水蕨精子发生过程中中心体蛋白和微管蛋白的免疫荧光定位

采用透射电镜技术和免疫荧光标记技术对水蕨精子发生的超微结构以及中心体蛋白和微管蛋白在精子发生过程中的动态表达进行了观察。研究发现：（1）生毛体分化早期周围有放射状微管分布,这与线粒体向生毛体的聚集有关。（2）免疫荧光观察表明,中心体蛋白仅定位于生毛体、基体和鞭毛带上,自生毛体至基体阶段呈现明亮的荧光标记,在核塑形、鞭毛形成至精子成熟阶段,中心体蛋白荧光标记随着鞭毛的发生而逐渐减弱,至游动精子阶段中心体蛋白荧光标记信号几乎消失。（3）微管蛋白早期荧光标记与中心体蛋白标记形相同,在生毛体、鞭毛带、基体等运动细胞器上呈现明亮荧光标记,但微管蛋白随着鞭毛的发生其荧光标记越来越强。从二者的时空表达特征可以推断,中心体蛋白主要是运动细胞器的组织者,而非这些运动细胞器的结构成分,其功能是参与或负责中心粒、基体和鞭毛的发生。     

蕨类植物精细胞运动器和细胞骨架的研究

介绍了近年来蕨类植物游动精子运动器和细胞骨架的研究进展。游动精子由配子体精子器中的非运动细胞发育形成,其分化过程包括了运动器官和细胞骨架的合成和组装。精子发生过程中形成的运动器的各部分结构包括鞭毛、基体、多层结构及附属结构;基体是细胞中新形成的结构,在不同类群的蕨类植物中分别由双中心粒、分支生毛体和生毛体产生。鞭毛、基体和多层结构中的微管带形成了游动精子三个独特的微管列阵,由于微管蛋白的后修饰作用这些微管列阵十分稳定;centrin是运动器中的重要成分, 但功能尚不清楚,可能和细胞骨架及运动器的构建有关。     

蕨类植物精细胞运动器和细胞骨架的研究

介绍了近年来蕨类植物游动精子运动器和细胞骨架的研究进展.游动精子由配子体精子器中的非运动细胞发育形成,其分化过程包括了运动器官和细胞骨架的合成和组装.精子发生过程中形成的运动器的各部分结构包括鞭毛、基体、多层结构及附属结构;基体是细胞中新形成的结构,在不同类群的蕨类植物中分别由双中心粒、分支生毛体和生毛体产生.鞭毛、基体和多层结构中的微管带形成了游动精子三个独特的微管列阵,由于微管蛋白的后修饰作用这些微管列阵十分稳定;centrin是运动器中的重要成分,但功能尚不清楚,可能和细胞骨架及运动器的构建有关.     

蕨类植物分株紫萁精子发生过程中生毛体和多层结构的超微结构

应用电镜技术对蕨类植物分株紫萁(Osmunda cinnamomea L. var．asiatica Fernald)精子发育过程中的生毛体和多层结构的超微结构进行了研究。牛毛体在幼精了细胞中出现,正在分化的生毛体略呈球状,球状体的中央由一团染色深的颗粒状物质构成,外围分化出若干柱状体。已分化的生毛体由柱状体分散或辐射状排列构成,呈球状,球体中心不含染色深的物质。多层结构位于精子细胞内的基体和巨大线粒体之间,刚形成时仅由片层构成,片层相互平行排列形成片层带。多层结构在分化中期由微管带、片层带和蚀斑三层构成。多层结构在分化末期又形成附属微管带、嗜锇冠和嗜锇层。微管带从多层结构长出,沿细胞核的表面伸展,并与核膜之间形成复合结构。基体由柱状体转变而成,它向两端生长,在远端产生鞭毛的轴丝,在近轴端形成楔状结构。本文首次详细阐明了原始薄囊蕨分株紫其生毛体和多层结构发育的超微结构特点,并与其他蕨类进行了比较,发现其片层带出现在微管带形成之前。     

家蚕精母细胞内基体和鞭毛的电镜观察

中心粒是小的圆柱状微管细胞器。它的最重要特征是具有九组三联体微管系统(DuPraw,1970;Phillip,1970;woIfe,1972)。中心粒几乎发生在所有的动物细胞内;在具有鞭毛或纤毛的细胞内,中心粒发育成基体,再从基体的远心端生长出鞭毛或纤毛来。在动物精子发生和形成过程中,也存在着从中心粒到基体,再由基体产生精子尾部的过程。     

褐菖■精细胞晚期的变化及精子结构研究

本文研究卵胎生硬骨鱼褐菖（Ｓｅｂａｓｔｉｓｃｕｓｍａｒｍｏｒａｔｕｓ）精细胞的成熟变化和精子结构。褐菖精细胞发育晚期已具有硬骨鱼类精子的结构雏形：细胞核的背面较平坦,腹面稍外鼓,呈弧面;染色质浓缩成团块状,核的腹侧和后端的染色质较致密;中心粒复合体由近端中心粒和基体组成,近端中心粒和基体排成“Ｌ”形;近端中心粒向细胞核的背侧伸出中心粒附属物,中心粒附属物由９条微管组成,９条微管围成一筒状结构,类似轴丝。在晚期精细胞形成精子的过程中,中心粒附属物和近端中心粒相继退缩以至消失不见,同时细胞核后端的形状也随着发生变化。中心粒附属物和近端中心粒的相继消失可以看作是成熟的最后标志。精子的中心粒复合体由基体及其上方的基体帽组成,袖套接于核的后端,其中约有３０～４０个线粒体;鞭毛从袖套腔中伸出,鞭毛的中心结构是轴丝;轴丝外方为细胞质形成的侧鳍,在鞭毛的近核段,轴丝两侧的侧鳍较宽且不对称。     

半滑舌鳎精子发生和精子形成的超微结构

用电子显微镜对半滑舌鳎(Cynoglossus semilaevis)精子发生的过程及精子的超微结构进行了观察。半滑舌鳎精巢属于小叶型,精小叶由各期生精细胞和支持细胞构成。半滑舌鳎的精子发生经历了初级精原细胞、次级精原细胞、初级精母细胞、次级精母细胞和精子细胞,再经过精子形成过程发育成为精子。初级精母细胞成熟分裂的前期Ⅰ,同源染色体经历了联会复合体形成和解聚的变化。在精子形成的过程中,精细胞大致经历了核质浓缩、线粒体迁移及鞭毛的发生等过程。核质浓缩时,精细胞核内位于植入窝周围的染色质首先由细颗粒状浓缩成粗大颗粒状,然后细胞核其他部位的染色质也逐渐浓缩成粗大颗粒状。这些已浓缩成粗大颗粒状的染色质再进一步浓缩为电子密度高的均匀状物质。随着核质的浓缩,核外膜与核内膜之间的间隙增大形成核膜间隙,核内一些没有参与染色质浓缩的物质通过出芽形成囊泡,先排入核膜间隙,然后再外排到细胞质中。核浓缩过程中细胞核的体积和表面积都大大缩小;鞭毛的形成与细胞核的浓缩是同步进行的,当一对中心粒移近细胞核时,核膜凹陷形成植入窝,其周围染色质浓缩的同时,远端中心粒(基体)逐渐向后产生轴丝。成熟精子无顶体,头细长,主要为核占据,核凹窝发达,线粒体4-5个环绕在鞭毛基部形成袖套,尾细长,具侧鳍,尾部轴丝为"9 2"结构。     

蕨类植物分株紫萁精子发生过程中生毛体和多层结构的超微结构

应用电镜技术对蕨类植物分株紫萁(Osmunda cinnamomea L. var.asiatica Fernald)精子发育过程中的生毛体和多层结构的超微结构进行了研究.生毛体在幼精子细胞中出现,正在分化的生毛体略呈球状,球状体的中央由一团染色深的颗粒状物质构成,外围分化出若干柱状体.已分化的生毛体由柱状体分散或辐射状排列构成,呈球状,球体中心不含染色深的物质.多层结构位于精子细胞内的基体和巨大线粒体之间,刚形成时仅由片层构成,片层相互平行排列形成片层带.多层结构在分化中期由微管带、片层带和蚀斑三层构成.多层结构在分化末期又形成附属微管带、嗜锇冠和嗜锇层.微管带从多层结构长出,沿细胞核的表面伸展,并与核膜之间形成复合结构.基体由柱状体转变而成,它向两端生长,在远端产生鞭毛的轴丝,在近轴端形成楔状结构.本文首次详细阐明了原始薄囊蕨分株紫萁生毛体和多层结构发育的超微结构特点,并与其他蕨类进行了比较,发现其片层带出现在微管带形成之前.     

埃及尼罗河鲶的精子发生和精子的超微结构

用扫描和透射电子显微镜研究了尼罗河鲶——盾头歧须鮠(Synodontis schall)的精子发生和精子的超微结构。精巢中含有无数肾形的生精小叶,我们将其称为"精原无限型"。尽管其精子发生的大体过程与同类鱼无异。但是,在细节上仍具其独特之处。这些特点未见在其他硬骨鱼中报道过。其特点主要是:生精过程中不发生细胞核的旋转,中心粒复合体和轴丝起始段直接发生在核的基底面垂直线上,有无数的粗的固定纤维将近端中心粒和远端中心粒的近侧部连接到细胞核上。另外,精子发生过程中还包括染色质浓缩,细胞质和线粒体向细胞核的尾端迁移,在核的后端中轴位置上形成中等大小的核后凹,近端中心粒和远端中心粒的一部分嵌在核后凹之内,短的胞质内陷管将线粒体与鞭毛分隔开。精子头部接近圆形,无顶体或顶体泡,鞭毛的中段及胞质内陷管均较短,整个鞭毛却很长,鞭毛侧面无翼膜,轴丝呈典型的9 2结构。上述结果显示,盾头歧须鮠的精子发生具有类型Ⅰ和类型Ⅱ的共同派生特征,这种特征在常见的其他硬骨鱼中也是常有的。但是,正如文献所报道过的另两种尼罗河鲶——金鯵(Chrysichthys auratus)和电鲶(Malapterurus electricus)中的情况一样,盾头歧须的精子发生与类型Ⅲ的精子发生过程更为相似。     

褶纹冠蚌精子发生的研究

光镜和透射电镜研究结果表明：褶纹冠蚌精子发生是非同步的,精子发生经历了一系列重要的形态和结构变化,主要包括：核逐步延长、染色质浓缩、线粒体逐渐发达与融合、胞质消除以及鞭毛的形成。精原细胞胞质中含有许多致密的轴纤丝,它们后来形成鞭毛轴丝。精母细胞质中含有线粒体、中心粒、内质网和电子透明的囊泡。精细胞分化为４个时期。成熟精子属原始类型,由头部、中段和尾部三部分组成。多核结构和细胞间桥自始至终存在于精子     

CENTRIOLE REPLICATION : II. Sperm Formation in the Fern, Marsilea, and the Cycad, Zamia

Sperm formation was studied in the fern, Marsilea, and the cycad, Zamia, with particular emphasis on the centrioles. In Marsilea, the mature sperm possesses over 100 flagella, the basal bodies of which have the typical cylindrical structure of centrioles. Earlier observations by light microscopy suggested that these centrioles arise by fragmentation of a body known as the blepharoplast. In the youngest spermatids the blepharoplast is a hollow sphere approximately 0.8 µ in diameter. Its wall consists of closely packed immature centrioles, or procentrioles. The procentrioles are short cylinders which progressively lengthen during differentiation of the spermatid. At the same time they migrate to the surface of the cell, where each of them puts out a flagellum. A blepharoplast is found at each pole of the spindle during the last antheridial mitosis, and two blepharoplasts are found in the cytoplasm before this mitosis. Blepharoplasts are also found in the preceding cell generation, but their ultimate origin is obscure. Before the last mitosis the blepharoplasts are solid, consisting of a cluster of radially arranged tubules which bear some structural similarity to centrioles. In Zamia, similar stages are found during sperm formation, although here the number of flagella on each sperm is close to 20,000 and the blepharoplast measures about 10 µ in diameter. These observations are discussed in relation to theories of centriole replication.     

SPERMATOGENESIS IN A HOMOSPOROUS FERN,ONOCLEA SENSIBILIS

A detailed study of spermatogenesis in a homosporous fern, Onoclea sensibilis L., is presented from the formation of the first spermatogenous cell to the release of the sperm. Two different walls are deposited around the developing spermatids at specific developmental stages as opposed to one wall reported for other species. Most ultrastructural changes that occur in Onoclea during spermatid differentiation resemble those described in previous studies on other fern species, with the following exceptions: 1) A previously undescribed structure appears during midspermatid stage. This dense layer of amorphous material with a row of evenly spaced light areas occurs between the anterior portion of the mitochondrion associated with the multilayered structure and the anterior plasmalemma of the spermatid. 2) An early stage in blepharoplast formation resembles that which occurs in the heterosporous fern Marsilea, in contrast to that which has been reported in Platyzoma, the only other homosporous fern studied at this stage. 3) The osmiophilic crest does not form as early as reported in other ferns. 4) The cap cell of Onoclea is removed intact, rather than collapsing or forming a pore during sperm release. Observations are reported on the number of sperm per antheridium, the time course of spermatogenous cell mitosis, and of differentiation of spermatids into sperm. In Onoclea, an antheridium may contain either 32 or 64 sperm. Regardless of the final number of sperm, each has approximately the same volume.     

Immunofluorescent localization of cytoskeletal tubulin and actin during spermatogenesis inPteridium aquilinum (L.) Kuhn

Summary Details concerning the appearance and behaviour of blepharoplasts during spermatogenesis, and the assembly of the cytoskeletal motile apparatus of spermatids were elucidated by immunofluorescence microscopy using antibodies to tubulin and actin, applied to material prepared from antheridia of the fernPteridium aquilinum (L.) Kuhn. Blepharoplast immunofluorescence with antitubulin first appears as spheres at the future spindle poles prior to the last spermatogenous division. Developing spermatids each have one blepharoplast, which gives rise to a triangular layer corresponding to the incipient microtubule ribbon. Compared to the ribbon, immunoreactivity of the multilayered structure is relatively weak. Intensely fluorescing basal bodies appear, increase in number, and become arranged in rows along two edges of the microtubule ribbon as it widens and elongates. Along the dorsal edge is a dense file of basal bodies spaced at about 0.3 m intervals, parallel to each other and oriented at 145° to the multilayered structure. This spacing and orientation is maintained throughout spermatid development. Basal bodies at the opposite edge are initially oriented at 115° to the multilayered structure but become rearranged into small groups that rotate so that the angle is reduced to 55–70° by the time the assembly of flagella commences on both sets of basal bodies. By this stage the microtubule ribbon has encircled about 2/3 of the nuclear circumference and the nucleus is assuming a crescent shape. In fully developed spermatozoids the groups of basal bodies are oriented at 25° to the multilayered structure, parallel to the long body of the now helical nucleus. Immunofluorescence using antiactin showed that towards the completion of nuclear shaping, actin forms a strip along the helical multilayered structure. Detergent-extraction of mature spermatozoids revealed that actin is associated also with the flagellar band, particularly with basal bodies.Abbreviations MLS multilayered structure - MT microtubule     

Ultrastructure of Spermatogenesis in the Testis of Paragonimus heterotremus

Lung fluke, Paragonimus heterotremus, is a flatworm causing pulmonary paragonimiasis in cats, dogs, and humans in Southeast Asia. We examined the ultrastructure of the testis of adult P. heterotremus with special attention to spermatogenesis and spermiogenesis using scanning and transmission electron microscopy. The full sequence of spermatogenesis and spermiogenesis, from the capsular basal lamina to the luminal surface, was demonstrated. The sequence comprises spermatogonia, spermatocytes with obvious nuclear synaptonemal complexes, spermatids, and eventual spermatozoa. Moreover, full steps of spermatid differentiation were shown which consisted of 1) early stage, 2) differentiation stage representing the flagella, intercentriolar body, basal body, striated rootlets, and electron dense nucleus of thread-like lamellar configuration, and 3) growing spermatid flagella. Detailed ultrastructure of 2 different types of spermatozoa was also shown in this study.     

海金沙精细胞中生毛体发育及多层结构起源的超微结构研究

蕨类植物海金沙（LygodiumJaponicum（Thunb．）Sw．）的游动精子发育过程中,生毛体在精母细胞的细胞质中出现,它是直径为0．5－0．6μm的椭球体,其结构紧密,由辐射排列的具轮辐结构的管状亚单位和无定形基质组成。大量微管从生毛体伸向细胞质。随着精细胞的发育,生毛体结构变得松散,亚单位分化形成的中心粒彼此分开扩散到外围,中心为无定形物质。伴随着中心粒的分化,多层结构出现,一端与无定形基质相连。多层结构由外侧的微管带及内侧的片层组成,形成后与一线粒体相连,移向靠近核的位置,并正对着核上出现凹点。研究发现在精原细胞后期出现一团絮状结构,为无定形基质,其中有深染色的小管状结构分布,同时可见微管从絮状结构边缘伸出,这一絮状结构可能与生毛体的产生有一定的关系。     

Spermatogenesis in animals as revealed by electron microscopy. VI. Researches on the spermatozoon-dimorphism in a pond snail,Cipango-paludina malleata

This paper reports an electron microscope study of typical and atypical spermatogenesis in the pond snail, Cipangopaludina malteata. In the typical spermatid the nucleus undergoes profound changes as development proceeds, affecting both its form and internal fine structure. A large number of roughly parallel, dense filaments, arranged along the long axis of the nucleus, fuse with each other to form in the end the homogeneous helical body characteristic of the head of the adult spermatozoa. The nebenkern is apparently mitochondrial in nature and, in its early development, is similar to that of insects except that it appears as a double structure from the beginning. As differentiation proceeds, the mitochondria lose their membranes, and the residual, now denuded cristae, reorganize to give a parallel radial arrangement. In the last stages of development, the nebenkern derivations become applied to the sheath of the middle piece in a compact helical fashion. In the development of the atypical spermatozoa, the nucleus fails to differentiate and simply shrinks in volume until only a remnant, devoid of DNA, is left. The cytoplasm shows numerous vesicles containing small Feulgen-positive bodies, 80 to 130 mmicro in diameter. These vesicles plus contents increase in number as spermatogenesis proceeds. The "head" structure of the atypical spermatozoa consists of a bundle (7 to 17) of tail flagella, each with a centriole at its anterior end. The end-piece of the atypical form appears brush-like and is made up of the free ends of the several flagella.