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。     

褐菖You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Ｙｏｕ（Ｓｅｂａｓｔｉｓｃｕｓ ｍａｒｍｏｒａｔｕｓ）精细胞的成熟变化和精子结构。褐菖Ｙｏｕ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;染色质浓缩和块状,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     

黄颡鱼(Pseudobagrus fulvidraco)精子的超微结构

黄颡鱼精子由头部、中段和鞭毛(尾部)三部分组成。头部的主要结构是细胞核。核中浓缩了的染色质呈颗粒状。染色质中有核泡存在。核泡中有致密颗粒状物。植入窝里井状,从核后端往前深陷入核的中央。中段的中心粒复合体位于植入窝中,结构独特。近端中心粒和基体首尾相对,排在同一直线上。某些精子的近端中心粒的中央腔中能见到一、二个粗大的颗粒状物。基体的中央腔中有一对中央微管。近端中心粒和基体之间有中心粒间体将两者隔开。中段的袖套连接于细胞核之后,其中分布着线粒体和一些囊泡。近袖套内膜处的细胞质中有一层膜与袖套内膜平行。鞭毛细长,其起始端位于袖套腔中。鞭毛上长有两排侧鳍。侧鳍呈波纹状,分居轴丝两侧,大致与轴丝的两条中央微管同在一个平面上。侧鳍的基部有囊泡。     

家蚕初级精母细胞内四个基体——轴丝复合体(英语)

应用细胞整装制备和穿透电子显微镜技术,在家蚕4龄幼虫睾丸育精囊的初级精母幼胞内检查出四个基体—轴丝复合体结构.呈两对,每对结构是由连结纤维将基体牢固地联结并使其相互成直角排列.生长的复合体呈现出丰满的远心端膨大.在此阶段,轴丝是由9个具有马达蛋白臂的双微管组成,缺乏辐射轴和两个中央单微管.在基体的三联体微管和轴丝的双微管的接合点,观察到连结节.     

昆虫精细胞内中心粒附体的来源和作用

本研究应用界面铺浮和超薄切片技术,观察了东亚飞蝗(Locusta migratoria manilensis)和七星瓢虫(Coccinella siptempunctata L.)精细胞内中心粒附体(CA)的形成和作用。结果发现,作为电子致密体的CA前体和原顶体颗粒出现在副核和细胞核之间区域。随后,这个主要是由约300 A颗粒组成的CA前体附着在核膜,核内、外膜加厚。在副核分化成两个线粒体衍生物或稍早些时刻,近心中心粒移向CA并嵌入。中心粒镶嵌到校膜上发育成基体,由此生长出轴丝来。随着精细胞的延长, CA的形状也跟着转变和伸长。 250-300A染色质纤维沿精细胞长纵轴连接在CA结构的基部。 当精细胞核向长形转变时,染色质纤维解旋并结合在一起形成缎带结构。因此,可以设想cA是作为暂时性细胞器在组织精细胞内,染色质纤维重新组织排列和指导中心粒移向精细胞核的特定区域中起作用。     

黄姑鱼（ Nibea albiflora） 与大黄鱼（ Pseudosciaena crocea） 精子超微结构的观察与比较

应用扫描电镜（SEM）与透射电镜（TEM）观察了黄姑鱼和大黄鱼精子的超微结构。结果显示,黄姑鱼和大黄鱼精子无论在形态、大小还是超微结构上都十分相似。黄姑鱼和大黄鱼精子均由头部、中段和尾部（鞭毛）3部分组成。精子头部形状近似椭圆形,无顶体,细胞核呈肾形。中心粒复合体位于细胞核背侧,近、远端中心粒相互垂直,远端中心粒分化成基体并形成轴丝。中段的袖套呈筒状,4～5个圆形的线粒体围绕轴丝呈环形排列。精子尾部为单鞭毛,轴丝为典型“9＋2”结构,鞭毛表面质膜形成不规则侧鳍。     

宽体沙鳅精子超微结构及Na~+、K~+、Ca~(2+)对其精子活力的影响

选取健康的性成熟雄性宽体沙鳅,运用JSM 6510LV型扫描电镜、H-7500型透射电镜及Motic-BA210数码显微镜分别观察了宽体沙鳅精子的超微结构及不同浓度Na~+、K~+、Ca~(2+)对其精子活力的影响。结果显示,宽体沙鳅精子头部圆球形,无顶体,细胞核后端有一植入窝凹陷,凹陷深度为细胞核长径的1/6。中片由中心粒复合体和袖套组成。中心粒复合体分为近端中心粒和基体,两者呈"L"型排列;袖套呈两侧不对称分布,一侧狭长,另一侧肥厚。尾部主要由轴丝组成,为典型的"9+2"型双联微管结构,微管动力蛋白臂明显。以Na Cl、KCl和Ca Cl_2浓度分别为75 mmol·L~(-1)、0.5 mmol·L~(-1)和5 mmol·L~(-1)作为宽体沙鳅精子的激活介质,效果最佳。建议实际生产中选取合适的激活介质进行人工授精。     

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.     

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。     

扩张莫尼茨绦虫(圆叶目:裸头科)精细胞分化、精子形成及精子形态

本项研究应用光学显微镜、扫描和透射电子显微镜,观察了扩张莫尼茨绦虫的精细胞分化、精子形成全过程及精子的精细结构。扩张莫尼茨绦虫的精细胞分化过程为：1)初级精原细胞主要发生于幼节的睾丸滤泡中;2)次级精原细胞发生不完全分裂形成16个细胞一簇的初级精母细胞群,以共同的中央细胞质相连;3)初级精母细胞的特征为细胞核中出现联会复合体结构;4)紧接着的第二次成熟分裂,产生64个由中央细胞质相连的细胞核较小的精细胞。精子形成始于精细胞中分化区的形成,成熟精子缺乏线粒体,具有质膜和冠状体、1—4个领域排布的质膜下皮层微管,细胞质中存在电子致密的颗粒状物质,具一个不规则形态的细胞核,具有“9 1”类型的轴丝构造,缺乏轴丝周围鞘。从精子的纵切面上可将精子区分为5个区段(Ⅰ一Ⅴ区)。在精子形成过程中,中心粒基部出现螺旋形小根结构在寄生虫中为首次报导;成熟精子具有游离鞭毛,在绦虫中为首次发现[动物学报49(3)：370—379,2003]。     

MORPHOGENESIS OF THE AXONEME IN THE SPERMATOCYTE OF COCCINELLA SEPTEMPUNCTATA LINNAEUS

Abstract  Using cell whole mount preparation, early morphogenesis and ultrastructure of the axoneme of Coccinella septempunctata L. spermatocyte were investigated by transmission electron microscope. During spermatogenesis two pairs of basal body-axoneme complexes originated from centrioles are found in the spermatocyte and they are separated completely from each other at interkinesis. The centriolar adjunct begins to generate while a basal body-axoneme complex is attached to the nuclear envelope of a spermatid nucleus, and it, on the proximal end of a growing axoneme, reaches a maximum before chromatin condensation. The growing axoneme is accompanied by the condensable nucleus elongation. The early axoneme of a basal body-axoneme complex consists nine doublets with only inner and outer dynein arms, no central microtubules.     

TETRAD BASAL BODY-AXONEME COMPLEXES IN THE PRIMARY SPERMATOCYTE OF THE SILKWORM, BOMBYX MORI

Abstract  Using cell whole mount preparation, tetrad basal boby-axoneme complexes in the primary spermatocyte from testicular cysts of fourth instar larvae of Bombyx mori are examined by transmission electron microscopy. There exist two paired basal body-axoneme complexes and the two orthogonally oriented basal bodies are linked together with distal and proximal linking fibers. The growing complex displays voluminous distal swelling. At this stage, the axoneme consists of nine microtubular doublets. A connecting nodule is found at the juncture of basal body's triplet and axoneme's doublet, and the A and B tubules of the former continue through the nodule to become the ones of the latter.     

大黄鱼精子的超微结构

大黄鱼的精子由头产和尾部两部分组成。头部结构较为独特,其腹侧有一较大的细胞核,背部有中心粒复合体。头部的后端是袖套。细胞核的腹面稍向外突出背面则稍向内凹。细胞核中的染以质浓缩成致密的团块状。团块状的染色质之间分布着松散的纤维状染色质。植入窝位于细胞核的背部表面,由细胞核背面向内凹陷而成,呈一沟状,其走向与精子的长轴平行。     

SPERMIOGENESIS OF THE TELEOST,ORYZIAS LATIPES,WITH SPECIAL REFERENCE TO THE FORMATION OF FLAGELLAR MEMBRANE *

In the early stage of Oryzias spermiogenesis, an axonemal bud appears at the distal end of a centriole characterized by its electron dense accessories. When the axoneme begins to grow in the cytoplasm, small vesicles come to surround it. These vesicles are similar to those produced by the Golgi apparatus which lies close to the growing axoneme. At this stage, the spermatid cell membranes disappear, causing transformation of the mononuclear spermatids into a multinucleated syncytium. As each axoneme elongates in the syncytium, it is enveloped by a cylindrical array of vesicles which are most likely derived from the Golgi apparatus. Shortly after this stage, the syncytium is again partitioned by cell membranes, restoring the existence of mononuclear spermatids. The arrayed vesicles fuse with each other to form two concentric membranes surrounding the axoneme. The inner membrane becomes the flagellar membrane and the outer one, the membrane of a flagellar sheath. These observations lead to the conclusion that the formation of the flagellar membrane is due to the fusion of vesicles surrounding the axoneme which are derived from the Golgi apparatus. In the course of spermiogenesis, no indication of an acrosomal structure is observed.     

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     

OBSERVATIONS ON THE CENTRIOLES OF THE SEA URCHIN SPERMATOZOON

The spermatozoon of Lytechinus variegatus has two parallel centrioles. The basal body of the flagellum consists of the proximal centriole (a short cylinder of nine tubule-triplets) and its distal extension of nine tubule-doublets. The distal centriole lies near the distal end of the basal body, between the nucleus and the mitochondrion. The observations suggest that both the proximal and the distal centrioles are polarized structures, their tubule-triplets pitched in the same direction and their distal ends associated with the flagellar axoneme and with the mitochondrion, respectively. The distal centriole in different spermatozoa occupies different positions around the basal body-flagellum complex.     

SPERMIOGENESIS IN THE PULMONATE SNAIL, EUHADRA HICKONIS IV. EFFECT OF X-RAYS ON THE SPERMIOGENESIS

When animals were irradiated early in spermiogenesis, i. e. , at the spherical nucleus stage (7), two or more flagella were observed to be formed in many cells at the subsequent stages. Other irradiation effects included the absence of cytoplasmic microtubules at an early stage followed by their excessive production later during formation of the flagellum, the abnormalities in structure of the mitochondrial sheath around the axoneme, and the extremely disordered arrangement of flagellar components. However, the basal body and axoneme showed a normal structure at all stages, and acrosome development appeared to be unaffected by the irradiation.