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Registros recuperados: 27 | |
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Gastón FIAD,Federico; CAREZZANO,Fernando José; CARDOZO,Miriam; RODRÍGUEZ,Claudia Susana. |
ABSTRACT Triatoma infestans and Triatoma platensis are interfertile species that frequently share ecotopes and produce natural fertile hybrids. Interspecific crossing allows the production of more suitable hybrid genotypes capable of colonizing new habitats. Therefore, studies of reproductive aspects in hybrids are of great importance. In this sense, oogenesis, a process that involves the development of the oocyte and allows the formation of viable eggs, is a relevant aspect. In this study, histological aspects focused on the follicular development of experimental hybrids were characterized. To do this, the ovaries of35 hybrid females were removed, paraffin-embedded and stained with hematoxylin-eosin. The development of the follicular epithelium and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oogenesis; Ovarian cycle; Reproductive biology; Triatominae. |
Ano: 2021 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2021000300462 |
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Melo, Gabriele Sauthier Romano de; Santana, Herick Soares de; Tos, Claudenice Dei. |
The construction of the Itaipu Hydroelectric Power Plant in 1982 led to the formation of a reservoir, which, in turn, leveled the waters of the Paraná River by flooding the geographic barrier Salto de Sete Quedas. This allowed the piranha Serrasalmus marginatus to invade and colonize the upper Paraná River. This study aimed to: i) confirm, through light microscopy, the reproductive phases of S. marginatus females; ii) estimate fecundity and iii) evaluate the reproduction areas of the population. A total of 764 females were collected from nine sampling sites on the upper Paraná River floodplain. Microscopic analysis of the ovaries showed the following phases: early developing subphase, developing phase, spawning capable phase, actively spawning subphase,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 2.05.02.00-1 Indeterminate fecundity; Type of spawning; Oogenesis; Oocytes; Piranha. Ecologia de Ecossistemas. |
Ano: 2017 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/33021 |
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Atella,Georgia C.; Gondim,Katia C.; Machado,Ednildo A.; Medeiros,Marcelo N.; Silva-Neto,Mário A.C.; Masuda,Hatisaburo. |
In triatomines, as well as in other insects, accumulation of yolk is a process in which an extra-ovarian tissue, the fat body, produces yolk proteins that are packed in the egg. The main protein, synthesized by the fat body, which is accumulated inside the oocyte, is vitellogenin. This process is also known as vitellogenesis. There are growing evidences in triatomines that besides fat body the ovary also produces yolk proteins. The way these yolk proteins enter the oocyte will be discussed. Yolk is a complex material composed of proteins, lipids, carbohydrates and other minor components which are packed inside the oocyte in an organized manner. Fertilization triggers embryogenesis, a process where an embryo will develop. During embryogenesis the yolk will... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oogenesis; Vitellogenesis; Embryogenesis; Triatomines; Rhodnius prolixus. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000300005 |
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Ravaglia,Mario Aldo; Maggese,María Cristina. |
Synbranchus marmoratus (Synbranchidae), commonly known as the swamp eel, is a protogynous diandric teleost fish widely distributed throughout South America. The purpose of this work was to study the ovarian anatomy and to describe oocyte developmental stages in the swamp eel, Synbranchus marmoratus. S. marmoratus has a unique sacular ovary. It is covered by a conspicuous muscular wall, probably involved in an egg-releasing system acting as a peristaltic-like mechanism. The internal ovarian anatomy shows a U-shaped ovarian lamella delimiting a dorsal ovarian lumen. The microscopic study shows evidence of the existence of a germinal epithelium in the inner surface of the lamella, which contains germinal cells, pre-follicular cells and epithelial cells. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Synbranchidae; Ovarian anatomy; Oogenesis; Micropyle. |
Ano: 2002 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452002000300003 |
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Ximenes,A.A; Oliveira,G.A; Bittencourt-Cunha,P; Tomokyo,M; Leite,D.B; Folly,E; Golodne,D.M; Atella,G.C. |
Lipid transport in arthropods is achieved by highly specialized lipoproteins, which resemble those described in vertebrate blood. Here we describe purification and characterization of the lipid-apolipoprotein complex, lipophorin (Lp), from adults and larvae of the cowpea weevil Callosobruchus maculatus. We also describe the Lp-mediated lipid transfer to developing oocytes. Lps were isolated from homogenates of C. maculatus larvae and adults by potassio bromide gradient and characterized with respect to physicochemical properties and lipid content. The weevil Lp (465 kDa) and larval Lp (585 kDa), with hydrated densities of 1.22 and 1.14 g/mL, contained 34 and 56% lipids and 9 and 7% carbohydrates, respectively. In both Lps, mannose was the predominant... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Callosobruchus maculatus; Lipophorin; Lipid transport; Oogenesis; Hydrocarbons. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000100004 |
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Ramirez Llodra, Eva; Segonzac, Michel. |
The caridean shrimp Alvinocaris niuricola has been observed forming high density populations over mussel beds on the giant pockmark cold seep site Regab in the Gulf of Guinea at 3150 m depth. Samples were collected using the ROV Victor 6000, a beam trawl and a TV grab from two sites. The specimens Were sexed and measured for population structure analysis. In one sample the sex ratio was 1:1, but the other sample had a sex ratio significantly biased towards females. The maximum size of females is larger than males. A sub-sample was used for gametogenesis and fecundity analysis. The oogenesis and spermatogenesis of A. muricola is characteristic of caridean shrimps. The oogonia proliferate from the germinal epithelium and develop into previtellogenic oocytes... |
Tipo: Text |
Palavras-chave: Reproduction biology; Oogenesis; Sex ratio; Population structure; Caridean shrimp. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2317.pdf |
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Gardes, Lionel; Buchet, Vincent; Villanove, Philippe; Fauvel, Christian. |
Artificial insemination mastery in red drum, Sciaenops ocellatus, requires a first experimental step wOOng at getting basic biological data. Regarding males, a relation between optical density of the solution (OD) measured by spectrophotometry and sperm concentration (SC) has been established : OD O,161*SC + 0,119. Mean sperm concentration measured is 4,36.10 10 spz.mL-1. This study shows an influence of the solution of dilution on spermatozoa motility and its evolution during short term preservation. As far as females are concemed, the follow-up of final maturation through the observation of samples taken during reguIar strippings, seems to he a good technique to limit overripening and spontaneous liheration of ovules. Some artificial insemination trials... |
Tipo: Text |
Palavras-chave: Fécondation artificielle; Concentration spermatique; Motilité du sperme; Ovogenèse; Ovulation; Sur maturation; Ombrine; Sciaenops ocellatus.; Artificial insemination; Sperm concentration; Sperm motility; Oogenesis; Ovulation; Overripening; Red drum.; Sciaenops ocella/us. |
Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00366/47755/47801.pdf |
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Benmeradi, N. |
During the reproductive period, the microscopical observation of Patella coerulea ovary shows some ovogonies forming neets, supported by a conjonctive network, previtellogenic oocytes which leave gradually the conjonctive tissue and vitellogenic oocytes isolated in the acinus lumen. In early stages of previtellogenesis, an important nucleolar activity, caracterised by cloud-shaped or nematosomes and ribonucleoproteinic extrusions in cytoplasm compartment can be observed. At the end of this stage, the oocyte becomes richer in organites, mitochondria, granular endoplasmic reticulum and Golgi. We further notice the outcome of the first vitellin platelets. Production of vitellus is higher as three kinds of vitellus are observed in the following order: dark... |
Tipo: Text |
Palavras-chave: Ultrastructure; Oogenesis; Sexual reproduction; Vitellogenesis. |
Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/1991/acte-1720.pdf |
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Hojati,Vida; Keshavarz,Seyed Mohammad; Behniafar,Reza; Shiravi,Abdolhossein. |
The Caspian Green Lizard, Lacerta strigata Eichwald, 1831, is a member of the Lacertidae family distributed in the Caspian coast of northern Iran. The specimens were found in coastal dunes, hilly areas and pastureland containing some shrubby cover. In this research, the reproductive biology of this species was studied from April 20 to September 5, 2013. Forty eight adult specimens including 24 females and 24 males were collected by hand at midday from three sampling stations (Goharbaran, Ab-Bandansar and Ab-Bandankesh) of Sari County, located in Mazandaran Province of Iran. Ovaries and testes were removed and processed for histological and morphometric studies. In females, there were 617 follicles in each ovary. Totally, 610 oviductal eggs were observed... |
Tipo: Journal article |
Palavras-chave: Lacertidae; Caspian green lizard; Oogenesis; Spermatogenesis; Caspian coast. |
Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022016000200005 |
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Branco,Ilka S. L.; Viana,Danielle L.; Félix,Renata T. S.; Véras,Dráusio P.; Hazin,Fábio H. V.. |
The oogenesis is a key stage in the reproductive development of an organism, which can be best understood from histological analysis of ovaries in different maturity stages. In order to provide information on the reproductive biology of the black triggerfish, M. niger, in particular on its oogenesis process, this study aimed at identifying and characterizing the oocyte development stages and its organization within the different stages of ovarian maturation based on specimens from São Pedro e São Paulo Archipelago. In this present report, a number of 294 ovaries were histologically analyzed. It was verified that they are composed of ovigerous lamellae containing oocytes at different development stages. Five different stages of oogenesis were identified:... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Histology; Oogenesis; Reef fish; Reproduction; Vitellogenesis. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300597 |
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Cassel,Mônica; Mehanna,Mahmoud; Mateus,Lúcia; Ferreira,Adelina. |
The comprehension of the reproductive cycle allows to understand which are the morphological changes that develop in the gonad during this interval. Thus, many studies have been undertaken in order to describe and classify the stages of gonadal development and reproductive status of Neotropical fishes. For this purpose, specimens of Melanorivulusaff. punctatus were collected in a permanent dam in Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were prepared for analysis by light microscopy. The oogenesis and spermatogenesis have been described, characterizing the stages of gonadal development, together with assessments of the gonadosomatic ratio, germ cell count and verification of variation of mature oocytes in females. Throughout the year the male... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gonadossomatic ratio; Histology; Oogenesis; Spermatogenesis. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000100179 |
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Registros recuperados: 27 | |
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