177 research outputs found

    Structural characterisation of the N-glycan moiety of the barnacle settlement-inducing protein complex (SIPC)

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    Many barnacle species are gregarious and their cypris larvae display a remarkable ability to explore surfaces before committing to permanent attachment. The chemical cue to gregarious settlement behaviour – the settlement-inducing protein complex (SIPC) – is an α2-macroglobulin-like glycoprotein. This cuticular protein may also be involved in cyprid reversible adhesion if its presence is confirmed in footprints of adhesive deposited during exploratory behaviour, which increase the attractiveness of surfaces and signal other cyprids to settle. The full-length open-reading frame of the SIPC gene encodes a protein of 1547 amino acids with seven potential N-glycosylation sites. In this study on Balanus amphitrite, glycan profiling of the SIPC via hydrophilic interaction liquid chromatography with fluorescence detection (HILIC-fluorescence) provided evidence of predominantly high mannose glycans (M2–9), with the occurrence of monofucosylated oligomannose glycans (F(6)M2–4) in lower proportions. The high mannose glycosylation found supports previous observations of an interaction with mannose-binding lectins and exogenous mannose increasing settlement in B. amphitrite cypris larvae. Transmission electron microscopy of the deglycosylated SIPC revealed a multi-lobed globular protein with a diameter of ∼8 nm. Obtaining a complete structural characterisation of the SIPC remains a goal that has the potential to inspire solutions to the age-old problem of barnacle fouling.No Full Tex

    Sperm Quality of Hatchery-Reared Lake Trout Throughout the Spawning Season

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    The objective of this study was to investigate variation in sperm quality metrics (motility, velocity, linearity, longevity, and density) of hatchery-reared Lake Trout Salvelinus namaycush throughout the spawning season. Seasonal variation in sperm quality was investigated using both a regression and repeated-measures approach. Sperm was collected from the same 16 individuals over four sampling periods, separated by 3-week intervals. Regression analyses showed that 727% of the variation in sperm traits could be explained by seasonal variation, indicating that seasonality can have a significant impact on the quality of sperm. Significant positive linear relationships were found for percent motility and linearity at 5s postactivation. Significant negative quadratic relationships were found for velocity at 5s postactivation, longevity, and density, whereas a positive quadratic relationship was found for linearity at 10s postactivation. Repeated measures ANOVAs showed a significant effect of season for percent motility and linearity at 5 and 10s postactivation, velocity at 10s postactivation, and longevity. Our findings are important for optimizing fertilization protocols for hatchery production and can also be used to understand reproductive biology and ecology of wild Lake Trout stocks. Received March 15, 2012; accepted June 30, 201

    A brief exposure to low pH prior to refrigerated storage reduces the motility and viability of goldfish sperm (Carassius auratus, Linnaeus, 1758)

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    Optimal conditions of short-term storage of fish sperm are important for successful artificial reproduction protocols or incubation of sperm in a cryoprotecting medium for successful sperm cryopreservation. The influence of acid or alkaline incubating conditions on short term storage of goldfish sperm was investigated in a series of experiments. Goldfish sperm was diluted an immobilizing solution (1: 3) and incubated for 1 h in acidic, pH 6.5 (AC group) or alkaline, pH 8.5 (AL group) conditions. Subsequently, the sperm of both groups was further diluted (1: 3) in the immobilizing solution and the pH was adjusted to pH 7.51 (±0.02) and 7.56 (±0.07) in the AC and AL group respectively. The samples were kept in sealed bags and stored at 4°C. Viability (%) and motility (%) was estimated in samples obtained daily for the next 4 days. The results indicate that even a brief exposure of sperm to acid acidic conditions prior to storage accelerated the decline of sperm viability and motility during refrigeration

    Sodium affects the sperm motility in the European eel

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    [EN] The role of seminal plasma sodium and activation media sodium on sperm motility was examined by selectively removing the element from these two media, in European eel sperm. Sperm size (sperm head area) was also measured using an ASMA (Automated Sperm Morphometry Analyses) system, in the different conditions. Intracellular sodium [Na+](i) was quantitatively analyzed by first time in the spermatozoa from a marine fish species. Measurement of [Na+](i) was done before and after motility activation, by Flow Cytometry, using CoroNa Green AM as a dye. Sperm motility activation induced an increase in [Na+](i) from 96.72 mM in quiescent stage to 152.21 mM post-activation in seawater. A significant decrease in sperm head area was observed post activation in seawater. There was a notable reduction in sperm motility when sodium was removed from the seminal plasma, but not when it was removed from the activation media. Sodium removal was also linked to a significant reduction in sperm head area in comparison to the controls. Our results indicate that the presence of the ion Na+ in the seminal plasma (or in the extender medium) is necessary for the preservation of sperm motility in European eel, probably because it plays a role in maintaining an appropriate sperm cell volume in the quiescent stage of the spermatozoa. (C) 2016 Elsevier Inc All rights reserved.Funded from the SPERMOT project (Spanish Ministry of Science and Innovation, MICINN; AGL2010-16009). M.C. Vilchez has a predoctoral grant from UPV PAID Program (2011-S2-02-6521), Marina Morini has a predoctoral grant from Generalitat Valenciana (Programa Grisolia, GRISOLIA/2012/006), Victor Gallego has a postdoctoral contract from UPV (PAID-10-14), and David S. Penaranda was supported by MICINN (PTA2011-4948-I) and UPV (PTA2011-4948-I). Grants to attend meetings were received from COST Office (Food and Agriculture COST Action FA1205: AQUAGAMETE).Vilchez Olivencia, MC.; Morini, M.; Peñaranda, D.; Gallego Albiach, V.; Asturiano Nemesio, JF.; Pérez Igualada, LM. (2016). Sodium affects the sperm motility in the European eel. Comparative Biochemistry and Physiology - B: Comparative Biochemistry. 198:51-58. https://doi.org/10.1016/j.cbpa.2016.04.008S515819

    Study of pufferfish (Takifugu niphobles) sperm: development of methods for short-term storage, effects of different activation media and role of intracellular changes in Ca2+ and K+ in the initiation of sperm motility

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    [EN] The first goal of this study was the development of a short-term storage method for pufferfish (Takifugu niphobles) sperm. In this respect, the best results were obtained by diluting the sperm in a seminal-like solution and keeping it in a Petri dish in chilled storage (4 degrees C). This method was successful in preserving sperm quality parameters without resulting in differences in fresh sperm for a relatively long-term period (7 days), for use in aquaculture matters. The addition of bovine serum albumin (BSA) to the medium did not improve the results. On the other hand, both the osmolality and the ion composition of the media are essential factors which can modulate the sperm motility parameters. The osmolality of the activating medium was the most important factor in triggering pufferfish sperm motility, and osmolalities of 750-825 mOsm/kg were necessary to initiate this process, demonstrating that it appears to be a dose-independent mechanism. Regarding the ion composition of the activation media, this study has shown that despite the spermatozoa being able to initiate movement without any ion in the activation medium, the absence of ions can negatively affect the kinetic parameters of the spermatozoa. Finally, in natural conditions (seawater), the activation of sperm motility generates intracellular increases in Ca2+ and K+, suggesting that these ions play an essential role in the activation mechanism of pufferfish sperm. (C) 2013 Elsevier B.V. All rights reserved.This study was funded by the Spanish Ministry of Science and Innovation (MICINN; AGL2010-16009). Victor Gallego has a predoctoral grant (MICINN; BES-2009-020310) and has been granted a fellowship (EEBB-I-12-05858) from the Spanish Personnel Research Training Programme to carry out this study in the Misaki Marine Biological Station (Miura, Japan).Gallego Albiach, V.; Pérez Igualada, LM.; Asturiano Nemesio, JF.; Yoshida, M. (2013). Study of pufferfish (Takifugu niphobles) sperm: development of methods for short-term storage, effects of different activation media and role of intracellular changes in Ca2+ and K+ in the initiation of sperm motility. Aquaculture. 414:82-91. https://doi.org/10.1016/j.aquaculture.2013.07.046S829141

    Role of potassium and pH on the initiation of sperm motility in the European eel

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    [EN] The role of potassium from the seminal plasma and/or the activation media was examined by selectively removing from this media, and by testing the use of channel inhibitors and a K-ionophore. Sperm motility was measured using a CASA system, intracellular K+ and pH were measured by flow cytometry, and sperm head area was measured by ASMA: Automated Sperm Morphometry Analyses. Sperm motility was notably inhibited by the removal of K+ from the seminal plasma and by treatment with the K+ ionophore valinomycin. This therefore indicates that a reduction of K+ levels in the quiescent stage inhibits further motility. The normal decrease in sperm head area induced by seawater activation was altered by the removal of K+ from the seminal plasma, and an increase in the pH; in the quiescent stage was also induced. Intracellular pH (pH;) was quantitatively measured for the first time in European eel spermatozoa, being 7.2 in the quiescent stage and 7.1 post-activation. Intracellular and external pH levels influenced sperm motility both in the quiescent stage and at activation. The alkalinization of the pH; (by NH4Cl) inhibited sperm motility activation, while acidification (by Na-acetate) did not have any effect. Our results indicate that a pH gradient between the sperm cell and the seminal plasma is necessary for sperm motility activation. The presence of the ion K+ in the seminal plasma (or in the extender medium) is necessary in order to maintain sperm volume, intracellular pH and sperm motility.Funded from the SPERMOT project (Spanish Ministry of Science and Innovation, MINECO AGL2010-16009). M.C. Vilchez has a predoctoral grant from UPV PAID Subprogramme 2 (2011-S2-02-6521), Marina Morini has a predoctoral grant from Generalitat Valenciana (Programa Grisolia, GRISOLIA/2012/006), Victor Gallego has a postdoctoral contract from UPV (PAID-10-14), and David S. Penaranda was supported by MICINN (PTA2011-4948-1) and UPV (PTA2011-4948-I). Grants to attend meetings were received from COST Office (AQUAGAMETE COST Action: FA1205).Vilchez Olivencia, MC.; Morini, M.; Peñaranda, D.; Gallego Albiach, V.; Asturiano Nemesio, JF.; Pérez Igualada, LM. (2017). Role of potassium and pH on the initiation of sperm motility in the European eel. Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology. 203:210-219. https://doi.org/10.1016/j.cbpa.2016.09.024S21021920

    Wirelessly powered drug-free and anti-infective smart bandage for chronic wound care

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    We present a wirelessly powered ultraviolet-C (UVC) radiation-based disinfecting bandage for sterilization and treatment in chronic wound care and management. The bandage contains embedded low-power UV light-emitting diodes (LEDs) in the 265 to 285 nm range with the light emission controlled via a microcontroller. An inductive coil is seamlessly concealed in the fabric bandage and coupled with a rectifier circuit to enable 6.78 MHz wireless power transfer (WPT). The maximum WPT efficiency of the coils is 83% in free space and 75% on the body at a coupling distance of 4.5 cm. Measurements show that the UVC LEDs are emitting radiant power of about 0.6 mW and 6.8 mW with and without fabric bandage, respectively, when wirelessly powered. The ability of the bandage to inactivate microorganisms was examined in a laboratory which shows that the system can effectively eradicate Gram-negative bacteria, Pseudoalteromonas sp. D41 strain, on surfaces in six hours. The proposed smart bandage system is low-cost, battery-free, flexible and can be easily mounted on the human body and, therefore, shows great promise for the treatment of persistent infections in chronic wound care

    Comparison of two techniques for the morphometry study on gilthead seabream (Sparus aurata) spermatozoa and evaluation of changes induced by cryopreservation

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    [EN] The development of powerful software has made possible spermatozoa morphology studies. However, some problems have emerged in relation to protocol standardization to compare results from different laboratories. This study was carried out to compare two techniques commonly used (staining vs phase contrast technique) for the morphometry study of gilthead sea bream spermatozoa using an integrated sperm analysis system (ISAS). Spermatozoa morphometry values were significantly affected by the technique used, and phase contrast technique was found to be the more accurate method, showing lower coefficients of variation on spermatozoa morphometry parameters measurements. Moreover, it has been shown that cryopreservation process produces damage in gilthead sea bream spermatozoa, causing negative effects in sperm parameters as spermatozoa morphometry (a decrease in cell volume), motility (from 95 to 68% motile cells) and viability (from 95 to 87% of live cells), being the addition of freezing medium containing cryoprotectant (DMSO) an important factor that caused the morphometry changes. (C) 2012 Elsevier Inc. All rights reserved.This work was financed by the Spanish Ministry of Science and Innovation (MICINN; AGL2007-64040-C03-00, Project SELECTBREAM). V. Gallego and I. Mazzeo were supported by predoctoral scholarships financed by the Spanish MICINN and Generalitat Valenciana, respectively. D.S. Penaranda had a postdoctoral grant from UPV.Gallego Albiach, V.; Peñaranda, D.; Marco Jiménez, F.; Mazzeo, I.; Pérez Igualada, LM.; Asturiano Nemesio, JF. (2012). Comparison of two techniques for the morphometry study on gilthead seabream (Sparus aurata) spermatozoa and evaluation of changes induced by cryopreservation. Theriogenology. 77(6):1078-1087. https://doi.org/10.1016/j.theriogenology.2011.10.010S1078108777
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