蓝尾石龙子精子的超微结构

蓝尾石龙子(Eumeces elegans)附睾以2．5％戊二醛和1％锇酸双重固定,按常规制作超薄切片,用H-600透射电镜研究观察精子的超微结构。精子由头部和尾组成,头部由顶体复合体和核组成,尾由颈段、中段、主段和末段组成。头部的顶体囊前部扁平,分为皮质和髓质,顶体下锥由类结晶状的顶体下物质组成,穿孔器顶端尖,、穿孔器基板塞子状,细胞核延长,核内小管缺,核伸展部前端具一电子透明区,核肩圆,核陷窝锥形。颈段具片层结构,近端中心粒和远端中心粒的长轴呈直角,9束外周致密纤维与远端中心粒相应的9束三联微管相联,向后与轴丝相应的9束双联微管相联,中央纤维与2个中央单微管相联。中段短,含有线状嵴的柱状线粒体,由连续的规则小卵状或小梯形致密体组成线粒体间的环状结构,纤维鞘伸入中段,终环紧贴于细胞膜的内表面。线粒体与环状结构的模式为：rs1／mi1,rs2／mi2,rs3／mi3,rs4／mi4,横切面上每圈线粒体数目为10个。主段前面部分具薄的细胞质颗粒区。纤维3和8至主段前端消失。轴丝复合体呈“9 2”型。蓝尾石龙子精子超微结构与已描述的石龙子科种类比较发现,与蜓蜥群和胎生群的石龙子相似;但没有发现石龙子科精子的独征。     

北草蜥精子的超微结构--兼评不同类群蜥蜴精子形态的差异

应用透射电镜对北草蜥精子的超微结构研究结果表明,北草蜥精子头部顶体囊始终呈圆形,由皮质和髓质组成;顶体囊单侧脊的皮质与髓质问具电子透亮区;穿孔器1个,无穿孔器基板;具顶体下腔;细胞核长形,核内小管缺,核前电子透亮区缺,核肩圆。尾部颈段具片层结构。中段短,多层膜结构缺;纵切面上具2层线粒体;横切面上每圈线粒体6个;2组致密体,具连续的环状结构;线粒体与环状结构的排列模式：rs1／mi1、rs2／mi2;纤维鞘伸人中段,具终环。主段前面部分具薄的细胞质颗粒区;纤维3和8至主段前端消失;轴丝呈“9＋2”型。蜥蜴科内不同种类的线粒体数目不同,但都具有2组致密体。不同类群蜥蜴的顶体囊、顶体下腔、核前电子透亮区、穿孔器基板、核肩,以及线粒体与致密体的数目和排列方式等精子超微结构特征都为研究蜥蜴的系统发生提供了辅助信息。     

Ultrastructure of the spermatozoon of the American Alligator,Alligator mississippiensis (Reptilia: Alligatoridae)

This study details the ultrastructure of the spermatozoa of the American Alligator, Alligator mississippiensis. American Alligator spermatozoa are filiform and slightly curved. The acrosome is tapered at its anterior end and surrounded by the acrosome vesicle and an underlying subacrosomal cone, which rests just cephalic to the nuclear rostrum. One endonuclear canal extends from the subacrosomal cone through the rostral nucleus and deep into the nuclear body. The neck region separates the nucleus and midpiece and houses the proximal centriole and pericentriolar material. The distal centriole extends through the midpiece and has 9 × 3 sets of peripheral microtubules with a central doublet pair within the axoneme that is surrounded by a dense sheath. The midpiece is composed of seven to nine rings of mitochondria, which have combinations of concentrically and septate cristae. The principal piece has a dense fibrous sheath that surrounds an axoneme with a 9 + 2 microtubule arrangement. The sheath becomes significantly reduced in size caudally within the principal piece and is completely missing from the endpiece. Dense peripheral fibers, especially those associated with microtubule doublets 3 and 8, penetrate into the anterior portion of the principal piece axoneme. The data reported here hypothesize that sperm morphology is highly conserved in Crocodylia; however, specific morphological differences can exist between species. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.     

中国石龙子成熟精子的超微结构

利用透射电镜观察中国石龙子附睾成熟精子的超微结构。顶体囊前部扁平、由皮质和髓质组成 ,穿孔器中度倾斜、顶端尖 ,穿孔器基板塞子状 ,细胞核长形 ,核内小管缺 ,核前电子透亮区小 ,核肩圆 ,核陷窝锥形。颈段具片层结构 ,近端中心粒和远端中心粒的长轴呈直角 ,9束外周致密纤维与远端中心粒相应的 9束三联微管相联 ,向后与轴丝相应的 9束双联微管相联 ,中央纤维与 2个中央单微管相联。中段短 ,多层膜结构缺 ,含有线状嵴的柱状线粒体 ,不规则卵状致密体组成不连续的环状结构 ,纤维鞘伸入中段 ,具终环。线粒体与环状结构的模式为 :rs1 /mi1 ,rs2 /mi2 ,rs3/mi3,rs4 /mi4。主段前面部分具薄的细胞质颗粒区。纤维 3和 8至主段前端消失。轴丝呈“9 2”型。中国石龙子精子超微结构具有塞子状的穿孔器基板、致密体形成不连续的环状结构和纤维鞘始于ms2等特征与巨石龙子群和蜓蜥 -胎生群不同。没有发现石龙子科精子的独征     

Descriptions of the mature spermatozoa of the lizards Crotaphytus bicinctores, Gambelia wislizenii (Crotaphytidae), and Anolis carolinensis (Polychrotidae) (Reptilia, Squamata, Iguania)

The spermatozoa of Crotaphytus bicinctores and Gambelia wislizenii (Crotaphytidae), and Anolis carolinensis (Polychrotidae) exhibit the squamate autapomorphies of a single perforatorium extending anteriorly from the apical tip of the paracrystalline subacrosomal cone, the presence of an epinuclear electron-lucent region, and extension of the fibrous sheath into the midpiece. Crotaphytid sperm differ from those of polychrotids in several respects, including: the structure of the perforatorium, the size of the epinuclear electron-lucent region, aspects of the acrosome complex, the arrangement and structure of intermitochondrial dense bodies, and in the distance the fibrous sheath extends into the midpiece. The sperm of C. bicinctores, G. wislizenii, and A. carolinensis are most similar to those of the agamids and phrynosomatids examined to date. No spermatozoal autapomorphies for Crotaphytidae or Polychrotidae were found. The condition of having the intermitochondrial dense bodies arranged in regular incomplete rings is tentatively defined as a synapomorphy of Iguania (although modified in Chamaeleonidae). Spermatozoal ultrastructure offers no characters that justify the separation of Iguanidae (sensu lato) into several separate families.     

两种石龙子精子超微结构的比较

利用透射电镜研究多线南蜥和印度蜓蜥附睾精子的超微结构。两种卵胎生石龙子的精子具有一些有鳞类精子的共同特征,即具有顶体囊、顶体下锥、单个核前穿孔器和核喙,无核内管,纤维鞘伸入中段,与双联微管3和8相邻的外周致密纤维具双份纤维结构。多线南蜥和印度蜓蜥精子超微结构的种间差异主要表现在:多线南蜥精子核前方的顶体下锥电子密度较小,顶体囊具单侧嵴,横切面上可见非连续的致密体环或11个线粒体;印度蜓蜥无单侧嵴,横切面上可见连续的致密体环或12个线粒体。迄今未发现石龙子科精子的独征,但该科不同类群的顶体囊、顶体下腔、核前方的顶体下锥电子致密程度、核肩、纵切面线粒体与致密体的排列方式、横切面致密体环形状和线粒体等精子超微结构特征有一定程度的差异。这些差异可为研究石龙子科系统发生提供辅助信息。     

The Ultrastructure of the Spermatozoa of Squamata—I. Scincidae,Gekkonidae and Pygopodidae (Reptilia)

Abstract Squamate autapomorphies seen in sperm of the Scincidae (e.g. Ctenotus robustus, Carlia pectoralis, Cryptoblepharus virgatus, and Lampropholis delicata) are penetration of the fibrous sheath of the axoneme into the midpiece, and the paracrystalline subacrosomal cone. Sphenomorphus group spermatozoa (e.g. Ctenotus) and the Egernia group (Tiliqua) differ from the more derived Eugongylus group (C. virgatus, L. delicata and C. pectoralis) in that the acrosome is elongate and apically depressed; the perforatorium is strongly oblique; the midpiece is relatively short, with four dense ring structures in longitudinal succession; mitochondria are columnar; and enlarged peripheral fibres 3 and 8 do not show the gross anterior enlargement seen in Carlia and Lampropholis. Heteronotia binoei (Gekkonidae) sperm have no epinuclear electron-lucent region; nuclear shoulders are smooth, as in sphenomorph but not Eugongylus group skinks; mitochondria are columnar; unlike skinks, the median surfaces of the mitochondria are indented by triangular, sometimes longitudinally, interconnected dense bodies. In Lialis burtonis (Pygopodidae) sperm, the perforatorium extends virtually to the tip of the fore-shortened apically domed acrosome; nuclear shoulders are absent; the mitochondria alternate singly or in groups with one or more dense bodies which also form an interrupted collar around the distal centriole. Spermatozoal ultrastructure suggests that a common ancestry of snakes and pygopods deserves consideration.     

The ultrastructure of the spermatozoa of Epipedobates flavopictus (Amphibia,Anura, Dendrobatidae), with comments on its evolutionary significance

We describe, for the first time, the spermatozoon ultrastructure of a dendrobatid frog, Epipedobates flavopictus. Mature spermatozoa of E. flavopictus are filiform, with a moderately curved head and a proportionally short tail. The acrosomal vesicle is a conical structure that covers the nucleus for a considerable distance. A homogeneous subacrosomal cone lies between the acrosome vesicle and the nucleus. The nucleus contains a nuclear space at its anterior end, and electron-lucent spaces and inclusions. No perforatorium is present. In the midpiece, the proximal centriole is housed inside a deep nuclear fossa. Mitochondria are scattered around the posterior end of the nucleus and inside the undulating membrane in the anterior portion of the tail. In transverse section the tail is formed by an U-shaped axial fiber connected to the axoneme through an axial sheath, which supports the undulating membrane. The juxta-axonemal fiber is absent. The spermatozoon of E. flavopictus has several characteristics not observed before in any anurans, such as a curved axial fiber, absence of a juxta-axonemal fiber, and presence of mitochondria in the typical undulating membrane. Our results endorse the view that, in anurans, the conical perforatorium and subacrosomal cone are homologous and that Dendrobatidae should be grouped within Bufonoidea rather than Ranoidea.     

Silver-staining patterns of mammalian epididymal spermatozoa

Epididymal spermatozoa from 12 species of mammals were stained using silver nitrate and examined with the light microscope. Silver nitrate differentiates many of the gross morphological features of spermatozoa, including the acrosome, subacrosomal region, perforatorium, postacrosomal sheath, neck, dense outer fibers of the core of the midpiece, annulus, principal piece, and end piece. Silver-staining patterns of spermatozoa reveal both species-specific and strain-specific differences, particularly of the sperm head. The biochemical basis of silver staining may be due in part to the presence of sulfhydryl- and disulfide-rich proteins; however, it cannot be explained entirely by the presence of these moieties. The detail obtained using silver nitrate staining, coupled with the ease and rapidity of the procedure, should be useful to workers in many areas of biological and medical research.     

Ultrastructure of the Spermatozoon of an Opisthobranch, Tornatina sp. (Mollusca, Gastropoda, Retusidae)

The spermatozoon of Tornatina sp. has been studied with phase-contrast light microscopy and transmission electron microscopy. The head of the spermatozoon consists of an elongate acrosome which caps the apex of an unusually complex, helical nucleus. This elaborate nuclear morphology has not been previously reported, but possibly is found in other opisthobranch gastropod spermatozoa. An axoneme is inserted deeply into the base of the nucleus whilst posterior from the nucleus, the axoneme is ensheathed successively by the mitochondrial derivative (midpiece) and 'glycogen' granules (glycogen piece). The midpiece exhibits fine structure similar to that observed in other euthyneuran spermatozoa (paracrystalline and matrix materials) and possesses a single helical compartment filled with what are probably glycogen granules. A dense ring structure occurs at the junction of the midpiece and glycogen piece. The spermatozoon of Tornatina and other gastropods (prosobranch and euthyneuran) are compared.     

文昌鱼精子的超显微结构

文昌鱼(Branchiostoma belcheri tsingtaoensis)的成熟精子由一个锥形的顶体,头部,颈(被核包裹)和尾部组成。尾可分为中段,主段和末段。微管对复合体为9+2。 文昌鱼精子的超显微结构与前人报道的线粒体由4—6个组成的不同。它由一个大的线粒体围绕尾主轴中段,而且精子属于对称性类型,可以见到核内管,中心粒和致密纤维,终环结构与隐窝位于尾中段与主段之间。本文并对文昌鱼在系统发生中的重要位置和意义作了讨论。     

An ultrastructural examination of developing and mature euspermatozoa in pyrazus ebeninus (Mollusca,Gastropoda, Potamididae)

Summary Mature and developing euspermatozoa of the prosobranch gastropod Pyrazus ebeninus, have been examined using transmission electron microscopy and phase-contrast light microscopy. The head of the mature euspermatozoon consists of a conical acrosome capping a short, rod-shaped nucleus (laterally compressed posteriorly). A basal invagination in the nucleus contains the proximal portion of the axoneme and a dense attachment matrix. Four apparently non-helical mitochondrial elements (two large, two small) comprise the midpiece each being composed of curved, inclined cristal plates and a granular matrix. The structure and arrangement of the mitochondrial elements is thus distinguishable from the helical midpiece elements found in euspermatozoa of neogastropods and most mesogastropods and possibly is widespread in the Cerithiacea. A dense ring-like structure is found closely applied to the inside of the plasma membrane at the junction of midpiece and glycogen piece.Acrosome and midpiece formation and nuclear condensation have been studied in developing euspermatozoa. Acrosome development is divided into two phases: (1) a pre-attachment phase — during which a complex early acrosome is formed often at great distance from the nuclear apex, and (2) an attachment/post-attachment phase — during which the completed preattachment phase acrosome tilts into position at the nuclear apex and subsequently elongates. The nucleus passes through a recognizable sequence of condensation phases (reticular, fibrillar and lamellar phases). Microtubules surround both the nucleus and midpiece in the final phase of maturation. The four, elongate midpiece elements of the mature euspermatozoon are apparently derived from the four large, spherical mitochondria of the euspermatid.The potential usefulness of spermatozoal ultrastructure with regard to indicating affinities between groups of gastropod families is briefly discussed.Abbreviations a acrosome - ac euspermatozoon acrosomal cone - ar euspermatozoon axial rod - ax axoneme - bp basal plate - cy cytoplasmic droplet - cs cylindrical support structures of developing acrosome - dg dense granule of pre-attachment phase developing acrosome - dp dense plates of developing acrosomal cone - g glycogen granules - gp glycogen piece - G Golgi complex - j junction of midpiece and glycogen piece - l large midpiece element - m mitochondrion - M midpiece - mt microtubules - n nucleus - pm plasma membrane - sGv small Golgi vesicles - s small midpiece element     

Ultrastructure of the spermatozoon of <Emphasis Type="Italic">Talpa romana</Emphasis> (Mammalia,Lipotyphla)

In this study, we used SEM and TEM to investigate the ultrastructure of spermatozoa from the cauda epididymis of Talpa romana. For comparison, we also analysed spermatozoa from the cauda epididymis of T. europaea captured in the same area. The male gamete of T. romana has a flattened head with an elliptic profile, consisting of a large acrosome and a nuclear region separated by a thin subacrosomal space. At the tip of the nucleus, the subacrosomal space ends in a finger-shaped projection. The tail includes a connecting piece, middle piece, principal piece and end piece. The male gametes of T. romana are substantially similar to those of T. europaea. A comparison with other species of insectivores permits extension of the similarity of sperm features to Scalopus aquaticus and Condylura cristata. Many spermatozoa from the cauda epididymis of T. romana and T. europaea have the tail bent at the annulus, and this is always associated with remnants of cytoplasmic droplets. This morphology is considered to be a common phenomenon.     

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.     

The evolution of sperm ultrastructure among Boidae (Serpentes)

We investigate the evolution of sperm ultrastructure of three species of Boidae (Epicrates cenchria, Boa constrictor amarali, and Corallus hortulanus). Spermatozoa of these species are filiform consisting of a head region, containing the nucleus and acrosome complex, a midpiece, and a tail region subdivided into principal piece and endpiece. Multilaminar membranes and extracellular microtubules were observed next to the plasma membrane of the spermatozoa. The following differences were observed among the species: ridge on acrosome surface in Boa constrictor amarali (absent in Epicrates cenchria and Corallus hortulanus), stopper-like perforatorium base plate in Boa constrictor amarali and Epicrates cenchria (absent in Corallus hortulanus), rounded mitochondria in transverse section in Epicrates cenchria and Corallus hortulanus (irregular in Boa constrictor amarali). We mapped sperm characters onto two phylogenies based on morphological (Kluge in Misc Publ Mus Zool Univ Michigan 178:1–58, 1991) and molecular (Austin in Copeia 2:341–352, 2000) data, using a number of squamate species as outgroups. We identified 31 unambiguous character transformations in the morphological phylogeny and 30 in the molecular phylogeny, but only 13 and 12 transformations, respectively, are possible synapomorphies. We identified novel sperm synapomorphies, which were common between the morphological and molecular phylogenies: absence of perforatorium base plate and mitochondria arranged as sinuous tubes in oblique section (Serpentes), acrosome vesicle not subdivided and fibers 3 and 8 at the anteriormost region of principal piece (Boidae), and absence of an electron dense structure inside the proximal centriole (Elapidae + Colubridae). Our results suggest greater agreement between sperm ultrastructure and gross anatomical characters. In addition, we found no tendency for more homoplasies in the sperm head than in the flagellum, as recorded in previous studies.     

Ultrastructure of the spermatozoon of Apus apus (Linnaeus 1758), the common swift (Aves; Apodiformes; Apodidae), with phylogenetic implications

The spermatozoon of Apus apus is typical of non‐passerines in many respects. Features shared with palaeognaths and the Galloanserae are the conical acrosome, shorter than the nucleus; the presence of a proximal as well as distal centriole; the elongate midpiece with mitochondria grouped around an elongate distal centriole; and the presence of a fibrous or amorphous sheath around the principal piece of the axoneme. The perforatorium and endonuclear canal are lost in A. apus as in some other non‐passerines. All non‐passerines differ from palaeognaths in that the latter have a transversely ribbed fibrous sheath whereas in non‐passerines it is amorphous, as in Apus, or absent. The absence of an annulus is an apomorphic but homoplastic feature of swift, psittaciform, gruiform and passerine spermatozoa. The long distal centriole, penetrating the entire midpiece, is a remarkably plesiomorphic feature of the swift spermatozoa, known elsewhere only in palaeognaths. The long centriole of Apus, if not a reversal, would be inconsistent with the former placement of the Apodiformes above the Psittaciformes from DNA–DNA hybridization. In contrast to passerines, in A. apus the microtubules in the spermatid are restricted to a transient single row encircling the cell. The form of the spermatozoon fully justifies the exclusion of swifts from the passerine family Hirundinidae.     

Interspecific Variation in Structural Organisation of the Spermatozoon in the Asian Bandicoot Rats,Bandicota Species (family Muridae)

The structural organisation of the spermatozoon from two species of bandicoot rats Bandicota bengalensis and Bandicota indica was investigated by light and electron microscopy together with the effect of incubation in Triton-X 100 and sodium dodecyl sulphate. The sperm head of B. bengalensis is invariably falciform, has a uniform electron-dense nucleus capped by an acrosome with a posteriolateral equatorial segment, a subacrosomal cytoskeleton with a large rostral perforatorium, and a sperm tail, attached to the lower concave surface of the sperm head, with typical coarse fibres and fibrous sheath. By contrast, the sperm head shapes of B. indica are generally conical or bulbous, the nucleus contains a few large vacuoles, the acrosome lacks an equatorial segment, no recognisable perforatorium occurs, and the sperm tail, which is attached basally, is very short with only modest development of coarse fibres and fibrous sheath. These results indicate that, within the genus Bandicota, huge interspecific differences in morphology of the spermatozoon have evolved. The spermatozoa of B. bengalensis are similar to those of Rattus and many other murids and thus presumably represent the ancestral condition, whereas those of B. indica (and B. savilei) are unlike spermatozoa from any other eutherian mammal so far described. © 1998 The Royal Swedish Academy of Sciences. Published by Elsevier Science Ltd. All rights reserved