两种草螽精子超微结构比较研究(直翅目,螽斯总科)

比较研究了长翅草螽Conocephalus longipennis与鼻优草螽Euconocephalus nasutus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;轴丝为典型的9 9 2型;轴丝两侧的副纤维结构前者为2副体,后者为2副微管;线粒体衍生体横切面前者为鞋履形,后者卵圆形;轴丝与线粒体衍生体之间的连接带前者为5条,后者3条;近线粒体衍生体的两扁平膜池在长翅草螽中连接在一起呈飞燕形。     

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。     

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.     

家鸽睾丸精子超微结构的观察

家鸽(Columbadomestica)精子分为头部、颈部及尾部。尾部又区分为中段、主段及末段。头部呈圆柱形,主要被精细胞核占据,核的前面包绕顶体,后端连接颈部。颈部有两个中心粒,与头部相邻接的是与精子纵轴垂直的近侧中心粒,远侧中心粒形成基底体向后发出尾部的轴丝。轴丝的结构为9+2型。中段在轴丝之外有线粒体鞘包绕,最外面为质膜。主段和末段无线粒体鞘,轴丝之外直接被以质膜。     

墨西哥湾扇贝精子的超微结构

报道了墨西哥湾扇贝成熟精子在SEM和TEM下的超微结构观察结果。墨西哥湾扇贝的精子为典型的原生型,精子全长约43～45μm,头部长约2．1～2．4μm。精子主要由头部、中段和尾部三部分组成。头部顶体明显突出,呈倒V形;顶体下方为细胞核,细胞核近似卵圆形。在细胞核内部或边缘,能观察到有一个或几个形状较为规则的核泡。中段的主要结构有线粒体和中心体,中段的横切面有4个线粒体围绕在中心体的周围。尾部细长,尾部鞭毛横切面为典型的“9 2”结构。     

毛蚶与青蚶精子超微结构及其所反映的蚶科进化关系

应用透射电镜技术,比较研究了毛蚶与青蚶精子的超微结构。毛蚶精子顶体为圆锥形,约为核长的1／2;精核无核前窝,具核后窝;中段横切面常见5个(偶见4个)线粒体环绕于中心粒周围;精子末段由轴丝及包绕轴丝的质膜组成,轴丝为典型的“9 2”结构。青蚶精子顶体轴向纵切面呈伞状,覆盖于细胞核前端,约为核长的1／3;精核具核前窝和核后窝;中段横切面常见有5个(偶见6个)线粒体环绕于中心粒周围;末段结构同毛蚶。顶体的形态、核前窝和核后窝的有无、中段线粒体的数量等是探索蚶科动物种间进化关系的线索。     

韦氏鳞(虫八)的精子结构(双尾目)

韦氏鳞(虫八)(Lepidocampa weberi)精子为细长的鞭毛精子,成束排列成精索。顶体由三层结构组成;核圆柱形,接于顶体后;鞭毛轴丝微管式为“9+9+2”,9条副微管排列不整齐,集中于轴丝的一侧;两条细长的线粒体衍生物位于顶体、核与轴丝之间,贯穿于精子中部;精子尾部围有大量片层结构。结果表明韦氏鳞(虫八)精子与康(虫八)精子较为接近,但可能比康(虫八)精子更为特化。     

赤眼蜂属(Trichogramma)精子的超微结构研究

利用透射电子显敢镜研究了赤眼蜂属的松毛虫赤眼蜂和玉米螟赤眼蜂精子的超微结构。精子呈线形,由头部、颈部和尾部组成。头部前端的顶体较小,为梭形,顶端稍有弯曲,它和核呈楔状拼接排列。颈部的中心粒以45°方向斜插入核内,在中心粒的外周不被中心粒侧体所包围。尾部的轴丝为9+9+2型。在副微管之间有九条粗纤维存在。一对线粒体衍生物内的晶体物质不明显。两种赤眼蜂的精子结构差异很小,松毛虫赤眼蜂精子尾部轴丝结构部分的九个链头之间没有横向联系,而在玉米螟赤眼蜂上能清楚见到。     

韦氏鳞(虫八)的精子结构(双尾目)

韦氏鳞(虫八)(Lepidocampa weberi)精子为细长的鞭毛精子,成束排列成精索.顶体由三层结构组成;核圆柱形,接于顶体后;鞭毛轴丝微管式为“9+9+2”,9条副微管排列不整齐,集中于轴丝的一侧;两条细长的线粒体衍生物位于顶体、核与轴丝之间,贯穿于精子中部;精子尾部围有大量片层结构.结果表明韦氏鳞(虫八)精子与康(虫八)精子较为接近,但可能比康(虫八)精子更为特化.     

川陕哲罗鲑精子超微结构及形态学研究

对川陕哲罗鲑Hucho bleekeri Kimura精子采用扫描电子显微镜及透射电子显微镜进行观察,结果显示:精子由头部、中片和尾部组成;精子全长41.07μm±2.18μm,头部长2.76μm±0.15μm,头部前端和后端的宽度分别为1.88μm±0.18μm和2.08μm±0.20μm;尾部长34.74μm±5.01μm。头部呈卵圆形,无顶体,主要由细胞核组成;中片由1个不规则的圆球状线粒体及袖套结构组成;线粒体直径为0.82μm±0.08μm;尾部呈细长形,并由一个过渡区域分为前端和末端,尾部内部主要由轴丝组成,轴丝为典型的"9+2"结构,外部有不对称性分布的侧鳍结构。结果表明,川陕哲罗鲑精子类型较为原始,属于硬骨鱼类中的TypeⅠ类型。     

Sperm structure of Mecoptera and Siphonaptera (Insecta) and the phylogenetic position of<Emphasis Type="Italic"> Boreus hyemalis</Emphasis>

Sperm ultrastructure has been studied in three species of the taxa Mecoptera and Siphonaptera. The spermatozoon of the scorpion fly Panorpa germanica shows an apical bilayered acrosome, a helicoidal nucleus, a centriolar region and a 9+2 flagellar axoneme helicoidally arranged around a long mitochondrial derivative. A second mitochondrial derivative is very short and present only in the centriolar region. A single accessory body is present and it is clearly formed as a prolongation of the centriole adjunct material. Two lateral lamellae run parallel to the nucleus. The snow fly Boreus hyemalis has a conventional sperm structure and shows a bilayered acrosome, a long nucleus, a centriolar region, two mitochondrial derivatives and two accessory bodies. The axoneme is of the 9+2 type and is flattened at the tail tip. Both P. germanica and B. hyemalis have two longitudinal extra-axonemal rods and have a glycocalyx consisting of longitudinal parallel ridges or filaments. The spermatozoon of the flea Ctenocephalides canis has a long apical bilayered acrosome, a nucleus, a centriolar region, a 9+2 axoneme wound around two unequally sized mitochondrial derivatives, and two triangular accessory bodies. In the posterior tail end the flagellar axoneme disorganises and a few microtubular doublets run helicoidally around the remnant mitochondrial derivative. The glycocalyx consists of fine transverse striations. In all three species, the posterior tail tip is characterised by a dense matrix embedding the disorganised axoneme. From this comparative analysis of the sperm structure it is concluded that Mecoptera, as traditionally defined, is monophyletic and that B. hyemalis is a member of Mecoptera rather than of Siphonaptera.     

Comparative spermatology in Plecoptera (Insecta): an ultrastructural investigation on four species

The ultrastructure of spermatozoa of four Plecoptera species, Leuctra fusca Linnaeus, Brachyptera risi (Morton), Taeniopteryx stankovitchi Ikonomov, T. kuehtreiberi (Aubert), was investigated by light microscopy, scanning and transmission electron microscopy, and immunofluorescence microscopy. The spermatozoa of all the species have a complex acrosome, are filiform and flagellate, with a '9+9+2' axoneme flanked by two mitochondrial derivatives. However, the structure shows a certain interspecific heterogeneity. L. fusca has a short conical nucleus in the apical position and an axoneme flanked by two accessory bodies. In the sperm of the Taeniopterygidae, the nucleus is a long cylindrical body which lies between the two mitochondrial derivatives flanking the axoneme for most of its length. Our results suggest a close phylogenetic affinity between Plecoptera and the other orders of Polyneoptera, although the proposed sister-group relationship between Plecoptera and Embioptera cannot be confirmed.     

Ultrastructural studies on euspermatozoa and paraspermatozoa in Mantispidae (Insecta, Neuroptera)

Previous studies have demonstrated the presence of sperm dimorphism in the Mantispidae Perlamantispa perla. We extended the study on several other mantidflies. In all the examined species the occurrence of euspermatozoa (typical) and paraspermatozoa (atypical) was established. The euspermatozoa are characterized by the presence of a cylindrical nucleus surrounded by an envelope that fans out laterally into two thin wings of different length. The acrosome seems to be missing. The nucleus is surrounded by extracellular material. The flagellum is provided with a 9 + 9 + 2 axonemal pattern; the accessory tubules contain 16 protofilaments and the intertubular material has the distribution typical of the taxon. Two elongated accessory bodies flank partially the axoneme and connect this structure with the mitochondrial derivatives. The flagellar axoneme of paraspermatozoa consists of an axoneme and two giant mitochondrial derivatives filled with large globular units. The axoneme exhibits a 9 + 9 + 2 pattern, in which the central 9 + 2 units have a normal structure, in that the microtubular doublets are provided with both dynein arms and radial links. On the contrary, the nine accessory microtubules have a large diameter and their tubular wall consists of 40 protofilaments. This comparative study provided evidences about the uniformity of sperm ultrastructure in Mantispidae. The function of non-fertilizing giant sperm in mantidflies is discussed.     

Sperm ultrastructure and spermiogenesis of Coniopterygidae (Neuroptera, Insecta)

The spermiogenesis and the sperm ultrastructure of several species of Coniopterygidae have been examined. The spermatozoa consist of a three-layered acrosome, an elongated elliptical nucleus, a long flagellum provided with a 9+9+3 axoneme and two mitochondrial derivatives. No accessory bodies were observed. The axoneme exhibits accessory microtubules provided with 13, rather than 16, protofilaments in their tubular wall; the intertubular material is reduced and distributed differently from that observed in other Neuropterida. Sperm axoneme organization supports the isolated position of the family previously proposed on the basis of morphological data.     

Sperm morphology of the Prorops nasuta (Waterston, 1923) (Hymenoptera: Bethylidae)

In the present study, spermatozoa of the Prorops nasuta (Hymenoptera: Bethylidae) parasitoid were described morphologically. This is the first publication to describe a species belonging to the superfamily Chrysidoidea. Light and transmission electron microscopy were used. The spermatozoa of P. nasuta are linear, with a mean length of 665 μm. The acrosome is composed of an acrosomal vesicle and a perforatorium. The nucleus measures approximately 17 μm in length and is circular at its cross-section; however, its anterior extremity is oval. The chromatin is electron-dense and compact, although there are clear areas in the posterior peripheral regions. In the nucleus-flagellum transition region, the cross-section of the centriole adjunct is oval, with a pleated border and an E-PTA-positive peripheral region. The axoneme shows a 9 + 9 + 2 microtubule arrangement. The microtubules are E-PTA positive and, at the posterior extremity, the accessories are the last to terminate. The diameters and shapes of the two mitochondrial derivatives are almost identical. One begins beside the nuclear base and the other after the centriole adjunct. Posteriorly, they terminate together, immediately before the axoneme. Both have mitochondrial cristae and a region of paracrystalline material; however, the format and arrangement of this material differs from those of all other species previously studied. The paracrystalline material is more strongly E-PTA positive than the cristae region. Accessories bodies are electron-dense and located between the mitochondrial derivatives and the axoneme. In general, P. nasuta spermatozoa are similar to those of the majority of Hymenoptera; however, they have various exclusive characteristics that may be useful for studying the phylogeny and taxonomy of the superfamily Chrysidoidea and of Hymenoptera in general.     

Ultrastructure of apyrene and eupyrene spermatozoa from the seminal vesicle of Euptoieta hegesia (Lepidoptera: Nymphalidae)

The ultrastructure of the seminal vesicle's spermatozoa of the butterfly Euptoieta hegesia was analyzed. The apyrene spermatozoa measure about 300 microm in length and swim freely in a secretion. The anterior end consists in a cap with a cylindrical extension and a globular structure. The flagellum has a 9+9+2 axoneme, two mitochondrial derivatives with paracrystalline matrices and an external coat formed by concentric layers. The eupyrene spermatozoa measure about 550 microm in length and are grouped into bundles. The anterior end consists in an amorphous globule. Posterior to this globule, a coat with a dense material covers the spermatozoon where an acrosome and a nucleus appear. The flagellum has a 9+9+2 axoneme and two mitochondrial derivatives. External to the coat and attached to the dense material, there is a reticular appendage, which has a paracrystalline core and extends to the distal tip of the spermatozoon.     

A novel membrane specialization in the sperm tail of bug insects (heteroptera)

The sperm tail of bug insects has 9 + 9 + 2 flagellar axonemes and two mitochondrial derivatives showing two to three crystalline inclusions in their matrix. During spermiogenesis, the axoneme is surrounded by a membrane cistern which, at sperm maturity, reduces to two short cisterns on the opposite sides of the axoneme adhering to the mitochondrial derivatives. Filamentous bridges connect the intertubular material of the axoneme to these cisterns. Such bridges, which represent a peculiar feature of bug insects, are resistant to detergent treatment, whereas part of the intertubular material and the inner content of microtubular doublets are affected by the treatment. After freeze‐fracture replicas, at the insertion of the bridges to the cisternal membrane, the P‐face of this membrane shows a characteristic ribbon consisting of four rows of 11 ± 1 nm staggered intramembrane particles, 13 ± 2 nm apart along each row. The bridges could be able to maintain the axoneme in the proper position during flagellar beating avoiding distortion affecting sperm motility. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.