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1.
Biofouling ; 35(8): 945-957, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31687858

RESUMEN

Ocean uptake of anthropogenic CO2 causes ocean acidification (OA), which not only decreases the calcification rate, but also impairs the formation of calcareous shells or tubes in marine invertebrates such as the dominant biofouling tubeworm species, Hydroides elegans. This study examined the ability of tubeworms to resume normal tube calcification when returned to ambient pH 8.1 from a projected near-future OA level of pH 7.8. Tubeworms produced structurally impaired and mechanically weaker calcareous tubes at pH 7.8 compared to at pH 8.1, but were able to recover when the pH was restored to ambient levels. This suggests that tubeworms can physiologically recover from the impacts of OA on tube calcification, composition, density, hardness and stiffness when returned to optimal conditions. These results help understanding of the progression of biofouling communities dominated by tubeworms in future oceans with low pH induced by OA.


Asunto(s)
Organismos Acuáticos/efectos de los fármacos , Incrustaciones Biológicas , Calcificación Fisiológica/efectos de los fármacos , Poliquetos/efectos de los fármacos , Agua de Mar/química , Ácidos , Exoesqueleto/química , Exoesqueleto/efectos de los fármacos , Animales , Organismos Acuáticos/fisiología , Incrustaciones Biológicas/prevención & control , Dióxido de Carbono/toxicidad , Predicción , Concentración de Iones de Hidrógeno , Océanos y Mares , Poliquetos/fisiología , Contaminantes Químicos del Agua/toxicidad
2.
Biofouling ; 35(8): 832-839, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31570009

RESUMEN

The attachment efficiency of biofouling organisms on solid surfaces depends on a variety of factors, including fouler species, nutrition abundance, flow rate, surface morphology and the stiffness of the solid to which attachment is to be made. So far, extensive research has been carried out to investigate the effects of these factors on the attachment of various fouling species. However, the results obtained are species-dependent and scattered. There is no universal rule that can be applied to predict the attachment efficiency of different species. To solve this problem, the authors carried out meta-analysis of the effects of ten selected factors on attachment efficiency, resulting in a universal correlation between the attachment density and the selected factors, which was validated by attachment tests of tubeworms on PDMS surfaces. The results provide a practical approach to predicting the attachment efficiency of fouling organisms and should be of great value in the design of anti-biofouling materials.


Asunto(s)
Organismos Acuáticos/fisiología , Incrustaciones Biológicas , Dimetilpolisiloxanos/química , Modelos Biológicos , Poliquetos/fisiología , Propiedades de Superficie , Animales , Fenómenos Fisiológicos
3.
Biol Bull ; 237(1): 16-25, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31441700

RESUMEN

Marine invertebrate larvae have often been reared in artificial rather than natural seawater, either for convenience or to avoid potentially confounding effects of unknown contaminants. This study sought to determine the impact of artificial seawater on various aspects of development for three marine invertebrate species. We examined the impact of Instant Ocean on growth, survival, and fecundity of the deposit-feeding polychaete Capitella teleta at 2 salinities: 24 and 34 ppt; the impact on survival, growth rate, and time to metamorphic competence for the slipper limpet Crepidula fornicata; and the impact on larval growth for the sea star Asterias forbesi. Juveniles of C. teleta survived better in natural seawater than in Instant Ocean at both salinities but at the higher salinity grew more quickly in Instant Ocean; fecundity was not significantly affected by the type of seawater used at either salinity. Using Instant Ocean in place of natural seawater had no pronounced impact on the survival of C. fornicata larvae or on how long it took them to become competent to metamorphose; however, larvae grew somewhat more quickly in Instant Ocean than in natural seawater for the first 4 days of development, but by day 7 they were about 4.5% larger if they had been reared in seawater. The type of seawater used affected the growth of A. forbesi larvae, with larvae growing significantly more slowly in Instant Ocean than in natural seawater, no matter how growth was measured. In conclusion, our results suggest that although Instant Ocean may be a reasonable substitute for natural seawater for work with some species, using it may affect experimental outcomes in some aspects of work with other species.


Asunto(s)
Gastrópodos/fisiología , Crecimiento y Desarrollo/fisiología , Poliquetos/fisiología , Agua de Mar/química , Estrellas de Mar/fisiología , Animales , Reproducción/fisiología , Estrés Fisiológico , Análisis de Supervivencia
4.
Nat Commun ; 10(1): 3383, 2019 07 29.
Artículo en Inglés | MEDLINE | ID: mdl-31358752

RESUMEN

Marine encrusting communities play vital roles in benthic ecosystems and have major economic implications with regards to biofouling. However, their ability to persist under projected warming scenarios remains poorly understood and is difficult to study under realistic conditions. Here, using heated settlement panel technologies, we show that after 18 months Antarctic encrusting communities do not acclimate to either +1 °C or +2 °C above ambient temperatures. There is significant up-regulation of the cellular stress response in warmed animals, their upper lethal temperatures decline with increasing ambient temperature and population genetic analyses show little evidence of differential survival of genotypes with treatment. By contrast, biofilm bacterial communities show no significant differences in community structure with temperature. Thus, metazoan and bacterial responses differ dramatically, suggesting that ecosystem responses to future climate change are likely to be far more complex than previously anticipated.


Asunto(s)
Aclimatación/fisiología , Ecosistema , Cubierta de Hielo , Biología Marina/métodos , Animales , Regiones Antárticas , Bacterias/crecimiento & desarrollo , Cambio Climático , Perfilación de la Expresión Génica/métodos , Calentamiento Global , Poliquetos/genética , Poliquetos/fisiología , Temperatura Ambiental
5.
Mar Pollut Bull ; 142: 178-182, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31232292

RESUMEN

The main objective of the present study was to explore the potential link between acetylcholinesterase (AChE) activity and burrowing behaviour of the ragworm Hediste diversicolor, which may have consequences at higher levels of biological organisation. Two complementary studies were conducted. AChE activity, at the sub-individual level, and behavioural responses, at the individual level, were evaluated in worms from the Loire estuary (France), whereas density and biomass of H. diversicolor were determined at the population level. A Spearman positive correlation between both biomarkers (AChE and burrowing) suggested that inhibition of AChE activity was linked to behaviour impairments. At the population level, lower AChE and behaviour activities were detected in worms corresponding to lower population density and biomass. These results provide direct empirical field evidence demonstrating the sensitivity of behaviour of H. diversicolor as a biomonitor of estuarine health status assessment.


Asunto(s)
Acetilcolinesterasa/metabolismo , Poliquetos/fisiología , Animales , Conducta Animal/fisiología , Biomarcadores/metabolismo , Ecotoxicología/métodos , Estuarios , Francia , Densidad de Población
6.
Environ Pollut ; 252(Pt B): 1180-1192, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31252116

RESUMEN

The increasing consumption of anticancer drugs through single and/or combinatory chemotherapy worldwide raised concern regarding their toxicity burden in coastal zones. The toxicity of a mixture of three compounds involving the drugs cisplatin (CisPt), cyclophosphamide (CP) and tamoxifen (TAM) was determined on the marine polychaete Nereis diversicolor exposed to an increasing range of their concentrations, respectively: Mix A: 0.1 + 10 + 0.1 ng L-1; Mix B: 10 + 100 + 10 ng L-1; Mix C: 100 + 500 + 25 ng L-1; Mix D: 100 + 1000 + 100 ng L-1. Different endpoints were assessed, including disturbance in the burrowing behaviour, neurotoxicity (acetylcholinesterase - AChE activity), antioxidant enzymes (superoxide dismutase - SOD; catalase - CAT; selenium-dependent glutathione peroxidase - Se-GPx and total glutathione peroxidases T-GPx activities), biotransformation metabolism (glutathione-S-transferases - GST), lipid peroxidation (LPO) and genotoxicity (DNA damage). Biological effects of the mixtures of anticancer compounds on N. diversicolor were compared with previous studies about effects on the same biological model under single-drug exposure conducted with the same molecules. Regarding SOD activity, TAM showed an antagonist effect over CisPt and CP in mixtures C and D. In Mix D, there was a synergistic effect of TAM and CisPt that inhibited CAT activity and an additive interaction of CisPt and CP on the Phase II biotransformation enzyme. Drugs in Mix A also suppressed polychaetes' GST activity, although different from the respective single-drug responses, besides able to induce T-GPx activity, that was not sufficient to avoid oxidative damage and mid-grade DNA damage. Due to the absence of burrowing impairment in Mix A, mechanisms involved in neurotoxicity were other than the one driven by AChE alterations. At the intermediary concentrations (Mix B and C), only LPO occurred. Data from drugs individually may not predict the risks provided by mixtures.


Asunto(s)
Antineoplásicos/toxicidad , Poliquetos/fisiología , Contaminantes Químicos del Agua/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Antineoplásicos/metabolismo , Antioxidantes/metabolismo , Biotransformación , Catalasa/metabolismo , Ciclofosfamida/metabolismo , Daño del ADN , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Estrés Oxidativo/fisiología , Poliquetos/metabolismo , Selenio/metabolismo , Superóxido Dismutasa/metabolismo
7.
Sci Total Environ ; 685: 19-27, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31170592

RESUMEN

Few data are available about the effect of dimethylated forms (DMA) on aquatic organisms. As rarely a contaminant occurs alone, studies evaluating the combined effect of different contaminants in aquatic organisms are needed. In fact, the presence of nanomaterials, such as titanium dioxide nanoparticles (nTiO2), in the aquatic environment is now a reality due to its intensive production and use. So, this study evaluated the toxicological effects of DMA in an acute exposure condition and considered the potential influence of nTiO2 on the effects induced by DMA in the polychaete, Laeonereis culveri. The animals were exposed over 48 h to DMA (50 and 500 µg/l) alone or in combination with nTiO2 (1 mg/l). Biochemical parameters such as concentration of reactive oxygen species (ROS), glutathione-S-transferase (GST) activity, levels of reduced glutathione levels (GSH) and macromolecular (lipid and DNA) damage were evaluated, as well the DNA repair system. In addition, the accumulation of total As and the chemical speciation of the metalloid in the organisms was determined. The results showed that: (1) only the group exposed to 500 µg of DMA/l accumulated As and when co-exposed to nTiO2, this accumulation was not observed. (2) The levels of ROS increased in the group exposed to 50 µg/l of DMA alone and the effect was reversed when this group was co-exposed to nTiO2 (3) None of the treatments showed altered GST activity or GSH levels. (4) All groups that received nTiO2 (alone or in combination with DMA) showed lipid peroxidation. (5) The exposure to DMA (both concentrations) alone or in combination with nTiO2 induced DNA damage in L. culveri. These results showed that DMA exhibits a genotoxic effect and that co-exposure to nTiO2 had an influence on its toxicity. So the occurrence of both contaminants simultaneously can represent a threat to aquatic biota.


Asunto(s)
Ácido Cacodílico/toxicidad , Nanopartículas del Metal/toxicidad , Poliquetos/fisiología , Titanio/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Glutatión/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Estrés Oxidativo
8.
Sci Total Environ ; 666: 1178-1187, 2019 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-30970483

RESUMEN

Ocean acidification events are recognized as important drivers of change in biological systems. Particularly, the impacts of acidification are more severe in estuarine systems than in surface ocean due to their shallowness, low buffering capacity, low salinity and high organic matter from land drainage. Moreover, because they are transitional areas, estuaries can be seriously impacted by a vast number of anthropogenic activities and in the last decades, carbon nanomaterials (CNMs) are considered as emerging contaminants in these ecosystems. Considering all these evidences, chronic experiment was carried out, trying to understand the possible alteration on the chemical behaviour of two different CNMs (functionalized and pristine) in predicted climate change scenarios and consequently, how these alterations could modify the sensitivity of one the most common marine and estuarine organisms (the polychaeta Hediste diversicolor) assessing a set of biomarkers related to polychaetes oxidative status as well as the metabolic performance and neurotoxicity. Our results demonstrated that all enzymes worked together to counteract seawater acidification and CNMs, however oxidative stress in the exposed polychaetes to both CNMs, especially under ocean acidification conditions, was enhanced. In fact, although the antioxidant enzymes tried to cope as compensatory response of cellular defense systems against oxidative stress, the synergistic interactive effects of pH and functionalized CNMs indicated that acidified pH significantly increased the oxidative damage (in terms of lipid peroxidation) in the cotaminated organisms. Different responses were observed in organisms submitted to pristine CNMs under pH control, where the lipid peroxidation did not increase along with the increasing exposure concentrations. The present results further demonstrated neurotoxicity caused by both CNMs, especially noticeable at acidified conditions. The mechanism of enhanced toxicity could be attributed to slighter aggregation and more suspended NMs in acidified seawater (as demonstrated by the DLS analysis). Therefore, ocean acidification may cause a higher risk of CNMs to marine ecosystems.


Asunto(s)
Nanotubos de Carbono/toxicidad , Neurotoxinas/toxicidad , Poliquetos/efectos de los fármacos , Agua de Mar/química , Contaminantes Químicos del Agua/toxicidad , Animales , Biomarcadores/metabolismo , Concentración de Iones de Hidrógeno , Estrés Oxidativo , Poliquetos/fisiología , Portugal
9.
Biol Bull ; 236(2): 130-143, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30933637

RESUMEN

Molluscan veliger larvae and some annelid larvae capture particulate food between a preoral prototrochal band of long cilia that create a current for both swimming and feeding and a postoral metatrochal band of shorter cilia that beat toward the prototroch. Larvae encountering satiating or noxious particles must somehow swim without capturing particles or else reject large numbers of captured particles. Because high rates of particle capture are inferred to depend on the beat of both ciliary bands, arrest of the metatroch could be one way to swim while reducing captures. Larvae in eight families of annelids arrest metatrochal cilia frequently during prototrochal beat, often over a large part of the metatrochal band and with the arrested cilia aligned near the beginning of the effective stroke. In contrast, metatrochs of veligers of gastropods and bivalves rarely arrested while the prototroch beat, and those arrests were more localized and variable in position. This difference in metatrochal arrest was unexpected under hypotheses of either a single origin of this feeding mechanism or multiple origins within each phylum. Although different in metatrochal arrests, larvae of both phyla can separate swimming from feeding while both prototroch and metatroch beat. One hypothesis explaining low rates of capture per encounter, without metatrochal arrest, is a change in adhesion of prototrochal cilia with algae. In a few observations, part of the velar edge was retained within the veliger's shell so that exposed prototrochal cilia contributed to swimming while the adjacent metatroch and food groove were sequestered.


Asunto(s)
Bivalvos/fisiología , Gastrópodos/fisiología , Poliquetos/fisiología , Animales , Bivalvos/crecimiento & desarrollo , Cilios/fisiología , Conducta Alimentaria , Gastrópodos/crecimiento & desarrollo , Larva/fisiología , Poliquetos/crecimiento & desarrollo , Natación
10.
Micron ; 121: 77-83, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30951928

RESUMEN

Bioturbation is one of the principle biological processes involved in transporting particles and solutes within sediments, which contributes to the maintenance of biodiversity. In muddy polluted environments, bioturbation may increase pollutant flux at the water-sediment interface, thereby enhancing contaminant bioavailability. The behavior of organisms dictates bioturbation, and gallery shape influences the magnitude of solute transport. Thus, quantitative investigations of gallery shape are fundamental to understanding how pollutant and solute transport is enhanced by bioturbators in muddy sediments. However, there is a lack of tools for quantitatively analyzing gallery geometry, especially for assessing bioturbation and gallery properties through time. Despite the potential of microcomputed tomography (µCT) for quantitative analyses of bioturbation, few such studies have been carried out. Here, we aimed to investigate the potential of µCT for quantitatively assessing the shape and geometric properties of galleries made by small marine polychaetes and their evolution through time in muddy sediments. We focused on Laeonereis acuta (Treadwell, 1923) (Nereididae, Polychaeta), which is a key bioturbator in marine coastal ecosystems. Using 2D and 3D images generated from µCT, we evaluated L. acuta galleries and propose several indexes to quantitatively assess gallery evolution and the role of gallery parameters in bioturbation. Quantitative investigations of polychaete galleries using µCT can assist in monitoring how bioturbation influences sedimentary systems.


Asunto(s)
Sedimentos Geológicos , Poliquetos/fisiología , Microtomografía por Rayos X , Animales , Biodiversidad , Imagen Tridimensional
11.
Philos Trans R Soc Lond B Biol Sci ; 374(1768): 20180428, 2019 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-30966961

RESUMEN

Little is known about the life-history trade-offs and limitations, and the physiological mechanisms that are associated with phenotypic adaptation to future ocean conditions. To address this knowledge gap, we investigated the within- and trans-generation life-history responses and aerobic capacity of a marine polychaete, Ophryotrocha labronica, to elevated temperature and elevated temperature combined with elevated salinity for its entire lifespan. In addition, transplants between treatments were carried out at both the egg mass and juvenile stage to identify the potential influence of developmental effects. Within-generation, life-history trade-offs caused by the timing of transplant were only detected under elevated temperature combined with elevated salinity conditions. Polychaetes transplanted at the egg mass stage grew slower and had lower activities of energy metabolism enzymes but reached a larger maximum body size and lived longer when compared with those transplanted as juveniles. Trans-generation exposure to both elevated temperature and elevated temperature and salinity conditions restored 20 and 21% of lifespan fecundity, respectively. Trans-generation exposure to elevated temperature conditions also resulted in a trade-off between juvenile growth rates and lifespan fecundity, with slower growers showing greater fecundity. Overall, our results suggest that future ocean conditions may select for slower growers. Furthermore, our results indicate that life-history trade-offs and limitations will be more prevalent with the shift of multiple global change drivers, and thus there will be greater constraints on adaptive potential. This article is part of the theme issue 'The role of plasticity in phenotypic adaptation to rapid environmental change'.


Asunto(s)
Adaptación Fisiológica , Calor , Rasgos de la Historia de Vida , Fenotipo , Poliquetos/fisiología , Agua de Mar/química , Animales , Epigénesis Genética/fisiología , Fertilidad/genética , Calentamiento Global , Océanos y Mares , Poliquetos/genética , Poliquetos/crecimiento & desarrollo , Salinidad
12.
Sci Total Environ ; 670: 18-30, 2019 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-30901572

RESUMEN

Macrozoobenthos may affect sediment stability and erodibility via their bioturbating activities, thereby impacting both the short- and long-term development of coastal morphology. Process-based models accounting for the effect of bioturbation are needed for the modelling of erosion dynamics. With this work, we explore whether the fundamental allometric principles of metabolic activity scaling with individual and population size may provide a framework to derive general patterns of bioturbation effect on cohesive sediment resuspension. Experimental flumes were used to test this scaling approach across different species of marine, soft-sediment bioturbators. The collected dataset encompasses a range of bioturbator functional diversity, individual densities, body sizes and overall population metabolic rates. Measurements were collected across a range of hydrodynamic stress from 0.02 to 0.25 Pa. Overall, we observed that bioturbators are able to slightly reduce the sediment resuspension at low hydrodynamic stress, whereas they noticeably enhance it at higher levels of stress. Along the whole hydrodynamic stress gradient, the quantitative effect of bioturbators on sediment resuspension can be efficiently described by the overall metabolic rate of the bioturbating benthic communities, with significant variations across the bioturbators' taxonomic and functional diversity. One of the tested species (the gallery-builder Polychaeta Hediste diversicolor) had an effect that was partially deviating from the general trend, being able to markedly reduce sediment resuspension at low hydrodynamic stress compared to other species. By combining bioturbators' influence with hydrodynamic force, we were able to produce a process-based model of biota-mediated sediment resuspension.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/análisis , Poliquetos/fisiología , Animales , Hidrodinámica , Modelos Teóricos , Contaminantes del Agua/análisis
13.
Sci Total Environ ; 670: 547-554, 2019 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-30909032

RESUMEN

Capitella teleta is a sediment-dwelling marine polychaete that is often found in high densities in association with organic matter and pollutants. While C. teleta has been reported to transform a variety of aromatic hydrocarbons, the mechanisms by which degradation occurs are unknown. Moreover, there is continuing debate on the role of host and microbiota in degradation activity. The aims of this study were to characterize the gut microbiome of C. teleta and to identify microbiota that could potentially play a role in degradation of organic matter and aromatic hydrocarbons. Sequencing analysis of the 16S rRNA genes from the intestinal tracts of adult worms revealed a unique microbiome that was distinct from that of the worm's sediment food source and fecal pellets. About 66% of the 775 identified OTUs from the C. teleta gut microbiome were found to be unique to the worm and displayed high inter-individual variability. The gut microbiome was dominated by members of the genera Arcobacter, Pseudoalteromonas, Methylobacterium, and Propionibacterium. Functional analyses of microbiota revealed that hydrocarbon treatment led to a proliferation of gene classes involved in chemoheterotrophy and aromatic compound degradation. Of the 18 most abundant taxa identified, 50% were members of genera containing hydrocarbon (PAH)-degrading members, including Acinetobacter, Thalassotalea, and Achromobacter. Data obtained in this study will be useful to understand the biology of this marine polychaete and to elucidate the role that gut bacteria play in worm catabolism and the transformation of sediment organic pollutants.


Asunto(s)
Biodegradación Ambiental , Poliquetos/microbiología , Contaminantes Químicos del Agua/metabolismo , Animales , Monitoreo del Ambiente , Microbioma Gastrointestinal/fisiología , Sedimentos Geológicos/química , Microbiota , Poliquetos/fisiología , Contaminantes Químicos del Agua/análisis
14.
Environ Sci Pollut Res Int ; 26(8): 7873-7882, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30684172

RESUMEN

Contamination of the aquatic environment by pharmaceutical drugs is an emerging issue in ecotoxicology. Aquatic organisms, in the presence of xenobiotics, tend to activate defensive mechanisms against toxic effects in order to mitigate and/or compensate for the toxic damages that frequently result from these interactions. Salicylic acid (SA) is a common drug, widely used in human medicine due to its analgesic, anti-inflammatory, and antipyretic properties, as well as its activity in terms of preventing platelet aggregation, among other clinical and cosmetic uses. It is commonly found in levels of the nanograms per liter to the micrograms per liter range in receiving waters, and its presence has been related to toxic effects in aquatic organisms, including oxidative stress. However, the number of studies that characterize the ecotoxicological profile of salicylates is still scarce and no studies have been published about the putative toxic effects of SA, especially in marine polychaetes. In order to determine the potential ecotoxicological effects caused by SA, individuals of the marine Polychaeta species Hediste diversicolor were exposed for 96 h to ecologically relevant concentrations of this compound, and several biochemical endpoints were evaluated, namely the activity of the antioxidant enzymes glutathione peroxidase (GPx) and catalase (CAT), the phase II biotransformation isoenzymes glutathione S-transferases (GSTs), the cholinergic enzyme acetylcholinesterase (AChE), and the determination of lipoperoxidative damage (thiobarbituric acid-reactive substances (TBARS) assay). The obtained results demonstrated that despite the pro-oxidative effects elicited by SA, exposure to realistic levels of this compound was not able to generate a state of oxidative stress, and the adaptive protective responses elicited by exposed individuals were effective enough to minimize and/or inhibit the damage potentially caused by overproduced reactive oxygen species.


Asunto(s)
Ecotoxicología , Poliquetos/fisiología , Ácido Salicílico/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Antioxidantes , Antipiréticos , Organismos Acuáticos , Biomarcadores , Catalasa , Glutatión Peroxidasa , Oxidación-Reducción , Estrés Oxidativo , Especies Reactivas de Oxígeno , Sustancias Reactivas al Ácido Tiobarbitúrico
15.
Mar Pollut Bull ; 138: 584-597, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30660310

RESUMEN

The increasing number of anthropogenic areas in the marine environment results in significant impact to adjacent ecosystems. In fact, the presence of marinas modifies the original environmental conditions and ends up disturbing the faunal community. However, despite the essential role displayed by the macrofauna on marinas' fouling biota, certain taxa such as polychaetes have been poorly studied. The present study provides the first spatial characterization of the epibiont polychaete fauna associated with the bryozoan Bugula neritina in marinas along the Iberian Peninsula and the north of Morocco. A total of 32 polychaete species were identified, with Syllidae being the most diverse family. Furthermore, the environmental factors involved in the occurrence and abundance of the dominant species Salvatoria clavata were also analyzed by Generalized Linear Models; results showed that the highest predicted values of S. clavata abundance appeared at marinas with high levels of nutrient enrichment and of heavy metals concentration.


Asunto(s)
Poliquetos/fisiología , Animales , Biodiversidad , Biota , Briozoos/fisiología , Ecosistema , Monitoreo del Ambiente , Modelos Lineales , Marruecos , Contaminantes Químicos del Agua/análisis
16.
Gene ; 683: 169-183, 2019 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-30316921

RESUMEN

Kinesin-14 KIFC1 plays an important role in vesicular transport, microtubule organization, and spermiogenesis. In this study, we first investigated the microtubule distribution and expression pattern of KIFC1 during spermiogenesis of P. esculenta. Microtubules are abundant during spermiogenesis of P. esculenta and may be related to the generation and maintenance of pseudopodia-like cytoplasmic protrusions and nuclear reshaping. The Pe-KIFC1 protein is conserved with a motor domain where microtubule and ATP binding sites are predicted, a coiled-coil domain and a divergent tail domain. The Pe-kifc1 gene was extensively expressed and showed the highest expression in coelomic fluid where spermiogenesis occurs. We further observed the expression of kifc1 mRNA and protein and found that Pe-KIFC1 protein primarily co-localized with microtubules during spermiogenesis, indicating that KIFC1 might play several roles during this process via its cargo transport and/or microtubule organization function. In addition, co-localization of mitochondria and KIFC1 was also detected during spermiogenesis, which were located in the midpiece in mature sperm, suggesting that mitochondria might be a cargo of Pe-KIFC1 that participates in the intracellular distribution of mitochondria and formation of the midpiece. Based on our detailed observations of the dynamic distribution of microtubules, KIFC1, and mitochondria during spermiogenesis and the conserved function of KIFC1 in cargo transport and microtubule organization, functional models of Pe-KIFC1 during spermiogenesis are proposed, including the participation of KIFC1 in nuclear reshaping and midpiece formation.


Asunto(s)
Cinesina/genética , Cinesina/metabolismo , Poliquetos/fisiología , Espermatogénesis , Animales , Sitios de Unión , Núcleo Celular/metabolismo , Regulación de la Expresión Génica , Cinesina/química , Masculino , Microtúbulos/metabolismo , Modelos Moleculares , Filogenia , Poliquetos/genética , Conformación Proteica , Dominios Proteicos , Transporte de Proteínas
17.
J Evol Biol ; 32(2): 177-186, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30461107

RESUMEN

The idea that male reproductive strategies evolve primarily in response to sperm competition is almost axiomatic in evolutionary biology. However, externally fertilizing species, especially broadcast spawners, represent a large and taxonomically diverse group that have long challenged predictions from sperm competition theory-broadcast spawning males often release sperm slowly, with weak resource-dependent allocation to ejaculates despite massive investment in gonads. One possible explanation for these counter-intuitive patterns is that male broadcast spawners experience strong natural selection from the external environment during sperm dispersal. Using a manipulative experiment, we examine how male reproductive success in the absence of sperm competition varies with ejaculate size and rate of sperm release, in the broadcast spawning marine invertebrate Galeolaria caespitosa (Polychaeta: Serpulidae). We find that the benefits of Fast or Slow sperm release depend strongly on ejaculate size, but also that the per-gamete fertilization rate decreases precipitously with ejaculate size. Overall, these results suggest that, if males can facultatively adjust ejaculate size, they should slowly release small amounts of sperm. Recent theory for broadcast spawners predicts that sperm competition can also select for Slow release rates. Taken together, our results and theory suggest that selection often favours Slow ejaculate release rates whether males experience sperm competition or not.


Asunto(s)
Fertilización , Poliquetos/fisiología , Animales , Evolución Biológica , Eyaculación , Masculino , Selección Genética
18.
Dev Biol ; 445(2): 189-210, 2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30445055

RESUMEN

Regeneration, the ability to restore body parts after an injury or an amputation, is a widespread but highly variable and complex phenomenon in animals. While having fascinated scientists for centuries, fundamental questions about the cellular basis of animal regeneration as well as its evolutionary history remain largely unanswered. Here, we present a study of regeneration of the marine annelid Platynereis dumerilii, an emerging comparative developmental biology model, which, like many other annelids, displays important regenerative abilities. When P. dumerilii worms are amputated, they are able to regenerate the posteriormost differentiated part of their body and a stem cell-rich growth zone that allows the production of new segments replacing the amputated ones. We show that posterior regeneration is a rapid process that follows a well reproducible path and timeline, going through specific stages that we thoroughly defined. Wound healing is achieved one day after amputation and a regeneration blastema forms one day later. At this time point, some tissue specification already occurs, and a functional posterior growth zone is re-established as early as three days after amputation. Regeneration timing is only influenced, in a minor manner, by worm size. Comparable regenerative abilities are found for amputations performed at different positions along the antero-posterior axis of the worm, except when amputation planes are very close to the pharynx. Regenerative abilities persist upon repeated amputations without important alterations of the process. We also show that intense cell proliferation occurs during regeneration and that cell divisions are required for regeneration to proceed normally. Finally, 5-ethynyl-2'-deoxyuridine (EdU) pulse and chase experiments suggest that blastemal cells mostly derive from the segment immediately abutting the amputation plane. The detailed characterization of P. dumerilii posterior body regeneration presented in this article provides the foundation for future mechanistic and comparative studies of regeneration in this species.


Asunto(s)
Poliquetos/fisiología , Regeneración/fisiología , Animales , Tipificación del Cuerpo , Diferenciación Celular , Proliferación Celular , Regulación del Desarrollo de la Expresión Génica , Microscopía Electrónica de Rastreo , Poliquetos/citología , Poliquetos/genética , Regeneración/genética , Células Madre/citología , Células Madre/metabolismo
19.
Genome Biol Evol ; 11(1): 295-318, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30535381

RESUMEN

Stolonization in syllid annelids is a unique mode of reproduction among animals. During the breeding season, a structure resembling the adult but containing only gametes, called stolon, is formed generally at the posterior end of the animal. When stolons mature, they detach from the adult and gametes are released into the water column. The process is synchronized within each species, and it has been reported to be under environmental and endogenous control, probably via endocrine regulation. To further understand reproduction in syllids and to elucidate the molecular toolkit underlying stolonization, we generated Illumina RNA-seq data from different tissues of reproductive and nonreproductive individuals of Syllis magdalena and characterized gene expression during the stolonization process. Several genes involved in gametogenesis (ovochymase, vitellogenin, testis-specific serine/threonine-kinase), immune response (complement receptor 2), neuronal development (tyrosine-protein kinase Src42A), cell proliferation (alpha-1D adrenergic receptor), and steroid metabolism (hydroxysteroid dehydrogenase 2) were found differentially expressed in the different tissues and conditions analyzed. In addition, our findings suggest that several neurohormones, such as methyl farnesoate, dopamine, and serotonin, might trigger stolon formation, the correct maturation of gametes and the detachment of stolons when gametogenesis ends. The process seems to be under circadian control, as indicated by the expression patterns of r-opsins. Overall, our results shed light into the genes that orchestrate the onset of gamete formation and improve our understanding of how some hormones, previously reported to be involved in reproduction and metamorphosis processes in other invertebrates, seem to also regulate reproduction via stolonization.


Asunto(s)
Gametogénesis/genética , Poliquetos/fisiología , Animales , Femenino , Expresión Génica , Hormonas/fisiología , Masculino , Poliquetos/ultraestructura , Transcriptoma
20.
Sci Rep ; 8(1): 17664, 2018 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-30518937

RESUMEN

The Japanese scallop (Mizuhopecten yessoensis) is one of the most important aquaculture species in Asian countries; however, it has suffered severe infection by Polydora in northern China in recent years, causing great economic losses. The Polydora parasitizes the shell of scallops, badly destroying the shell's structure. To investigate the molecular response mechanism of M. yessoensis to Polydora infestion, a comprehensive and niche-targeted cDNA sequence database for diseased scallops was constructed. Additionally, the transcriptional changes in the edge mantle, central mantle and hemocytes, tissues directly related to the disease, were first described in this study. The results showed that genes involved in shell formation and immunomodulation were significantly differentially expressed due to the infestation. Different transcriptional changes existed between the two mantle regions, indicating the different molecular functions likely responsible for the formation of different shell layers. The differential expression of genes for immune recognition, signal transduction and pathogen elimination presented an integrated immune response process in scallops. Moreover, neuromodulation and glycometabolism involved in the regulation process with relevant function significantly enriched. The study provides valuable information for mechanism study of shell formation and immunomodulation in scallops.


Asunto(s)
Exoesqueleto/parasitología , Pectinidae/genética , Pectinidae/parasitología , Poliquetos/fisiología , Transcriptoma , Exoesqueleto/inmunología , Exoesqueleto/metabolismo , Animales , Regulación de la Expresión Génica , Interacciones Huésped-Parásitos , Inmunidad , Japón , Pectinidae/inmunología , Poliquetos/inmunología
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