105 research outputs found

    Nme protein family evolutionary history, a vertebrate perspective

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    Background: The Nme family, previously known as Nm23 or NDPK, is involved in various molecular processes including tumor metastasis and some members of the family, but not all, exhibit a Nucleoside Diphosphate Kinase (NDPK) activity. Ten genes are known in humans, in which some members have been extensively studied. In non-mammalian species, the Nme protein family has received, in contrast, far less attention. The picture of the vertebrate Nme family remains thus incomplete and orthology relationships with mammalian counterparts were only partially characterized. The present study therefore aimed at characterizing the Nme gene repertoire in vertebrates with special interest for teleosts, and providing a comprehensive overview of the Nme gene family evolutionary history in vertebrates. Results: In the present study, we present the evolutionary history of the Nme family in vertebrates and characterize the gene family repertoire for the first time in several non-mammalian species. Our observations show that vertebrate Nme genes can be separated in two evolutionary distinct groups. Nme1, Nme2, Nme3, and Nme4 belong to Group I while vertebrate Nme5, Nme6, Nme7, Nme8, and Nme9 belong to Group II. The position of Nme10 is in contrast more debatable due to its very specific evolutionary history. The present study clearly indicates that Nme5, Nme6, Nme7, and Nme8 originate from duplication events that occurred before the chordate radiation. In contrast, Nme genes of the Group I have a very different evolutionary history as our results suggest that they all arise from a common gene present in the chordate ancestor. In addition, expression patterns of all zebrafish nme transcripts were studied in a broad range of tissues by quantitative PCR and discussed in the light of the function of their mammalian counterparts. Conclusion: This work offers an evolutionary framework that will pave the way for future studies on vertebrate Nme proteins and provides a unified vertebrate Nme nomenclature that is consistent with the nomenclature in use in mammals. Based on protein structure and expression data, we also provide new insight into molecular functions of Nme proteins among vertebrates and raise intriguing questions on the roles of Nme proteins in gonads

    Gamete quality and management for in vitro fertilisation in meagre (Argyrosomus regius)

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    The aquaculture of meagre (Argyrosomus regius) requires methods for the control of reproduction that enable the production of families from specific individuals for selective breeding programs. We experimentally determined the parameters required for an in vitro fertilisation protocol. A total of 14 females and 5 males (mean ± S.D. weights of 20.45 ± 6.22 and 15.94 ± 2.75 kg, respectively) were used. Selected females had vitellogenic oocytes >550 μm in diameter and males had fluid sperm upon application of abdominal pressure. Both sexes were treated with an injection of 15 μg kg−1 of gonadotropin-releasing hormone agonist (GnRHa) to induce oocyte maturation/ovulation and enhance sperm production. To determine the timing of ovulation and window of high egg viability, females were stripped serially every 2.5 h beginning 35 h after GnRHa treatment. Sperm was obtained 24 h after GnRHa treatment and was diluted 1/4 in modified Leibovitz for storage at 4 °C until use. Sperm quality parameters such as percentage initial spermatozoa motility, duration of motility, velocity and density were determined using computer assisted sperm analysis (CASA). In vitro inseminations were made in duplicate or triplicate batches of eggs from each spawn by mixing 0.5–1 mL of eggs, 20–40 μL diluted sperm (pooled from two males) and 100 mL of seawater. Fertilisation success was examined at spermatozoa (spz): egg ratios between ~2000 and 400,000 spz egg−1. The optimal time for stripping ovulated females was ≤3 h after ovulation, which was the window of optimal egg viability. Ovulation under the conditions of this study was close to 38 h after GnRHa treatment, with a range from 35 to 41 h. Beginning from 3 h after ovulation, egg viability declined probably due to overripening. Sperm diluted in Leibovitz maintained motility and velocity for as long as 7 h after collection. Spermatozoa motility (%) and average path velocity (VAP, μm/s) of sperm samples obtained from males before GnRHa injection declined rapidly after activation compared to the samples obtained 24 h post-injection, with significant decreases respectively after 75 and 45 s. A minimum ratio of 150,000 spermatozoa egg−1 was necessary to ensure high fertilisation success. The acquired knowledge of the present study will aid the aquaculture industry and future research on selective breeding programs for meagre.info:eu-repo/semantics/acceptedVersio

    Wreckfish (Polyprion americanus). New Knowledge about reproduction, larval husbandry and nutrition. Promise a new species for aquaculture

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    Four different wreckfish (Polyprion americanus) broodstock batches were maintained in research facilities under different photo and thermo-period conditions, one in Greece, the Helenic Center for Marine Research (HCMR, n = 3) and three in Spain: Instituto Español de Oceanografía (IEO, n = 13) in Vigo, Aquarium Finisterrae (MC2, n = 21) in A Coruña and Consellería do Mar (CMRM, n = 11). The CMRM includes two centers that work together: Instituto Galego de Formación en Acuicultura (IGAFA) and Centro de Investigacións Mariñas (CIMA), both in Pontevedra. During the five years of the project DIVERSIFY (Exploring the biological and socio-economic potential of new-emerging candidate fish species for the expansion of the European aquaculture industry, 2013–2018) works focused on the reproductive biology of the species, broodstock, and larvae nutrition and development of incubation and larval rearing protocols have been carried out. In terms of reproduction, catch methods of new wild animals, the reproductive cycle, sperm characteristics evaluation, and spontaneous and induced spawning methods have been described for wreckfish. Regarding nutrition, the positive effect of two types of enrichment on the fatty acid profiles of Artemia and rotifer has been verified. The relationship between the fatty acid profile of the diets supplied to the broodstock and the fatty acid profile obtained in the oocytes and eggs of the females fed with different diets, has also been demonstrated. Finally, early larval ontogeny has been described and incubation and larval rearing protocols have been proposed based on the results obtained in the different experiments of temperature, growth, survival, and larval feeding that were carried out.Versión del edito

    4D-Var inversion of European NH3 emissions Using CrIS NH3 measurements and GEOS-Chem adjoint with bi-directional and uni-directional flux schemes

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    We conduct the first 4D-Var inversion of NH3 accounting for NH3 bi-directional flux, using CrIS satellite NH3 observations over Europe in 2016. We find posterior NH3 emissions peak more in springtime than prior emissions at continental to national scales, and annually they are generally smaller than the prior emissions over central Europe, but larger over most of the rest of Europe. Annual posterior anthropogenic NH3 emissions for 25 European Union members (EU25) are 25% higher than the prior emissions and very close (<2% difference) to other inventories. Our posterior annual anthropogenic emissions for EU25, the UK, the Netherlands, and Switzerland are generally 10%–20% smaller than when treating NH3 fluxes as uni-directional emissions, while the monthly regional difference can be up to 34% (Switzerland in July). Compared to monthly mean in-situ observations, our posterior NH3 emissions from both schemes generally improve the magnitude and seasonality of simulated surface NH3 and bulk NHx wet deposition throughout most of Europe, whereas evaluation against hourly measurements at a background site shows the bi-directional scheme better captures observed diurnal variability of surface NH3. This contrast highlights the need for accurately simulating diurnal variability of NH3 in assimilation of sun-synchronous observations and also the potential value of future geostationary satellite observations. Overall, our top-down ammonia emissions can help to examine the effectiveness of air pollution control policies to facilitate future air pollution management, as well as helping us understand the uncertainty in top-down NH3 emissions estimates associated with treatment of NH3 surface exchange

    Rapport de mission aux Etats-Unis du 4 au 22 janvier 1988

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    During this visit, research work on the physiology and zootechny of reproduction of different US teams were compared to ours. It is clear that we have the same problems to solve and that research programs are rather similar, but they must take into account the local conditions. This fact limits the possibilities of cooperation. Nevertheless a very good knowledge of each work has been noted.Au cours de la mission, le point a été fait sur les travaux réalisés dans plusieurs équipes américaines en physiologie et zootech­nie de la reproduction. Les préoccupations des différentes équipes correspondent aux nôtres et les programmes de recherche sont proches mais doivent tenir compte des conditions locales limitant ainsi les possibilités de collaboration. On note, cependant, une très bonne connaissance réciproque des travaux

    Reproductive dynamics of swordfish (

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    Batch fecundity and relative fecundity of swordfish (Xiphias gladius) in the southwestern Indian Ocean were estimated from seven gravid swordfish females (size range 127–225 cm lower jaw-to-fork length, LJFL) with unovulated, hydrated oocytes collected onboard Reunion-based (France) longline swordfish fishing vessels between December 1999 to January 2001. To investigate the spawning pattern of swordfish, we used data collected through a combination of two at sea sampling regimes. A total of 17 007 geo-located size data of swordfish were recorded during 8 years (1993-2001) and a total of 1727 (size range 75–289 cm, LJFL) swordfish gonads (1107 females and 620 males) were sampled from May 1998 to January 2001. The estimated batch fecundity ranged from 995 000 hydrated oocytes for the smallest ripe female to 4.3 millions for the largest female sampled measuring respectively 127 to 225 cm in curved length (LJFL). The relative fecundity ranged from 25 to 72 hydrated oocytes per gram of body weight. We found that batch fecundity was positively correlated with fish length and that the older/larger females have earlier and longer spawning seasons than younger/ smaller females. These findings suggested that older/larger females which are seasonally migrating in this spawning ground seem to play a major role in reproductive success of the species in producing significantly more offspring than younger females during an extended spawning season. Examination of the length-frequency date from the fishery indicated that the young fish are resident around Reunion and around the seamounts off Reunion Island. Our results highlight the important role of the older/larger females in the reproductive capacity of southwestern Indian Ocean stock. We discuss the potential implications of fishing the older/larger females for this stock in terms of reproduction and recruitment

    La domestication des poissons : le cas du thon rouge

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    Bluefin tuna shows adaptative physiology features allowing life in a wide range of physical and climatic parameters like temperature, salinity and hydrostatic pressure, hence the species fulfil the main basic requirements for progressive domestication and rearing in captivity. The high mortalities recorded after handling and the losses observed after abrupt variations of environment in the cages, emphasised the extreme sensitivity to stress of tuna. As consequences, the progresses about the control of tuna biological cycle are very slow due to limited handling possibilities and tuna aquaculture is restricted to fattening of wild fish. At this time, bluefin tuna production progresses without domestication of the species.Le thon rouge présente des caractères adaptatifs lui permettant de vivre dans une gamme large de paramètres physiques et climatiques tels que la température, la salinité et la pression hydrostatique. L’élevage de l’espèce et une domestication progressive pouvaient donc être envisagés. Les mortalités importantes observées après manipulation et les pertes liées aux variations brutales de l’environnement en cage ont révélé l’extrême sensibilité du thon au stress. Cette nouvelle caractéristique de ce poisson pélagique diminue les possibilités d’intervention humaine durant l’élevage. Celui-ci se limite à l’engraissement d’individus sauvages et les progrès sur le contrôle du cycle biologique de l’espèce sont extrêmement lents. On peut dire que la production de thon progresse sans domestication de l’espèce

    Optimizing the exploitation of wild and reared bluefin tunas under the constraint of sustainability: the Ifremer R&D project

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    A brief account is given of a research project commenced in 2000 by IFREMER concerning aspects of wild bluefin farming in offshore cages and reproduction control in land-based facilities. Three inter-related sub­ projects have been suggested: (i) wild fish ongrowing and/or fattening; (ii) reproduction; and (Hi) fingerling production and improvement of the understanding of early stage recruitment limitations. The Integration of this project in other EU community activities is discussed."Optimisation de l'exploitation de thons rouges sauvages et élevés, en tenant compte de la contrainte de durabilité: Le projet de R&D d'IFREMER". Un bref rapport est présenté sur un projet de recherche entamé en l'an 2000 par IFREMER concemant des aspects d'élevage du thon rouge sauvage dans des cages offshore et sous reproduction contrôlée dans des installations à terre. Trois sous-projets étroitement liés ont été suggérés: (i) élevage de poissons sauvages et/ou engraissement; (ii) reproduction; et (iii) production d'alevins et meilleure compréhension des limitations du recrutement des stades précoces. L'intégration de ce projet dans d'autres activités de la communauté de l'UE est discutée

    Nme gene family in the fish ovary

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