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dc.creatorCárdenas Reygadas, Rodolfo
dc.creatorChávez, Mónica
dc.creatorGonzález, José Luis
dc.creatorAley, Patricia
dc.creatorEspinoza, Jesús
dc.creatorJiménez García, Luis Felipe
dc.date2007-07-11
dc.date.accessioned2016-05-03T15:30:51Z
dc.date.available2016-05-03T15:30:51Z
dc.identifierhttp://revistas.ucr.ac.cr/index.php/rbt/article/view/5762
dc.identifier10.15517/rbt.v56i4.5762
dc.identifier.urihttp://hdl.handle.net/10669/26932
dc.descriptionThe structural and ultrastructural features of gonads from endemic Mexican fish have received scarce attention. This study describes the histological and ultrastructural characteristics of the oocyte in Chirostoma humboldtianum. The ovary is asynchronic, and as such, most phases of oocyte development are found in the same ovary. The complete process of oogenesis was divided in five stages: oogonium and folliculogenesis, primary growth, cortical alveoli and lipid inclusions, vitellogenesis and maturation. The presence of big filaments, which appear at the end of primary growth, induces some common follicular adaptation. During primary growth, abundant ribosomes, rough endoplasmic reticulum, and mitochondria are grouped in the cytoplasm. At the end of this stage, the Z1 layer of the chorion is developed, while microvilli start to be evident as well. In the cortical alveoli and lipid droplets phase, intense PAS positive vesicles, some of them containing nucleoid material, are observed in the peripheral cytoplasm and the lipid droplets take a more central position. In vitellogenesis, the proteic yolk accumulates in a centripetal way while the chorion is completely formed. In maturation, the germinal vesicle migrates to the animal pole, meiosis is restored, and there is nuclear breakdown. The oocyte increases its size and holds some oil droplets and a big fluid mass of yolk. On the outside, filaments surround the oocyte completely.en-US
dc.formatapplication/pdf
dc.languageeng
dc.publisherUniversidad de Costa Ricaen-US
dc.rightsCopyright (c) 2014 International Journal of Tropical Biology and Conservationen-US
dc.sourceRevista de Biología Tropical/International Journal of Tropical Biology and Conservation; Vol. 56 (4) December 2008en-US
dc.sourceRevista de Biología Tropical/International Journal of Tropical Biology and Conservation; Vol. 56 (4) December 2008es-ES
dc.sourceRevista Biología Tropical; Vol. 56 (4) December 2008pt-PT
dc.source2215-2075
dc.source0034-7744
dc.source10.15517/rbt.v56i4
dc.titleOocyte structure and ultrastructure in the Mexican silverside fish Chirostoma humboldtianum (Atheriniformes: Atherinopsidae)en-US
dc.typeinfo:eu-repo/semantics/article
dc.typeinfo:eu-repo/semantics/publishedVersion


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