RESUMO
The male accessory glands (MAGs) in insects are pair(s) of internal reproductive organs that produce and secrete the plasma component of seminal fluid. In various insects, MAG size is important for male reproductive success because the fluid provides physiologically active substances and/or nutrients to females to control sperm as well as female reproductive behaviors. Although the MAG epithelial cells in most insect species are standard mononucleate cells, those in some insect taxa are binucleate due to incomplete cytokinesis (e.g., Drosophila [Fallén] [Diptera: Drosophilidae]) or cell fusion (e.g., Cimex [Linnaeus] [Hemiptera: Cimicidae]). In the case of Drosophila, the apicobasal position of the two nuclei relative to the epithelial plane changes from vertical to horizontal after nutrient intake, which allows the volume of the MAG cavity to expand effectively. On the other hand, in the case of Cimex, the positions of the two nuclei do not change apicobasally in response to feeding, but their position relative to the proximodistal axis varies depending on the tubular/spherical organ morphology. Here, we report that the MAG of the benthic water bug Aphelocheirus vittatus (Matsumura) (Hemiptera: Aphelochiridae) shows binucleation in all epithelial cells. Despite the phylogenetically close relationship between Aphelocheirus and Cimex, the MAG cells in Aphelocheirus showed a Drosophila-like apicobasal change in the position of the two nuclei in response to feeding. Furthermore, the cytological processes during binucleation are more similar to those in Drosophila (incomplete cytokinesis) than to those in Cimex (cell fusion). These results indicate that the physiological role and mechanism of binucleation in MAG cells changed during the evolution of Hemiptera.
Assuntos
Hemípteros/anatomia & histologia , Hemípteros/crescimento & desenvolvimento , Animais , Genitália/anatomia & histologia , Genitália/crescimento & desenvolvimento , Genitália/ultraestrutura , Hemípteros/ultraestrutura , Masculino , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Ninfa/anatomia & histologia , Ninfa/crescimento & desenvolvimento , Ninfa/ultraestruturaRESUMO
Eurytrema coelomaticum is a digenean flatworm of ruminants that is the causative agent of eurytrematosis, a disease of veterinary health concern. Although modern techniques of morphological analysis have provided new insights about the morphology and anatomy of parasitic helminths, most studies on E. coelomaticum adults are based on conventional light microscopy. In the present study, a combined approach using brightfield, fluorescence, confocal and scanning electron microscopies (SEMs), together with the cryofracture technique, have updated morphological data on E. coelomaticum recovered from cattle in Rio de Janeiro State, Brazil. Light microscopy confirmed the presence of several structures present in the current description, such as suckers, pharynx, oesophagus, intestinal bifurcation and the cirrus-sac. Fluorescence stereomicroscopy revealed for the first time the cubic crystal protein inclusions in the forebody, which were further detailed by confocal and SEMs. Confocal microscopy provided detailed information of the muscular architecture associated with the attachment structures (suckers), digestive system (pharynx and oesophagus), egg-forming complex (ovary, Mehlis' gland and Laurer's canal) and male reproductive system, which are similar to those found in other digenean flukes. SEM images of cryofractured parasites showed mucus and developing eggs within uterine loops. It was demonstrated that the combination of advanced tools generated complementary information, confirming the importance of experimental morphology in parasitology. Therefore, the knowledge of the adult structural organization of E. coelomaticum was improved and this work has contributed to propose new morphological criteria to evaluate the effects of antiparasitic drugs on flukes of medical and veterinary importance.
Assuntos
Heterophyidae/anatomia & histologia , Heterophyidae/ultraestrutura , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Ovos , Feminino , Genitália/anatomia & histologia , Genitália/ultraestrutura , Masculino , Microscopia Confocal , Microscopia Eletrônica de Varredura , Platelmintos , Infecções por Trematódeos/veterináriaRESUMO
We present a detailed review of fetal development of the male and female human urogenital tract from 8 to 22 weeks gestation at the macroscopic and morphometric levels. Human fetal specimens were sexed based on macroscopic identification of fetal testes or ovaries, Wolffian or Müllerian structures and the presence of the SRY gene in the specimens at or near the indifferent stage (8-9 weeks). Specimens were photographed using a dissecting microscope with transmitted and reflected light. Morphometric measurements were taken of each urogenital organ. During this time period, development of the male and female urogenital tracts proceeded from the indifferent stage to differentiated organs. The kidneys, ureters, and bladder developed identically, irrespective of sex with the same physical dimensions and morphologic appearance. The penis, prostate and testis developed in males and the clitoris, uterus and ovary in females. Androgen-dependent growth certainly influenced size and morphology of the penile urethra and prostate, however, androgen-independent growth also accounted for substantial growth in the fetal urogenital tract including the clitoris.
Assuntos
Diferenciação Celular/genética , Ovário/ultraestrutura , Testículo/ultraestrutura , Sistema Urogenital/ultraestrutura , Feminino , Desenvolvimento Fetal , Feto , Genitália/embriologia , Genitália/crescimento & desenvolvimento , Genitália/ultraestrutura , Humanos , Masculino , Ovário/embriologia , Ovário/crescimento & desenvolvimento , Testículo/embriologia , Testículo/crescimento & desenvolvimento , Sistema Urogenital/crescimento & desenvolvimentoRESUMO
Stevia rebaudiana belongs to the Asteraceae family with high economic and medicinal potential. This article describes and illustrates morphological and histological aspects of leaves and reproductive organs, and the germination process, to provide detailed information on this species and to contribute to taxonomic, phylogenetic and pharmacobotanical projects. The fruit is a cypsela, small, simple, dry, indehiscent, monospermic, light or dark colored, with aristate pappus, and the seed presents a spatulate axile embryo. Germination is phaneroepigeal with a pivotal root system and many absorbing root hairs. The leaves are simple, elliptical to obovate, with two types of trichomes (glandular and tector), with a short petiole, exhibiting an opposite decussate phyllotaxy. Our results showed 37.5% germination after 12 days, only in the dark cypsela, the light colored being considered unviable. The inflorescence is paniculate and the florets are grouped in capitula with isomorphic ends, monoclinous (bisexual), dichlamydeous, heterochlamydeous, pentamerous calyx and corolla, gamossepalous and gamopetalous. The androecium is gamostemone comprised of five stamens with free filaments, isodynamous and epipetalous stamens, synandrous and rimose anthers. The flower presents an inferior ovary, bicarpelar, unilocular and ovules with a basal placentation. The pollen grains are small, isopolar, radial symmetry, tricolporate, with echinate ornamentation.
Assuntos
Germinação/fisiologia , Stevia/embriologia , Genitália/embriologia , Genitália/ultraestrutura , Microscopia Eletrônica de Varredura , Stevia/ultraestruturaRESUMO
Eriophyoids are an ancient group of highly miniaturized, morphologically simplified and diverse phytoparasitic mites. Their possible numerous host-switch events have been accompanied by considerable homoplastic evolution. Although several morphological cladistic and molecular phylogenetic studies attempted to reconstruct phylogeny of Eriophyoidea, the major lineages of eriophyoids, as well as the evolutionary relationships between them, are still poorly understood. New phylogenetically informative data have been provided by the recent discovery of the early derivative pentasetacine genus Loboquintus, and observations on the eriophyoid reproductive anatomy. Herein, we use COI and D1-2 rRNA data of 73 eriophyoid species (including early derivative pentasetacines) from Europe, the Americas and South Africa to reconstruct part of the phylogeny of the superfamily, and infer on the basal divergence of eriophyoid taxa. In addition, a comparative CLSM study of the female internal genitalia was undertaken in order to find putative apomorphies, which can be used to improve the taxonomy of Eriophyoidea. The following molecular clades, marked by differences in genital anatomy and prodorsal shield setation, were found in our analyses: Loboquintus(Pentasetacus((Eriophyidae + Diptilomiopidae)(Phytoptidae-1, Phytoptidae-2))). The results of this study suggest that the superfamily Eriophyoidea comprises basal paraphyletic pentasetacines (Loboquintus and Pentasetacus), and two large monophyletic groups: Eriophyidae s.l. [containing paraphyletic Eriophyidae sensu Amrine et al. 2003 (=Eriophyidae s.str.) and Diptilomiopidae sensu Amrine et al. 2003] and Phytoptidae s.l. [containing monophyletic Phytoptidae sensu Boczek et al. 1989 (=Phytoptidae s.str.) and Nalepellidae sensu Boczek et al. 1989]. Putative morphological apomorphies (including genital and gnathosomal characters) supporting the clades revealed in molecular analyses are briefly discussed.
Assuntos
Ácaros/classificação , Filogenia , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Evolução Biológica , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Genitália/ultraestrutura , Microscopia Confocal , Ácaros/genética , Ácaros/ultraestrutura , RNA Ribossômico 28S/genética , RNA Ribossômico 28S/metabolismoRESUMO
Tardigrades are invertebrates known to science for over 250 years. Although the ability of some species of tardigrades to form cysts has been reported, little is known about the encystment and internal organisation of the cysts. During cyst formation, contraction of the body affects the internal organs' morphology. The organs are compressed and have a compact appearance. The organisation of the digestive system, associated structures, and the reproductive system are analysed in cysts on indefinite and well-defined encystment periods - up to eleven months. The digestive system of encysted animals was organised into three main parts - a foregut, a midgut, and a hindgut. The presence of digestive system-associated structures, such as buccal glands or muscles, was noted and described. The excretory organs, called Malpighian tubules, open into the zone between the midgut and the hindgut. Furthermore, the oviduct opens into the hindgut. The first analysis of the reproductive system of cysts at the ultrastructural level is presented here, revealing interesting and undescribed aspects related to the physiology. Besides the anatomical and histological examination, the morphology and changes that occur during cyst formation are described.
Assuntos
Sistema Digestório , Tardígrados , Animais , Tardígrados/fisiologia , Sistema Digestório/ultraestrutura , Sistema Digestório/anatomia & histologia , Genitália/anatomia & histologia , Genitália/ultraestrutura , Água Doce , Microscopia Eletrônica de Transmissão , FemininoRESUMO
A new pentasetacine mite Loboquintus subsquamatus n. gen. & n. sp. was found living under scale-like leaves of 2-3 years old twigs of Cupressus sempervirens in Montenegro. This mite species possesses a number of morphological features (uncommon teardrop-shaped body, traits of prosoma, atypical primitive anatomy of the genital apparatus and morphological traits of immatures) which clearly distinguish it from all other known eriophyoids. Adults of L. subsquamatus have seta vi situated on the anterior margin of a uniquely elongate lingua-like thin frontal lobe, three pits on the posterior prodorsal shield margin, a remarkable tube-like structure in the basal part of gnathosoma, a complicated three-layered epigynium, spermathecae directed antero-laterad, short spermathecal tubes and setae eu suppressed in males and possibly expressed in females. External genitalia of males and females of L. subsquamatus are fundamentally similar. Hypothesized remnants of coxisterna III or IV (forming a postgenital plate) are remarkably distinct in males. Two new morphometrical variables are proposed to supplement the CLSM protocol for description of internal genitalia of eriophyoids proposed by Chetverikov et al. (Zootaxa 3560:41-60, 2012b): (a) the length of ventral projection of the transvers genital apodeme and (b) the length of the posterior (=postspermathecal) part of the longitudinal bridge which in L. subsquamatus is remarkably long, whereas in many other eriophyoids it is reduced.
Assuntos
Ácaros/classificação , Filogenia , Sequência de Aminoácidos , Animais , Composição de Bases , Classificação/métodos , Código de Barras de DNA Taxonômico , DNA Mitocondrial/química , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Genitália/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura , Ácaros/anatomia & histologia , Ácaros/genética , Dados de Sequência Molecular , Análise de Sequência de ProteínaRESUMO
The fine structural organization of the male and the female inner reproductive apparatuses of the water-strider Gerris lacustris was studied. The sperm of the species shows a long helicoidal acrosome provided with longitudinal tubules, and a short nucleus. The flagellum is characterized by crescent mitochondrial derivatives and a 9 + 9 + 2 axoneme, as occurs in all Heteroptera. The female reproductive apparatus is characterized by an extremely long spermathecal duct, filled with sperm, which plays the role of the main sperm storage organ. The duct has a thin epithelium surrounded by a complex of secretory and duct-forming cells. The spermathecal duct flows into the gynatrial sac. This region, together with the fertilization chamber, exhibits a simple epithelium with deep apical plasma membrane invaginations, and it does not show conspicuous secretions. The basal cell region shows plasma membrane infoldings forming thin cytoplasmic bands hosting mitochondria and large intercellular spaces. This organization is typical of epithelia active in fluid reabsorption. Two lateral large gynatrial glands open into the gynatrial sac. Such glands also exhibit secretory and duct forming cells. The same structure of these glands is also present along the proximal region of the fecundation canal. The duct forming cells of these regions have very wide ducts with peculiar cuticular finger-like structures at their opening into the gland duct lumen. The results of the present study suggest the occurrence of a coevolution between the sperm and the spermathecal duct lengths.
Assuntos
Evolução Biológica , Heterópteros , Animais , Feminino , Genitália/fisiologia , Genitália/ultraestrutura , Heterópteros/classificação , Heterópteros/ultraestrutura , Inseminação , Masculino , Espermatozoides/ultraestruturaRESUMO
BACKGROUND: Accurate species identification of South American anophelines using morphological characters of the fourth-instar larva is problematic, because of the lack of up-to-date identification keys. In addition, taxonomic studies, employing scanning electron microscopy of the eggs and DNA sequence data, have uncovered multiple complexes of morphologically similar species, and resulted in the resurrection of other species from synonymy, mainly in the subgenus Nyssorhynchus. Consequently, the identification keys urgently need to be updated to provide accurate morphological tools to identify fourth-instar larvae of all valid species and species complexes. METHODS: Morphological characters of the fourth-instar larvae of South American species of the genus Anopheles were examined and employed to elaborate a fully illustrated identification key. For species for which no specimens were available, illustrations were based on published literature records. RESULTS: A fully illustrated key to the fourth-instar larvae of South American species of the genus Anopheles (Diptera: Culicidae) is presented. Definitions of the morphological terms used in the key are provided and illustrated. CONCLUSIONS: Morphological identification of South American Anopheles species based on the fourth-instar larvae has been updated. Characters of the spiracular apparatus were determined useful for the identification of morphologically similar species, in the Strodei Group and some taxa in the Myzorhynchella Section. The single versus branched abdominal seta 6-IV used to differentiate Myzorhynchella species from other Nyssorhynchus species was shown to be variable in Myzorhynchella species. Also, the abdominal setae 1-IV,V of Anopheles atacamensis and Anopheles pictipennis were shown to be slightly serrate at the edges. Recognition of this character is important to avoid inaccurate identification of these species as members of the subgenus Anopheles.
Assuntos
Anopheles/anatomia & histologia , Anopheles/classificação , Larva/anatomia & histologia , Animais , Feminino , Genitália/anatomia & histologia , Genitália/ultraestrutura , Larva/classificação , Masculino , Microscopia Eletrônica de Varredura , América do SulRESUMO
Termites are eusocial cockroaches, which have received great attention due to their diversity of reproductive strategies. Although these novelties allow new interpretations concerning the mating biology of these insects, studies highlighting the structure of the reproductive system are limited to some termite lineages. Here we provide the first comparative analysis of the reproductive system of a drywood termite, using different aged males of Cryptotermes brevis as models. This species represents an important structural pest in tropical regions, and most aspects of its reproductive biology remain unknown, especially on males. The reproductive apparatus of C. brevis is equipped with paired testes, composed of seven testicular lobes, in which developing spermatozoa are located. The basal portion of the lobes connects to the vasa deferentia and transport spermatozoa to a pair of enlarged chambers, the seminal vesicles. These structures join in a median ejaculatory duct, which opens to the external region through a retractile penis. Spermatozoa were observed in all C. brevis males, exhibiting elongated morphology and measuring about 10 µm in length/4 µm in width. Compared with last-instar nymphs and alates, functional kings showed enlarged testes and seminal vesicles, as well as an intense secretory activity towards the lumen of the latter structures. Histochemical tests evidenced strongly PAS and xylidine Ponceau positive reactions of the secretion only in functional kings, indicating the occurrence of glycoproteins. Thus, we suggest that morphophysiological changes establish during the maturation of the reproductive system in C. brevis.
Assuntos
Envelhecimento/fisiologia , Genitália/anatomia & histologia , Genitália/crescimento & desenvolvimento , Isópteros/anatomia & histologia , Isópteros/crescimento & desenvolvimento , Animais , Genitália/citologia , Genitália/ultraestrutura , MasculinoRESUMO
Mating plugs have been proposed as a mechanism that has evolved to avoid sperm competition. Their structure and composition vary across taxa and are related to the effectiveness of its function. This effectiveness could be related to different evolutionary interests of the sexes. Urophonius brachycentrus and Urophonius achalensis (Scorpiones, Bothriuridae) are highly suitable species to study mating plugs because both are monandrous species with specific morphological and physiological responses in the female's genitalia. Here, we analyze (a) the morphology and fine structure of the mating plugs of both species, (b) the site of production in males and the formation process of the mating plug, and (c) the changes that it undergoes over time in the female's reproductive tract. In both species, a complex mating plug obliterates the female's genital aperture and fills the genital atrium. We observed considerable interspecific variation in the mating plug morphology. A mating hemi-plug was found surrounding the capsular lobes of the hemispermatophore, which could have a mixed composition (involving portions of the hemispermatophore and glandular products). The glandular portion was transferred in a semi-solid state filling the female's genital atrium and then hardening. Changes that the plug undergoes in the female's genitalia (darkening and increase of the "distal" area of the plug) indicate a participation of the female to the formation of this type of plug. Our study provides new insights into the plugging phenomenon in scorpions, and we discussed the adaptive significance as a post-copulatory mechanism to avoid sperm competition.
Assuntos
Genitália/anatomia & histologia , Escorpiões/anatomia & histologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Genitália/diagnóstico por imagem , Genitália/ultraestrutura , Imageamento Tridimensional , Masculino , Escorpiões/ultraestrutura , Especificidade da EspécieRESUMO
Sea slugs are interesting models to study post-copulatory sexual selection in simultaneous hermaphrodites due to the enormous variation of their reproductive systems. However, the knowledge of the functional morphology of their reproductive system is limited to few species, and it is rarely discussed in the context of sexual selection theory. In this study, we investigated the functional morphology of the sperm-containing chambers (i.e., ampulla, seminal receptacle, and bursa copulatrix) of the reproductive system of Okenia polycerelloides (Ortea & Bouchet, 1983), based on light, confocal, and electron microscopy. Although the morphology of the ampulla is similar to other species, indicating that it is a site for autosperm storage, we found some sperm facing the ampullar epithelium, a feature commonly regarded as characteristic of the seminal receptacle of sea slugs. The seminal receptacle of O. polycerelloides showed secretory activity and contained sperm with distribution and orientation suggestive of stratification of allosperm from distinct mating events, a feature that would affect sperm competition. The bursa copulatrix had epithelial cells with secretory and absorptive characteristics, and contained degraded sperm and yolk granules within its lumen. Comparative analyses of the contents of each organ demonstrated that sperm digestion occurs in the bursa copulatrix and affects sperm heads first, changing their morphology from slender and curved to shorter and ellipsoid before complete lysis. Although digestion and absorption of surplus sperm are currently the main hypothesized functions for the bursa copulatrix, its role in cryptic female choice should not be ruled out. The close structural connection between the seminal receptacle and bursa copulatrix, as well as their muscular walls, would enable control over the fate of the sperm received in each mating event, that is, storage or digestion.
Assuntos
Gastrópodes/anatomia & histologia , Preferência de Acasalamento Animal/fisiologia , Espermatozoides/citologia , Animais , Feminino , Gastrópodes/citologia , Gastrópodes/ultraestrutura , Genitália/anatomia & histologia , Genitália/ultraestrutura , Masculino , Reprodução , Espermatozoides/ultraestruturaRESUMO
Neoechinorhynchus (Neoechinorhynchus) johnii Yamaguti, 1939 is redescribed from Eleutheronema tetradactylum (Polynemidae), Johnius carouna (Sciaenidae), Johnius sp., and Otolithes ruber (Sciaenidae) along the north and south coasts of Vietnam. Our description completes missing and inadequate information in the original descriptions and line drawings from Johnius goma in Japan and from Pseudosciaena diacanthus in the Indian Ocean. We add new information documented by scanning electron microscopy (SEM) and photomicroscopy, and explore the wide morphological diversity attributed to host species. The redescription includes: worms cylindrical with round proboscis with prominent apical organ, and large anterior hooks distant from small middle and posterior hooks; neck longer than the proboscis, nucleated lemnisci subequal, and receptacle with large basal triangulate cephalic ganglion and attached para-receptacle structure (PRS); male reproductive system in posterior half of trunk; adult females with introvert genital vestibule; and eggs spherical or rectangular. Gallium cuts and X-ray scans of hooks show high concentrations of sulfur on edge layer aiding in forming hardened calcium phosphate apatite of that layer with calcium and phosphorus in higher concentration in central part of hook. Molecular results consistently yielded a strongly supported distinct clade for the Neoechinorhynchus species from Vietnam for both 18S gene and the ITS1-5.8S-ITS2 region of ribosomal RNA. Phylogenetic analysis demonstrated that N. johnii occupies a separate position in the trees, probably indicating an Asian origin of this species.
Assuntos
Acantocéfalos/anatomia & histologia , Acantocéfalos/classificação , Doenças dos Peixes/parasitologia , Peixes/parasitologia , Filogenia , Acantocéfalos/ultraestrutura , Animais , DNA Intergênico/genética , Feminino , Genitália/ultraestrutura , Helmintíase Animal , Masculino , Microscopia Eletrônica de Varredura , Oceano Pacífico , RNA Ribossômico 18S/genética , VietnãRESUMO
The pharaoh cuttlefish, Sepia pharaonis, is an important cephalopod fishery species in southeastern Asia, with understudied reproductive physiology. The present study aimed to investigate the cellular characteristics of epithelial cells found in the nidamental glands (NGs) and accessory NGs (ANGs), as well as the structural connections between these two glands in mature female S. pharaonis. A histological analysis revealed two types of epithelial cells in NGs: Alcian blue-positive, PAS-negative mucosubstance-secreting cells and eosinophilic, PAS-positive granule-secreting cells. Using transmission electron microscopy, three types of epithelial cells were identified: cells with electron-dense granules, cells with electron-lucent granules, and cells with both cilia and microvilli in the apex. Mature ANGs contain an abundance of tubular units composed of epithelial cells resting on a thin layer of basal lamina. Innervated muscle cells are tightly adhered to the basal lamina. In addition, we observed epithelial canalization of ANG tubules penetrating through the connective tissue linking NGs and the walls of the tubules in ANGs, which allows the contents of the ANG tubules to be transported to the NGs. Our results suggest that ANGs participate in the encapsulation of the ova via the same pathway as NGs, which provides an important basis for future studies on the mechanism of protection provided by NGs and ANGs during embryonic development in S. pharaonis.
Assuntos
Genitália/anatomia & histologia , Óvulo/fisiologia , Sepia/anatomia & histologia , Animais , Células Epiteliais/citologia , Feminino , Genitália/citologia , Genitália/ultraestrutura , Sepia/citologia , Sepia/ultraestruturaRESUMO
The study describes the morphology and topography of internal reproductive organs in the domestic cat from the early prenatal period to maturity, using macroscopic and scanning electron microscope (SEM) observations with three-dimensional (3D) reconstructions. Fifty-seven female cat fetuses aged between the 27th and 63rd day postconception (p.c.), two newborn cats, three juveniles (3-month-old) cats, and three mature (12-month-old) cats were used in the study. The age of fetuses was determined on the basis of the growth curve for the domestic cat. The rudiments of cat ovaries develop on the ventral surface of the mesonephroi and within 30 days p.c. move to the sides of the abdominal cavity, which is similar to the position of the ovaries in the adult cat. The mesonephroi regress at about the 50th day p.c., when the residual mesonephric ducts are still found in the lower part of the body of the uterus. The paramesonephric ducts develop on the lateral surface of the mesonephroi and by the 45th day p.c., differentiate into the uterine tubes and the uterus. The arrangement of the paramesonephric ducts in the abdominal cavity changes from the U- to the V-shaped system. The final topography of the uterine tubes is established between the 54th and 60th day p.c., as the uterine tubes become convoluted. Before the 54th day p.c., the uterine horns undergo rapid elongation and convolution, forming the W-shaped system. By the third month of postnatal life, the uterine horns become straight, as in the adult cat.
Assuntos
Gatos/anatomia & histologia , Gatos/crescimento & desenvolvimento , Genitália/anatomia & histologia , Genitália/ultraestrutura , Imageamento Tridimensional , Microscopia Eletrônica de Varredura , Animais , Animais Recém-Nascidos , Tubas Uterinas , Feminino , Genitália/crescimento & desenvolvimento , Ovário , ÚteroRESUMO
Megasecoptera is an extinct group of insects with specialized rostrum-like mouthparts, which is a synapomorphy shared with all members of the Late Paleozoic Palaeodictyopterida, and markedly slender wings that are unable to flex backwards. Here we describe the close up morphology of Protohymenidae and Scytohymenidae and uncover new aspects of the endoskeleton (tentorium) of the head, structure of the mouthparts with discernible proximal part of stylets controlled by muscles, surface of compound eyes that consist of a hexagonal pattern of large facets, structure and microstructures on the wings and reconstruct male and female external genitalia using ESEM and light stereomicroscopy. Furthermore, we describe Protohymen novokshonovi sp. n. based on an exceptionally well preserved fossil from the early Permian at Tshekarda in Russia, which shows crucial details, and the earliest species of Protohymenidae, Carbohymen testai gen. et sp. n. from a late Carboniferous siderite nodule at Mazon Creek in Illinois, USA. Our comparative study confirmed a set of structural and microstructural details on their wings, such as the composite anterior wing margin, development of an apical cell and the previously unknown external genitalia. Based on the results and comparison of homologous structures known primarily for extant relatives, such as mayflies and dragonflies, we outline for the first time the function of the mouthparts, in particular, the stylets, structure of the tentorium, vision provided by large hexagonal ommatidia and male copulatory structures bearing curved claspers for holding a female during copulation and penial lobes with seminal grooves.
Assuntos
Fósseis/anatomia & histologia , Insetos/anatomia & histologia , Insetos/classificação , Asas de Animais/anatomia & histologia , Animais , Fósseis/ultraestrutura , Genitália/anatomia & histologia , Genitália/ultraestrutura , Insetos/ultraestrutura , Microscopia Eletrônica de Varredura , Boca/anatomia & histologia , Boca/ultraestrutura , Asas de Animais/ultraestruturaRESUMO
Gold, a heavy yellow-colored metal, is usually found in nature as a metallic element or as salts. This noble metal historically had a reputation as an anti-inflammatory medicine for rheumatoid arthritis, a nervine, and a remedy for nervous disorders, as well as a potential anticancer agent. It has also been used as component in dental restorations and in implant materials. The present study was undertaken to point out histological and ultrastructural effects of gold, administered by intraperitoneal route, in pregnant female reproductive organs (ovary and uterus), in order to clarify its side effects on the reproductive function. Using the transmission electron microscopy (TEM), the ultrastructural investigations of both ultrathin ovarian and uterine sections of treated pregnant rats revealed the existence of numerous heterogeneous clusters with very electron-dense inclusions characterized by various aspects in the lysosomes of granulosa, theca interna cells, and theca externa cells. Degeneration of these tissues, like cell vacuolization, marked expansion of the endoplasmic reticulum, mitochondrial alterations, and necrotic foci, were also highlighted. Moreover, huge phagolysosomes and high numbers of eosinophils as signs of inflammation were also identified especially in endometrial and myometrial cells of gold-treated rats. The ultrastructural investigations of reproductive organ sections of control pregnant rats showed a normal ultrastructural aspect and no loaded lysosomes. These results speculated the toxicity of gold at the used dose. The observed signs of toxicity allowed concluding that the important role of lysosome in the sequestration of this element under an insoluble form in all categories of cells in the studied tissues does not seem to be efficient.
Assuntos
Ouro/farmacologia , Ovário/ultraestrutura , Útero/ultraestrutura , Animais , Endométrio/efeitos dos fármacos , Endométrio/ultraestrutura , Feminino , Genitália/efeitos dos fármacos , Genitália/ultraestrutura , Microscopia Eletrônica de Transmissão , Miométrio/efeitos dos fármacos , Miométrio/ultraestrutura , Ovário/efeitos dos fármacos , Gravidez , Ratos , Útero/efeitos dos fármacosRESUMO
Sexual conflict can produce several evolutionary outcomes, one of which is female-limited trait polymorphism. We examine the African bat bug Afrocimex constrictus (Cimicidae), a species where both sexes are subjected to traumatic intromission from males. We show that males possess female genital structures that in related species ameliorate the costs of traumatic insemination. Moreover, the male form of these structures differs morphologically from the standard female form. Examination of females in our isolated study population revealed a discrete polymorphism in female genitalia. Some females had the typical cimicid form, while others had genitalia that more closely resembled the distinctive male form. Males, as well as females with the distinctive male form, experienced fewer traumatic copulations than the typical female morph. We propose that some females mimic the bizarre male condition in order to reduce the frequency of costly traumatic inseminations. To our knowledge this is the first example of a distinct female-limited genital polymorphism: its nature, as well as its association with traumatic sexual interactions, strongly suggests that sexual conflict underpins this unique phenomenon.
Assuntos
Cimicidae/genética , Cimicidae/fisiologia , Copulação/fisiologia , Polimorfismo Genético , Animais , Cimicidae/ultraestrutura , Feminino , Genitália/ultraestrutura , Masculino , Reprodução/fisiologiaRESUMO
Archaeognatha represent the oldest living lineage of true insects (=Ectognatha), which are remarkable, among others, for plesiomorphic genital morphology and complicated mating behaviour. I used scanning electron microscopy and He-ion microscopy to examine the ovipositor morphology of seven species, in order to describe the cuticle microsculpture. The species studied are characterised by different types of the ovipositor setation pattern, which are considered an important taxonomic feature for Archaeognatha. The common and well discernible elements of ovipositor setation in Archaeognatha are: (1) non-articulated terminal seta, (2) grooved type I basiconic sensillum with apical pore, (3) multiporous type II basiconic sensillum, (4) articulated setae of different length. Coeloconica-like sensilla and campaniform sensilla demonstrate a variety of transient morphology. Results of this study provide morphological evidence of presence of olfactory receptors on the ovipositor in Archaeognatha. The possible functions of the ovipositor setation in Archaeognatha are discussed.
Assuntos
Genitália/fisiologia , Genitália/ultraestrutura , Insetos/fisiologia , Insetos/ultraestrutura , Oviposição , Animais , Microscopia Eletrônica de VarreduraRESUMO
Impaired androgen activity induces defective sexual differentiation of the male reproductive tract, including hypospadias, an abnormal formation of the penile urethra. Androgen signaling in the urethral mesenchyme cells (UMCs) plays essential roles in driving dimorphic urethral development. However, cellular events for sexual differentiation remain virtually unknown. In this study, histological analyses, fluorescent staining, and transmission electron microscopy (TEM) were performed to reveal the cellular dimorphisms of UMCs. F-actin dynamics and migratory behaviors of UMCs were further analyzed by time-lapse imaging. We observed a prominent accumulation of F-actin with poorly assembled extracellular matrix (ECM) in female UMCs. In contrast, thin fibrils of F-actin co-aligning with the ECM through membrane receptors were identified in male UMCs. Processes for dimorphic F-actin assemblies were temporally identified during an androgen-regulated masculinization programming window and spatially distributed in several embryonic reproductive tissues. Stage-dependent modulation of the F-actin sexual patterns by androgen in UMCs was also demonstrated by time-lapse analysis. Moreover, androgen regulates coordinated migration of UMCs. These results suggest that androgen signaling regulates the assembly of F-actin from cytoplasmic accumulation to membranous fibrils. Such alteration appears to promote the ECM assembly and the mobility of UMCs, contributing to male type genital organogenesis.