|
|
|
| Registros recuperados: 155 | |
|
|
| Deniz Koç,Nazan; Yüce,Rikap. |
| In sexually reproducing organisms, primordial germ cells (PGCs) give rise to the cells of the germ line, the gametes. In many animals, PGCs are set apart from somatic cells early during embryogenesis. This study explores the origin of primordial germ cells (PGCs) of the zebra fish and examines their morphology during early development (1st day-15th day). PGCs were selectively stained by the alkaline phosphatase histochemical reaction and viewed by light and electron microscopy from the time they are first detectable in the yolk sac endoderm. PGCs occurred in the subendodermal space on the syncytial periblast; differing from the surrounding endodermal cells. Later the PGCs moved to between the blastoderm and yolk sac and transferred to the dorsal mesentery... |
| Tipo: Journal article |
Palavras-chave: Primordial germ cell; Zebra fish; Ultrastructure; Morphology. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602012000400001 |
| |
|
| |
|
|
| RAHMY,T. R.. |
| The effect of intramuscular (IM) injection of a sub-lethal dose of Naja haje cobra venom (0.015 mug/gm body weight) on the ultrastructure of renal cortical tissues of rabbits was studied at different time intervals after envenomation. Succinic dehydrogenase (SDH) enzyme activity was also detected in the renal cortical tubules. Three hours after venom injection, slight changes were seen in visceral cells and glomerular endothelia. The cortical tubular epithelia revealed an increase of lysosomal structures, cytoplasmic vacuolization, and nuclear irregularity. Severe ultrastructural changes were recorded 6 hours after envenomation, including hypertrophied parietal cells, blebbed visceral epithelial cells, and foot process disorganization. Dilated glomerular... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Snake venom; Nephrotoxicity; Kidney; Ultrastructure. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-79302001000100007 |
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
| Hine, P; Cochennec, Nathalie; Berthe, Franck. |
| Bonamia sp. is a pathogenic parasite that occurs in the haemocytes of dredge oysters Ostrea chilensis Philippi in New Zealand, Ultrastructurally it resembles other haplosporidians in the possession of haplosporosomes, haplosporogenesis, persistence of mitotic microtubules during interphase and of the nuclear envelope during mitosis, and occurrence of a diplokaryotic or multi-nucleate plasmodial stage. Another stage containing a large vacuole derived from enlargement of 1 or more mitochondria has not previously been described from other haplosporidians. It most closely resembles B, ostreae Pichot et al., 1979, which parasitises and is pathogenic in haemocytes of European flat oysters, O. edulis. However, B. ostreae is smaller and denser, and has fewer... |
| Tipo: Text |
Palavras-chave: New Zealand; 18S rDNA; Ultrastructure; Ostrea chilensis; Bonamia exitiosus. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-818.pdf |
| |
|
|
| Oliveira,F.D.; Sangalli,J.R.; Meirelles,F.V.; Perecin,F.; Silva Filho,P.P.C.; Watanabe,Y.F.; Miglino,M.A.; Assis Neto,A.C.. |
| In cattle, embryo development is characterized by the appearance of two distinct cell layers, the trophectoderm and the inner cell mass. The latter will undergo differentiation to form the embryonic disc consisting of the epiblast and hypoblast. The aim of this study was to ultrastructurally characterize the bovine embryo from different in vitro production techniques, with emphasis on trophectoderm and inner cell mass cells. Bovine embryos on day 7 (conception = D1) of pregnancy, derived via in vitro production techniques, were fixed for light and transmission electron microscopy processing. Results suggested that embryos produced by nuclear transfer of somatic cells and parthenogenesis showed significant changes in macroscopic and microscopic structure.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Embryo; Blastocyst; In vitro production; Ultrastructure. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352015000601483 |
| |
|
| |
|
| |
|
|
| Henry, M; Vicente, N; Houache, N. |
| The study of tinctorial affinities, in vitro behaviour and ultrastructure of the hemocytes of Pinna nobilis allows us to group them into two main families: basophilic, neutrophilic and acidophilic granulocytes; hyalinocytes, three categories can be distinguished among these cells: small hyalinocytes, hyalinocytes containing smooth endoplasmic reticulum and the macrophage population. The hemocytes participate in the regulation of metabolism by the storage and degradation of glycogen. They contribute to the detoxification process by the sequestration of mineral elements in their lysosomes. Their role in antibacterial defense is suggested by their bacterian phagocytic activity. |
| Tipo: Text |
Palavras-chave: Pinna nobilis; Bivalvia; Haemolymph; Animal metabolism; Marine molluscs; Ultrastructure. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-1711.pdf |
| |
|
|
| Dorange, G; Lepennec, M. |
| The spermatozoon of Pecten maximus is of the primitive type usually associated with species having external fertilization or emitting the sperm in the water. The size of the nucleus is reduced. The middle piece is similar to that reported for several Bivalves. It contains glycogen. But the spermatozoon of P. maximus exhibits its own ultrastructural characteristics: the short acrosome differs in size, shape, position and ultrastructure or by a combination of these from that of many bivalves. No axial rods was observed in contrast to several species of Mytilidae, Veneridae and Ostreidae. These originalities could go to the genus level. |
| Tipo: Text |
Palavras-chave: Pecten maximus; Bivalvia; Ultrastructure; Sperm. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-1725.pdf |
| |
|
|
| Suquet, Marc; Labbe, C.; Brizard, Raphael; Donval, Anne; Le Coz, Jean-rene; Quere, Claudie; Haffray, P.. |
| Changes in sperm features during the movement phase are especially interesting to study in external fertilization species whose sperm duration movement is long because this implies a significant adaptation of moving cells to the external medium. This study describes the changes in tetraploid Pacific oyster sperm characteristics in relation to time post activation. Sperm individually collected on three tetraploid males were activated in seawater. Their features were analysed over a 24 h period and compared to a sperm pool collected on three diploid males as a reference. The percentage of motile spermatozoa, the intracellular ATP content, and the fine structure of spermatozoa were studied in relation to time post activation. Furthermore, the fertilisation... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Sperm; Tetraploid; Motility; ATP; Ultrastructure. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11756/8639.pdf |
| |
|
|
| Alves,Eduardo; Leite,Breno; Pascholati,Sérgio Florentino; Ishida,Maria Lúcia; Andersen,Peter Craig. |
| Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa, is an important disease of citrus in Brazil. X. fastidiosa is restricted to xylem vessels of plants and knowledge regarding xylem colonization is still limited. Our goal was to verify how this bacterium colonizes and spreads within xylem vessels of sweet orange Citrus sinensis cv. Pêra. Petioles and pieces of leaf blades from naturally infected plant exhibiting characteristic symptoms were prepared for light microscopy (LM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and immunogold labeling (IGL). Petioles from healthy plants were used as control. IGL results, using an antibody against wall hemicelluloses, revealed that the pit membrane of vessels was altered.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ultrastructure; Scanning electron microscopy; Transmission electron microscopy; Immunolabel. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000200011 |
| |
|
|
| GIACOSA,JUAN P. RAMOS; MORBELLI,MARTA A.; GIUDICE,GABRIELA E.. |
| The genus Lygodium Sw. is one of the few climbing ferns in the world. The spores of L. venustum Sw. and L. volubile Sw. were studied using light, scanning, and transmission electron microscopy. This work is based on herbarium material. The spores are trilete, triangular, with straight to convex sides in polar view. The equatorial diameter is 72-104 µm, and the polar diameter is 64-84 µm. The ornamentation in L. venustum is verrucate-tuberculate while in L. volubile, it is verrucate-tuberculate in the proximal face but with a few ridges on the distal face, where a micro-ornamentation constituted by verrrucae and tubercles is observed. An equatorial ridge is also present. The exospore is two-layered; in L. venustum, it is smooth in contrast with the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lygodiaceae; Lygodium; Morphology; Spores; Ultrastructure. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000200699 |
| |
| Registros recuperados: 155 | |
|
|
|
