The male reproductive system and mechanism of sperm transfer in Argulus japonicus (Crustacea: Branchiura)

The histomorphology of the male reproductive system and surface morphology of the “peg-and-socket” in Argulus japonicus are described from serial sagittal and transverse sections and scanning electron micrographs. The prostate complex consists of a glandular part, a reservoir for storing the secretion, and an efferent duct opening into the ejaculatory duct. The openings of both the vas deferens and the prostate duct into the ejaculatory duct are guarded by sphincters. The ejaculatory ducts, which are lined by tall columnar epithelial cells, do not open into the cuticle-lined genital atrium but are blind-ending tubes. This observation and results obtained from observing live specimens, as well as the fact that no spermatophores are formed, suggest that semen could leave the ejaculatory duct only after puncturing of its walls. It is suggested that sperm transfer is accomplished in the following manner: during copulation contraction of the muscular walls of the vas deferens and prostate duct causes semen to be pumped into the ejaculatory duct, which is then closed off by sphincters and a high internal pressure is developed. When a spermathecal spine penetrates the walls of the ejaculatory duct, semen flows from the ejaculatory duct into the spermathecal vesicle due to the higher pressure in the ejaculatory duct. This mechanism is analogous to the sucking up of fluid with a hypodermic syringe. © 1993 Wiley-Liss, Inc.     

Observations on the ultrastructure of the copulatory organ of Archilopsis unipunctata (Fabricius, 1826) (Proseriata,Monocelididae)

The copulatory organ in adult specimens of Archilopsis unipunctata has been studied by transmission electron microscopy.This copulatory organ is of the conjuncta-duplex type with eversible cirrus. The seminal vesicle, lined with a nucleate epithelium, is surrounded by spirally arranged muscles. The fibres are enclosed in a sheath that is continuous with the septum of the bulbus and the basement lamina of the male canal epithelium. Distally to the seminal vesicle the bulbus is filled with the secretory cell-necks of the prostate glands. The male canal shows three different parts: seminal duct, ejaculatory duct and eversible cirrus. At the transition of seminal duct and ejaculatory duct two prostate ducts open into the lumen. The structure of the epithelium lining the different parts of the canal is described. The transition into the cirrus may be recognized by an abrupt change in the thickness, the electron density and the stratification in the basement lamina and by the disappearance of the epithelium absent indeed in the cirrus. The material found inside the cirrus-lumen is different according to the zone considered. The origin of this material and of the cirrus teeth is discussed.Abbreviations ab- apoptotic body - ba- bacteria - bb- basal bodies of cilia - bl- basement lamina - bw- body wall - c- cilia - cb- cell body - cgp- common genital porus - ci- cirrus - cip- cirrus plug - cl- lumen of cirrus - cm- circular muscles - cr- cytoplasmatic remnants - cs- cytoplasmatic sheets - ejd- ejaculatory duct - ep_ej- epithelium of ejaculatory duct - d- desmosomes - f- flagella of spermatozoa - fd- female duct - fp- female porus - gc- golgi complex - gl- glycogen particles - hd- hemidesmosomes - lm- longitudinal muscles - ly- lysosome-like body - m- muscles - m_b- muscles of the bulbus - m_c- muscles of the cirrus - m_c- muscles of the seminal vesicle - mi- mitochondria - ml- microvilli - ms- mesenchyme - n_sd- nuclei of the seminal duct - pd- prostate duct - pg- prostate glands - ri- ribosomes - s- septum - sb- secretory vesicle - sd- seminal duct - sp- spines - sv- seminal vesicle - v- vagina - vd- vas deferens     

Ultrastructure of the male accessory glands ofAllacma fusca(Insecta, Collembola)

The accessory glands ofAllacma fusca(L.) (Insecta, Collembola, Sminthuridae) consist of a series of secretory units that are arranged in parallel and open into the ejaculatory duct. Each unit is composed of microvillate cells stacked around a common cavity. Basal cells are involved in ion-control of fluids from the hemocoel to the cavity. The intermediate and apical cells, which have a laminar appearance and contain many microtubules, are involved in the structural integrity of the unit. Supporting cells ensheath the most apical cells. Large openings in the cuticle allow the gland secretion to flow into the ejaculatory duct lumen. These openings are protected by a porous cuticle different from that lining the epithelium of the ejaculatory duct. Conspicuous muscle fibers run along the lateroventral side of the ejaculatory duct beneath the insertion of the accessory glands. The fine structure of the accessory glands indicates that they are type I ectodermic glands as defined by Noirot & Quennedey (1974). Their function could be to control the fluidity of the material for spermatophore formation and to ensure the proper physiological conditions for spermatozoa stored in the ejaculatory duct lumen.     

Developmental sequence for the copulatory organs of Kontikia mexicana with remarks on taxonomic significance (Turbellaria: Tricladida: Geoplanidae)

Five specimens, presumably representing different developmental stages of the land planarian Kontikia mexicana (Hyman, 1939), were used to reconstruct the development of the copulatory apparatus in this species. The results support the notion that Kontikia differs from the closely related Caenoplana in its possession of a penis papilla. In the earliest stage available, a penis papilla was absent and other components were not differentiated. In a late-juvenile condition, the gonopore, seminal vesicle, and ejaculatory duct were present. The short penis papilla appeared to arise in this stage by elongation of the terminal tissue around the ejaculatory duct and its separation from the antral wall. The female canal was guarded by an epithelial fold and the glandular duct was present. In the mature condition, the penis papilla was more elongate, and the secretory (prostatic) region of the ejaculatory duct was functional. The female canal, guarded by an epithelial fold, was well-developed with enlarged glandular duct but lacking the posterior diverticulum and the sperm storage system associated with the ovovitelline ducts known in Kontikia orana Froehlich, 1955.     

Anatomy and histology of the male reproductive system of the fire ant,Solenopsis invicta Buren (Hymenoptera : Formicidae)

The male reproductive system of the fire ant, Solenopsis invicta Buren (Hymenoptera : Formicidae), consists of the testes, vasa efferentia, vasa deferentia, seminal vesicles, accessory glands, ejaculatory duct, wedge, aedeagal bladder, and external genitalia. The testes in newly eclosed males appear as 4 large white lobes filled with packets of sperm. Each lobe of the testes contains only one follicle. As the testes degenerate, the maturing sperm migrate through the vasa efferentia and vasa deferentia into the seminal vesicles. The seminal vesicles attach to the accessory glands, which are lined with secretory columnar epithelium. The posterior ends of the accessory glands taper and unite to form the ejaculatory duct. A sclerotized wedge is found at the junction of the accessory glands and the ejaculatory duct. An aedeagal bladder, joining the ejaculatory duct posterior to the wedge, is lined with squamous epithelium enveloped by heavy musculature. The ejaculatory duct continues posteriorly to form a distal aedeagus surrounded by 3 pairs of valves, comprising the external genitalia.     

Mating behavior and genitalic counterparts in tiger beetles (Carabidae: Cicindelinae)

Comparative studies on the structure of genitalia in Pseudoxychila tarsalis Bates and the copulating behavior in 5 species of Cicindela respectively complement similar findings by Freitag [1] on Cicindela spp. and Palmer [4] on P. tarsalis. These strengthen the hypothesis that in tiger beetles the flagellum fits into the spermatheca duct during copulation; that the main function of the flagellum, which is closed at the apex and not connected to the ejaculatory duct, is to open and prepare the lumen of the spermatheca duct for sperm movement from the bursa copulatrix to the spermatheca; and that copulation proceeds in 3 phases: phase 1 in which the lumen of the spermatheca duct is cleared by the flagellum, phase 2 in which the flagellum is withdrawn from the spermatheca duct, and phase 3 in which semen is transferred from the gonopore of the ejaculatory duct to the bursa copulatrix, usually with a spermatophore.     

Structure of the accessory reproductive glands of the male migratory grasshopper,Melanoplus sanguinipes

The accessory reproductive glands of Melanoplus sanguinipes comprise two bilateral masses of 16 tubules each, distinguishable in sexually mature insects as four white, ten short hyaline, one long hyaline, and a seminal vesicle. Over most of its length, the wall of each tubule consists of a simple glandular epithelium resting on a basal lamina, surrounded by a thin layer of circular muscle. However, near the junction with the ejaculatory duct, the wall of each tubule has a much thickened circular muscle layer and squamous or cuboidal epithelium, the region serving to regulate movement of secretion into the ejaculatory duct. Interdigitation of adjacent epithelial cells is common, and several kinds of specialized junctions occur. In the glandular region, all epithelial cells appear the same and may be flattened, cuboidal, or columnar depending on the tubule type. Except for those of the seminal vesicle, the glandular epithelial cells share ultrastructural features typical of cells engaged in the synthesis of protein for export. Despite these general similarities, in most instances subtle differences occur in the cellular ultrastructure of the epithelia of each tubule and in the appearance of their luminal secretions, suggesting that the tubules are functionally specialized.     

Genetic control and expression of the major ejaculatory bulb protein (PEB-me) inDrosophila melanogaster

PEB-me is a predominant protein of matureDrosophila melanogaster ejaculatory bulbs. It is resolved into four or five closely spaced subfractions (apparent molecular weight 35–39 kD) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Four electrophoretic variants of PEB-me differing in apparent molecular weight by 200–800 daltons were found. These appear to be controlled by four alleles of a gene (peb) located by recombination and deletion mapping to the 60F1-2 region of chromosome 2. A minor ejaculatory bulb protein of ca. 80 kD (hPEB) was found to be immunochemically related to PEB and possibly encoded bypeb. PEB is not detected by immunoblotting techniques in virgin females, in male tissues other than the ejaculatory bulb, or during developmental stages preceding the formation of this organ. The results of transplantations of genital imaginal discs and of immature ejaculatory bulbs between two strains having different PEB alleles suggest that the ejaculatory bulb is the site of PEB synthesis. In flies mutant fortra, tra-2, dsx, orix, tissue specificity of PEB localization is retained and the protein is found whenever the ejaculatory bulb is formed, regardless of the chromosomal sex of the fly. The protein is transferred into the female genital duct during mating, where it can be detected for up to 12 hr. Possible functions of PEB inDrosophila reproduction are discussed.     

Correlated evolution of the cis-acting regulatory elements and developmental expression of the Drosophila Gld gene in seven species from the subgroup melanogaster

The tissue-specific expression patterns of glucose dehydrogenase (GLD) exhibit a high degree of inter specific variation in the adult reproductive tract among the species in the genus Drosophila. We chose to focus on the evolution of GLD expression and the evolution of the Gld promoter in seven closely related species in the mela-nogaster subgroup as a means of elucidating the relationship of changes in cis-acting regulatory elements in the Gld promoter region with changes in tissue-specific expression. Although little variation in tissue-specific patterns of GLD was found in nonreproductive tissues during development, a surprisingly high level of variation was observed in the expression of GLD in both developing and ma-ture reproductive organs. In some cases this variation is correlated with changes in sequence elements in the Gld promoter which were previously shown to direct tissue-specific expression in the reproductive tract. In particular D. teissieri adult males do not express GLD in their ejaculatory ducts, atypical of the melanogaster subgroup species. The Gld promoter region of D. teissieri specifically lacks all three of the TTAGA regulatory elements present in D. melanogaster. The TTAGA elements were previously shown to direct reporter gene expression to the ejaculatory duct. Together these data suggest the absence or presence of the TTAGA elements may be responsible for variation in the absence or presence of GLD in the ejaculatory duct among species. © 1994 Wiley-Liss, Inc.     

Molecular dissection of nuptial gifts in divergent strains of Ostrinia moths

Seminal fluid proteins (SFPs) produced in the male accessory glands and ejaculatory duct are subject to strong sexual selection, often evolve rapidly and therefore may play a key role in reproductive isolation and species formation. However, little is known about reproductive proteins for species in which males transfer ejaculate to females using a spermatophore package. By combining RNA sequencing and proteomics, we characterize putative SFPs, identify proteins transferred in the male spermatophore and identify candidate genes contributing to a one‐way gametic incompatibility between Z and E strains of the European corn borer moth Ostrinia nubilalis. We find that the accessory glands and ejaculatory duct secrete over 200 highly expressed gene products, including peptidases, peptidase regulators and odourant‐binding proteins. A comparison between Ostrinia strains reveals that accessory gland and ejaculatory duct sequences with hormone degradation and peptidase activity are among the most extremely differentially expressed. However, most spermatophore peptides lack reproductive tissue bias or canonical secretory signal motifs and aproximately one‐quarter may be produced elsewhere before being sequestered by the male accessory glands during spermatophore production. In addition, most potential gene candidates for postmating reproductive isolation do not meet standard criteria for predicted SFPs and almost three‐quarters are novel, suggesting that both postmating sexual interactions and gametic isolation likely involve molecular products beyond traditionally recognized SFPs.     

Ultrastructure of the male reproductive accessory glands in the medfly Ceratitis capitata (Diptera: Tephritidae) and preliminary characterization of their secretions

The morphology and the ultrastructure of the male accessory glands and ejaculatory duct of Ceratitis capitata were investigated. There are two types of glands in the reproductive apparatus. The first is a pair of long, mesoderm-derived tubules with binucleate, microvillate secretory cells, which contain smooth endoplasmic reticulum and, in the sexually mature males, enlarged polymorphic mitochondria. The narrow lumen of the gland is filled with dense or sometimes granulated secretion, containing lipids. The second type consists of short ectoderm-derived glands, finger-like or claviform shaped. Despite the different shape of these glands, after a cycle of maturation, their epithelial cells share a large subcuticular cavity filled with electron-transparent secretion. The ejaculatory duct, lined by cuticle, has epithelial cells with a limited involvement in secretory activity. Electrophoretic analysis of accessory gland secretion reveals different protein profiles for long tubular and short glands with bands of 16 and 10 kDa in both types of glands. We demonstrate that a large amount of accessory gland secretion is depleted from the glands after 30 min of copulation.     

Coevolution of the glucose dehydrogenase gene and the ejaculatory duct in the genus Drosophila

The glucose dehydrogenase gene (Gld) in Drosophila melanogaster exhibits a unique spatial and temporal pattern of expression. GLD expression switches from a non-sex-limited state at the pupal stage to a male-limited state at the adult stage. At the adult stage, the enzyme is restricted to the ejaculatory duct. Within the genus Drosophila, the ejaculatory duct has undergone a simple morphological divergence. In order to determine whether correlated changes in GLD expression had occurred, GLD activity during the pupal and adult stages was determined for several Drosophila species. It was found that virtually all of the species exhibit pupal GLD activity, whereas only those species with an expanded ejaculatory duct express male-limited GLD. The results of interspecific genital imaginal disc transplantation experiments indicate that the expanded morphology and GLD expression do not require any species- or sex-specific diffusible factors. An apparent regulatory polymorphism exists within the D. takahashii species with respect to male-limited GLD expression.      

New physiological activities of myosuppressin,sulfakinin and NVP-like peptide in <Emphasis Type="Italic">Zophobas atratus</Emphasis> beetle

Three neuropeptides Zopat-MS-2 (pEDVDHVFLRFa), Zopat-SK-1 (pETSDDYGHLRFa) and Zopat-NVPL-4trunc. (GRWGGFA), recently isolated from the neuroendocrine system of the Zophobas atratus beetle, were tested for their myotropic and hyperglycaemic activities in this species. These peptides exerted differentiated dose-dependent and tissue specific physiological effects. Zopat-MS-2 inhibited contractions of the isolated heart, ejaculatory duct, oviduct and hindgut of adult beetles and induced bimodal effects in the heart contractile activity of pupae in vivo. It also increased the haemolymph free sugar level in larvae of this species, apart from myotropic activity. Zopat-SK-1 showed myostimulatory action on the isolated hindgut of the adult beetles, but it decreased contractions of the heart, ejaculatory duct and oviduct. Injections of this peptide at a dose of 2 μg also caused delayed cardioinhibitory effects on the heartbeat of the pupae. Together with the ability to increase free sugar level in the haemolymph of larvae these were new physiological activities of sulfakinins in insects. Zopat-NVPL-4trunc. inhibited the muscle contractions of the two organs: hindgut and ejaculatory duct but it was inactive on the oviduct and the heart of the adult beetles. This peptide also increased free sugar level concentration in the haemolymph of Z. atratus larvae. These physiological actions are the first biological activities discovered for this group of the insect peptides. The present work showed pleiotropic activity of three neuropeptides and indicates that the visceral muscle contractions and the haemolymph sugar homeostasis in Z. atratus are regulated by complex mechanisms.     

大猿叶虫滞育进程中成虫内生殖系统的形态特征

大猿叶虫Colaphellus bowringi Baly是十字花科蔬菜的一种重要害虫,以成虫在土壤中滞育越冬和越夏。本研究通过解剖大猿叶虫非滞育成虫,观察描述了雌雄成虫内生殖系统的结构特点,并绘制了雌雄成虫内生殖系统模式图。对滞育初期、滞育期间、滞育解除后未取食和滞育解除后取食成虫解剖显示,滞育初期,雌雄成虫内生殖系统几乎与羽化初期成虫一致。滞育期间雄成虫的附腺和射精管亦不发达,滞育解除后未取食雄成虫的附腺膨大且粗于输精管,射精管略膨大,取食雄成虫的射精管呈不透明淡桔黄色。滞育期间雌成虫的卵巢小,略大于滞育初期卵巢,少数卵巢小管的基部可见具卵黄原沉淀的卵粒。滞育解除后未供食雌成虫卵巢明显膨大可见大量成形卵粒,部分卵粒可见卵黄原沉淀;取食雌成虫的卵巢膨大,可见大量成熟卵粒,侧输卵管和总输卵管中可见待产的卵。作者认为,大猿叶虫成虫在滞育期间能够缓慢发育,部分滞育前积累的代谢物质被用于滞育后发育,但只有经过取食,成虫才能正常交配和产卵。     

The ultrastructure of the ejaculatory duct in the springtail Orchesella villosa (Geoffroy) (Hexapoda, Collembola) and the formation of the spermatophore

The initial part of the ejaculatory duct of Orchesella villosa contains a “valve” and a “sorter” avoiding respectively the reflow and allowing the separation of the secretion for the spermatophore stalk from the sperm fluid. For most of its length, the ejaculatory duct lumen is divided into two parts: in the dorsal part the sperm fluid flows while in the ventral district the secretion for the stalk occurs. Laterally, on both sides of the duct, longitudinal muscle fibers are present. The epithelium of the dorsal region consists of two types of long secretory cells; the most peculiar of them are those provided with extracellular cisterns flowing directly into the duct lumen as it occurs in 1st type of epidermal cells. These cells could be involved in the control of the viscosity of the sperm fluid. The second type of cells produce a secretion probably involved in the formation of the outer coat of the apical sperm droplet. The ventral epithelium consists of short cells contributing to the enrichment of the secretion for the spermatophore stalk and perhaps also to the viscosity of the secretion flowing in the lumen. In the distal part of the ejaculatory duct, the ventral district is provided with a thick layer of muscle fibers and with 3 + 3 cuticular laminae dividing the lumen into a series of slits through which the secretion of the stalk is squeezed out into filaments. This organization allows the twisting and hardening of these filaments. A drop of sperm fluid is laid on top of the long and rigid spermatophore stalk.     

A new species of Alboglossiphonia (Hirudinea: Glossiphoniidae) from Egypt

A new Alboglossiphonia species from Egypt is described and figured. This leech is placed in the genus Alboglossiphonia on the basis of having three pairs of eyes, diffuse salivary glands, seven pairs of crop caeca, and the attachment of its eggs to the venter. It differs from other Alboglossiphonia species with seven pairs of crop caeca in its combination of very prominent dorsal papillae, two annuli between the gonopores, lobed first six pairs of crop caeca, and paired ducts of male system at peak of activity with conspicuously differentiated sperm duct, seminal vesicle and ejaculatory duct regions.     

Diversification and biogeographic history of the Western Palearctic freshwater flatworm genus Schmidtea (Tricladida: Dugesiidae), with a redescription of Schmidtea nova

The freshwater flatworm genus Schmidtea is endemic in the Western Palearctic region, where it is represented by only four species, thus contrasting with the high species diversity of the closely related genus Dugesia within Europe. Although containing an important model species in developmental and regeneration research, viz. Schmidtea mediterranea, no evolutionary studies on the genus Schmidtea have been undertaken. For the first time, we present a well‐resolved molecular phylogenetic tree of the four species of the genus, inferred on the basis of two molecular markers, and provide also the first detailed morphological account of Schmidtea nova. The phylogenetic tree generated corroborates an earlier speciation hypothesis based on karyological data and points to chromosomal rearrangements as the main drivers of speciation in this genus. The high genetic divergence between the four species, in combination with previous dating studies and their current geographic distribution, suggests that Schmidtea could have originated in Laurasia but lost most of its diversity during the Oligocene. Thus, its present distribution pattern may be the result of the expansion of three of its four relictual species over Europe, probably after the Pleistocene glaciations. Our detailed morphological study of S. nova revealed that it shows a number of remarkable features: interconnected testis follicles, parovaria, an ejaculatory duct exiting into the primary as well as the secondary seminal vesicle by means of a nipple, and the wall of the distal section of the ejaculatory duct being sclerotic or chitinized.     

Developmental Expression of the Glucose Dehydrogenase Gene in Drosophila Melanogaster

The Gld gene of Drosophila melanogaster is transiently expressed during every stage of development. The temporal pattern of Gld expression is highly correlated with that of ecdysteroids. Exogeneous treatment of third instar larvae with 20-hydroxyecdysone induces the accumulation of Gld mRNA in the hypoderm and anterior spiracular gland cells. During metamorphosis Gld is expressed in a variety of tissues derived from the ectoderm. In the developing reproductive tract, Gld mRNA accumulates in the female spermathecae and oviduct and in the male ejaculatory duct and ejaculatory bulb. These four organs are derived from closely related cell lineages in the genital imaginal disc. Since the expression of Gld is not required for the development of these reproductive structures, this spatial pattern of expression is most likely a fortuitous consequence of a shared regulatory factor in this cell lineage. At the adult stage a high level of the Gld mRNA is only observed in the male ejaculatory duct.     

Obstructions des canaux éjaculateurs: diagnostic et traitements

The management of male factor infertility has been frustrated by the large group of men with idiopathic infertility in whom treatment options have been limited to either empiric medical thrapy,orassisted reproductive technologies or donor insemination. Therefore, the identification of reversible causes of infertility in these patients is extremely attractive to couples and physicians. Recent reports suggest that partial ejaculatory duct obstruction may be responsible for infertility in some men previously labelled as having idiopathic infertility. Complete ejaculatory duct obstruction is suspected in azoospermic or severely oligospermic patients with low ejaculate volume (less than 1 ml), absence of sperm from the post-ejaculatory urine, normal endocrine studies and normal testis size. Demonstration of dilatation of the seminal vesicles and/or ejaculatory ducts by transrectal ultrasonography is diagnostic of ejaculatory duct obstruction in patients with the afore-mentioned clinical features. However, in the absence of definitive transrectal ultrasonography findings, vasography remains the gold standard for the diagnosis of ejaculatory duct obstruction. Ejaculatory duct obstruction is diagnosed in approximately 5% of azoospermic infertile men and is treated by transurethral incision of the ducts. After the surgical procedure semen parameters can improve and pregnancies have been initiated. Although, the patient must be informed that surgical therapy can also fail and can be associated with significant complications.     

Two species of Prodistomum Linton, 1910 (Digenea: Lepocreadiidae) from marine fishes of Australia

Prodistomum angelae (Kruse, 1981) n. comb. [originally Lepocreadium] is redescribed from the type-host, Scorpis georgiana, from off southwestern Western Australia. P. keyam n. sp. is described from Monodactylus argenteus from off southeastern Queensland. It differs from other members of the genus in its short ejaculatory duct. The genus Prodistomum Linton is discussed and redefined, and an updated key and record list of the nine recognised species are given.