Ultrastructure des spermatozoides des males haploides et diploides de Diadromus pulchellus wesmeal (Hymenoptera : Ichneumonidae)

The mature spermatozoa were described in the haploïd and diploïd males of Diadromus pulchellus Wesmeal (Hymenoptera : Ichneumonidae). Diploïd males produce spermatozoa, which do not seem to be different from those produced by haploïd males. The spermatozoon is about 100 μm long, and consists of a head, 0.8 μm in diameter, and a tail 0.3 μm in diameter. Its anterior part shows an acrosomal complex, including a perforatorium and a compact and electron-dense fusiform nucleus. The postnuclear region includes a longitudinal axoneme with 2 mitochondrial derivatives. The axoneme shows 2 typical central units, 9 peripheral doublet microtubules, 9 accessory internal tubules, and 9 external microtubules with dense contents. In the testes of diploïd males, a great number of abnormal spermatozoa were observed. These spermatozoa with degenerative structures are probably not implicated in egg fertilization.     

The sperm of Hexagenia (Pseudeatonica) albivitta Walker (Ephemeroptera: Fossoriae: Ephemeridae)

This study describes the sperm morphology of the mayfly Hexagenia (Pseudeatonica) albivitta (Ephemeroptera). Its spermatozoon measures approximately 30 μm of which 9 μm corresponds to the head. The head is composed of an approximately round acrosomal vesicle and a cylindrical nucleus. The nucleus has two concavities, one in the anterior tip, where the acrosomal vesicle is inserted and a deeper one at its base, where the flagellum components are inserted. The flagellum is composed of an axoneme, a mitochondrion and a dense rod adjacent to the mitochondrion. A centriolar adjunct is also observed surrounding the axoneme in the initial portion of the flagellum and extends along the flagellum for at least 2 μm, surrounding the axoneme in a half‐moon shape. The axoneme is the longest component of the flagellum, and it follows the 9+9+0 pattern, with no central pair of microtubules. At the posterior region of the flagellum, the mitochondrion has a dumb‐bell shape in cross sections that, together with the rectangular mitochondrial‐associated rod, is responsible for the flattened shape of the flagellum. An internal membrane is observed surrounding both mitochondrion and its associated structure.     

Substructure of the axoneme of pterygote insect spermatozoa: Phylogenetic considerations

Spermatozoa from a great number of insect species were fixed in a tannic acid-containing fixative and the ultrastructure of the flagellar axoneme was examined in a search for apomorphies. Most of the examined species, representing a majority of insect orders. have accessory tubules outside the axoneme (hence a 9 + 9 + 2 pattern), and these consist of 16 protofilaments. Some important apomorphies concern the number of protofilaments in the accessory tubules: 13 (plus 7 inner elements) in Ephemeroptera, 13 in the (elliptic) tubules of Psocoptera + Anoplura + Mallophaga (thus a synapomorphy), 13 in Tipulidae + Brachycera, 15 in the dipteran families Dixidae + Chironomidae (with a 9 + 9 + 2 axoneme) and Culicidae + Bibionidae (with a 9 + 9 + “1” axoneme), 17 in Phasmatodea, and 17–20 in Trichoptera. Other apomorphies concern the appearance of the so-called intertubular material outside the microtubular doublets, the appearance of the interior of the various microtubules, and the loss, in some taxa, of outer or inner dynein arms of both dynein arms. In some cases, the flagellum is completely abnormal; the sperm tail of Thysanoptera, for example, consists of 27 elements of 3 different kinds. The different taxa within orders Diptera and Trichoptera have sperm tail axonemes of different appearances, where those from other orders have a rather uniform appearance. The conclusions that can be drawn from this spermatological study, generally agree with data from classical studies, except with some variations, in some cases.     

七星瓢虫精子鞭毛的超微结构(英文)

应用细胞整装制备和超薄切片技术,在透射电子显微镜下检查了七星瓢虫成熟精子鞭毛的超微结构。精子鞭毛是由一个典型的9＋9＋2轴丝,两个同形结晶的线粒体衍生物,两个附体（每个附体具有两部分,一个嗜锇致密月牙体和一个海绵月牙体）和一个非结晶体组成,在鞭毛终端部,仅存的轴丝失去了两个中央微管保留了9个具有动力蛋白臂的双微管和9个附微管。     

ULTRASTRUCTURE OF THE FLAGELLUM IN SPERM OF CKCINELLA SEPTEMPUNCTATA

Abstract  Using cell whole mount preparation and ultrathin section technique, the ultrastructure of the flagellum in the sperm of Coccinella septempunctata L. was examined with transmission electron microscope. The flagellum is made up of a classic 9+9+2 axoneme containing two similar crystallized mitochondria1 derivatives, two accessory bodies, which are divided in to two portions, an osmiophilic dense crescent and a spongy one, and a non-crystalline body. At the end of the flagellum, only the axoneme is present, it loses the two central microtubules but retains the nine doublets with dynein arms and the nine accessory microtubules.     

Ultrastructural analysis of spermatozoa of Korscheltell us lupulinus L. (Lepidoptera : Hepialidae) and Micropterix calthella L. (Lepidoptera : Micropterigidae)

In Korscheltellus lupulinus (Lepidoptera : Hepialidae), both eusperm and parasperm can be found, whereas Micropterix calthella (Lepidoptera : Micropterigidae) produces only eusperm. The eupyrene sperm in K. lupulinus is 250 μm long. Spermatozoa found in K. lupulinus are very similar to those found in higher Lepidoptera, but the eusperm of M. calthella do not possess similar features. As in other Lepidoptera, the axoneme pattern of K. lupulinus is 9 + 9 + 2. Anteriorly, the axoneme is replaced by a fibrous stem similar to an acrosomal structure; posteriorly it becomes progressively uneven. The sperm of K. lupulinus has other original features. The anterior region of the sperm is rigid and contains the nucleus, which has a longitudinal groove adjacent to the axoneme. The 2 mitochondrial derivatives extend from the posterior end of the nucleus. There are no accessory bodies. Many peripheral cytoplasmic vesicles are present. A thin sheath surrounds the cell. It is thick in the parasperm and made of concentric or spiralling lamellae; it does not have any lacinate appendages.The axoneme of the sperm of M. calthella extends over the entire length of the cell and spirals in a helix around the nucleus. The nucleus is also almost as long as the cell. The 2 mitochondrial derivatives, flanked by accessory bodies, follow this spiralling. The axoneme has a 9 + 2 pattern. The plane, which contains the 2 central microtubules, is at an angle with the median plane of the nucleus.     

Sperm structure of Trichoptera. I. Integripalpia : Limnephiloidea

Spermal ultrastructure in 16 caddisflies (Trichoptera) belonging to the suborder Integripalpia, superfamily Limnephiloidea, was examined in a search for apomorphic and plesiomorphic features. In all species examined, the sperm tail axoneme was of the 9 + 9 + 2 + type, the axonemal doublets lacked outer dynein arms but had inner ones, and the cell membrane was scalloped with a prominent glycocalyx. The number of protofilaments in the accessory tubules depended on the phylogenetic position: 18 in the family Leptoceridae, 19 in Limnephilidae, Goeridae and Odontoceridae (with a reduction in the number distally), and 20 in Sericostomatidae. Spermatozoa in Leptoccridae are further characterized by the 2 central microtubules being flattened and eccentric and not being surrounded by a central sheath. Spermatozoa of Sericostomatidae have an accessory body and a helicoidal array of the sperm tail.     

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。     

Ultrastructure of the spermatozoon of Megaselia scalaris Loew (Diptera:Brachycera:Cyclorrhapha:Phoridea:Phoridae)

When viewed by scanning electron microscopy (SEM), the spermatozoon of the phorid dipteran Megaselia scalaris appears threadlike, lacking distinct head and tail areas. These areas can be observed, however, in appropriately stained material. Measurements of Feulgen-stained material reveal average lengths of the head, tail, and total cell of 18.7, 128.7, and 147.4 μm, respectively. When tested for sulfhydryl and disulfide groups, the head displays only disulfide groups. Transmission electron microscopy (TEM) reveals 12 different regions: three (1–3) in the head, four (9–12) in the tail, and five (4–8) in a short zone of overlap between the head and tail. Most of the cell lies in regions 9 and 11 of the tail and 3 of the head, accounting for, respectively, 37.3%, 45.7%, and 11.2% of the total length. A tubelike acrosome indents the anterior end of the nucleus. The tail originates asymmetrically in relation to the long axis of the cell as a peglike structure associated with the dorsolateral region of the nucleus. No centriole is visible, and the nucleus has a notched appearance in longitudinal sections. Two mitochondrial derivatives and an axoneme displaying a 9+9+2 microtubule configuration and ATPase activity extend throughout most of the tail. In regions 9 and 10, an asymmetrically arranged accessory body is also present. Features having possible taxonomic utility include the asymmetrically arranged accessory body, the size and shape of the acrosome, and the notched appearance of the nucleus. The present report is apparently the first to describe the spermatozoon of a cyclorrhaphous dipteran which is not a member of the Schizophora.     

Ultrastructure of a Coccidium (Apicomplexa: Sporozoea: Coccidia) in Priapulus caudatus (Priapulida)1

Stages in the life cycle of a coccidium are described from the intestine of Priapulus caudatus Lamarck, 1816. Meronts, merozoites, microgamonts, microgametes, and walled and unwalled macrogametes were seen in intestinal cells. Meronts were about 8 μm long and 3–7 μm wide and produced up to seven merozoites. Free merozoites were about 9 μm long and 4 μm wide and contained about 43 subpellicular microtubules that terminated in the outer polar ring. Microgamonts were up to 23 μm long and 7 μm wide and usually were delimited by a single membrane. Microgametes were about 5 μm long, exclusive of the two flagella, about 2 μm wide, and contained a nucleus that was not uniformly dense. Macrogametes, about 6 μm in diameter, had a nucleus largely without dense chromatin. The oocyst wall formed around intracellular macrogametes to a thickness of 0.2–0.5 μm as thin, osmiophilic elements that became arranged in reticular and tubular layers. Wall-forming bodies were not seen, but fine filaments may participate in wall formation, as these were found between the outer membrane of the pellicle and the nearest wall elements. Microgametes and walled macrogametes were delivered to the lumen of the host intestine during apocrine secretion or excretion by the intestinal cells. Fertilization may occur in the intestinal lumen. Unsporulated ovoid oocysts, 18–27 μm long and 10–14 μm wide, with a 3 μm micropyle and a wall 0.6–0.7 μm thick, were passed from the host.     

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.     

Structural and ultrastructural studies of male reproductive tract and spermatozoa in Xylocopa frontalis (Hymenoptera,Apidae)

Fiorillo, B. S., Zama, U., Lino‐Neto, J. and Báo, S. N. 2010. Structural and ultrastructural studies of male reproductive tract and spermatozoa in Xylocopa frontalis (Hymenoptera, Apidae). —Acta Zoologica (Stockholm) 91 : 176–183. In Xylocopa frontalis the reproductive tract is composed of testes, deferent ducts, seminal vesicles, accessory glands and an ejaculatory duct. Each testis comprises four testicular tubules in which multiple cysts are present containing approximately 64 spermatozoa per cyst. The seminal vesicle consists of an epithelium, a thick basement lamina and a muscular external sheet. In the luminal region some vesicles can be observed; however, the epithelial cells of the seminal vesicle do not display morphological features associated with secretory functions. The spermatozoa, measuring approximately 260 µm long, are similar to the hymenopteran pattern. The head region consists of an acrosome with an inner perforatorium that penetrates an asymmetrical nuclear tip. The nucleus is linear, electron‐dense and its posterior tip projects into the beginning of the axoneme. The centriolar adjunct is asymmetric with many electron‐lucent lacunae interspersed throughout. The axoneme has the 9 + 9 + 2 pattern of microtubules and in the posterior region the central microtubules finish first, followed by the doublets and finally the accessory microtubules. The mitochondrial derivatives are asymmetric in both length and diameter with paracrystalline material present only in the larger one. These features may be useful characters for taxonomy and phylogenetic studies.     

[A functional flagella with a 6 + 0 pattern]

The male gamete of the Gregarine Lecudina tuzetae has been studied with transmission electron microscopy and microcinematography. It is characterized by a flagellar axoneme of 6 + 0 pattern, a reduction of the chondriome, and the abundance of storage polysaccharide or lipid bodies. The movements of the flagella are of the undulating type and they are performed in the three dimensions of space. They are very slow, with a cycle time of about 2s. The structure of the axoneme components are similar to those of flagella with a 9 + 2 pattern. Each doublet has overall dimensions of 350 x 220 A; the space between the adjacent doublets is about 160 A. The A subfiber bears arms like dynein arms. The diameter of the axoneme is about 1,000 A. The basal body consists of a cylinder of dense material 2,500 A long and 1,300-1,400 A in diameter; a microtubule 200 A in diameter is present in the axis. This study shows that a 6 + 0 pattern can generate a flagellar movement. The mechanism of the flagellar movement of the male gamete of L. tuzetae does not require the presence of central microtubules and it would include molecular interactions of the dynein-tubulin type between the adjacent peripheric doublets. The slowness of the movements is discussed in terms of the axoneme's structure and its energy supply. Finally, the phylogenetic significance of this flagella is examined on the basis of the morphopoietic potentialities of the centriolar structures.     

SPERMIOGENESIS IN THE PULMONATE SNAIL,EUHADRA HICKONIS III. FLAGELLUM FORMATION*

The formation of the flagellum in the spermatid of the Japanese land snail, Euhadra hickonis, is introduced by the appearance of a central indentation in the differentiated posterior side of the spherical nucleus early in spermiogenesis. One centriole moves to this part of the cell, changes in several structural respects and acquires a short-lived “centriole adjunct”. At first it lies tangential to the nuclear surface as it begins to induce formation of the flagellar axoneme; then it turns so that its proximal end fits into the deepening nuclear indentation (“implantation fossa”). Cytoplasmic tubules appear to mediate this shift in direction. Internal changes in the centriolar components begin as it initiates formation of the axoneme, and continue throughout spermiogenesis. First, a dense “cap” forms at its proximal end, the microtubular triplets become doublets and a pair of singlets occupies the center of the complex. All these microtubules extend from the dense cap and are continuous with those of the axoneme. As the basal body (modified centriole) becomes set in the implantation fossa, the material of the centriole adjunct forms 9 strands, which are continuous with the peripheral coarse fibers when these develop. The microtubular doublets of the basal body are visible for a short time between the fiber strands; in the mature spermatozoon they are found embedded in the basal body portions of the coarse fibers in a degenerated form. Posterior to the basal body, however, they separate from the inner sides of the striated coarse fibers and become the doublets of the axoneme. The proximal part of the elongating axoneme lies in a posterior extension of the cell, in which glycogen particles and mitochondria are conspicuous. As the mitochondria unite into a sheath tightly surrounding the axoneme, the structure of their cristae changes to form a paracrystal-line “mitochondria derivative”, which consists of many layers close to the nucleus and progressively fewer posteriorly. Outside of this “primary sheath”, more modified mitochondria unite to form a “secondary sheath” of paracrystalline lamellae which encloses a compartment, filled with glycogen particles, that extends in a low-pitched helix nearly to the end of the flagellum. In the late spermatid, microtubules become arranged at regular intervals around the nucleus and secondary sheath of the flagellum for a short period while the remaining cytoplasm and spermatid organelles such as the Golgi complex are being discarded. The flagellum of the mature spermatozoon is 250–300 μm in length, tapering gradually from a diameter of ca 1 μm just behind the nucleus to less than 0.3 μm at its tip, as the result of reduction in the amount of stored glycogen, the number of paracrystalline lamellae and the diameter of the peripheral fibers.     

Sperm structure of Trichoptera. IV. Rhyacophilidae and Glossosomatidae

The families Rhyacophilidae and Glossosomatidae (Trichoptera) are considered to be the most primitive ones within the order. We examined the spermatozoa of members of these families to see whether their ultrastructure is consistent with an ancestral position. Axonemal structures, after fixation with a tannic acid-containing fixative, have been shown to be particularly useful as taxonomical indicators. It was found that 4 members of Rhyacophilidae, representing 3 subgenera (Rhyacophila, Pararhyacophila, and Hyporhyacophila) all have motile spermatozoa, with a 9 + 9 + 2 axoneme in which inner (but no outer) dynein arms are present. The accessory tubules have a wall consisting of 17 protofilaments, decreasing to 16 near the distal end, whereas the examined member of Glossosomatidae, Catagapetus nigrans, has accessory tubules with 18 protofilaments and a 9 + 9 + 2 axoneme with inner dynein arms and with motility similar to the Rhyacophilidae. Sperm motility is consistent with the inclusion of these 2 families within the suborder Integripalpia, and the axonemal pattern 9 + 9 + 2 indicates that the families indeed occupy a primitive position within Trichoptera.     

An ultrastructural analysis of the mature spermatozoon of Anguispira alternata (say) (pulmonata,stylommatophora)

Mature spermatozoa from the hermaphroditic duct of adult snails were examined using various techniques of light microscopy as well as scanning and transmission electron microscopy. The sperm are approximately 557 μm in length including a dextrally spiral head approximately 13 μm long. The head consists of an electron-dense nucleus sculptured into a double-ridged spiral and an acrosome projecting approximately 0.45 μm beyond the apex of the nucleus. The acrosome consists of a membrane-bound vesicle approximately 0.1 μm in diameter and a column of homogeneous material which extends along one side of the terminal spiral of the nucleus. This material is separated from the nucleus by the nuclear envelope. The neck region, though similar to that found in other pulmonates, possesses a unique coiled structure surrounding the central doublet of the axoneme. The midpiece axoneme possesses a 9+9+2 configuration anteriorly grading into a 9+2 pattern for the majority of its length. There are three mitochondrial helices – one primary and two secondary – in the midpiece. Only the primary helix persists throughout the midpiece.     

A Cytological Study and Reclassification of Trichophrya collini (Saedeleer & Tellier)1

ABSTRACT. Trichophrya collini has a polygonal, dorsoventrally flattened body (up to 75 μm diam.), with capitate tentacles arranged in 1–3 rows within peripheral fascicles. There is a central polymorphic macronucleus, an associated micronucleus, and numerous peripheral contractile vacuoles with ventral discharge pores. The cell has a multilayered cortex and the cytoplasm contains suctorian organelles such as crescentic bodies, elongate dense bodies, and haptocysts. The highly contractile tentacles have an axoneme with an outer ring of 24 microtubules separated into six groups and an inner ring of six curved lamellae, each with five microtubules. The lamellae at the distal and proximal ends of the axoneme are arranged in a helix, and the outer ring microtubules are joined in a distal connective sheath. In the apical knob of the tentacle, the haptocysts are borne on a central capsule, Reproduction is by endogenous budding to produce a single oval-shaped swarmer, with equatorial ciliature, which metamorphoses within 3 h. These observations suggest that this organism, previously known as Heliophrya collini Saedeleer & Tellier, is synonymous with Platophrya rotunda Gönnert, Craspedophrya rotunda Rieder, and Heliophrya rotunda Matthes. Its endogenous mode of budding assigns it to the genus Trichophrya. but it is distinct from Trichophrya rotunda Hentschel, and should be reclassified to Trichophrya collini (Saedeleer & Tellier).     

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.