Morphological and histological structure of the male reproductive system of the water strider Gerris lacustris (Linnaeus 1758) (Gerridae,Heteroptera)

This work presents the male reproductive system morphology and histology of the water strider Gerris lacustris (Linnaeus 1758) (Gerridae, Heteroptera) using light microscopy and scanning electron microscopy. The male reproductive system of G. lacustris comprise of a pair of testes, two vasa deferentia, two seminal vesicles, an ejaculatory duct. There is no bulbus ejaculatorius and the long vas deferantia uniting to form a simple ductus ejaculatorius which is connected to the aedeagus. The testes are white colored and this cylindiric‐shaped structure lies along genital abdominal segment. The testicular follicles have three different development zones (growth zone, maturation zone, differentiation zone). Each testis has two follicles, which are not lined by a common peritoneal sheath and involving many cysts arranged in a progressive order of maturation from the distal to the proximal region; spermiogenesis occurs in mature males, finishing with the organization of sperm bundles. The testes are connected to the seminal vesicles, specialized sperm storage places, by the vas deferentia.     

Structural and histological observations on the male reproductive system of adult red poplar leaf beetle Chrysomela populi Linnaeus, 1758 (Coleoptera: Chrysomelidae)

This study described the anatomy and histology of the male reproductive system in Chrysomela populi, which is an economically important species belonging to the family Chrysomelidae. Therefore, reproductive biology has been studied to combat this insect. As well as, the characters associated with the reproductive tract have been potential to discuss aspects of the system and to better understand the reproductive dynamics. The male reproductive system of C. populi has a pair of testes, a pair of vas efferentia and deferentia, a pair of seminal vesicles, a pair of accessory glands, an ejaculatory bulb, an ejaculatory duct, and an aedeagus. The testis consists of two flower-shaped lobes. Each testis has 20 sperm tubules (testicular follicles) containing cysts of germ cells at various developmental stages within the light orange peritoneal sheath. Testicular follicles are composed of three different (growth, maturation, and differentiation) zones. In the middle region of each testis joins with the vas efferens. The testis is attached to the seminal vesicle by a small stalk like vas efferens. In the lumen of the vas efferens, seminal vesicle, and vas deferens, sperms form clumps in the form of thin threads. The proximal end of the vas deferens is connected to the common ejaculatory duct. It joins with the ejaculatory bulb. Around the ejaculator bulb, there is a pair of convoluted, flat-surface tubular structure accessory glands. Posterior ejaculatory duct joins with the aedeagus.     

The histomorphological structure of the male reproductive system of maize leaf weevil Tanymecus dilaticollis Gyllenhal, 1834 (Coleoptera: Curculionidae)

The histomorphology of the reproductive system and the germ cells has been useful to establish phylogenetic relationships in many insects. However, these elements remain little known in the Curculionidae. In this study, histomorphological structure of the male reproductive system of Tanymecus dilaticollis, which is economically important, is described, illustrated using stereomicroscopy, light microscopy, and scanning electron microscopy techniques, and discussed in relation to other Coleoptera species. Results showed that distinctive features of the male reproductive system of T. dilaticollis consist of a pair of yellowish testes, a pair of seminal vesicles, a pair of vasa deferentia, an ejaculatory duct, accessory glands, prostate glands, and aedeagus. Each testis is subdivided into two testicular follicles, enclosed by a peritoneal sheath. Each follicle of the mature testes is full sperm cysts with germ cells at various stages development of spermatogenesis. The testes have four types of germ cells (spermatogonia, spermatocytes, spermatids, and spermatozoa). They are occupied by the growth zone containing spermatogonia and spermatocytes, the maturation zone containing spermatids, while differentiation zone containing spermatozoa. There is a seminal vesicle at the center of each testis. Most mature sperms are stored in the seminal vesicle. Each testis is attached to the vas deferens by a stalk‐like seminal vesicle. In the distal part, vasa deferentia fuse with the ejaculatory duct. It is linked to the aedeagus. The provided results will contribute to the understanding of the reproductive cell biology of Curculionidae.     

Ultrastructure of the male reproductive system of Cotesia vestalis (Hymenoptera: Braconidae) with preliminary characterization of the secretions

The morphology and ultrastructure of testes and accessory glands along with the characterization of their secretions were investigated for a braconid species Cotesia vestalis (Hymenoptera: Braconidae) using light and electron microscopes. The male internal reproductive system of this species is distinguished by a pair of testes, one vas deferens, and a pair of male accessory glands. The testes are separate, and the accessory glands are oval and not fused. It was observed that the secretory cells of testes have characteristic smooth and rough endoplasmic reticulum, and that the cytoplasm is filled with an array of granule droplets usually of two to three types. The secretory cells in the case of accessory glands are typified by the presence of microvilli on their apical cell surfaces and numerous mitochondria in their cytoplasm. SDS-PAGE profile when performed depicted a similarity in most bands of the secretions from both testes and accessory glands, except for four proteins of which two were present only in testes, while the other two only appeared in accessory glands. Their molecular weights were 117 and 55 kDa for testes and 196 and 30 kDa for accessory glands, respectively. This study gives new insights into the intriguing features of male internal reproductive system and it especially constitutes the first report of its kind about the secretion properties of these organs in C. vestalis.     

Histology and ultrastructure of the testis and vas deferens in Pseudochorthippus parallelus parallelus (Orthoptera,Acrididae)

Pseudochorthippus parallelus parallelus (Zetterstedt, 1821) (Orthoptera, Acrididae) is a widespread species in Europe, and also it is localized in some regions in Turkey such as Bursa, Eski?ehir, Ankara, Bolu, Düzce, and Çank?r?. The features of the reproductive organs such as the numbers and shapes of testes and follicles can be used as taxonomical characters. For this purpose, the ultrastructural and histological features of testis and vas deferens in P. parallelus parallelus were examined with using light microscope, scanning electron microscope, and transmission electron microscope. The mature P. parallelus parallelus has two conjugated testes produce spermatozoa. Each testis is composed of numerous testis follicles in which different stages of spermatogenesis and spermiogenesis develop. First, spermatocytes are formed by the mitosis division of the germ cells at the distal end of the follicles. Then, spermatocytes form spermatids by meiosis division in the middle region of the follicles. Finally, spermatids are differentiated to spermatozoa at the proximal region of the follicles. After maturation of the spermatozoa, sperm tails come together as the sperm bundles called as spermatodesm. Each follicle is connected to vas deferens via vas efferens to discharging spermatozoa. In spite of some differences, the testes and the vas deferens in P. parallelus parallelus are highly similar to the those of other species, especially Orthopteran species.     

Cytopathological and ultrastructural changes in the male reproductive organs of freshwater crab Paratelphusa jacquemontii (Rathbun) exposed to nurocombi

Accumulation of pollutants in the aquatic system has a high impact on the reproductive physiology of crustaceans. The objective of the present study was to assess the possible histopathological effects of combined chlorpyrifos and cypermethrin (nurocombi) exposure on reproductive tissue in male freshwater crab Paratelphusa jacquemontii using light and electron microscopy. The testis of experimental crabs showed disorganization of testicular lobules, increased inters cellular space, necrosis, and cellular damage in both germinal cells and Sertoli cells. The treated vas deferens exhibited epithelial degeneration, misshaped spermatophores, decline in the number of spermatophores, and dehiscence of spermatophore wall. These clinical manifestations expressed in crabs following the exposure of nurocombi significantly reduce the testicular activity and substantially inhibits the seminal secretions, which ultimately lead to impairment of reproduction.     

Marsupial morphology of reproduction: South America opossum male model

This study aims to describe the morphology of Didelphis sp. male genital organs (penis, testes, epididymis, ductus deferens, prostate, and bulbourethral gland). Ten male animals were used, eight for macroscopic and light microscopy analysis, and two for scanning electron microscopy. The testes and epididymis showed similarity to other eutherian mammals. The bifid penis showed the urethra ending in the medial region where the bifurcation begins, occurring in each segment extension of the urethral groove until the beginning of the glans. Histologically, the penis consists of a cavernous and spongy body, covered by stratified squamous epithelium with loose connective tissue. The urethra was lined by transitional stratified epithelium. In the prostate, prostatic segments were found consisting of tubular glands in a radial arrangement around the urethra, coated externally by a dense connective tissue associated with a relatively thick layer of smooth muscle arranged in two layers that surround the glandular tissue. The animals had three pairs of bulbourethral glands placed at the membranous and cavernous urethra junction with descending and parallel excretory ducts ending caudally in the urethral lumen. Microsc. Res. Tech. 76:388–397, 2013. © 2013 Wiley Periodicals, Inc.     

General morphology and ultrastructure of the female reproductive apparatus of Trichomalopsis shirakii crawford (Hymenoptera,Pteromalidae)

The morphology and ultrastructure of the female reproductive system were examined for a larval–pupal parasitoid Trichomalopsis shirakii Crawford of Oulema oryzae Kuwayama using light and electron microscopes. The reproductive system includes two ovaries, two pairs of accessory glands, an unbranched venom gland, a large venom reservoir and a Dufour gland. Each ovariole contains follicles and oocytes at different stages of maturation. A fibrous layer covers the surface of mature egg. The accessory glands are made up of a layer of secretory cells surrounded by muscle fibers. In these secretory cells, numerous mitochondria, electron‐dense secretory granules and vesicles filled with dense granular particles are present. These granular particles appear as virus‐like particles (VLPs). The venom gland consists of a single layer of secretory cells which are organelle rich with abundant rough endoplasmic reticulum, mitochondria and vesicular organelles, a layer of duct cells and an inner intima. The reservoir consists of a muscular sheath, epidermal cells with few organelles and an intima layer. The Dufour gland has a relatively large lumen surrounded by a single layer of columnar epithelial cells which are characterized by clusters of smooth endoplasmic reticulum and lipid droplets. Aside from the venom, the fibrous layer coating the egg and the granular particles which may be VLPs have been discovered in our study. They may serve as one of the parasitoid‐associated factors in their host–parasitoid relationship and play a role in host immune suppression. Microsc. Res. Tech. 79:625–636, 2016. © 2016 Wiley Periodicals, Inc.     

Region‐specific localization of NOS isoforms and NADPH‐diaphorase activity in the intratesticular and excurrent duct systems of adult domestic cats (Felis catus)

Nitric oxide (NO) is produced by nitric oxide synthases (NOSs) and plays an important role in all levels of reproduction from the brain to the reproductive organs. Recently, it has been discovered that all germ cells and Leydig cells in the cat testis exhibit stage‐dependent nuclear and cytoplasmic endothelial (eNOS) and inducible (iNOS)‐NOS immunoreactivity and cytoplasmic nicotinamide adenine dinucleotide phosphate‐diaphorase (NADPH‐d) reactivity. As a continuation of this finding, in this study, cellular localization of NADPH‐d and immunolocalization and expression of all three NOS isoforms were investigated in the intratesticular (tubuli recti and rete testis), and excurrent ducts (efferent ductules, epididymal duct and vas deferens) of adult cats using histochemistry, immunohistochemistry and western blotting. NADPH‐d activity was found in the midpiece of the spermatozoa tail and epithelial cells of all of ducts, except for nonciliated cells of the efferent ductules. Even though the immunoblotting results revealed similar levels of nNOS, eNOS and iNOS in the caput, corpus and cauda segments of epididymis and the vas deferens, immunostainings showed cell‐specific localization in the efferent ductules and region‐ and cell‐specific localization in the epididymal duct. All of three NOS isoforms were immunolocalized to the nuclear membrane and cytoplasm of the epithelial cells in all ducts, but were found in the tail and the cytoplasmic droplets of spermatozoa. These data suggest that NO/NOS activity might be of importance not only for the functions of the intratesticular and excurrent ducts but also for sperm maturation. Microsc. Res. Tech. 79:192–208, 2016. © 2016 Wiley Periodicals, Inc.     

Intramandibular glands in different castes of leaf‐cutting Ant,Atta laevigata (Fr. Smith, 1858) (Formicidae: Attini)

Intramandibular glands have been poorly studied in polymorphic ants, where the differences between castes were unsufficiently scrutinized. Leaf‐cutting ants possess one of the most complex systems of communication and labor division, which is polymorphic well as age polyethism, and makes them an ideal model for the study of intramandibular glands. This study has investigated the occurrence of intramandibular glands in female castes and subcastes of Atta laevigata. The mandibles of the queen, medium, and minor workers, and soldiers were submitted to histological, histochemical, ultrastructural, and morphometric analyses. The class‐3 gland cells and the epidermal gland with a reservoir were found in all the castes. The queens and soldiers showed a higher number of class‐3 gland cells, distributed within the mandible as well as a greater gland size in comparison to the workers. The histochemical tests, periodic acid‐Schiff (PAS), mercury‐bromophenol, and Nile blue, were similar for the class‐3 gland cells and epidermal glands with a reservoir. However, the tests evidenced differences between the castes, with carbohydrates strongly positive in all of them, whereas neutral lipids were found in the queen and soldiers. The protein was weakly positive in the queen, whereas in the soldier, medium, and minor workers these reactions were strongly positive in the intramandibular glands. Our findings in A. laevigata suggest that intramandibular glands are directly involved in labor division and consequently in chemical communication between the castes. Microsc. Res. Tech. 78:603–612, 2015. © 2015 Wiley Periodicals, Inc.     

Light and electron microscopy study of the spermatheca of Eupholidoptera chabrieri bimucronata (Ramme, 1927) and Uromenus brevicollis trinacriae La Greca 1964 (Orthoptera: Tettigoniidae)

A study by both optical and electron microscopy has been carried out on the spermatheca of Eupholidoptera chabrieri bimucronata and Uromenus brevicollis trinacriae (Orthoptera: Tettigoniidae). In both the examined species, the spermatheca consists of a sac/kidney‐shaped seminal receptacle and a more or less tortuous spermathecal duct that opens into the common oviduct. The wall of both the organs consists of a pseudostratified epithelium surmounted by a cuticular intima; the latter is made up of a thicker endocuticle and an epicuticle. The epithelium shows two different cell types, irregularly arranged and with well differentiated functions: cuticle‐forming and gland cells. In both the species, the cuticle‐forming cells perform other functions, in addition to producing the cuticular intima. The gland cells never come in contact with the cuticular intima, have inside the reservoir a secretion whose appearance can diversify also in contiguous zones of the seminal receptacle. Based on our findings in both the species, the functions of the seminal receptacle would differ from those of the spermathecal duct. In the latter, some areas of the wall of the connecting tract show an activity of lysis, by contiguous epithelial cells, that could play a role in control and selection of spermatozoa. As for the feather‐shaped spermatodesms, similar in both the species, freeze‐fracture observations have shown that the acrosome of each spermatozoon regularly covers three‐quarters of the extension of the acrosome of the following spermatozoon. Finally, the significance of our findings, compared with what is known in literature, is discussed. Microsc. Res. Tech. 78:577–586, 2015. © 2015 Wiley Periodicals, Inc.     

Fluorescence microscopy study on the cytoskeletal displacements during sperm differentiation in the bush‐cricket Tylopsis liliifolia (Fabricius) (Orthoptera: Tettigoniidae)

A study by fluorescence microscopy has been carried out on male gametes from testicular follicles, seminal vesicles, spermatophores, and seminal receptacles of the bush‐cricket Tylopsis liliifolia, focusing the attention on localization and movements of F‐actin and α‐tubulin during sperm differentiation, since data in this respect are lacking in the Orthoptera. F‐actin and α‐tubulin positivity was detected in the testicular follicles, in particular at the bridges connecting spermatids of a same clone and around their nucleus, during the first differentiation stages. During the following differentiation stages in the testes, F‐actin was found at one of the spermatid poles and then, during nucleus elongation, at the whole acrosomal region. A peculiar F‐actin‐positivity was found at the flagellum, more markedly immediately posterior to the nucleus, at the basal body region of the gametes from the testicular follicles and from the other examined districts. Other interesting data from our investigations concerns the α‐tubulin displacements during the differentiation stages of the spermatid and a constant absence of α‐tubulin‐positivity where the centrioles are located. No positivity was also found for both α‐tubulin and nuclear markers at the anterior region of the gamete, where the acrosomal wings are localized. Our results, compared with what is so far known in literature for the insects, lead us to assert that microfilaments and microtubules undergo gradual displacements, markedly in the testicular follicles, during the morphogenesis of the male gamete of T. liliifolia aimed to its organization and motility and probably also to its interaction with the female gamete. Microsc. Res. Tech. 79:81–88, 2016. © 2015 Wiley Periodicals, Inc.     

Sperm ultrastructure of Panorpodes kuandianensis (Mecoptera: Panorpodidae)

The sperm ultrastructure of the short‐faced scorpionfly Panorpodes kuandianensis Zhong et al. was investigated using transmission electron microscopy. The spermatozoon is composed of a short head containing a bilayered acrosome and an elongate nucleus, a neck transition region, and a long flagellum. The acrosome consists of an acrosomal vesicle and a central perforatorium. The nucleus has two deep, U‐shaped lateral grooves and its chromatin contains a series of parallel, regularly arrayed nuclear fibers. The barrel‐shaped centriolar adjunct occupies the most volume of the neck region. The flagellum is helical for its whole length and is formed by an axoneme, two mitochondrial derivatives, a pair of accessory bodies, and peculiar accessory structures. The axoneme has nine accessory microtubules at the anterior flagellum region, displaying a 9 + 9 + 2 microtubular pattern, but the accessory microtubules are short and disappear quickly. The two mitochondrial derivatives differ in length and diameter. In the more posterior region, the remaining anchor‐shaped mitochondrial derivative has a circular crystalline region, differing from other mecopteran species. The filiform materials are peculiar and lie beside the nucleus and in the flagellum region. Sperm ultrastructural comparison of P. kuandianensis with other families supports a close affinity of Panorpodidae with Panorpidae. In addition, the occurrence of the nine accessory microtubules in the sperm axoneme of Panorpodes indicates that the 9 + 9 + 2 axonemal pattern might be a symplesiomorphy of the Mecoptera. Microsc. Res. Tech. 77:394–400, 2014. © 2014 Wiley Periodicals, Inc.     

Ethanol exposure during peripubertal period increases the mast cell number and impairs meiotic and spermatic parameters in adult male rats

Puberty is characterized by psychosomatic alterations, whereas chronic ethanol consumption is associated with morphophysiological changes in the male reproductive system. The purpose of this study was to show the toxic effects on testis and epididymal morphophysiology after ethanol administration during peripuberty. To this end, male Wistar rats were divided into two groups: ethanol (E) group: received a 2 g dose of ethanol/kg in 25% (v/v); and control (C) group: received the same volume of filtered water; both were treated by gavage for 54 days. On the 55th day of the experiment, epididymis, and testis were collected for sperm count, histopathology, mast cell count, and morphometry. The vas deferens was collected for sperm motility analysis. The femur and testicle were used for cytogenetic analysis. Ethanol exposure caused reduction in daily sperm production (DSP) and in sperm motility, multinucleated cells or those having no chromosomal content, and late chromosome migrations. No changes were observed in the number of chromosomes in the mitotic analysis. However, some alterations could be seen in meiocytes at different stages of cell division. Stereological analysis of the epididymis indicated reorganization of its component in the 2A and 5A/B regions. The epididymal cauda had greater recruitment, and both degranulated and full mast cells showed an increase in the initial segment, in the ethanol group. In conclusion, ethanol administration during the pubertal phase affects epididymis and testis in adult rats, as indicated mainly by our new findings related to mast cell number and meiotic impact. Microsc. Res. Tech. 79:541–549, 2016. © 2016 Wiley Periodicals, Inc.     

Seasonal testicular changes in <i>Dendropsophus minutus</i> Peters, 1872 (Anura,Hylidae)

The reproductive cycle in anurans may be either continuous or discontinuous. These differences may be connected to seasonal climate changes and/or to anthropic activity. Forty adult male individuals of the Dendropsophus minutus species were collected during one year, in the municipality of Chapada dos Guimarães (Mato Grosso, Brazil). The testicles were studied under light and transmission electron microscopy. No variations were observed when the diameter of the seminiferous tubules and the thickness of the interstitial tissue were studied. However, changes in spermatogenesis were conspicuous and indicated that the reproductive cycle of D. minutus in Chapada dos Guimarães is discontinuous and seems related to variations in air temperature and rainfall.     

Heat exposure promotes apoptosis and pyroptosis in Sertoli cells

Heat stress is an important influence on the male reproductive organs. Therefore, the effects of heat stress on genes or pathways related to the reproductive system of male mice were experimentally explored in this paper to further determine the effects of heat stimulation on mammals. Herein, models of heat-exposed mouse testicular tissue and heat-excited cells were successfully established. Many scorched vesicles were found after heat excitation of testis supporting cells, testicular mesenchymal (TM4) cells. Western blot, in situ terminal deoxynucleotide transferase dUTP Nick end labeling (TUNEL) and transmission electron microscopy showed that membrane rupture, mitochondrial damage and autophagic vesicles occurred in TM4 cells after thermal excitation. The N-segment fragment of the associated protein shear was increased, and the TUNEL result was positive. In conclusion, thermal excitation induced apoptosis and scorch death in TM4 cells. Thus, the Hippo pathway and apoptosis-related pathway were significantly enriched after heat stimulation in mouse testis, and the scorch death effect in TM4 cells was induced by heat excitation.     

Electron microscopic observation of the sagittal structure of Drosophila mature sperm

Observation of sperm development and determination of their morphological characteristics are very important to the understanding of phylogenetic relationships and the study of sperm function during fertilization. Although ultrastructural studies of sperm development in the testes of the fruit fly Drosophila have been performed, there are few reports describing electron microscopic morphology of mature sperm, that is, those released from the testes to the seminal vesicles. Here, we present the first report of the sagittal organization of Drosophila sperm head and neck regions by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The head and tail structures of a mature sperm, for example, the acrosome, nucleus, and flagellum, were easy to distinguish by the morphological characteristics of the sperm surface by SEM. The morphological relationships between the surface and internal structures of mature sperm were confirmed by observing longitudinal sections with TEM. Our approach overcame the technical difficulties involved in sample preparation for electron microscopic observation of the Drosophila mature sperm head, and therefore, this study serves as an important foundation for future genetic dissection of sperm ultrastructure and function in male sterile mutants. Microsc. Res. Tech. 77:661–666, 2014. © 2014 Wiley Periodicals, Inc.     

Macroanatomic,light, and electron microscopic examination of pecten oculi in the seagull (Larus canus)

The present study was conducted to determine macroanatomic characteristic as well as light and electron microscopic examination (SEM) of pecten oculi and totally 20 bulbus oculi belonging to 10 seagulls (Larus canus) were used. Pecten oculi formations consisted of 18 to 21 pleats and their shape looked like a snail. Apical length of the pleats forming pecten oculi were averagely measured as 5.77 ± 0.56 mm, retina‐dependent base length was 9.01 ± 1.35 mm and height was measured as 6.4 ± 0.62 mm. In pecten oculi formations which extend up to 1/3 of the bulbus oculi, two different vascular formations were determined according to thickness of the vessel diameter. Among these, vessels with larger diameters which are less than the others in count were classified as afferent and efferent vessels, smaller vessels which are greater in size were classified as capillaries. Furthermore, the granules which were observed intensely in apical side of the pleats of pecten oculi were observed to distribute randomly along the plica.