Morphology of the male reproductive system and sperm of Leptoglossus zonatus (Dallas, 1852) (Heteroptera: Coreidae).

Taxonomic data on Coreidae have been fragmented over time and need to be revised. Likewise, data related to the development of germ cells and the features of the male reproductive system, including sperm, will contribute to understanding the biological mechanisms of reproduction and the systematics of its representatives. Aiming to provide these data, we describe the morphology of the male reproductive system and spermatozoa of Leptoglossus zonatus using light and transmission electron microscopies, respectively. Each of the two testes is surrounded by a bright red-pigmented sheath and formed by seven follicles arranged side by side. The two vasa deferentia are filled with individualized sperm, especially in their final portion, which is dilated and curved. After dilation, the vasa deferentia receive the ducts of the accessory glands of mesodermal origin. The other unpaired accessory gland is of ectodermal origin and opens into the ejaculatory duct. Both glandular types are densely coiled and have lumens filled with secreted material. Testicular follicles contain cysts with germ cells at different stages of spermatogenesis, indicating continuous production of gametes throughout adult life. Mature sperm measure around 310 µm long, with a nucleus of 36 µm and a flagellum formed only by an axoneme of 9 + 9 + 2 microtubules and two symmetrical mitochondrial derivatives. Like the sperm of other Heteroptera, the acrosome has a single structure (without perforatorium), there are no accessory bodies in the flagella, and the mitochondrial derivatives are connected to the axonemes, supporting the synapomorphic condition of these characteristics for this suborder of bedbugs. RESEARCH HIGHLIGHTS: The Leptoglossus zonatus sperm are slender and long, about 310 µm in length, and a nucleus 36 µm long. Spermatogenesis occurs throughout adult life and equally in the seven testicular follicles. The centriole adjunct in L. zonatus sperm does not give rise to accessory bodies. The ectodermal gland produces a filamentous secretion, whereas in the ectodermal sac, the secretion is globular.

Sperm morphology of Tingidae Laporte, 1833 (Miroidea: Cimicomorpha).

Here, we describe for the first time the sperm morphology of Tingidae (Heteroptera). They are small insects presenting lacy patterns on their pronotum and hemielytra and are exclusively phytophagous, with many economically important species. We studied five species of the tribe Tingini (Tinginae): Teleonemia scrupulosa, Vatiga illudens, Gargaphia lunulata, Leptopharsa sp., and Corythucha arcuata. Their spermiogenesis process is similar to other Heteroptera, with some differences in the formation of the centriole adjunct. This structure extends in the anteroposterior spermatid axis, flanking the nucleus, possibly contributing to nucleus remodeling and sperm elongation. The mature sperm of Tingidae is also similar to that of other Heteroptera, with features that corroborate the group's monophyly. Our data support previous results for their sister family, Miridae, which exhibits some characteristics exclusive to this taxon, not present in Tingidae or other Heteroptera. They also support the sister relationship of the genera Gargaphia and Leptopharsa and suggest closer relationship between Vatiga and Corythucha. Overall, this study sheds light on the sperm ultrastructure of Tingidae and provides information for understanding the evolution and diversity of Heteroptera. RESEARCH HIGHLIGHTS: The spermiogenesis process and mature sperm are similar to other Heteroptera The centriole adjunct is derived from a strip of a pericentriolar material extending from the centriole Tingidae and Miridae are distinguishable using sperm morphology.

Morphology of the male reproductive system and spermatozoa of Smicridea (Rhyacophylax) iguazu Flint, 1983 (Trichoptera, Hydropsychidae).

The Trichoptera, holometabolous aquatic insects found worldwide except in Antarctica, exhibit a unique feature in their sperm, which are solely nucleated (eupyrene). Current knowledge on Trichoptera sperm is limited to Old World species. To enhance our understanding of their reproductive biology and contribute to systematic discussions, we describe the male reproductive system and spermatozoa of Smicridea (Rhyacophylax) iguazu Flint, 1983 (Hydropsychidae). This species lacks seminal vesicles, possesses piriform to oval-shaped testes with spermatozoa grouped in apical bundles and dense filamentous material filling other areas. The vasa deferentia are long and a pair of elongated accessory glands displays distinct proximal and distal regions. The relatively short (∼40 µm) spermatozoa are nucleated, aflagellated, and immobile. Further research could explore variations and assess the taxonomic utility of these features for genus identification within Hydropsychidae.

Morphology of the male reproductive system and spermatozoa of Mahanarva fimbriolata (Stål, 1854) (Hemiptera: Cercopidae) with evidence of a spermatostyle in the sperm conjugation.

Changes in harvesting methods in the early 1990s led to Mahanarva fimbriolata becoming the most prevalent pest in sugarcane plantations. Encouraged by the scarcity of research on the reproductive system and spermatology of Auchenorrhyncha, we provide a detailed description of the male reproductive system and spermatozoa of this cercopid. This will not only aid in taxonomic purposes but also help in understanding the reproductive biology of the species. The male reproductive system, spermatozoa, and sperm bundles of M. fimbriolata were investigated using light microscopy. Our results reveal a reproductive system consisting of a pair of testes, each with 36 follicles, two vasa deferentia, two well-developed seminal vesicles, a single pair of accessory glands, and an ejaculatory duct. Here, we also describe and explore the particularities of the formation of secondary sperm bundles, where cells interestingly bind only to the apical region of the spermatostyle. We also propose some possible benefits of this unusual organization for the reproductive success of the species.

Sperm ultrastructure of Pycnoderes incurvus (Hemiptera: Miridae).

The sperm morphology can provide helpful information about sexual selection, phylogeny, and the evolutionary history of a given animal group. However, there is limited or no knowledge of many taxa, especially those belonging to insects, a vast and highly diverse group. An example is the Miridae, or plant bugs, which belong to the infraorder Cimicomorpha (Heteroptera), where only three out of 17 families have published data on their sperm morphology. Here we described the Miridae sperm structure by analyzing Pycnoderes incurvus sperm under light and transmission electron microscopy. In this species, the spermatozoa were as long and slender as those of most insects. However, the anterior-most region was twisted, a characteristic first reported for Heteroptera. The acrosome was coated with electron-dense material, most likely extra-acrosomal. The centriole adjunct was a notably long, cylindrical and compact structure connecting the nucleus to the flagellar elements, with just clove-like electron-lucent points in cross-section, also features unique to Miridae so far. The flagella exhibited an axoneme of 9 + 9 + 2 microtubules and two symmetrical mitochondrial derivatives. The latter two partially embrace the axoneme, and each exhibits two paracrystalline areas and a bridge connecting it to the axoneme; these are considered Heteroptera synapomorphies that support their monophyly. RESEARCH HIGHLIGHTS: The P. incurvus sperm showed a twisted acrosome, the first reported for Heteroptera. The centriolar adjunct is a sole structure linking the nucleus and flagellum. The flagella presented the synapomorphies supporting Heteroptera monophyly.

New Findings on the Sperm Structure of Tenebrionoidea (Insecta, Coleoptera).

The sperm ultrastructure of a few representative species of Tenebrionoidea was studied. Two species belong to the Mordellidae (Mordellistena brevicauda and Hoshihananomia sp.), one species to Oedemeridae (Oedemera nobilis), and one species to Tenebrionidae (Accanthopus velikensis). It is confirmed that Mordellidae are characterized by the lowest number of spermatozoa per cyst (up to 64), a number shared with Ripiphoridae. In contrast, in the two other families, up to 512 spermatozoa per cyst are observed, the same number present, for example, in Tenebrionidae. Also, as in the other more derived families of tenebrionoids studied so far, during spermatogenesis in O. nobilis and A. velikensis, sperm nuclei are regularly distributed in two sets at opposite poles of the cysts. On the contrary, the Mordellidae species do not exhibit this peculiar process. However, during spermiogenesis, the bundles of sperm bend to form a loop in their median region, quite evident in the Hoshihananomia sp., characterized by long sperm. This process, which also occurs in Ripiphoridae, probably enables individuals to produce long sperm without an increase in testicular volume. The sperm looping could be a consequence of the asynchronous growth between cyst size and sperm length. The sperm ultrastructure of the Mordellidae species reveals that they can be differentiated from other Tenebrionoidea based on the shape and size of some sperm components, such as the accessory bodies and the mitochondrial derivatives. They also show an uncommon stiff and immotile posterior flagellar region provided with only accessory tubules. These results contribute to a better knowledge of the phylogenetic relationship of the basal families of the large group of Tenebrionoidea.

The sperm ultrastructure of members of basal Tenebrionoidea (Coleoptera).

The sperm ultrastructure of some beetles of Tenebrionoidea was studied with particular attention to those of the Ripiphoridae, Mordellidae, and Meloidae. These three groups are often thought to form a clade, which is the sister group of the remaining Tenebrionoidea. The testes of the two former families have thinner but longer spermatic cysts containing fewer and longer sperm. Within each cyst all sperm cells have the same orientation, but cross sections showed that the orientation of the axonemes alternate between adjacent cysts, possibly due to the cysts bending on themselves. In both families the sperm has a bilayered acrosome and the flagellum, which shows mitochondrial derivatives starting laterally to the nuclear base, has a typical 9 + 9+2 axoneme with accessory tubules provided with 16 protofilaments in their wall, and well-structured triangular shaped accessory bodies. In Mordellistena sp (Mordellidae) sperm, both mitochondrial derivatives and accessory bodies are somewhat asymmetrical. Moreover, the flagellum shows a very thin and long tail end provided with only accessory tubules. Meloidae species have testes with thicker sperm cysts containing numerous shorter sperm. Within the individual cysts the sperm flagella exhibit an alternating orientation of their axonemes as consequence of a peculiar spermatogenetic process. The flagellar structure is similar to that of the above-mentioned species, but the accessory bodies are not well defined and constituted by fuzzy material. In Mylabris hieracii (Meloidae) sperm, the acrosome is flat with a conspicuous perforatorium and its nucleus has a peculiar quadrangular section. Berberomeloe majalis sperm has a large acrosome with an unusual pentagonal perforatorium. The centriolar structure of Mylabris variabilis shows a complex of dense radial links connecting the microtubular structures to the plasma membrane. These results suggest that Ripiphoridae have a closer relationship with Mordellidae than with Meloidae. These findings are in agreement with results obtained with molecular data.

The sperm ultrastructure of Pytho depressus (Linnaeus, 1767) (Coleoptera, Pythidae).

The sperm ultrastructure of Pytho depressus (Pythidae) is described in this study. The sperm are short cells, about 85-90 µm long, with an acrosome consisting of three layers, a cylindrical nucleus, which at its base has the initial region of two mitochondrial derivatives. The flagellum has two well-developed triangular accessory bodies, and a 9 + 9+2 axonemal pattern with accessory tubules provided with 16 protofilaments in their wall. The structure and shape of the accessory bodies are diagnostic characters within the superfamily. The sperm morphology of P. depressus can be easily distinguished from those of Ripiphoridae, Meloidae and Tenebrionidae. The P. depressus sperm are organized in cysts as in other species of the group but the sperm are not well aligned and show an antiparallel orientation, a feature also observed in other tenebrionids. The phylogenetic implications of the observed sperm features are discussed in the context of comparative sperm ultrastructure of other insect species.

The sperm ultrastructure of the click beetles (Elateridae) and related groups (Buprestidae and Lampyridae).

In the present study, we describe the sperm morphology of 11 species of Elateriformia (9 elaterids, 1 lampyrid and 1 buprestid) using transmission electron microscopy. All species exhibited sperm that is not usually observed in insects in general. The most highlighted features are the displacement of the nucleus running parallel to the flagellar components, hitherto observed only in coccinellid and carabid beetles, and the presence of thin and dense structures along the nucleus, probably derived from the centriole adjunct, a feature that is so far exclusive to these insects. The other structures are a typical axoneme for insects with 9 + 9 + 2 microtubules, in a position diametrically opposite relative to the nucleus, two slender, symmetrical mitochondrial derivatives and a pair of discrete accessory bodies. This arrangement provides a bilaterally symmetrical flagellum, which favourably influences sperm hydrodynamics, as will be discussed. The occurrence of this unusual structural arrangement in the sperm of species from superfamilies that are phylogenetically as distant as Elateroidea and Buprestoidea support the monophyly of the infraorder Elateriformia, as proposed by some previous molecular studies.

Sperm ultrastructure of three species of ladybirds (Coleoptera, Coccinellidae).

The sperm of three coccinellid species belonging to the subfamilies Chilocorinae, Coccinellinae and Epilachninae were studied under light and transmission electron microscopy. The basic sperm structure of these ladybirds is common to that of the other previously studied species, especially the acrosome in front of the basal body and not the nucleus, with this latter running parallel with the flagellar components. In the Chilocorinae Platynaspis luteorubra (Platynaspidini) the sperm are of the type 1, as in Scymnini and Coccinellini, since they exhibited a cylindrical basal body with 9 + 0 and then 9 + 2, microtubules continuing further in an initial flagellar portion with the only axoneme devoid of accessory structures. The sperm exhibits a thin nucleus and mitochondrial derivatives. Such uniformity of sperm ultrastructure could be indicative of the occurrence of a close relationship between Platynaspidini and Scymnini as also proposed in the previous studies. Conversely, they differ markedly from the sperm of type 3 observed in the Chilocorini Exochomus quadripustulatus. In the Coccinellini Propylea quatuordecimpunctata the sperm are also of the type 1, but they can be easily differentiated from those of the other Coccinellinae studied so far, because of their very short acrosome without the posterior extension, the relatively thicker mitochondrial derivatives and the cylindrical nucleus. Epilachna clandestina sperm resemble those of E. quadripustulatus but differ from them, because they exhibit an elliptical nucleus which is anteriorly very thin, and the asymmetrical mitochondrial derivatives in the anterior extremity, with the greater one starting at the same level of the basal body, rather than at the nucleus level, as it occurs in E. quadripustulatus. Because of the differences observed in the sperm ultrastructure we propose a new sperm type (Type 4) for E. clandestina. This study on ladybird spermatozoon ultrastructure clearly indicates that the current classifications of coccinellids do not reflect the natural history of this well-known insect family.

Sperm morphology of Elasmus polistis Burks, 1971 (Hymenoptera: Chalcidoidea: Eulophidae).

The sperm morphology of the parasitoid Elasmus polistis (Eulophidae) has been investigated with light and transmission electron microscopy. The sperm were filiform and spiraled, with 165.6 (± 4.6) µm in length, and showed a distinctive head, formed by a one-layered small acrosome and a nucleus, and a flagellar region. An extracellular sheath from which many long filaments radiated out covered the acrosome and part of the nucleus. The spiral nucleus, with 24.1 (± 1.3) µm in length, was filled with homogeneously compact chromatin. In the nucleus-flagellum transition, the centriole adjunct extended posteriorly from the nuclear base in a spiral around the basal body, which has two central microtubules, and axoneme for approximately 1.1 µm. The two mitochondrial derivatives began roughly at the same level and at the base of the centriole adjunct. In cross-section, they were symmetrical, with a slightly oval shape and a smaller diameter in comparison to the axoneme. The latter, also spiraled, consisted of 9 + 9 + 2 microtubules that was formed from the basal body situated just below and aligned with the nucleus. The E. polistis sperm showed the same basic structures and morphological characteristics as observed in other Chalcidoidea. However, it was possible to distinguish the sperm of this species from those of other Eulophidae by (i) the long length of the centriole adjunct on the flagellum, and (ii) the presence of two central microtubules within the basal body. The sperm characteristics suggest that Eulophidae is closely related to Trichogrammatidae and both families are more similar to Eurytomidae, Pteromalidae, and Torymidae than Agaonidae.

The peculiar structure of the flagellar axoneme in Coccinellidae (Insecta-Coleoptera).

The ultrastructure of the complex organisation of the spermatozoa in Harmonia axyridis and Adalia decempunctata (Coccinellidae) was studied, with particular emphasis on the origin of the anterior shifting of the axonemal structure, which becomes parallel to the nucleus in the sperm flagellum. In studying the spermiogenesis, a centriolar remodelling was observed with the long centriole, present in the early spermatids, transformed in the spermatozoa into an exceptionally long and narrowed basal body (about 0.16 × 3.5-4.0 µm long) displaying a 9 + 0 microtubular pattern in the proximal part and a 9 + 2 pattern in the following part; this is a characteristic not observed in any other pterygotan insect. The sperm also have a very long acrosome surrounded by a dense layer of material extending along the whole basal body. These two uncommon features were discussed in the light of sperm movement.

Re-description of the sperm morphology of Dalbulus maidis (Hemiptera: Cicadellidae: Deltocephalinae).

The corn leafhopper, Dalbulus maidis, which is one of the most important vectors of maize diseases, had the morphology of its spermatozoa described more than 40 years ago. However, the description is imprecise, requiring certain rectifications. Hence, we re-describe the sperm morphology of this species using light microscopy and transmission electron microscopy. Their spermatozoa measured from 118.1 to 128.5 µm in length, this value being about three times smaller than what was previously described. The head region is formed by a small acrosome and the nucleus. The acrosome is paracrystalline and has the bifurcated base that is docked in two cavities on one side of the anterior region of the nucleus. The nucleus, which is linear and thin, measured from 19.3 to 22.9 µm in length, and exhibited homogeneously compact chromatin. In cross-section, it has a thumbtack shape, except in the anterior and posterior regions, where it is oval. The flagellum consists of an axoneme with 9 + 9 + 2 microtubules, two similar mitochondrial derivatives, two accessory bodies each associated with a small sub-ellipsoidal structure, and a 'center-flagellar material'. In all the spermatozoa observed, the final portion of the flagellum was branched into four filaments. Some of these morphological features are now being re-described, while others have been observed for the first time in the Cicadellidae family, as the center-flagellar material.

Fine structure of the ladybird spermatozoa (Insecta, Coleoptera, Coccinellidae).

The sperm structure of several ladybird species belonging to different subfamilies of Coccinellidae was studied. Three main sperm types were clearly recognized, and were characterized by differences in acrosomal length, the presence of a dense coat around the acrosome, the length of the basal body, the amount of the centriole adjunct material, and the diameter of the mitochondrial derivatives. However, the whole group shares a pattern of the posterior sperm region uncommon for insects, in which the axoneme and other flagellar components are running parallel with the nucleus. As a general conclusion, this study has revealed an inconsistency between the sperm structure and the systematics of the group, indicating that the generic concepts within the group do not reflect a natural classification, a statement also shared by molecular studies.

Evidence of a procentriole during spermiogenesis in the coccinellid insect Adalia decempunctata (L): An ultrastructural study.

We studied spermatogenesis and spermiogenesis in Adalia decempunctata (L), a beetle of the Coccinellidae family. The spermatocyte exhibits two centrioles which elongate to form a pair of primary cilia. A novel structure, appearing in cross sections as a dense droplet, is observed near the long centriole during spermiogenesis, and is soon accompanied by a procentriole (PCL). PCL structure consists of singlet microtubules, a central tubule and an incomplete cartwheel. The PCL persists until the end of spermiogenesis, when it vanishes together with the dense droplet. The sperm has an exceptionally long basal body and the nucleus is disposed parallel to the flagellar components, a peculiar trait shared by other species of the coccinellid group. The presence of a procentriole suggested by the use of antibodies is discussed.

RELEVANCE OF WHOLE BODY VIBRATION EXERCISE IN SPORT: A SHORT REVIEW WITH SOCCER, DIVER AND COMBAT SPORT.

BACKGROUND: Whole body vibration exercise (WBVE) has been used as a safe and accessible exercise and important reviews have been published about the use of this exercise to manage diseases and to improve physical conditions of athletes The aim of this paper is to highlight the relevance of WBVE to soccer players, divers and combat athletes. MATERIAL AND METHODS: This study was made through a systematic review of publications involving WBVE and the selected sports in two databases (Pubmed and PEDRo). RESULTS: It were identified 10 studies involving WBVE and sports (6 of soccer, 2 of diving and 2 of sport combat) with 156 subjects (80 soccer players, 32 divers and 44 combat athletes), with age from 17 to 44 years old. CONCLUSION: The use of WBVE has proven to be a safe and useful strategy to improve the physical conditions of players of different sports. These findings may have clinical relevance and should be considered as a strategy to be used to try improve the physical conditions of players.

Testicular, spermatogenesis and sperm morphology in Martarega bentoi (Heteroptera: Notonectidae).

The testicular, spermatogenesis and sperm morphology of the backswimmer Martarega bentoi was described using light and transmission electron microscopy. In this species, a pair of testes, two deferent ducts, two different pairs of accessory glands, and an ejaculatory duct form the male reproductive system. Each testis consists of two testicular follicles, which are arranged side by side in snail shape. The follicles are filled with cysts at different stages of spermatogenesis, but in the same cyst the germ cells (up to 64) are in the same stage. At the end of spermatogenesis, the sperm cells are very long, with the flagellum measuring approximately 2500 µm in length, the nucleus only 19 µm, and the acrosome, with two distinct regions, 300 µm. The flagellum is composed of an axoneme, with a 9 + 9 + 2 microtubular pattern, and 2 asymmetric mitochondrial derivatives (MDs). These have the anterior ends inserted into two cavities at the nucleus base, exhibit two paracrystalline inclusions, and have bridges linking them to the axoneme. Few spermatozoa per cyst, asymmetry in size and shape of the MDs, as well as their insertion at the nuclear base are characteristics considered derived, and that differentiate the sperm of M. bentoi from those of the Nepomorpha, Belostomatidae and Nepidae.

Sperm morphology of the leafhopper Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Psylloidea: Liviidae).

In this study, by using light and electron microscopy, we describe the sperm morphology of the leafhopper Diaphorina citri, a serious pest of citrus throughout the world. In this species the sperm measures 538.49±8.75µm in length, and as observed in psylloids, the sperm, when manipulated, opens into two filaments, one of which is attached to the nuclear base and the other becomes free. Along the flagellum, and only of it, there are lateral projections, about 2µm in length. Furthermore, at the end of the flagellum three appendages, with approximately 7µm in length, are observed. The head region is formed by the nucleus with compact chromatin, and, parallel to it, a structure of median electron density that extends about 25µm in length ahead of the nuclear tip. The flagellum consists of an axoneme with a 9+9+2 microtubule arrangement, two mitochondrial derivatives, and two accessory bodies each with two regions of different electron density. The presence of lateral projections is a characteristic observed in other Sternorrhyncha. As seen previously, the sperm opening in two filaments, when manipulated, was observed only in Psylloidea, and the presence of the three appendices at the end of the flagellum distinguishes D. citri from the other Psylloidea species studied.

First record of gregarines (Apicomplexa) in seminal vesicle of insect.

Gregarines (Apicomplexa) are a diverse group of protozoan parasites, which infects gut and other body cavities of invertebrate hosts. In reproductive system of insects, gregarine has been reported only in the accessory glands and spermathecae of females; therefore, this is the first report of a gregarine species in seminal vesicles of insects. Different developmental stages, including sporozoytes, oocysts and trophozoites were described from morphological descriptions using light and electron transmission microscopy. The parasites were described in seminal vesicles of the beetle Tribolium castaneum a model organism and an important insect pest. DNA sequence analysis suggests that the protozoan parasite was an Ascogregarina sp.

The sperm structure and spermiogenesis of the heteropteran Coptosoma scutellatum (Geoffroy) with emphasis on the development of the centriole adjunct.

The sperm structure and spermiogenesis of the morphologically peculiar heteropteran Coptosoma scutellatum has been examined with electron microscopy. The sperm has a short monolayer acrosome, a cylindrical nucleus, a 9+9+2 axoneme and two mitochondrial derivatives with crystallized matrix. It shows the synapomorphies typical of the group, consisting of (a) two crystallized areas in the mitochondrial derivatives; (b) the presence of two bridges connecting the intertubular material of the flagellar axoneme to the flattened cisterns adhering to the inner sides of the mitochondrial derivatives; (c) the absence of accessory bodies. The most interesting feature is the presence, in the early spermatid, of an extended centriole adjunct material with the shape of a large ribbon-like structure. This material surrounds the posterior nuclear region and extends anteriorly along the nucleus. It is a microtubule-organizing-center (MTOC) producing the many microtubules surrounding the sperm components At the end of spermiogenesis, the centriole adjunct material modifies into two kidney-like structures accompanying the nuclear posterior end and surrounding the modified centriole.