Consulta: subjectFacets:"Gametogenesis"
Registros recuperados: 41
Data/hora: 06/06/2024 15:16:16

Gonad transcriptome analysis of pearl oyster Pinctada margaritifera: identification of potential sex differentiation and sex determining genes
Provedor de dados: 5
Autores: Teaniniuraitemoana, Vaihiti; Huvet, Arnaud; Levy, Peva; Klopp, Christophe; Lhuillier, Emeline; Gaertner-mazouni, Nabila; Gueguen, Yannick; Le Moullac, Gilles.
Background  Black pearl farming is based on culture of the blacklip pearl oyster Pinctada margaritifera (Mollusca, lophotrochozoa), a protandrous hermaphrodite species. At first maturation, all individuals are males. The female sex appears progressively from two years old, which represents a limitation for broodstock conditioning for aquaculture production. In marine mollusks displaying hermaphroditic features, data on sexual determinism and differentiation, including the molecular sex determining cascade, are scarce. To increase genomic resources and identify the molecular mechanisms whereby gene expression may act in the sexual dimorphism of P. margaritifera, we performed gonad transcriptome analysis.  Results  The gonad transcriptome of P. margaritifera...
Tipo: Text
Palavras-chave: Pinctada margaritifera; Gametogenesis; Transcriptome; Differential expression; Sex determinism.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00201/31194/29593.pdf

Characterization of summer mortalities of C. gigas oyster in France in relation to environmental parameters
Provedor de dados: 5
Autores: Soletchnik, Patrick; Ropert, Michel; Bedier, Edouard; Costil, K. S.; Dubois, Brice; Degremont, Lionel; Bouget, Jean-francois; Martin, Jean-louis; Enriquez-diaz, M.; Faury, Nicole; Le Moine, Olivier; Renault, Tristan; Gagnaire, Beatrice; Huvet, Arnaud; Moal, Jeanne; Samain, Jean-francois.
Field characterization of summer mortality was performed in France in the frame of the Morest project. Natural and hatchery spat were compared between three oyster production areas in France. Regardless of the natural or hatchery origin, oysters died during the reproduction period after temperature reaches 19 degree C. Thus, in southern areas, temperature accelerated gametogenesis of small spat (10mm) as well as adults, and mortality appeared for the two age classes. In contrast, sexual maturation proceeded more slowly in northern where spat mortality was lower compared to 18 months old oysters. However, critical gametogenesis and temperature were not sufficient to induce mortalities, as observed in examples with stable environment. Alternatively sediment...
Tipo: Text
Palavras-chave: Seasonal variation; Oyster culture; Mortality causes; Hatcheries; Gametogenesis; Environmental factors; Crassostrea gigas; Oysters.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/acte-3348.pdf

Reproduction naturelle de Crassostrea gigas Thunberg dans le bassin de Marennes-Oleron en 1979 et 1981: Aspects biochimiques et energetiques.
Provedor de dados: 5
Autores: Deslous-paoli, Jean-marc; Heral, Maurice; Berthome, Jean-paul; Razet, Daniel; Garnier, Jacqueline.
In summer 1979, the natural reproduction of oysters Crassostrea gigas Thunberg, in Marennes-Oleron basin, produced a large number of juveniles which was not the case in summer 1981. If one compares the evolution of the main constituents of the flesh, one can see that, at the beginning of August, before spawning the male oysters in 1981 contained 6,3% less proteins, 34,2% less lipids and 61,2% less glucids than those in 1979 and respectively 12,3%, 21,3% and 69,8% less as far as females are concerned. The energetic value of ash-free dry flesh of female oysters is nearly the same for the two years whereas for male oysters the value is slightly lower in 1981 than in 1979. The total energetic values of male and female oysters show a slight difference between...
Tipo: Text
Palavras-chave: Crassostrea gigas; Seasonal variations; Food availability; Water temperature; Saccharides; Proteins; Lipids; Biochemical composition; Gametogenesis; Spawning; Sexual reproduction.
Ano: 1981
URL: http://archimer.ifremer.fr/doc/1981/publication-1891.pdf

Variabilité et bioénergétique de la reproduction chez l'huître creuse Crassostrea gigas
Provedor de dados: 5
Autores: Enriquez Diaz, Marta Rosalia.
The variability in reproductive cycle of Pacific oyster, Crassostrea gigas, was evaluated in situ (Bay of Veys, BOV and Marennes-Oléron bay, MOB) and in hatchery culture conditions. Two trophic levels were tested over one year: high food level (HFL) and low food level (LFL). We observed that the phytoplanktonic concentration (chlorophyll a) was the principal factor that influenced gametogenesis intensity and duration. The oysters reared within a high trophic ration (BOV and HFL) shown a hyper-gonad development. However, the spawning efficiency was reduced and partial. Therefore, the resorption period was prolonged until winter. Meanwhile, the oysters reared in a low trophic ration (MOB and LFL) produced a normal gonad with a total spawning in summer and...
Tipo: Text
Palavras-chave: Aquaculture; Crassostrea gigas; Genetic factor; Ecophysiology; Gametogenesis; Aquaculture; Crassostrea gigas; Bilan énergétique; Ecophysiologie; Gamétogénèse.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/these-1095.pdf

Morphogenese sexuelle et regulation hormonale de l'activite genitale chez la crevette Penaeus japonicus en elevage
Provedor de dados: 5
Autores: Laubier, A; Chim, Liet; Payen, G.
A study of the sexual physiology of penaeid prawns essentially based upon Penaeus japonicus is performed in both descriptive and experimental ways, using the controlled rearings conducted at the Centre Oceanologique de Bretagne (CNEXO-COB), Brest. Sexual morphogenesis is described. This preliminary study enables definition of simple criteria for determination of the stage of genital development of the prawns during their growth. The neuroendocrine control of the genital system development is studied, using eyestalks ablations and male eyestalks extracts injection in prawns belonging to the same sex. A biochemical criterion as a test of the effect of eyestalks extract injections on the genital system development is discussed. The evolution of the specific...
Tipo: Text
Palavras-chave: Penaeus japonicus; Malacostraca; Controlled conditions; Neurosecretion; Cytochemistry; Ultrastructure; Sexual reproduction; Sexual maturity; Sexual dimorphism; Endocrinology; Eyestalk extirpation; Gametogenesis; Sex determination; Morphogenesis; Contrôle neuroendocrine de la reproduction; Morphogénèse sexuelle; Physiologie sexuelle; Élevage contrôlé; Penaeus japonicus.
Ano: 1983
URL: http://archimer.ifremer.fr/doc/1983/acte-1188.pdf

Origine et développement des cellules germinales chez l'huître creuse Crassostrea gigas : Intérêt pour le contrôle de la reproduction en écloserie.
Provedor de dados: 5
Autores: Fabioux, Caroline.
A comprehensive knowledge of Crassostrea gigas oyster reproduction processes is essential to optimize controlled reproduction in hatchery. This study aimed to determine the origin and the mechanisms of annual renewal of germ cells, still unknown in oysters, and the influence of temperature and photoperiod parameters on the regulation of the reproductive cycle. We characterized an orthologue of the vasa gene, the Oyvlg (Oyster vasa-like gene), the first germ cell specific marker isolated in molluscs. This marker was used to study C. gigas germline development. Oyster germ cells appeared specified during early development from mesentoblast 4d, as primordial germ cells (PGCs) determined by maternal cytoplasmic determinants, including Oyvlg mRNA. In adult...
Tipo: Text
Palavras-chave: Controlled reproduction; Regulation; Oyster vasa like gene; Gametogenesis; Germ cells; Crassostrea; Reproduction contrôlée; Régulation; Oyster vasa like gene; Gamétogenèse; Cellules germinales; Crassostrea.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/these-1380.pdf

Genetic basis of gametogenesis in diploid and triploid Pacific oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Normand, Julien; Ernande, Bruno; Boudry, Pierre.
Today, triploidy is the most common method used to genetically improve marine bivalve aquaculture production. In the Pacific oyster Crassostrea gigas, triploidy affects many traits. The most proeminent one is reproductive effort, which is greatly reduced compared to diploids. The combined effects of physiological trade-offs between survival, growth and reproduction together with the reduction of reproductive effort in triploids explains the global enhancement of yield observed. However, the sterility of triploid oysters is only partial and some triploid individuals can show normal gametogenesis (i.e. similar to diploids), especially under warm conditions. In diploid oysters, the heritability of reproductive effort has been shown to be relatively low, but a...
Tipo: Text
Palavras-chave: Parentage analysis; Triploidy; Oyster; Quantitative genetics; Gametogenesis.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/acte-4525.pdf

Conditionnement artificiel de l'huître Crassostrea gigas
Provedor de dados: 5
Autores: Jorge Eduardo, Chávez Villalba.
In France, 90% of the annual cup oyster (Crassostrea gigas) production comes from larvae caught in the Arcachon and Marennes-Oléron basins. However, the spat catch shows many interannual irregularities and oyster farmers increasingly say they need spat outside of the reproductive period. Thus, the role of hatcheries in Japanese oyster spat production in France is becoming increasingly evident. However, the current state of knowledge about cup oyster reproduction in controlled conditions is limited, and hatchery professionals must confront various problems to optimise treatment of genitors so as to obtain larval breeds in good health and a lengthening of the reproductive season. To respond to this, we have carried out a study on three aspects that seem...
Tipo: Text
Palavras-chave: Water temperature; Biochemical studies; Gametogenesis; Breeder conditioning; Larval rearing.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/these-1456.pdf

Effect of food conditioning on gonadic activity in the oyster Pinctada margaritifera
Provedor de dados: 5
Autores: Le Moullac, Gilles; Hui, Belinda; Vonau, Vincent; Levy, Peva; Cochard, Jean-claude.
Preliminary experiments allowed defining basic requirements of Pinctada margaritifera for somatic and gonadic growth in controlled conditions. This study was continued by observation of the gametogenesis at a cellular level. In April/May 2008, 125 oysters were conditioned for 30 days in 25 tubular tanks (30 L). Water was renewed 4 times/hour. A mixed (v:v) diet of Isochrysis galbana (T-Iso) and Chaetoceros gracilis was supplied continuously. A control batch of 125 oysters was maintained in trays in the lagoon. An initial sample of 30 individuals was made. Gonadic changes were first characterized using a gonadal development index (GDI) based on the ratio of the gonad area to the total visceral mass area on a sagittal section of the body. Histological...
Tipo: Text
Palavras-chave: Pearl oyster; Reproduction; Gametogenesis; Broodstock.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00029/14010/11196.pdf

Sex-Specific Regulation of AMP-Activated Protein Kinase (AMPK) in the Pacific Oyster Crassostrea gigas
Provedor de dados: 5
Autores: Guevelou, Eric; Huvet, Arnaud; Galindo-sanchez, Clara E.; Milan, Massimo; Quillien, Virgile; Daniel, Jean-yves; Quere, Claudie; Boudry, Pierre; Corporeau, Charlotte.
The hermaphrodite Pacific oyster Crassostrea gigas displays a high energy allocation to reproduction. We studied the expression of AMP-activated protein kinase (AMPK) during gametogenesis in the gonad and characterized the mRNA sequences of the AMPK subunits: the AMPK alpha mRNA sequence was previously characterized; we identified AMPK beta, AMPK gamma, and mRNAs of putative AMPK-related targets following bioinformatics mining on existing genomic resources. We analyzed the mRNA expression of the AMPK alpha, beta, and gamma subunits in the gonads of male and female oysters through a reproductive cycle, and we quantified the mRNA expression of genes belonging to fatty acid and glucose metabolism. AMPK alpha mRNA levels were more abundant in males at the...
Tipo: Text
Palavras-chave: AMP-activated protein kinase; Crassostrea gigas; Gametogenesis; Marine bivalve; Reproduction.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00168/27911/26470.pdf

The effects of eight single microalgal diets on sex-ratio and gonad development throughout European flat oyster (Ostrea edulis L.) conditioning
Provedor de dados: 5
Autores: Gonzales, Ricardo; Quillien, Virgile; Robert, Rene.
To determine the effects of food quality on Ostrea edulis reproduction, European flat oysters were conditioned during two sets of experiments, carried out in spring and autumn, during 40 days at 19 degrees C, in 50 l transparent flow-through tanks, in triplicate, and fed constantly at 900 mu m(3) mu l(-1), with eight different types of microalgae. Four species were fed per group of trials: Isochrysis affinis galbana, Chaetoceros gracilis, Skeletonema marinoi, and Tetraselmis suecica were fed to flat oysters in the first set; whereas Rhodomonas salina, Thalassiosira weissflogii, Thalassiosira pseudonana, and Pavlova lutheri were provided during the second set of experiments. At the beginning and end of both conditioning periods, oysters were sampled and...
Tipo: Text
Palavras-chave: Ostrea edulis; Broodstock conditioning; Gametogenesis; Microalgal diets.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00144/25497/24163.pdf

Etude cytologique de la gamétogenèse, de la sex-ratio et du cycle de reproduction chez l'huître perlière Pinctada margaritifera (L) var. cumingii (Jameson), (mollusques, bivalves). Comparaison avec le cycle de Pinctada maculata (Gould)
Provedor de dados: 5
Autores: Thielley, Maryse.
The population of Pinctada margaritifera and Pinctada maculata lay eggs throughout the year. Temperature variations induce huge but asynchronous laying. Preferential periods of gonad maturity correspond to the season changings in both species. However. some differences between the two specics are noticed. Both species are protandric hermaphrodites. Female condition is unstable: a reversion to the male condition may be observed and is probably linked with stress. The average size for the first sexual maturation as weil as for sexual conversion are specified in P. margaritifera. The breeding conditions induce modifications in some reproductive cycle processes (maturation, sex-ratio). Some conditions suitable for reproduction may become unfavorable to...
Tipo: Text
Palavras-chave: Gamétogenèse; Cycle de reproduction; Sex-ratio; Pinctad margaritifera; Mollusque; Bivalve; Huître perlière; Gametogenesis; Reproductive cycle; Sex-ratio; Pinctada margaritifera; Mollusca; Bivalvia; Pearl oyster.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00440/55208/56677.pdf

Disruption of amylase genes by RNA interference affects reproduction in the Pacific oyster Crassostrea gigas
Provedor de dados: 5
Autores: Huvet, Arnaud; Beguel, Jean-philippe; Pereira Cavaleiro, Nathalia; Thomas, Yoann; Quillien, Virgile; Boudry, Pierre; Alunno-bruscia, Marianne; Fabioux, Caroline.
Feeding strategies and digestive capacities can have important implications for variation in energetic pathways associated with ecological and economically important traits, such as growth or reproduction in bivalve species. Here, we investigated the role of amylase in the digestive processes of Crassostrea gigas, using in vivo RNA interference. This approach also allowed us to investigate the relationship between energy intake by feeding and gametogenesis in oysters. Double-stranded (ds)RNA designed to target the two α-amylase genes A and B was injected in vivo into the visceral mass of oysters at two doses. These treatments caused significant reductions in mean mRNA levels of the amylase genes: −50.7% and −59% mRNA A, and −71.9% and −70.6% mRNA B in 15...
Tipo: Text
Palavras-chave: Alpha-Amylase; DsRNA; Gametogenesis; Marine bivalve; Dynamic energy budget.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00271/38239/36422.pdf

Slow-release GnRHa treatment prevented atresia during vitellogenesis and induced ovulation of captive wreckfish (Polyprion americanus)
Provedor de dados: 5
Autores: Fauvel, Christian; Suquet, Marc; Severe, Armelle; Mylonas, Constantinos C.; Papandroulakis, Nikos.
The potential of wreckfish (Polyprion americanus) to breed in captivity was examined. Ovarian activity varied seasonally, with vitellogenesis beginning in November and ending in May. Slow-release implant with gonadotropin-releasing hormone agonist (GnRHa) prevented atresia, and both GnRHa injections or implants at the end of vitellogenesis triggered ovulation after 7 days. Spontaneous spawning was obtained only in one female, and the few eggs produced were of poor viability. Manual stripping and artificial fertilization produced viable gametes and embryos. Therefore, present captivity conditions inhibited final oocyte maturation (FOM) and spawning, but not vitellogenesis and spermatogenesis. GnRHa treatments stimulate FOM and ovulation of viable eggs.
Tipo: Text
Palavras-chave: Aquaculture; Polyprion americanus; Wreckfish; GnRHa; Gametogenesis.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-6554.pdf

Comparative histological study of gametogenesis in diploid and triploid pacific oysters (Crassostrea gigas) reared in an estuarine farming site in France during the 2003 heatwave
Provedor de dados: 5
Autores: Normand, Julien; Le Pennec, Marcel; Boudry, Pierre.
We compared the temporal dynamics of gametogenesis in diploid and triploid Pacific oysters (Crassostrea gigas) using histology. Oysters were reared in an estuarine farming site in Brittany over 3 years and their gametogenesis was monitored over the exceptionally hot summer of 2003. Both diploids and triploids showed active gametogenesis, but a high proportion of triploids remained at early stages of gonad development. Gametogenesis of triploids was characterized by the simultaneous occurrence of gonias and immature cytes together with mature gametes rather than overall retardation, though some triploids showed complete gonad maturation. Evidence of spawning was seen in both groups, and the quantity of germinal products emitted appeared to be similar in...
Tipo: Text
Palavras-chave: Triploidy; Crassostrea gigas; Oyster; Gametogenesis.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4152.pdf

Gametogenic cycle and reproductive effort of the tropical blacklip pearl oyster, Pinctada margaritifera (Bivalvia : Pteriidae), cultivated in Takapoto atoll (French Polynesia)
Provedor de dados: 5
Autores: Pouvreau, Stephane; Gangnery, Aline; Tiapari, Jerome; Lagarde, Franck; Garnier, Matthieu; Bodoy, Alain.
The gametogenic cycle and the reproductive effort of the blacklip pearl oyster, Pinctada margaritifera, cultivated in Takapoto lagoon were studied for a 1-year period (March 1997-April 1998) by bimonthly observations of gonadal sections, dry tissue weights and gonadal index in a population of pearl oyster composed of three age-groups. pearl oysters attained sexual maturity in the end of their first year (height approximate to 40 mm), implying that P. margaritifera is a late-maturing species in comparison with other Pteriidae. This species was also confirmed to be a marked protandrous successive hermaphrodite in culture, with 100 % of males at first maturity and 75 % in older pearl oyster (height &gt; 120 mm). The general pattern of gametogenic activity,...
Tipo: Text
Palavras-chave: French Polynesia; Reproductive effort; Reproductive cycle; Tropical aquaculture; Gametogenesis; Blacklip pearl oyster; Polynésie française; Effort de reproduction; Cycle de reproduction; Aquaculture tropicale; Gamétogenèse; Huître perlière.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-1391.pdf

Feeding the pearl oyster Pinctada margaritifera during reproductive conditioning
Provedor de dados: 5
Autores: Le Moullac, Gilles; Soyez, Claude; Sham-koua, Manaarii; Levy, Peva; Moriceau, Jacques; Vonau, Vincent; Maihota, Mayalen; Cochard, Jean-claude.
This study aimed to model the food intake of P. margaritifera in order to examine the relationship between food level and reproductive activity. The effect of microalgae concentration on ingestion rate and assimilation efficiency was studied over a broad concentration range, using a mixture of Isochrysis galbana and Chaetoceros gracilis. Reproductive effort was assessed using three microalgae concentrations of 0.5, 7 and 18 cell μL-1. Reproductive status was assessed by gonad development index (GDI) – the ratio of the gonad surface to the visceral mass surface – and histological analysis of the gonad based on the presence (continuous or discontinuous) or the absence of gonial cells (GC). Ingestion is a saturating function of seston concentration for...
Tipo: Text
Palavras-chave: Pinctada margaritifera; Food level; Ingestion rate; Reproduction; Gametogenesis.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00050/16085/13562.pdf

Reproductive strategy of the invasive green mussel may result in increased competition with native fauna in the southeastern United States
Provedor de dados: 5
Autores: Mcfarland, Katherine; Soudant, Philippe; Jean, Frederic; Volety, Aswani K.
Understanding the population dynamics of invasive species, such as the green mussel Perna viridis (Linnaeus, 1758), can aid in explaining the success of newly introduced populations and help predict the potential for spread. During a two-year field study of established populations in the invaded region of southwest Florida, year round gametogenesis and continuous spawning capabilities were observed through histological analysis of mussels collected monthly. This was supported by overall stable energetic reserves as measured through proximal biochemical composition (protein, glycogen and lipid content). However, egg outputs in the summer (6.4 x 10(6) +/- 2.6 x 10(6) eggs / female) were significantly higher than egg outputs of winter-spawned mussels (7.7 x...
Tipo: Text
Palavras-chave: Gametogenesis; Protein; Glycogen; Lipid; Induced spawning.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00616/72842/72974.pdf

Environmental stress in the pacific oyster Crassostrea gigas during gametogenesis : role of herbicides?
Provedor de dados: 5
Autores: Burgeot, Thierry; Quirion, Sophie; Quiniou, Francoise; Knoery, Joel; Soletchnik, Patrick; Gagnaire, Beatrice; Renault, Tristan; Osada, M.; Geret, F.; Communal, P. Y.; Jadas-hecart, A.; Gagne, F.
In the Atlantic French coast, significant mortalities were observed in oyster communities during gametogenesis. These deaths possibly result from the cumulative effects of various stressors such as seasonal temperature variations, pesticide application and the release of contaminants from the resuspension of sediments. A field survey, based on aquaculture conditions at 15 and 70 cm from the sediment bed with genetically-resistant (R) and -sensitive (S) lines, showed a stress condition. Significant weight loss was observed during May 14th through June 10th for both R and S lines. On one hand, the levels of the egg yolk vitellin in females were decreased at May 14th for both R and S lines.  On the other hand, a significant increase in vitellin production was...
Tipo: Text
Palavras-chave: Mortalities; Herbicides; Sediment; Biomarkers; Gametogenesis; Crassostrea gigas; Pacific oysters.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/acte-3384.pdf

Influence of plankton concentration on gametogenesis and spawning of the black lip pearl oyster Pinctada margaritifera in Ahe atoll lagoon (Tuamotu archipelago, French polynesia)
Provedor de dados: 5
Autores: Fournier, Jonathan; Levesque, Emmanuelle; Pouvreau, Stephane; Le Pennec, Marcel; Le Moullac, Gilles.
Pearl culture industry represents one of the dominant business sector of French Polynesia. However, it still entirely relies on unpredictable spat collection success. Our aim was to assess the influence of natural plankton concentration fluctuations on maturation and spawning of the black lip pearl oyster Pinctada margaritifera, during a 4 months survey conducted in Ahe atoll lagoon. Plankton concentration was assessed by chlorophyll a extraction and by microscope counts while gonadic index, gonado-visceral dry weights and histology were used to measure pearl oysters reproduction activity. We found that (i) plankton concentration fluctuations were mainly related to wind regime, (ii) gametogenesis rate was mainly related to plankton concentration, (iii)...
Tipo: Text
Palavras-chave: Pearl Oyster; Gametogenesis; Spawning; Phytoplankton; French Polynesia.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00101/21201/19697.pdf

Le déterminisme du sexe de l’huître creuse Crassostrea gigas au cours de son développement et du cycle gamétogénétique adulte : recherche de déterminants moléculaires
Provedor de dados: 5
Autores: Naimi, Amine.
The pacific oyster Crassostrea gigas is a successive protandric irregular hermaphrodite. The factors involved in the first gonadic differentiation in juveniles and those involved in sex reversal in adults are still unknown. This thesis consisted in the identification of molecular factors of the oyster’s gonadic differentiation during its adult cycle and its development. Thus, the respective orthologs to a DM-family factor and to Foxl2, Cg-DMl and Cg-Foxl2, have been characterized in the oyster by RT-PCR. Their study by real-time PCR, in situ hybridization and immunohistochemistry, has highlighted a ubiquitous expression of Cg-DMl in potentially proliferating / differentiating cells in the gonads of both sexes. The Cg-Foxl2 expression is specific to the...
Tipo: Text
Palavras-chave: Différenciation sexuelle; Crassostrea gigas; Mollusques marins; Gamétogenèse; Hermaphrodisme; DMRT; FOXL2; Sex differentiation; Crassostrea gigas; Marin molluscs; Gametogenesis; Hermaphroditism; DMRT; FOXL2.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00012/12291/9080.pdf

Effect of phytoplankton and temperature on the reproduction of the Pacific oyster Crassostrea gigas: investigation through DEB theory
Provedor de dados: 5
Autores: Bernard, Ismael; De Kermoysan, Goulwen; Pouvreau, Stephane.
DEB theory can be used to obtain a detailed description of energy allocation in organisms and the control of this allocation by temperature and food concentration. In this study, we modified the model of Bourlès et al. (2009) developed for the Pacific oyster, Crassostrea gigas, to improve the description of reproductive effort. The model was amended in two ways: a new set of parameters was incorporated and a full description of gonad construction in spring was added, with a new state variable. The application of this model to a dataset for oyster growth measured in four bays over two years showed that this model better described reproductive effort, without modifying overall growth dynamics. We then explored the reproductive responses of oysters to their...
Tipo: Text
Palavras-chave: DEB model; Crassostrea gigas; Gametogenesis; Reproductive effort; Spawning date; Functional response.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00059/17047/14606.pdf

Maturation and spawning of tropical and subtropical marine finfish by environmental manipulations
Provedor de dados: 5
Autores: Roberts Jr, D.
Circannual, diel, and lunal periodic mechanisms in naturally reproducing stocks of tropical and subtropical fishes are reviewed. Manipulations of biological clocks, used to control reproduction in captive broodstocks, are detailed. Experiments to induce controlled maturation and spawning in fishes either test efficacy of changing environmental conditions (regimes), or constant environmental conditions (controlled). Data have been generated in experimental/scientific studies, as well as applied research. Effects of controlled environmental regimes on serum steroids, gametogenesis, spawning, fry performance and egg quality are summarized for selected members of Centropomidae, Serranidae, and Sciaenidae.
Tipo: Text
Palavras-chave: Sciaenidae; Serranidae; Centropomidae; Fish culture; Controlled conditions; Sexual maturity; Photoperiods; Fish eggs; Gametogenesis; Steroids; Animal reproductive organs; Brood stocks; Marine fish; Spawning; Sexual reproduction.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/acte-1437.pdf

The oyster vasa-like gene: a specific marker of the germline in Crassostrea gigas
Provedor de dados: 5
Autores: Fabioux, Caroline; Pouvreau, Stephane; Leroux, Frederique; Huvet, Arnaud.
The vasa gene is,a key determinant for germline formation in eukaryotes. This gene, highly conserved through evolution, encodes a RNA helicase protein member of the DEAD-box family. To understand the germline formation in oyster, we report here the isolation and the characterization of a vasa orthologue in Crassostrea gigas (Oyvlg). OyVLG contained the eight consensus domains of the DEAD-box including those providing RNA unwinding activity. The expression pattern of Oyvlg was examined in adult oyster tissues at different reproductive stages. Its expression was restricted to germline cells both in males and females, including germinal stem cells and auxiliary cells. The expression of Oyvlg, strongest in early germ cells, decreased as the maturation...
Tipo: Text
Palavras-chave: RNA helicase; DEAD box; Vasa; Germline; Gametogenesis; Oyster.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-646.pdf

Etude comparative du cycle de reproduction de la palourde Ruditapes decussatus en milieu naturel (sud Tunisie) et contrôlé (écloserie)
Provedor de dados: 5
Autores: Hamida, Leila; Medhiouband, Mohamed; Cochard, Jean-claude; Romdhane, Mohamed; Le Pennec, Marcel.
A comparative study of the reproductive cycle of Ruditapes decussatus under natural (South of Tunisia) and controlled conditions (hatchery). The aim of this study was to describe and compare the gametogenic activity of Ruditapes decussatus in situ and in hatchery. Criteria of maturity were characterized and the positive role of conditioning in the success of artificial reproduction was underlined. Specimens sampled in the South of Tunisia were conditioned at the experimental station of Monastir (Tunisia). The parameters studied were the variation of the condition index and the frequency distribution of oocyte diameters. Results showed that the reproductive cycle was continuous in situ. Gametogenesis started in January and February. Gonadic activity...
Tipo: Text
Palavras-chave: Ruditapes; Natural conditions; Hatchery; Reproduction; Gonatic activity; Gametogenesis.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-882.pdf

Ecophysiologie de l'huître creuse Crassostrea gigas (Thunberg) : analyse bioénergétique de la gamétogenèse sous trois conditions trophiques distinctes
Provedor de dados: 5
Autores: Bourles, Yves.
The Pacific oyster (Crassostrea gigas) is a major cultivated shellfish resource in France, which represented a tumover of 220 millions € in 2000. Mass mortalities among this commercially important bivalve species are known in France since about 40 years, but have become a recun'ing obstacle for growers of oysters and a threaten for commercial production along the French Atlantic coast in the last 20 years. Since 2000, IFREMER is canying out a multidisciplinary program, MOREST, ta understand the problem of summer mortality, and possibly ta solve il. As part of the MOREST program, the present study focuses on the relationship between gametogenesis, metabo lism and mortality of 7-month, i.e. juvenil e, C. gigas. In April 2004, a total of 2250 oysters were...
Tipo: Text
Palavras-chave: Crassostrea gigas; Naissain; Mortalité estivale; Gamétogenèse; Bilan énergétique; Crassostrea gigas; Spot; Summer mortalities; Gametogenesis; Energy budget.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/00448/55961/57444.pdf

Physiological and molecular basis of gametogenesis in triploid Pacific oysters, Crassostrea gigas
Provedor de dados: 5
Autores: Normand, Julien; Huvet, Arnaud; Fabioux, Caroline; Raguenes, Morgane; Boudry, Pierre.
Genetic improvement of the Pacific oyster, Crassostrea gigas, can be achieved through triploidisation, which leads to partially sterility, allowing higher growth and survival together with improved meat quality during the reproductive period. Most triploids are not fully sterile and the genetic and environmental factors involved in their partial fertility remained to be investigated.  We examined gametogenesis by image analysis of histological cross sections in diploid (2n) and triploid oysters obtained either by crossing tetraploids and diploid broodstock (« natural » triploids: 3nn) or from second polar body retention (« chemical » triploids: 3nc).  5-month old triploid spat reared in a standard intensive nursery system only showed a reduction of 50% of...
Tipo: Text
Palavras-chave: Gametogenesis; Triploid; Crassostrea gigas; Genetic; Oysters.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/acte-3327.pdf

Déterminismes génétiques de l'allocation à la reproduction chez les huîtres creuses (Crassostrea gigas) triploïdes
Provedor de dados: 5
Autores: Normand, Julien.
In diploid Pacific oyster Crassostrea gigas, gonadic development can be important in terms of energetic investment. Phenotypic and genetic negative correlations have also been observed between gonadic occupation and traits related to survival and growth, and this fact suggests that this trait could be deleterious for its aquaculture production. Triploidy can be been artificially induced to improve the production of Pacific oysters as it results in a general diminution of mean gonadic development. This trait is however highly variable. In this context, this study aimed to quantify and qualify the allocation to reproduction in triploid oysters and to study its genetic bases. Variability for allocation to reproduction and growth was first studied in 3 sets of...
Tipo: Text
Palavras-chave: Triploidy x genetic interaction; Genetic determinism; Sexual dimorphism; Gametogenesis; Allocation to reproduction; Triploid; Oyster; Interaction triploïdie x génétique; Déterminisme génétique; Dimorphisme sexuel; Gamétogenèse; Allocation à la reproduction; Triploïde; Huître.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/these-6971.PDF

Reproductive effort and growth in Crassostrea gigas: comparison of young diploid and triploid oysters issued from natural crosses or chemical induction
Provedor de dados: 5
Autores: Normand, Julien; Ernande, Bruno; Haure, Joel; Mccombie, Helen; Boudry, Pierre.
Early reproductive effort and growth were measured in 3 groups of the Pacific oyster Crassostrea gigas: 1 diploid group and 2 triploid groups resulting from either chemical induction (3nCB) or crosses between tetraploid and diploid parents (3nDT). Oysters were reared under intensive nursery conditions and sampled when 5 mo old. Reproductive effort was estimated by cross-sectional area measurements of the visceral mass (i.e. gonadic occupation) and maturation stage was assessed by qualitative histology. As expected, comparison of the reproductive patterns of these 3 groups revealed a lower reproductive effort in triploid individuals relative to diploid. However, gonadic occupation in triploid oysters was higher than expected in both 3nCB and 3nDT groups, as...
Tipo: Text
Palavras-chave: Triploidy; Oyster; Gametogenesis; Crassostrea gigas.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6978.pdf

Gametogenesis, reproductive investment, and spawning behavior of the Pacific giant oyster Crassostrea gigas: evidence of an environment-dependent strategy
Provedor de dados: 5
Autores: Enriquez-diaz, M.; Pouvreau, Stephane; Chavez-villalba, J.; Le Pennec, M.
The progress of gametogenesis was studied in oysters Crassostrea gigas having the same origin (Tremblade), but cultured during 1 year in two distinctive French marine areas, the Baie des Veys and Marennes-Ol,ron. We assessed seasonal changes in the reproduction cycle on the basis of stereological techniques to estimate reproductive investment and measurement of gonad evolution area by quantitative histology. From a qualitative point of view, both oyster groups presented typical reproductive stages, but showed differential timing, in particular during the sequence of spawning and duration of the re-absorption stage. Oysters in Baie des Veys had a single partial spawning in August and a re-absorption stage that extended until winter. Oysters in...
Tipo: Text
Palavras-chave: Stereology; Reproductive investment; Pacific oysters; Image analysis; Gametogenesis; Crassostrea gigas.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-7300.pdf

Histological Validation of Morphochromatically-Defined Gonadal Maturation Stages of Green Abalone (Haliotis fulgens) Philippi,1845 and Pink Abalone (Haliotis corrugata) Wood, 1828
Provedor de dados: 77
Autores: Vélez-Arellano,Nurenskaya; García-Domínguez,Federico Andrés; Lluch-Cota,Daniel B; Gutiérrez-González,José L; Sánchez-Cárdenas,Rebeca.
Identifying the maturity stage of specimens is essential for the determination of the spawning season, which in turn facilitates the formulation of adequate fisheries management measures for the sustainable use of sea resources, such as abalone. This study aims to validate, based on histological evidence, a gonad maturation scale that encompasses four morphochromatically-defined stages (developing, maturity, spawning and resting) for females and males, plus an additional stage for reproductively inactive (undifferentiated) specimens, to be used as an identification key. Given the similarity between Haliotis fulgens and Haliotis corrugata as to their morphochromatic features, the gonadal maturation scale can be used for both species.
Tipo: Journal article
Palavras-chave: Assessment tools; Gametogenesis; Gonads; Reproduction.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022015000300039

Gonadal Development of Peprilus medius (Peters, 1869) (Perciformes: Stromateidae) from Southeast of the Gulf of California, Mexico
Provedor de dados: 77
Autores: Maldonado-Amparo,Maria de los Angeles; Sánchez-Cárdenas,Rebeca; Salcido-Guevara,Luis Antonio; Ramírez-Pérez,Jorge Saúl.
The gonadal development assessment is a fundamental work in researching the reproduction of Peprilus medius, on the way to understand its population dynamics and to achieve a sustainable management of its fisheries. The diagnosis based on morphochromatic features is the quicker, more practical and cheaper method, and properly validated, it may be an accurate procedure. This is particularly useful in researches when it is required to provide prompt and accurate information to support decision-making for fisheries management, and during long-term fisheries monitoring to detect changes in reproductive patterns due to environmental anomalies. These are issues of concern in P. medius and other fishery resources. In this context, a scale that describes the...
Tipo: Journal article
Palavras-chave: Ovaries; Testes; Gametogenesis; Reproductive anatomy.
Ano: 2017
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022017000100011

Anther wall formation, sporogenesis and gametogenesis of Tripterospermum chinense (Gentianaceae), with emphasis on uniformity of characters in Tripterospermum and its systematic values
Provedor de dados: 16
Autores: Ao, C.
Tripterospermum sensu T.N.Ho comprises two sections that are readily discriminated morphologically. In the present paper, embryological characters in anther wall formation, sporogenesis and gametogenesis of Tripterospermum chinense, a member of sect. Platyspermum, are reported. Comparisons based on available data show that as far as the two recognized sections are concerned, embryological characters are uniform in all aspects, disapproving of the splitting of the genus into two sections. The notable differences between Tripterospermum and closely related genera support the phylogenetic conclusion that Tripterospermum is monophyletic.
Tipo: Article / Letter to the editor
Palavras-chave: Anther wall; Gametogenesis; Sect. Platyspermum; Sect. Tripterospermum; Sporogenesis; Systematic values; Tripterospermum chinense.
Ano: 2012
URL: http://www.repository.naturalis.nl/record/525218

Induced reproduction in a migratory teleost species by water level drawdown
Provedor de dados: 83
Autores: Chehade,Chayrra; Cassel,Mônica; Borella,Maria Inês.
Captive reproduction is one of the problems faced in aquaculture requiring the manipulation of environmental factors and/or hormonal treatment. Thus, we seek to verify experimentally which gonadal changes were present in mature individuals of Astyanax altiparanae arising from decreased water level. Collections were made every four hours, initiated four hours before and finished 28 hours after stimulation, at the Fish Farming Station of Companhia Energética de São Paulo, São Paulo, Brazil. The gonads were analyzed by light microscopy. The females had ovaries in the spawning capable phase until 12h; in 16h, in a more advanced stage of spawning capable phase; and, from 20h, in the regressing phase. Males had testes in the spawning capable phase until 8h; in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Asynchronous reproduction; Characidae; Gametogenesis; Gonadosomatic index; Histology.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000100205

Biología reproductiva de algunas especies de la tribu Thenaria (Cnidaria: Anthozoa) en el litoral marplatense
Provedor de dados: 20
Autores: Excoffon, A.C.
Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales (Argentina).
Tipo: Theses and Dissertations
Palavras-chave: Sexual reproduction; Asexual reproduction; Gametogenesis; Reproductive cycle; Embryonic development; Larval development; Comparative studies; Asexual reproduction; Gametogenesis; Embryonic development; Sexual reproduction; Http://aims.fao.org/aos/agrovoc/c_664; Http://aims.fao.org/aos/agrovoc/c_27931; Http://aims.fao.org/aos/agrovoc/c_2545; Http://aims.fao.org/aos/agrovoc/c_26876.
Ano: 1993
URL: http://hdl.handle.net/1834/2957

Fertilidad y fecundidad de Montastraea annularis en un arrecifes degradado
Provedor de dados: 20
Autores: Alvarado-Ch., E.; Acosta, A.
Este estudio determinó el ciclo gametogénico, fecundidad y fertilidad de Montastraea annularis en el arrecife de isla Grande, archipiélago de Nuestra Señora del Rosario, uno de los arrecifes más degradados del Caribe colombiano. La población de estudio se caracteriza por poseer colonias medianas (alrededor de 3379 cm2), con mortalidad parcial en 27 % de los ramets y totoal en el 10 % de los mismos. Las colonias presentan un alto número de ramets pequeños producto de la fisión (76 % menores a 50 cm2). Basado en las características de la estructura de tallas de la población mencionada, el objetivo de esta investigación fue explicar el bajo reclutamiento registrado en la zona, a través de la respuesta reproductiva de una población con dominancia de ramets...
Tipo: Journal Contribution
Palavras-chave: Degradation; Fecundity; Fertility; Gametogenesis; Degradation; Gametogenesis; Fecundity; Fertility; Http://aims.fao.org/aos/agrovoc/c_2159; Http://aims.fao.org/aos/agrovoc/c_27931; Http://aims.fao.org/aos/agrovoc/c_15725; Http://aims.fao.org/aos/agrovoc/c_2862.
Ano: 2009
URL: http://hdl.handle.net/1834/3610

Estrategias reproductivas de moluscos bivalvos y equinoideos
Provedor de dados: 20
Autores: Calvo, J.; Morriconi, E.; Orler, P.
The theoretical aspects of reproductive strategies and life histories are analyzed. The gonadal structures and the main features of gametogenesis of bivalves and echinoids are described. Research on the reproductive characteristics and gametogenic cycles of the bivalve molluscs in the Argentinian littoral and the echinoid Loxechinus albus is reviewed. Special references to Mytilus edulis, Aulacomya ater, Brachidontes purpuratus, Aequipecten tehuelchus, Zygochlamys patagonica, Ostrea puelchana, Clausinella gayi, Protothaca antiqua, Eurhomalea exalbida and Mesodesma mactroides are made. Analysis of reproductive cycles includes histological and ponderal descriptions of gonadal variations. The main trend found is the partial and multiple spawning episodes....
Tipo: Book Section
Palavras-chave: Hermaphroditism; Gametogenesis; Life cycle; Marine molluscs; Reproduction; Reproductive cycle; Hermaphroditism; Gametogenesis; Life cycle; Reproduction; Http://aims.fao.org/aos/agrovoc/c_3571; Http://aims.fao.org/aos/agrovoc/c_27931; Http://aims.fao.org/aos/agrovoc/c_4317; Http://aims.fao.org/aos/agrovoc/c_6507.
Ano: 1998
URL: http://hdl.handle.net/1834/2581

Gametogenic cycle of Ophioderma januarii, a common Ophiodermatidae (Echinodermata: Ophiuroidea) in southeastern Brazil
Provedor de dados: 103
Autores: Borges,Michela; Yokoyama,Leonardo Q; Amaral,Antonia C. Z.
This study describes the gametogenic cycle of Ophioderma januarii Lütken, 1856, a common species of ophiuroid in Southeastern Brazil. The specimens were collected during the project "Biodiversidade Bêntica Marinha no Estado de São Paulo-BIOTA/FAPESP-Bentos Marinho" (Marine benthic biodiversity in the State of São Paulo-BIOTA/ Fapesp-Marine Benthos) which was conducted off the northern coast of the state of São Paulo. Specimens were captured monthly between February 2001 and December 2002. Due to the low number of individuals the monthly data was grouped in seasons (spring to winter). A total of 101 specimens were obtained: 33 in spring, 10 in summer, 23 in autumn, and 35 in winter. The gonads of eighty-eight individuals (45 females, 42 males, and one...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Gametogenesis; Ophiuroid; Recruitment.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000100018

Gonadal development and sexuality of Larkinia grandis (Arcida: Arcidae) inhabiting southeastern Gulf of California
Provedor de dados: 103
Autores: Sotelo-Gonzalez,Maria I.; García-Ulloa,Manuel; Góngora-Gómez,Andrés M.; Salcido-Guevara,Luis A.; Arzola-González,Juan F.; Sepúlveda,Carlos H.; Sánchez-Cárdenas,Rebeca.
ABSTRACT Larkinia grandis (Broderip &amp; G.B. Sowerby I, 1829), an important fishing resource for Mexican communities, is an Arcidae clam. It is also considered a species with aquaculture potential. In this work we investigated the gonadal phases and sexuality in a population of L. grandis in the Gulf of California. Our findings support the hypothesis that there is one male per female in the population studied. It also documents that the shape, position and color of the gonads of L. grandis are consistent with observations in other Arcidae species. Additionally, five gonadal phases are differentiated and described in males and females (development, mature, spawning, post-spawning and resting), with a noticeable presence of brown cells during post-spawning...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bivalve; Estuary; Gametogenesis; Gonad; Mangrove cockle; Sex cells.
Ano: 2021
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702021000100306

Reproductive biology in the starfish Echinaster (Othilia) guyanensis (Echinodermata: Asteroidea) in southeastern Brazil
Provedor de dados: 103
Autores: Mariante,Fátima L. F.; Lemos,Gabriela B.; Eutrópio,Frederico J.; Castro,Rodrigo R. L.; Gomes,Levy C.
Echinaster (Othilia) guyanensis Clark, 1987 is an endangered starfish distributed throughout the Caribbean and Atlantic Ocean. Even though it has been extensively harvested, little is known about the biology and ecology of this starfish. Here, we examine reproduction seasonality in E. (O.) guyanensis. Individuals were collected monthly for one year, including four complete lunar phases. The gonad index (GI) was calculated to determine annual and monthly reproductive peaks. Gametogenesis stages were also determined. Sex ratio was 1:1.33 (M:F). Gonadosomatic index, body weight, central disc width and arm length were similar for both sexes. Gonads were present in all animals with arm length greater than 36.2 mm. Lunar phase was not associated with E. (O.)...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazil; Reproduction; Gametogenesis; Gonad index; Lunar periodicity.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000600010

Biological variables of Hypostomus francisci (Siluriformes: Loricariidae) from Itapecerica River, Minas Gerais State, Brazil
Provedor de dados: 42
Autores: SALES,CAMILA F.; DOMINGOS,FABRÍCIO FLÁVIO T.; BRIGHENTI,LUDMILA S.; RIBEIRO,ROSY I.M.A.; SANTOS,HÉLIO B.; THOMÉ,RALPH G.
ABSTRACT Herein we determine for the first time the reproduction parameters and population structure of Hypostomus francisci in the Itapecerica River, São Francisco Basin. A total of 250 specimens was captured quarterly between March 2010 and February 2012. Body weight, total length and weight of the gonads were obtained in the laboratory. Gonad samples were submitted to histological and histochemical techniques. Females with spawning capable ovaries were used to determine the fecundity and relative fecundity. Sex ratio with 1:1.01 (female:male) was observed. Males were more numerous than females for individuals smaller than 170 mm, however the number of females was significantly greater for specimens larger than 330 mm. The length-weight relationship...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fecundity; Gametogenesis; Neotropical freshwater fish; Population structure; Reproduction.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000501603