日本沼虾精子发生的研究

对日本沼虾精子发生全过程的电镜观察表明：精原细胞核染色质分散,胞质内有线粒休、内质网的分布。初级精母细胞核染色质块状,不均匀地分布于核中,内质同多小泡多。次级精母细胞核染色质大多分布于核膜内侧,内质网聚集成团,精细胞分化形成精子的早期,胞核增大,核侧形成内质同多小泡的聚合体;中期的核内染色质浓缩,同时形成空囊状结构,     

三疣梭子蟹精子的发生及超微结构研究

用透射电镜观察三疣梭子蟹的精子发生过程及精子的超微结构。发现精原细胞较大，卵圆形。核大而圆，染色质分散，附着于核膜之内侧。胞质少，内含线粒体和粗面内质网等结构。初级精母细胞比精原细胞略小，卵圆形，核内染色质凝聚成团块，散布于核质中，除线粒体外，胞质中尚含有很多内质网小泡和游离核糖体。次级精母细胞多边形，核卵圆形，染色质致密，线粒体等含量均下降。早期精细胞质中由内质网产生许多颗粒，这些颗粒合并成为大     

烟草花粉母细胞中果胶酶细胞化学定位及其在次生胞间连丝和胞质通道形成中的作用

对果胶酶在烟草(Nicotiana　tabacum　L.)花粉母细胞减数分裂前期Ⅰ的活性进行了电镜细胞化学定位,以研究其在次生胞间连丝和胞质通道形成中的作用。结果表明:在细线期,酶反应产物主要存在于光面内质网及其衍生小泡内;偶线期,当次生胞间连丝和胞质通道开始形成时,反应产物明显增强。同时果胶酶活性也出现在细胞壁上,尤其是出现在简单或者复杂分枝状的胞间连丝和胞质通道内部或沿着它们附近细胞壁的中胶层分布。胞吐小泡中的酶活性表明果胶酶和纤维素酶一样,也是通过内质网及其衍生小泡由胞吐作用分泌到细胞壁的,并在那里通过特异性降解果胶质而和纤维素酶协同作用导致次生胞间连丝和胞质通道的形成。     

烟草花粉母细胞中果胶酶细胞化学定位及其在次生胞间连丝和胞质通道形成中的作用

对果胶酶在烟草(Nicotiana tabacum L.)花粉母细胞减数分裂前期Ⅰ的活性进行了电镜细胞化学定位,以研究其在次生胞间连丝和胞质通道形成中的作用.结果表明:在细线期,酶反应产物主要存在于光面内质网及其衍生小泡内;偶线期,当次生胞间连丝和胞质通道开始形成时,反应产物明显增强.同时果胶酶活性也出现在细胞壁上,尤其是出现在简单或者复杂分枝状的胞间连丝和胞质通道内部或沿着它们附近细胞壁的中胶层分布.胞吐小泡中的酶活性表明果胶酶和纤维素酶一样,也是通过内质网及其衍生小泡由胞吐作用分泌到细胞壁的,并在那里通过特异性降解果胶质而和纤维素酶协同作用导致次生胞间连丝和胞质通道的形成.     

脂质营养对中华绒螯蟹幼体肝胰腺超微结构的影响

采用透射电镜技术研究了中华绒螯蟹（Eriocheir sinensis)各期幼体肝胰腺的超微结构,结果表明,蟹的肝胰腺腺管上皮由Ｅ,Ｆ,Ｂ和Ｒ４种细胞组成,其中Ｅ细胞为胚胎细胞,能分化成其他３种细胞;Ｂ,Ｒ和Ｆ细胞均呈,高柱状,腔面有发达的微绒毛,基底部有基膜,呈明显的极性分布;Ｂ细胞粗面内质网丰富,胞质中有１－２个大液泡,起分泌作用,属分泌液;Ｆ细胞内含发达的粗面内质网,还可见酶原颗粒;Ｒ细胞胞质中有丰富的滑面内质网、游离的核糖体和脂肪滴,主要起贮存养人的作用。细胞的连接有紧密连接和中间连接２种方式。与脂质营养缺乏时相比,脂质营养充足的幼体其肝胰腺超微结构有如下特点：Ｒ细胞质中有连多的脂肪滴,线粒体呈饱满的圆形或椭圆形,且膜未见有内陷或萎缩,滑面内质网膨胀成小泡状结构。     

荞麦水合花粉和花粉管中的被膜小泡

荞麦水合花粉粒和生长中的花粉管中内质网潴泡形成的囊袋状结构较少见,但内质网囊袋中含有丰富的被膜小泡,直径约为100－150nm。刚刚形成的花粉管中,被膜小泡主要来自于花粉粒营养细胞的细胞质。生长中的花粉管的被膜小泡可由高尔基体分泌形成。另外还观察到内质网的碎裂也是荞麦花粉管中产生被膜小泡的一种机制。花粉管的被膜小泡中含有花粉管壁的前体物质,与花粉管的壁融合参与花粉管的生长。被膜小泡可能含有与脂体和造粉质体水解有关的酶,参与此类物质的降解。荞麦花柱和柱头细胞内含物的解体物质参与花粉管的生长。     

内质网蛋白定位信号研究进展

内质网是蛋白质合成的主要细胞器,一方面选择性运出分泌蛋白和膜蛋白,另一方面保留内质网定位蛋白以维持其结构和功能。内质网保持驻留蛋白主要通过两种方式完成：阻止其进入运输小泡而停留于内质网中;内质网蛋白进入转运小泡后重新运回内质网。这些内质网蛋白的定位是受到周密调控的,对这些过程的了解有助于对内质网功能和许多疾病致病机制的阐述。综述了近年来内质网定位信号及研究方法,并在此基础上探讨了内质网定位信号研究的意义。     

白刺胚乳早期发育的超微结构研究

白刺(Nitraria sibirica)胚乳发育经历游离核阶段、细胞化阶段和被吸收解体阶段。游离核胚乳沿胚囊壁均匀排列为一层,胞质浓厚,其中有丰富的质体、线粒体、高尔基体、内质网和各种小泡等细胞器。珠孔区域的胚囊壁具发达的分枝状壁内突,而周缘区域的胚囊壁具间隔的钉状内突,内突周围的细胞质中具多数线粒体和小泡。胚乳细胞化时,初始垂周壁源于核有丝分裂产生的细胞板。在细胞板两端开始壁的游离生长,一端与胚囊壁相连接,另一端向心自由延伸。壁的游离生长依赖于小泡的融合。早期胚乳细胞具大液泡,具核或无核,细胞质中有大量的线粒体,质体缺乏,其壁仍由多层膜结构组成。     

内质网区蓖麻毒素的逆向转运

蓖麻毒素是植物来源的核糖体失活蛋白。蓖麻毒素必须通过细胞的内膜系统到达内质网,然后转位至胞质,才能作用于胞质内的核糖体。在内质网中毒素的两条链分离,具有催化活性的A链被内质网上的蛋白质识别,并被转位到胞质内催化核糖体失活。现对内质网在参与蓖麻毒素胞内转运过程中的作用进行综述。     

荇菜腺毛的发育及其分泌过程的超微结构研究

荇菜 (Nymphoides peltatum (Gmel.) O.Kuntz)腺毛由具分泌功能的单列圆筒状细胞组成。它们起源于苗端倒数第二叶原基近轴面 ,由原表皮细胞发育而来。处于分泌期的腺毛细胞其胞质浓厚 ,液泡化程度小。细胞内具丰富的线粒体、高尔基体和内质网等细胞器 ,还具发达的胞间连丝。粘液物质由高尔基体分泌小泡、内质网分泌小泡及多膜体共同携带至细胞边缘 ,经胞吐和渗透相结合的方式分泌至细胞外。腺毛细胞侧壁因积有大量分泌物而呈膨胀状态。经检测 ,粘液由多糖和蛋白质组成 ,对营养芽的生长发育起保护作用。     

Ultrastructure of spermatogenesis in Cerastoderma glaucum (Cardiacea) and Spisula subtruncata (Mactracea)

Summary

In Cerastoderma glaucum, Sertoli cells are rich in lipids, glycogen and lysosomes, and premeiotic cells exhibited nuage, a prominent Golgi complex and endoplasmic reticulum cisternae encircling the nucleus. The Golgi complex gives rise to proacrosomal vesicles during mid-spermiogenesis, and the round acrosomal vesicle, with a dense fibrillar core, migrates laterally while linked to the plasma membrane as it develops the subacrosomal material. In its final position, the vesicle becomes cap-shaped (0.6 μm) and differentiates into apical light and basal dense regions. The elongated and helicoidal nucleus (8–9.9 μm) has a thin tip (0.3 μm) that invades the subacrosomal space, and in the midpiece (0.8 μm) two of the four mitochondria extend laterally to the nucleus (1.5–2.1 μm). In Spisula subtruncata, Sertoli cells are rich in lipids, glycogen and phagocytosed sperm. Premeiotic cells exhibit nuage, a prominent Golgi complex that gives rise to proacrosomal vesicles from the leptotene stage and a flagellimi that is extruded at zygotene. The acrosomal vesicle forms during the round spermatid stage and differentiates into a large and dense basal region and an apical light region. It then migrates while linked to the plasma membrane by its apical pole. Development of the subacrosomal perforatorium is associated with nuage materials and endoplasmic reticulum vesicles. The mature cap-shaped (0.6 μm) acrosomal vesicle exhibits a large apical and irregular region with floccular contents and a basal dense region. The round nucleus becomes barrel-shaped (1.5 μm) and the midpiece (0.8 μm), with four mitochondria, contains a few glycogen particles.     

东方扁虾精子发生的超微结构

应用电镜技术研究了东方扁虾（Thenus orientalis)精子发生的全过程,精原细胞呈椭圆形,其染色质分布较均匀,线粒体集中于细胞一端形成“线粒体区”。初级精母细胞较大,染色质凝聚成块,次级精母细胞核质间常出现大的囊泡,胞质内囊泡丰富而线粒体数量却明显减少,早期精细胞核发生极化、解聚,部分胞质被抛弃。中期精细胞外观呈金字塔形,分为三区;正在形成的顶体位于塔顶,核位于塔基部,居间的细胞质基质内富含膜复合物,后期精细胞顶体进一步分化。形成顶体帽和内、外顶体物质等三个结构组份。成熟精子核呈盘状或碗状,具有5-6条内部充满微管的辐射臂。     

Ultrastructure of spermiogenesis in the American alligator,Alligator mississippiensis (Reptilia,Crocodylia, Alligatoridae)

Testicular samples were collected to describe the ultrastructure of spermiogenisis in Alligator mississipiensis (American Alligator). Spermiogenesis commences with an acrosome vesicle forming from Golgi transport vesicles. An acrosome granule forms during vesicle contact with the nucleus, and remains posterior until mid to late elongation when it diffuses uniformly throughout the acrosomal lumen. The nucleus has uniform diffuse chromatin with small indices of heterochromatin, and the condensation of DNA is granular. The subacrosome space develops early, enlarges during elongation, and accumulates a thick layer of dark staining granules. Once the acrosome has completed its development, the nucleus of the early elongating spermatid becomes associated with the cell membrane flattening the acrosome vesicle on the apical surface of the nucleus, which aids in the migration of the acrosomal shoulders laterally. One endonuclear canal is present where the perforatorium resides. A prominent longitudinal manchette is associated with the nuclei of late elongating spermatids, and less numerous circular microtubules are observed close to the acrosome complex. The microtubule doublets of the midpiece axoneme are surrounded by a layer of dense staining granular material. The mitochondria of the midpiece abut the proximal centriole resulting in a very short neck region, and possess tubular cristae internally and concentric layers of cristae superficially. A fibrous sheath surrounds only the axoneme of the principal piece. Characters not previously described during spermiogenesis in any other amniote are observed and include (1) an endoplasmic reticulum cap during early acrosome development, (2) a concentric ring of endoplasmic reticulum around the nucleus of early to middle elongating spermatids, (3) a band of endoplasmic reticulum around the acrosome complex of late developing elongate spermatids, and (4) midpiece mitochondria that have both tubular and concentric layers of cristae. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.     

Spermiogenesis in the Marine Shrimp, Sicyonia ingentis

Spermiogenesis in the marine prawn Sicyonia ingentis was examined using transmission electron microscopy. The acrosomal vesicle, derived from the fusion of pro-acrosomal vesicles blebbed from the nuclear envelope, contains the membrane pouches, anterior granule and a spike. The anterior granule is formed from the coalescence of granular aggregates within the proacrosomal vesicles. Primordia underlying the apical acrosomal vesicle membrane polymerize to form a spike approximately 6 μm long. The convoluted pouch membranes arise from the posterior acrosomal vesicle membrane. Lateral and apical portions of the acrosomal vesicle are surrounded by a pentalaminar membrane comprised of the spermatid plasma membrane and the acrosomal vesicle membrane. Subacrosomal structures include the dense saucer plate, granular core and crystalline lattice. These components condense just posterior to the acrosomal vesicle and are separated from the chromatin by a nuclear plate.
The spermatid nucleus becomes surrounded by rough endoplasmic reticulum (RER) and membranous lamellar bodies. RER gives rise to smooth endoplasmic reticulum. These membrane systems degenerate, forming a band of reticular elements around the lateral and posterior portions of the nucleus. The nucleus undergoes condensation followed by decondensation with concomitant breakdown of the nuclear envelope. The resultant chromatin is fibrillar in appearance.     

A transmission electron microscopy investigation: the membrane complex in spermatogenesis of <Emphasis Type="Italic">Fenneropenaeus chinensis</Emphasis>

The transforming characteristics of the membrane complex in spermatogenesis of Fenneropenaeus chinensis have been studied by using transmission electron microscopy. Two types of membrane complex have been investigated based on their sources: one originating from nucleus and the other from cytoplasm. The first one, consisted of annular structures, monolayer membrane blebs, and double or multi-lamellar membrane vesicles, emerges in the primary spermatocyte, then diffuses with the nuclear membrane and finally enters the cytoplasm. This type of membrane complex seems to play an important role in the materials transfusion from nucleus to cytoplasm, and it mainly exists inside the primary spermatocyte with some inside the secondary spermatocyte. The latter, originated from cytoplasm, is formed during the anaphase of spermiogenesis. It also exists in mature sperm, locating at both sides of the nucleus under the acrosomal cap. This type of membrane complex mainly comprises rings of convoluted membrane pouches, together with mitochondria, annular lamina bodies, fragments of endoplasmic reticulum, nuclear membrane and some nuclear particles. It releases vesicles and particles into the acrosomal area during the formation of the perforatorium, suggesting a combined function of the endoplasmic reticulum, mitochondria and Golgi’s mechanism.     

Fine structural study of the spermatogenic cycle in Pitar rudis and Chamelea gallina (Mollusca,Bivalvia, Veneridae)

A comparative ultrastructural study of spermatogenesis was performed in the bivalve molluscs Pitar rudis and Chamelea gallina (Veneridae) from Turkey. Sertoli cells appeared to be rich in glycogen, lipid droplets and germ-cell phagolysosomes. Premeiotic cells exhibited nuage and a flagellum, with the Golgi complex and the rough endoplasmic reticulum originating proacrosomal vesicles during the pachytene stage. In round spermatids, the acrosomal vesicle migrated linked to the plasma membrane. In P. rudis, the acrosomal vesicle base formed a thin expansion that attached to the nuclear apex and was associated with development of the perforatorium. The cap-shaped acrosomal vesicle then differentiated into external and internal regions, and also into a small apical light region, although some cells exhibited an apical extension of the external component. On the contrary, two lateroapical light pouches developed in C. gallina. During spermiogenesis, chromatin became fibrillar and then condensed while the nucleus turned conical shaped in P. rudis or slightly curved in C. gallina. In P. rudis, the midpiece contained glycogen and four mitochondria, although five mitochondria were sometimes observed, whereas in C. gallina the midpiece contained four mitochondria. Comparison with other members of Veneroida shows a common ectaquasperm type, but novel findings in acrosome biogenesis.     

Ultrastructural study of spermiogenesis in a rare desert amphisbaenian Diplometopon zarudnyi

Spermiogenesis, in particular the head differentiation of Diplometopon zarudnyi, was studied at the ultrastructural level by Transmission Electron Microscope (TEM). The process includes acrosomal vesicle development, nuclear elongation, chromatin condensation and exclusion of excess cytoplasm. In stage I, the proacrosomal vesicle occurs next to a shallow fossa of the nucleus, and a dense acrosomal granule forms beneath it. This step commences with an acrosome vesicle forming from Golgi transport vesicles; simultaneously, the nucleus begins to move eccentrically. In stage II, the round proacrosomal vesicle is flattened by projection of the nuclear fossa, and the dense acrosomal granule diffuses into the vesicle as the fibrous layer forms the subacrosomal cone. Circular manchettes surrounded by mitochondria develop around the nucleus, and the chromatin coagulates into small granules. The movement of the nucleus causes rearrangement of the cytoplasm. The nucleus has uniform diffuse chromatin with small indices of heterochromatin. The subacrosome space develops early, enlarges during elongation, and accumulates a thick layer of dark staining granules. In stage III, the front of the elongating nucleus protrudes out of the spermatid and is covered by the flat acrosome; coarse granules replace the small ones within the nucleus. One endonuclear canal is present where the perforatorium resides. In stage IV, the chromatin concentrates to dense homogeneous phase. The circular manchette is reorganized longitudinally. The Sertoli process covers the acrosome and the residues of the cytoplasmic lobes are removed. In stage V, the sperm head matures.     

Spermiogenesis and sperm structure in the crabUca tangeri (Crustacea,Brachyura), with special reference to the acrosome differentiation

Summary Early spermatids of the crabUca tangeri consists of the nucleus of granular chromatin and the cytoplasm, which contains a proacrosomal vesicle in close association with membrane lamellae. In the mid spermatids an invagination of the acrosomal vesicle membrane gives rise to the formation of the perforatorium, a spindle-shaped tubule which encloses tubular membranous structures. The pair of centrioles located at the base of the acrosome is not directly involved in perforatorial differentiation. The acrosomal vesicle shows a heterogeneous content composed of the operculum, the thickened ring, and three layers of different materials concentrically arranged around the perforatorium. During the late spermatid stage the nuclear profile differentiates numerous slender arms and the chromatin arranges into fibers. Membranous tubules from the cytoplasm become incorporated into the tubular structures of the perforatorium. The mature spermatozoon has the typical structure of the branchyuran sperm, with a complex acrosome, cupped by the nucleus, and a thin cytoplasmic band intervening between the former main elements. The centrioles are degenerate. The nuclear arms are unusually numerous (more than 20) and lack microtubules or microtubular derivatives.