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RAMALHO-SANTOS,JOÃO; MORENO,RICARDO D.. |
Regulated exocytosis is controlled by internal and external signals. The molecular machinery controlling the sorting from the newly synthesized vesicles from the Golgi apparatus to the plasma membrane play a key role in the regulation of both the number and spatial location of the vesicles. In this context the mammalian acrosome is a unique vesicle since it is the only secretory vesicle attached to the nucleus. In this work we have studied the membrane trafficking between the Golgi apparatus and the acrosome during mammalian spermiogenesis. During bovine spermiogenesis, Golgi antigens (mannosidase II) were detected in the acrosome until the late cap-phase spermatids, but are not found in testicular spermatozoa (maturation-phase spermatids). This suggests... |
Tipo: Journal article |
Palavras-chave: Acrosome; Spermatid; Golgi; Fertilization; Spermiogenesis. |
Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602001000200021 |
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Fernandes Boaro Martins,Márcia Regina; Carvalho Pinto e Silva,José Ricardo de. |
The objective of this study was to describe some changes in spermatids differentiating events during spermiogenesis, leading to spermatozoa final formation. The animals were sacrificed with ethylic acid inhalation and, then, testis fragments were collected, fixed in Karnovsky and post-fixed in osmium tetroxide. After dehydration, the sections were stained with uranyl acetate 2%. It was observed in early spermatids at Golgi phase, formation of acrosomal granule contained in the acrosomal vesicle, spheroidal nucleus with rugous reticulum around it, and Golgi apparatus made up of lamellae and vesicular structures. At cephalic hood phase, the granule suffers flattening and the marginal fossa is formed. In both phases, it was possible to observe the presence of... |
Tipo: Journal article |
Palavras-chave: Spermiogenesis; Spermatids; Mice. |
Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022005000400007 |
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Baicere-Silva,Clarianna Martins; Ferreira,Katiane M.; Malabarba,Luiz R.; Benine,Ricardo C.; Quagio-Grassiotto,Irani. |
The monophyly and phylogenetic relationships among the members of Clade A characids (sensu Malabarba & Weitzman), later redefined and named as the Stevardiinae (sensu Mirande), have been primarily supported by traditional morphological and molecular data. Herein were examined, described and compared spermiogenesis and sperm ultrastructure of 12 species of the genera Boehlkea, Bryconacidnus, Bryconamericus, Creagrutus, Cyanocharax, Hemibrycon, Knodus, Odontostoechus, Piabina, and Rhinobrycon in order to evaluate possible phylogenetic signals and their potential use in recovering relationships of the Stevardiinae. All examined species demonstrated a nuclear rotation equal or less than 95º resulting in a lateral position of the double nuclear fossa... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Clade A; Phylogeny; Spermiogenesis; Sperm morphotype. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000200016 |
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