Axoneme
Mostrando 1-12 de 70 artigos, teses e dissertações.
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1. Cytogenetics and sperm ultrastructure of Atelopus spumarius (Anura, Bufonidae) from the Brazilian Amazon
The current taxonomy of most Atelopus species is based on morphological and color data only. Recent studies suggest that A. spumarius may represent a species complex assigned under the same name. Karyotypic data and description of sperm ultrastructure for 13 specimens of A. spumarius are presented here for the first time. A chromosomal analysis revealed 2n =
Genet. Mol. Biol.. Publicado em: 03/09/2013
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2. Caracterização ultraestrutural dos espermatozóides de três espécies do gênero Idarnes
Idarnes is a nonpollinating fig wasp genus associated with Ficus, section Americana. These wasps are known as mutualisms parasites because they exploit the mutualism established between the fig and their pollinator, causing a negative effect on pollinator wasp production, therefore affecting the figs ability to disperse pollen. We studied three species of Id
Publicado em: 2010
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3. Análise morfológica das espermátides e dos espermatozóides de Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) nos tratos reprodutores
Diptera constitutes one of the four largest orders of insects. The Oriental latrine-fly Chrysomya megacephala (Fabricius) belongs to the family Calliphoridae and is associated with medic, veterinary, sanitary and forensic issues. The aim of this research was to characterize the utrastructural aspects of the spermiogenesis and spermatozoa of the C. megacephal
Publicado em: 2008
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4. Morfologia do sistema reprodutor masculino e dos espermatozóides de duas espécies de Ichneumonidae (Hymenoptera: Ichneumonoidea) / Male reproductive system and sperm morphology in two Ichneumonidae (Hymenoptera: Parasitic)
The male reproductive system of the Lymeon dieloceri and Myschocyttarus atramentarius parasitoids is formed by a pair of testes with one folicles each, a pair of accessory glands, a pair of vasa deferentia and one ejaculatory duct. The vasa deferentia are thin, long, without characteristic dilatation of the seminal vesicle, and they get in the base of the te
Publicado em: 2007
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5. Structure and ultrastructure of the spermatozoa of Prorops nasuta (Hymenoptera : Bethylidae) / Estrutura e ultra-estrutura dos espermatozóides de Prorops nasuta (Hymenoptera : Bethylidae)
Nas relações evolutivas entre os Hymenoptera ainda há muitas dúvidas devido à sua considerável diversidade, ao grande número de espécies e também ao pequeno tamanho da maioria dos himenópteros parasitóides, o que dificulta sua classificação. As investigações ultra-estruturais dos espermatozóides têm fornecido valiosas contribuições para o
Publicado em: 2007
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6. Ultra-estrutura e citoquimica dos espermatozoides em Euptoieta hegesia (Insecta : Lepidoptera) ao longo dos tratos reprodutores masculino e feminino
Butterflies and moths present one of the most evident examples of sperm polymorphism, with the production of two types of spermatozoa: the apyrene and the eupyrene, that differ in functional and morphological characteristics. Ultrastructural studies were carried out to describe the morphology and organization of both sperm types along the male and female rep
Publicado em: 2003
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7. IN VITRO ACTION OF COBRA VENOM ON GOAT SPERMATOZOA ULTRASTRUCTURE BY TRANSMISSION AND SCANNING ELECTRON MICROSCOPY
Goat spermatozoa were incubated in vitro in Tris-citrate buffer, pH 7.2, containing 0, 40, 80, or 160 mug of Naja haje venom/mL buffer for 4 hours. During incubation, the percentages of sperm motility were decreased, while percentages of dead spermatozoa were increased in a time and concentration-dependent manner. The effect of venom concentrations on the ul
Journal of Venomous Animals and Toxins. Publicado em: 2002
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8. Estrutura fina do espermatozóide de Mellita quinquiesperforata Leske (Echinodermata) do litoral norte do Brasil
The fine structure of the spermatozoon in the Mellita quinquiesperforata Leske, 1778 was studied. Collected from the Amazon region, were described by light and transmission electron microscopy. The spermatozoon consisted of a acrosome complex, nucleus, four to six mitochondria, two centrioles and flagellum. The acrosome was composed of a acrosome complex, th
Revista Brasileira de Zoologia. Publicado em: 2000-09
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9. Estudo ultra-estrutural da espermiogenese e dos espermatozoides de Cosmopolites sordidus germar (Coleoptera : Curculionidae)
The spermiogenesis of Cosmopolites sordidus was investigated with the use of thin sections, negative staining preparations, and scanning electron microsoopy of spermatic cells obtained from the testicles or spermathecae.1n this species as with insects in general, this process is characterized by the following events: flagellar formation, chromatin condensati
Publicado em: 1993
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10. Estudo estrutural, ultra-estrutural e citoquimico da espermatogenese, com enfasena espermiogenese de Hyla ranki (amphibia, anura, hylidae)
The present study was undertaken to determine morphologically, cytochemically and ultrastructurally the maturation process of spermatozoa Of Hyla rank. Histological and cytochemical.techniques where used with sections of material included in paraffin, as .well as observation of semi-thin and ultra-thin sections of testicles included 1n epan. Analysis of the
Publicado em: 1990
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11. Kinesin force generation measured using a centrifuge microscope sperm-gliding motility assay.
To measure force generation and characterize the relationship between force and velocity in kinesin-driven motility we have developed a centrifuge microscope sperm-gliding motility assay. The average (extrapolated) value of maximum isometric force at low kinesin density was 0.90 +/- 0.14 pN. Furthermore, in the experiments at low kinesin density, sperm pulle
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12. Structural Analysis of Mutations in the Drosophila β2-Tubulin Isoform Reveals Regions in the β-Tubulin Molecule Required for General and for Tissue-Specific Microtubule Functions
We have determined the lesions in a number of mutant alleles of βTub85D, the gene that encodes the testis-specific β2-tubulin isoform in Drosophila melanogaster. Mutations responsible for different classes of functional phenotypes are distributed throughout the β2-tubulin molecule. There is a telling correlation between the degree of phylogenetic conserva