池连接在一起;两种精子的中心粒侧体部位具五纵层细胞器.     

膜翅目精子结构研究新进展

根据观察,膜翅目昆虫精子由顶体,精核,中部,尾部四个主要部分构成。顶体具顶体丝,中部具轴丝,中部与精核间具线粒体衍生物。本文同时对膜翅目,分别隶属12个科,10个总科中的2个亚目昆虫精子的顶体、精核、线粒体衍生物、轴丝等结构的研究状况进行概括,并应用精子结构特征对上述类群的系统发育状况进行讨论。     

黄腹角雉精子超微结构的研究

透射电镜研究表明,黄腹角雉精子的结构与家鸡的相似,圆锥形的顶体位于精核前部,与精核的前端有少许重叠。顶体刺位于顶体下腔里,其部分区域的电子密度较低。核前窝内容纳着顶体部的基部,远端的植入窝则为中心粒复合体和无条纹连接体所占据,后者构成了精子短的颈部。     

长江华溪蟹精子超微结构的研究

透射电镜下观察长江华溪蟹成熟精子的形态和超微结构。精子呈椭球形,无鞭毛,具数条由核延伸而成的辐射臂精子。由球形的顶体,膜复合体,核杯及辐射臂组成,顶体由头帽,亚帽带,丁体囊及中央管组成。在中央管的基部发现有中心粒。核膜与质膜紧贴在一起形成了精子的界膜。     

锯缘青蟹精子超微结构的研究

利用光镜和电镜观察了锯缘青蟹成熟精子的形态和超微结构。精子呈陀螺形，无鞭毛，在较宽的一端环生着１０余辐射臂。精子由球状的顶体、核杯以及核衍生的辐射臂三部分组成。顶体包括顶体管和顶体囊，后者包绕在顶体管的中央管周围，并可分为头帽带，内层和外层区。顶体被杯状的核包裹，仅头帽露于精子表面。成熟的精子中，位于核杯和顶体管之间的核膜出现局部断续或消失，中心粒和一些胞器出现的核杯腔中。     

大熊猫精子获能和顶体反应过程中钙分布变化规律的研究

应用焦锑酸钾原位定位法对大熊猫精子获能和顶体反应过程中进行钙定位研究,发现未获能精子的 Ｃａ２＋主要结合于顶体前区和赤道段质膜外侧和顶体内膜内侧（核膜侧）;随着获能的进行,Ｃａ２＋进入精子内部并主要结合于顶体区质膜内侧和顶体外膜外侧;顶体反应的精子,Ｃａ２＋结合于顶体内膜外侧、顶体后区质膜外侧和分散存在于释放的顶体内容物中,有些顶体反应精子的顶体内膜外侧结合的Ｃａ２＋特别丰富。精子尾部的Ｃａ２＋主要分布于中段线粒体内,且其内所含Ｃａ２＋含量随着获能和顶体反应而增加。另外尾部致密纤维和轴丝处也有少量Ｃａ２＋分布。     

Scanning electron-microscopical and other observations of sperm fertilization reactions in Limulus polyphemus L. (Merostomata: Xiphosura).

Sperm fertilization reactions of Limulus polyphemus were examined by scanning electron and/or light microscopy. The following were considered: sperm motility, attachment of sperm to egg, acrosome reaction, and penetration of the acrosomal filament. The spermatozoa after semination are non-motile and become active only in close proximity to a defined region surrounding the egg. Egg materials diffusing into this region induce sperm motility and stimulate large numbers of spermatozoa to move towards the egg surface. Each sperm initially attaches by the apical tip and undergoes the acrosome reaction which causes a more permanent secondary attachment by the adhesion of acrosomal contents to the egg surface. The acrosome reaction also initiates the penetration of the acrosomal filament through the egg envelope, an event occurring in 70-80% of the attached spermatozoa (about 10(6). Shortly after this penetration, a secondary reaction occurs which involves a spiralling of the flagellum and an incorporation into the sperm body of the flagellar fibrous components, which then become closely apposed to the sperm nucleus. These sperm fertilization reactions were performed or initiated with 0-34 M CaCl2 in whole eggs, egg sections, excised egg envelopes and/or the outer basement lamina of the egg envelope. The Limulus fertilization system is very valuable since sperm reactions can be examined biochemically, which may lead to a better understanding of the chemical mechanisms involved in sperm-egg interactions in all animal species.     

东方扁虾精子的超微结构

利用电镜研究了东方扁虾（Ｔｈｅｎｕｓ ｏｒｉｅｎｔａｌｉｓ）精子的形态和结构。精子由核、膜复合物区和顶体区３部分组成。核内含非浓缩的染色质、微管及细纤维丝,外被核膜;５～６条辐射臂自核部位伸出,臂内充满微管。膜复合物区位于核与顶体之间,由许多膜片层结构及其衍生的囊泡共同组成。顶体区由顶体囊和围顶体物质组成,顶体结构复杂,由顶体帽、内顶体物质和外顶体物质等构成;围顶体物质呈细颗粒状,主要分布于顶体囊     

Characterization of matrix domains of the hamster acrosome

In this study we describe the purification and the structural and biochemical properties of a detergent-stable complex of the hamster sperm acrosome. This complex consists of two distinct acrosomal matrix domains and a layer of electron-dense material, termed the acrosomal lamina, derived from the luminal surface of the outer acrosomal membrane. This complex has been isolated by centrifugation of detergent-extracted sperm suspensions on Percoll density gradients. The complex contains two major polypeptides of Mr 29,000 and Mr 22,000 and minor polypeptides of Mr 64,000-62,000, 56,000 and 35,000. Gelatin-containing sodium dodecyl sulfate-polyacrylamide gels demonstrate that bands of proteinase activity are not the major polypeptide components of the complex. These data demonstrate that the matrix of the acrosome is compartmentalized into domains of differing structural properties that occupy specific locations in the intact acrosome and that matrix components are physically associated with the outer acrosomal membrane. These data indicate that a structural framework is present within the acrosome and we speculate that it may be involved in sequestering hydrolases into specific spatial domains and could affect the temporal release of activity of selected hydrolases during the acrosome reaction.     

Involvement of an acrosin-like enzyme in the acrosome reaction of sea urchin sperm

Extracts of the jelly coat of eggs of several marine invertebrates are known to induce in homologous sperm morphological changes known as the acrosome reaction. When sperm of the sea urchin Strongylocentrotus purpuratus are treated with low concentrations (0.2 μg fucose/ml) of egg jelly coat or 30 mM CaCl₂ in artificial seawater the acrosome reaction does not occur. However, either of these treatments causes the exposure of an acrosin-like enzyme to exogenous substrate and inhibitors. Subsequent addition of jelly coat to 3.7 μg fucose/ml to sperm in this “initial stage” induces the acrosome reaction (as judged by the appearance of an acrosomal filament). This concentration is also effective for untreated sperm. If inhibitors of the enzyme (diisopropylphosphofluoridate or phenylmethanesulfonyl fluoride) are added to sperm in the initial stage, no acrosomal filaments are observed when the high concentration of jelly coat is added. Whether other morphological changes occur in these sperm has not been examined. If phenylmethanesulfonyl fluoride is added 4 sec after the jelly coat, the acrosomal filaments are observed, but the sperm still fail to fertilize eggs. These results suggest a dual role for the acrosin-like enzyme(s), first in the mechanism of the acrosomal filament formation and then in a subsequent event in the fertilization process.     

Acrosome reaction in sperm of the toad,bufo bufo japonicus

The acrosome in the sperm of the toad, Bufo bufo japonicus, consists of a membrane-limited acrosomal cap and a fibrous perforatorium. When sperm are incubated with the oviducal pars recta extract (PRE) for 30–60 min, the outer acrosomal membrane fuses with the overlying plasma membrane at several points with concomitant loss of the contents of the acrosomal cap. The inner acrosomal membrane thus exposed fuses with the plasma membrane at the caudal end of the acrosomal region. This PRE-induced acrosome reaction is completely inhibited by soybean trypsin inhibitor. Sperm found in the innermost jelly layer of inseminated eggs possess an intact acrosome, but those either passing through the vitelline coat or localizing in the perivitelline space are acrosome-reacted in the same manner as when treated with PRE. These observations, combined with recent evidence showing involvement of the pars recta substance in fertilization, indicate that the acrosome reaction occurring in a fertilizing sperm at or near the surface of the vitelline coat is a response to a substance that is derived from the pars recta and deposited in the vitelline coat.     

Fine structure of spermiogenesis, spermatozoa and spermatophore of Saxidromus delamarei (Saxidromidae, Actinotrichida, Acari)

Ultrastructural details of spermiogenesis, spermatozoa and the spermatophore of the early derived actinedid mite Saxidromus delamarei are described. Spermatids and mature sperm cells are provided with up to four acrosomal complexes and nuclei derivatives (chromatin bodies). Due to this reason, the sperm cells may be classified as synspermia, a sperm type found only in some spiders until now. The acrosomal complex is composed of a remarkably complicated vacuole and filament. Other peculiarities of sperm structure correspond to those found in prostigmatic mites, i.e. penetration of the chromatin body by the acrosomal filament and the presence of peripheral invaginations of the plasmalemma. The sperm cells are covered by a thin secretion layer of probably proteinaceous material. Stalked spermatophores are rather large, but simply structured and contain relatively few sperm cells. The results are discussed taking systematical and behavioural aspects into account. In particular, it is suggested that the peculiar mating behaviour of these mites secures both sperm transfer and first male's sperm priority and that this allowed reduction of sperm numbers.     

乌梢蛇精子头部形成的超微结构

摘要：为了解乌梢蛇（Zaocys dhumnades）精子形成的规律,用透射电镜对其头部超微结构进行了观察。结果表明,乌梢蛇精子头部形成可分为4个阶段：阶段Ⅰ,前顶体囊泡内的颗粒物质融合形成1个顶体颗粒而发育为顶体囊泡,随着顶体囊泡的增大,在顶体囊泡与核膜之间形成了致密的纤维物质层。阶段Ⅱ,顶体囊泡变扁平,顶体颗粒分散...