Cell junctions in fish seminiferous epithelium

Similar to mammals, in fish the cellular interactions between Sertoli cells (SC) and germ cells (GC) in the seminiferous epithelium have important structural and functional roles. In this review, we give a brief summary of these interactions, in particular those on the cell junctions. Despite the scarcity of detailed empirical data, it appears that both basic types of adhesive junctions (actin- and intermediate filaments-related) are present between SC. However, the actin-related multifunctional junction known as the ectoplasmic specialization is seemingly present only in some cartilaginous fish. Conversely, SC in other fish species are joined by actin-related junctions similar to typical zonulae or puncta adherens found in other epithelia. Adhesive junctions are also found between SC and GC and between GC and GC, and due to their particular characteristics these junctions are known as desmosome-like junctions. In terms of intercellular communication, connexins and gap junctions have been shown to occur between SC in fish, and they may be involved in the coordination of the synchronous development of GC within the cysts. It is also possible that gap junctions may form an interconnected network between SC and GC within a cyst. Concerning the SC barrier, tight junctions between fish SC apparently form a functional barrier only in cysts containing haploid GC, and different from mammals, meiotic GC in fish are not shielded from the vascular system. In summary, although still not well investigated, cell-cell interactions in the seminiferous epithelium of fish seem to be crucial for GC development, and their disturbance, for example by changing environmental conditions, will probably affect GC survival and fertility. © Springer Science+Business Media B.V. 2008.

Arranjos configurados pelos nervos do plexo braquial no urubu (Coragyps atratus foetens - Linnaeus, 1758)

The anatomical study of the origin and distribution of brachial plexus in vulture (Coragyps atratus foetens) was performed in 14 animals, adults, males and females, deriving of the region of Araçatuba (SP). After fixed in watery solution of formaldehyde 10,00%, became dissected bilateral of the origin of the brachial plexus, and yours distribution. The analysis allowed verify that brachial plexus of vulture, four root possess, which originate from the ventral branches of cervical spinal nerves eleven (C11), twelve (C12) and thirteen (C13) and of the ventral branches of thoracic spinal nerve one (T1) and (T2) in both sides (100%). The first root part of C11 in the right and left side, and of the edge skull of the dorsal lace the nerves subescapular, subcoracoescapular e supracoracóide in both antímeros (100%). As the root originates from C12 in both sides, giving origin to the dorsal lace, giving the axilar, radial and anconeal nerves (100%). The third root of plexus originates solely from C13 (100%) and the root of T1 in both sides (100%). The roots of C12, C13 and T1 was united the ventral lace originates, which breaks the nerves to medianoulnar that divided in medium and to ulnar and the pectoral nerves (100%). T2 emits filaments that join it root nervous of T1, being one filament (35,55%) and two filaments (64,29%) in side right, while that in the left one filament (42,85%), two filaments (50%) and three filaments (7,15%).

The taxonomic value of floral characters in Rapateaceae (Poales-Monocotyledons)

The floral anatomy of Cephalostemon, Monotrema, Rapatea, Spathanthus, and Stegolepis was studied for taxonomic purposes. All species studied share colleters between the floral parts; sepals, petals, anthers, and style covered by an ornamented cuticle; short epidermal cells with sinuous walls on the abaxial surface of the petals; tetrasporangiate anthers with phenolic idioblasts in the epidermis; endothecium with spiral thickenings; incompletely septate ovary; and anatropous, bitegmic ovules. The floral anatomy is useful not only for characterizing the family, but also for delimiting the subfamilies and genera. Sepals with silica bodies in the epidermal cells; mature anther wall composed of epidermis, endothecium, and middle layer; absence of phenolic idioblasts in the sepals, filaments, and ovary; and stylar epidermal cells with thickened external periclinal wall support Rapateoideae. Cephalostemon and Rapatea show a great number of similarities, corroborating their close relationship indicated in the phylogenetic analyses of the family. Monotrema shares few characters with the genera of Rapateoideae, corroborating its placement in Monotremoideae. Stegolepis shows several distinctive characters, probably related to the greater diversity found in this genus. © 2012 Springer-Verlag Wien.

Intriguing thigmonastic (sensitive) stamens in the Plains Prickly Pear Opuntia polyacantha (Cactaceae)

The movement of sensitive stamens in flowers of the Plains Prickly Pear (Opuntia polyacantha) is described in detail along with the external and internal filament anatomy. The goals of this investigation were: (1) to provide a synthesis of floral phenology and determine whether this rather unique stamen movement is nastic or a tropism and (2) to conduct macro- and micro-morphological analyses of filaments to determine if there are anatomical traits associated with this movement. To better understand the internal and external structure in sensitive filaments of O. polyacantha, we performed comparative anatomical analyses in two additional species from the Opuntioideae with stamens lacking such sensitivity. The consistent unidirectional movement of stamens, independent of the area stimulated, indicates a thigmonastic response. This movement serves multiple purposes, from enhancing pollen presentation to facilitating cross-pollination, protecting pollen and preventing insects from robbing pollen. Anatomically, the sensitive and non-sensitive filaments exhibit different tissue organization. Cuticle thickness, presence of capsular structures, two layers of curved cells, and more and larger intercellular spaces are characteristic of sensitive filaments. A thin unicellular epidermal layer is characteristic in sensitive filaments versus 2-3 epidermal layers in non-sensitive filaments. Another striking feature in sensitive filaments is the presence of papillae and capsular structures. We believe that these elements are related to water mobility with subsequent contraction during the thigmonastic response. Capsular structures might have a role in fluid mobility according to the stimulus of the filaments. We hypothesize that the thigmonastic response is controlled by cells with elastic properties, as evidenced by the plasmolyzed curved and contracted cells in the filaments and the fact that the movement is activated by changes in cell turgor followed by contraction as a result of plasmolysis. © 2013 Elsevier GmbH.

Caracterização morfológica das brânquias do bivalve endêmico Diplodon expansus antes e após exposição ao herbicida atrazina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribuição ecológica das comunidades de macroalgas de ambientes lóticos em duas unidades de conservação abrangendo os biomas da Floresta Estacional Semidecidual e Campos no estado do Paraná

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos taxonômicos e amplitude ecológica de Schizomeris leibleinii (Chaetophorales, chlorophyta)

Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

Injeção peridural de lidocaína associada à xilazina ou detomidina na prevenção da dor pós-incisional em éguas

Pós-graduação em Cirurgia Veterinária - FCAV

Morfo-anatomia e envelhecimento acelerado em diásporos de oenocarpus bacaba Mart. - Arecaceae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anestesia por tumescência com lidocaína ou ropivacaína em diferentes concentrações em cadelas submetidas à mastectomia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da preparação de nanocompósitos magneto-luminescentes unidimensionais baseados em telúrio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de Mytella falcata (Mollusca, Bivalvia) como indicadora de efeitos genotóxicos e citotóxicos no estuário de Santos, SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Anatomia floral e aspectos reprodutivos de espécies de Poales (Monocotiledôneas)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficácia anti-hiperalgésica das associações de cetamina e seus isômeros com ifenprodil administradas de forma preventiva e por via subaracnóidea em ratos e cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos analgésico, hemostático, renal e digestório na administração perioperatória de vedaprofeno, tramadol ou de sua associação em felinos submetidos à ovariosalpingohisterectomia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)