The neurohormonal induction of the release of oocytes and sperm from Pecten maximus

In order to induce in vitro maturation of Pecten maximus oocytes, experiments were carried out using different concentrations of the serotonin and dopamine agonists TFMPP, 8-OHDPAT, quinpirole and bromocriptine. The greatest germinal vesicle breakdown (GVBD) occurred using TFMPP. Metaphasic blocks were rarely observed. Oocytes treated with TFMPP at 10 super(-3) and 5x10 super(-4) M could be fertilized at low levels. The maximum fertilization rate recorded was 23%. A second series of experiments was conducted to determine the effects of serotonin, dopamine, the agonists cited above and PGE sub(2) on the release of oocytes and sperm from P. maximus. These inducers were injected into both the male and female parts of the gonads and spermiation was systematically tested approximately 20 minutes following injection. No oocyte release was recorded, except after one injection of 8-OHDPAT at 5x10 super(-4) M; the effect of 8-OHDPAT on the release of oocytes was nevertheless insignificant

Induction de la ponte chez la coquille Saint Jacques: utilisation des neuromediateurs

Les gamètes de coquille St-Jacques sont récoltés de manière empirique dans les éc/oseries. Les produits sont obtenus dans des délais variables, en quantité et en qualité imprévisibles. L'effet des neuromédiateurs en tant que régulateurs potentiels du phénomène d'émission des gamètes, communément appelé ponte, a été testé. La sérotonine s'est avérée être un excellent régulateur de la spermiation. Un protocole de collecte du sperme a été établi. En revanche l'obtention des ovocytes s'est révélée plus délicate. Elle est possible, mais un protocole standard n 'a pu être défini

Variations de la qualié des embryons de Crassostrea gigas et de Pecten maximus dues à la qualité des gamete

La variabilité qualitative des embryons de bivalves produits en écloserie est d'origine endogène ou exogène. La recherche de méthodes adaptées à la réduction de la variabilité et à l'optimisation des résultats d'élevage nous a conduit à étudier les causes possibles des variations de qualité. Ce papier présente des résultats d'expériences conduites sur les relations entre variations de la qualité des gamètes mâles et fécondation ou développement embryonnaire. La qualité des gamètes femelles est traitée par la présentation de résultats sur les variations de la densité des ovocytes et par une analyse bibliographique

Systematic review of randomized controlled trials in the treatment of dry eye disease in Sjogren syndrome

Primary Sjögren’s syndrome is an autoimmune disease characterized by dry eye and dry mouth. We systematically reviewed all the randomized controlled clinical trials published in the last 15 years that included ocular outcomes. We found 22 trials involving 9 topical, 10 oral, 2 intravenous and 1 subcutaneous modalities of treatment. Fluoromethalone eye drops over 8 weeks were more effective than topical cyclosporine in the treatment of dry eye symptoms and signs; similarly, indomethacin eye drops over 1 month were more efficacious than diclofenac eye drops. Oral pilocarpine 5 mg twice daily over 3 months was superior to use of lubricants or punctal plugs for treating dry eye, but 5% of participants had gastrointestinal adverse effects from pilocarpine, though none discontinued treatment. In contrast, etanercept, a TNF-alpha blocking antibody, administered as subcutaneous injections twice weekly, did not improve dry eye significantly compared to placebo injections. In conclusion, topical corticosteroids have been shown to be effective in dry eye associated with Sjögren’s syndrome. As some topical non-steroidal anti-inflammatory drugs may be more effective than others, these should be further evaluated. Systemic secretagogues like pilocarpine have a role in Sjögren’s syndrome but the adverse effects may limit their clinical use. It is disappointing that systemic cytokine therapy did not produce encouraging ocular outcomes but participants should have assessment of cytokine levels in such trials, as those with higher baseline cytokine levels may respond better.published_or_final_versio

Sea bass (

This paper describes the large-scale production of eggs and larvae of sea bass (Dicentrarchus labrax) and shows how spawning can be planned to produce viable eggs throughout the year by manipulation of photoperiod and temperature. The rearing temperature was 9.5-22 °C during spawning and 9-24 °C during the gametogenesis. The photoperiodic cycles tested were normal (i. e. the photoperiodic cycle observed at Palavas-les-Flots, mediterranean coast, France, 1984/1987) advanced by 3 to 5 months and delayed by 2 months

Décalage de la période de reproduction par raccourcissement des cycles photopériodique et thermique chez des poissons marins *

Sea bass (Dicentrarchus labrax), turbot (Scophthalmus maximus) and gilthead sea bream (Sparus aurata) spawners were kept in 2 identical 40 m3 tanks, one outdoors (control) and one indoors (test) during a 5-year experiment. The control tank was under natural yearly photoperiod and the temperature cycles of western Brittany. The test tank was under similar variation for 3 years but with the cycles compressed into 10 months. The 3 species spawned naturally in these artificial conditions at various stages of the experiment. After 3 years, the fish in the test tank spawned an average 5 months ahead of the others. [NOT CONTROLLED OCR

Review of the reproductive physiology of the scallop,

This paper presents a summary of information on reproduction biology in the scallop, Pecten maximus, which is required for the successful reseeding and intensive aquaculture programs developed in France since 1982. Data are presented on the following subjects: environmental factors that sustain gametogenic activity and the time of year this activity occurs; biochemical changes that are associated with gametogenesis; the consistency of egg quality; and development of a simple test to predict egg quality

Maturation and fertilisation in vitro of Pecten maximus oocytes using serotonine and dopamine agonists

Maturation and fertilisation in vitro of Pecten maximus oocytes using serotonine and dopamine agonist

The characteristics of sea bass (

This paper concerns eggs of captive fish and gonads of wild fish, from the Brittany coast obtained in the 7-18 °C thermal range. The diameters of eggs, 1.07-1.32 mm are compared to those observed in other areas, especially along the Mediterranean coast. The duration of embryogenesis as a function of temperature and the efficiency of different incubators are discussed. The quality of eggs in relation with larval survival is discussed through the biochemical composition of the eggs collected in captivity compared to that of wild fish gonads. The absolute values of lipids, proteins, fatty acids, lipid classes, phosphatides and minerals measured, also the positive relations obtained between egg dry weight, diameters, mortality during incubation are presented as criteria of egg quality

Programme de recherche pour la mise au point d'une méthode d'élevage de coquilles Saint-Jacques en Méditerranée. Rapport d'avancement des travaux, résultats obtenus en écloserie en 1989 et au cours du premier semestre 1990

Au cours de la période considérée, il a été effectué 4 cycles d'élevage larvaire complets et 5 cycles d'élevage post-larvaire matérialisant une importante évolution quantitative par rapport aux deux années antérieures du programme. Le protocole, décrit dans le rapport d'avancement des travaux 1988, n'a pas subi d'aménagements majeurs saufen matière de conditionnement des géniteurs. Malgré les progrès réalisés dans la production de larves "D" et en survie larvaire, il n'a pas été possible d'obtenir un nombre de post-larves significatif de Pecten jacobaeus pour cause de mortalité à la fixation. En revanche, un essai mené en parallèle à partir de pédivéligères de Pecten maximus, originaires d'Argenton, s'est soldé par l'obtention de près de 30.000 naissains dans des conditions de rendement satisfaisants. Enfin, le suivi mensuel de l'indice gonadique de la population naturelle de Pecten jacobaeus, associé à un examen histologique des gonades pendant une année, a permis de préciser pour la première fois en Méditerranée française le cycle de reproduction, ainsi que la période optimale de réponse à un stimuli de déclenchement de ponte