21 resultados para Spermatheca


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The presence of spermatozoa in vesicles in the cytoplasm of the epithelial cells that constitute the spermathecal wall of Melipona bicolor queen (Meliponini) is discussed in relation to the organ structure. The epithelial wall is lined by an apparently continuous cuticle in the luminal surface that should be a non-transposable barrier to the luminal spermatozoa. However, some spermatozoa were seen crossing the cuticle through interruptions that was first interpreted as sectioning defects. Nevertheless, the sperm cells in well-structured cytoplasmic vesicles, bound by membranes and sometimes associated to multivesicular bodies, as well as cytoplasmic structures representative of intracellular digestion and the occurrence of the phenomenon in two of the three spermathecae studied, suggest a real spermiophagic hole in the spermathecal epithelial cells.

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The structure of the spermatheca was investigated in specimens of five termite families with the aid of light microscopy. In longitudinal section, the spermatheca of Zootermopsis nevadensis (Termopsidae) showed the shape of an umbrella with a secretory portion and duct. The other termite species, which belong to the families Kalotermitidae, Serritermitidae, Rhinotermitidae and Termitidae showed a spermatheca constituted only by the secretory portion. This structure was an elongate, fingerlike tube with a recurved and blind extremity. The spermatheca wall was composed of a single epithelium formed by class 3 secretory cells with a lumen lined by cuticle. The cuticle was thin and smooth or thick with digitiform projections in the species examined. All the termite females showed bundles of musculature outside of the spermatheca.

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Estudos em animais experimentais evidenciaram associações significativas entre esquistossomose mansoni e hipercolesterolemia. Estudos in vitro e in vivo já demonstraram que o colesterol é essencial para Schistosoma mansoni, embora este não tenha capacidade de sintetizá-lo. A captação é realizada a partir do ambiente (cultivo ou hospedeiro) através do tegumento. O colesterol está envolvido nos mecanismos de evasão do helminto contra a resposta imunológica, além de poder participar na modulação da sinalização celular e reprodução, estimulando os órgãos reprodutores dos helmintos adultos como observado na fase aguda da infecção experimental. Este trabalho tem como objetivo avaliar se o mesmo fenômeno ocorre na fase crônica. Os helmintos foram recuperados de dez camundongos submetidos à dieta hiperlipídica ou padrão (controle) foram corados pelo carmin cloridrico e montados, individualmente, em lâmina histológica com bálsamo do Canadá. A preparação foi analisada por microscopia de campo claro nos seguintes caracteres: tegumento e o sistema reprodutor nos vermes machos (lobos testiculares, vesícula seminal, lobos testiculares supranumerários e canal ginecóforo) e, nas fêmeas (ovário, oótipo, útero, ovo, glândulas vitelínicas e espermateca). Posteriormente, algumas lâminas foram separadas para visualização pela microscopia confocal dos órgãos do sistema reprodutores acima descritos. Apesar de ter sido observado uma maior quantidade de espermatozoides, uma maior quantidade de oócitos sendo liberados no grupo da dieta, não houve diferença estatística significativa (p>0,05) entre os grupos analisados. Houve um aumento na oogênese como observado na fase aguda. Dessa forma, o colesterol pode estar relacionado com a estimulação na atividade dos órgãos reprodutores dos helmintos adultos na fase crônica da infecção.

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Fridericia dianchiensis, a new enchytraeid species collected from Yunnan Province, is described here. It is characterized by a combination of the following characters: 1) lateral bundles containing maximum 3 chaetae; 2) esophageal appendages with 3-4 simple, terminal branches; 3) dorsal vessel originating in XX-XXIII; 4) sub-neural glands absent; 5) seminal vesicle large, occupying two segments; 6)clitellum girdle-shaped or gland cells absent between bursal slits and pre-middle ventrally; 7) coelomocytes without refractile vesicles, 8) spermatheca without diverticula and both ampullae broadly united; and 9) long spermathecal ectal duct without gland at the orifice.

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We describe three enchytraeid species, including two new species, from Mt. Changbaishan, Jilin Province, northeastern China. Oconnorella cheni sp. nov. is characterized by a simple spermatheca; absence of the oesophageal appendages and seminal vesicle; and nephridia from 6/7, with a distinct funnel and the efferent duct arising from the anterior part of the postseptale. Oconnorella globula sp. nov. is distinguished by a spermatheca with two diverticula; lack of oesophageal appendages and seminal vesicle; and nephridia from 6/7, with distinct funnel and the efferent duct arising from the mid-ventral or posteroventral part of the postseptale. We redescribe Oconnorella changbaishanensis (Xie et al., 2000) from type and live specimens, and amend some characters that cannot be investigated clearly from mounted specimens. We revise the generic diagnosis of Oconnorella.

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Bryodrilus fuscistriatus, a new enchytraeid species from Mt. Changbaishan, Jilin Province, north-eastern China, is described. It is characterized by brown epidermal glands, 7 pairs of preclitellar nephridia, poorly-developed clitellar glands, spermatheca with 2 sessile globular diverticula, and a long sperm funnel with a very broad collar. It is similar to the Alaskan B. tunicatus Dozsa-Farkas & Christensen, 2002 in possessing two diverticula in the spermathecal ampulla and the origin of the dorsal vessel, and the Chinese B. longifistulatus and B. macrotheca Xie et al., 2000c in body size, long sperm funnel and undeveloped clitellar glands, but it differs from B. tunicatus by the presence of brown-striped epidermal gland cells in III-V, a poorly-elevated clitellum, the absence of copulatory glands in XIII-XIV, the regular outline of coelomocytes, and 7 pairs of preclitellar nephridia; from B. longifistulatus and B. macrotheca by the shape of spermatheca, the color of epidermal gland cells, the position of the first pair nephridia, and the origin of dorsal vessel.

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We describe the mating behavior in the spermatheca-lacking theraphosid species Sickius longibulbi Soares & Camargo 1948. The behavior in captivity of nine pairs of S. longibulbi was videotaped and analyzed. The matting of this species presented an uncommon theraphosid pattern. There is little in the way of overt courtship by the male, the primary behavior seen being the male`s use of legs I and II to touch the female`s first pairs of legs and her chelicerae. Sometimes the male clasped one of the female`s first pairs of legs, bringing her close to him. While the female raised her body, the male clasped her fangs and held her tightly with his legs III wrapped around her prosoma. The male seemed to try to knock the female down, pushing her entire body until she lay on her dorsum. In this phase we observed the male biting the female on the sternum or on the leg joints. When the female fell, the male attempted to position himself at an angle of 90 degrees from the female. These movements appear to demand a lot of energy, particularly because the female is not passive during the mating. Our findings suggest that copulating in this position is, for the male, more successful than adopting other positions because it allows his extremely long palpal bulbs to deposit more sperm in the female oviduct where - since she lacks spermathecae - she retains the sperm. We suggest that the further he reaches into the oviduct, the greater the chance that he will fertilize the female`s eggs.

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We describe Kochiana new genus to accommodate a small Brazilian theraphosine species described originally as Mygale brunnipes by Koch (1842), resulting in Kochiana brunnipes new combination. Recently, specimens were rediscovered in northeastern Brazilian Atlantic rainforest. A preliminary cladistic analysis using equal weights parsimony and implied weights, was carried out to examine its phylogenetic placement. Kochiana new genus was monophyletic in all trees regardless of weighting scheme or concavity used. There is preliminary evidence for Kochiana new genus monophyly and weak evidence for its placement as sister group of Plesiopelma. Kochiana new genus can be characterized by the presence of a hornshaped spermatheca in females and males with a palpal bulb having prolateral accessory keels and a well developed medial crest on the embolus apex.

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The present work showed that the newly emerged queen weight, the number of ovarioles. and the spermatheca mass are not influenced by the sizes of the wax cups. The first two characters suffered time transference influence, and the best acceptances were obtained mainly, in wax cups with diameters of 7, 8, and 9 min.

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Chromosome evolution, in the Bidens genus, was by polyploidy mechanisms. The basic number to the genus is X = 12 chromosomes, as all the Fitchinae subtribe. The association of chromosome number and environment in these plants was made some time ago, concerning the cytotypes of the species. In this paper, the chromosome number of nine Bidens pilosa populations was studied. The chromosome numbers found were 2n = 48, 70 and 72. In six of the nine populations analysed the most frequent number was 2n = 72. The Ibiuna population had 2n = 70 chromosomes and two had the lowest chromosome number (2n = 48). Observations of the B. pilosa population suggests that ploidy levels were related to a geographical gradient establishing the environmental altitudes. The data showed that lower ploidy levels, that is 2n = 48, were found at lower altitudes, while the populations higher ploidy levels were found in several environments, over a wide distribution.

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Toward the end of the larval phase (pre-pupa), the reproductive systems of Melipona quadrifasciata and Frieseomelitta varia workers are anatomically similar. Scanning electron microscopy showed that during this developmental phase the right and left ovaries are fused and form a heart-shaped structure located above the midgut. Each ovary is connected to the genital chamber by a long and slender lateral oviduct. During pupal development, the lateral oviducts of workers from both species become extremely reduced due to a drastic process of cell death, as shown by transmission electron microscopy. During the lateral oviduct shortening, their simple columnar epithelial cells show some signs of apoptosis in addition to necrosis. Cell death was characterized by cytoplasmic vesiculation, peculiar accumulation of glycogen, and dilation of cytoplasmic organelles such as mitochondria and rough endoplasmic reticulum. The nuclei, at first irregularly contoured, became swollen, with chromatin flocculation and various areas of condensed chromatin next to the nuclear envelope. At the end of the pupal phase, deep recesses marked the nuclei. At emergence, worker and queen reproductive systems showed marked differences, although reduction in the lateral oviducts was an event occurring in both castes. However, in queens the ovarioles increased in length and the spermatheca was larger than that of workers. At the external anatomical level, the reproductive system of workers and queens could be distinguished in the white- and pink-eyed pupal phase. The metamorphic function of the death of lateral oviduct cells, with consequent oviduct shortening, is discussed in terms of the anatomical reorganization of the reproductive system and of the ventrolateral positioning of adult worker bee ovaries. (C) 2000 Wiley-Liss, Inc.

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This paper describes the influence of the colony cycle on caste differences in Protonectarina sylveirae. Despite invariably keeping the main aspects of the conspicuous dimorphism between the castes, it is shown that: 1- queen-worker differences varied according to the progress of the colony cycle, 2- queens in pre-emergence colonies were smaller than those in male-producing ones, 3- workers were larger in pre-emergence than in other colony stages, 4- at particular steps of the colony cycle, non-inseminated ovary-developed queens and workers were detected. The size of the spermatheca differed between inseminated and non-inseminated queens with the highest values appearing in those bearing the most developed kind of ovary development. Differences between inseminated and non-inseminated queens were found in tergites III and IV, ovarian development and amount of fatty tissues. Because tergite size relates to gaster size, this character may be an important stimulus for selection of larger queens in the course of the colony cycle.

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This is a histological and histochemical analysis of the terminal portion of the female reproductive system and genital ducts of the blue land crab (Cardisoma guanhumi). Animals were collected in the Jaguaribe estuary (Ceará, Brazil) and dissected. Genital duct fragments were fixed and submitted to different staining techniques. The female reproductive system consists of a pair of ovaries and a pair of genital ducts. In the mid-posterior portion of each lobe, the ovaries communicate with the genital ducts, which are subdivided into oviduct, spermatheca, vagina, and gonopore. Histologically, the spermatheca of C. guanhumi is composed of columnar secretory epithelium and is divided into a dorsal zone and a ventral zone, the latter covered internally by a cuticle layer. Both zones are enveloped by a thin layer of loose connective tissue. Histological cross sections revealed the vagina to be concave, a pattern considered phylogenetically more advanced than the simple, tubular form. Our findings suggest fertilization is internal, favoring sperm from the most recent copulation. © 2012 The Authors. Acta Zoologica © 2012 The Royal Swedish Academy of Sciences.