scholarly journals Behavioural Responses of the Colonial Sea Squirt Botrylloides violaceus Oka to Suspended Food Micro-Particles in Laboratory Cultures

2020 ◽  
Vol 8 (12) ◽  
pp. 1021
Author(s):  
Chiara Gregorin ◽  
Luigi Musco ◽  
Emanuele Somma ◽  
Valerio Zupo
Keyword(s):  
Feeding Activity ◽  
Experimental Studies ◽  
Milk Powder ◽  
Isochrysis Galbana ◽  
Arthrospira Platensis ◽  
Model Organisms ◽  
Filter Feeding ◽  
Behavioural Responses ◽  
Micro Particles ◽  
Sea Squirt

Violet sea squirts are noteworthy model organisms, because they provide insights into various physiologic processes, including cell senescence, ageing, apoptosis and allorecognition. Consequently, their culture is critical to permit experimental studies. Most papers refer to short periods of rearing using various feeds, both living and conserved, missing a formal justification for their use or indications of their actual nutritional value. Here, we use two behavioural responses—the percentage of open siphons and the frequency of zooid contractions—as compared to the abundance of suspended microparticles during feeding tests, to identify feeds able to promote filter-feeding. The results will enable to formulate compound diets that maximise positive physiological responses. Our tests demonstrated that plant items, such as dry microalgae and cyanobacteria (Arthrospira platensis, commercially known as Spirulina), along with living planktonic Haptophyta (Isochrysis galbana), trigger clear positive reactions, represented by a higher frequency of zooid contractions and larger proportions of open siphons. These responses correspond to decreases in the concentrations of suspended microparticles during the experiment and indicate higher filter-feeding activity. In contrast, feeds commonly administered to colonies, such as milk powder, dried eggs and artificial plankton, triggered negative behavioural responses, and their intake was lower during the feeding trials.

scholarly journals Interactions between Filter-Feeding Bivalves and Toxic Diatoms: Influence on the Feeding Behavior of Crassostrea gigas and Pecten maximus and on Toxin Production by Pseudo-nitzschia

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 577
Author(s):  
Aurore Sauvey ◽  
Françoise Denis ◽  
Hélène Hégaret ◽  
Bertrand Le Roy ◽  
Christophe Lelong ◽  
...  
Keyword(s):  
Crassostrea Gigas ◽  
Domoic Acid ◽  
Diet Composition ◽  
Isochrysis Galbana ◽  
Toxin Production ◽  
Pecten Maximus ◽  
Bivalve Species ◽  
Feeding Rates ◽  
Filter Feeding ◽  
Complex Interactions

Among Pseudo-nitzschia species, some produce the neurotoxin domoic acid (DA), a source of serious health problems for marine organisms. Filter-feeding organisms—e.g., bivalves feeding on toxigenic Pseudo-nitzschia spp.—are the main vector of DA in humans. However, little is known about the interactions between bivalves and Pseudo-nitzschia. In this study, we examined the interactions between two juvenile bivalve species—oyster (Crassostrea gigas) and scallop (Pecten maximus)—and two toxic Pseudo-nitzschia species—P. australis and P. fraudulenta. We characterized the influence of (1) diet composition and the Pseudo-nitzschia DA content on the feeding rates of oysters and scallops, and (2) the presence of bivalves on Pseudo-nitzschia toxin production. Both bivalve species fed on P. australis and P. fraudulenta. However, they preferentially filtered the non-toxic Isochrysis galbana compared to Pseudo-nitzschia. The presence of the most toxic P. australis species resulted in a decreased clearance rate in C. gigas. The two bivalve species accumulated DA in their tissues (up to 0.35 × 10−3 and 5.1 × 10−3 µg g−1 for C. gigas and P. maximus, respectively). Most importantly, the presence of bivalves induced an increase in the cellular DA contents of both Pseudo-nitzschia species (up to 58-fold in P. fraudulenta in the presence of C. gigas). This is the first evidence of DA production by Pseudo-nitzschia species stimulated in the presence of filter-feeding bivalves. The results of this study highlight complex interactions that can influence toxin production by Pseudo-nitzschia and accumulation in bivalves. These results will help to better understand the biotic factors that drive DA production by Pseudo-nitzschia and bivalve contamination during Pseudo-nitzschia blooms.

scholarly journals Computational Prediction of Ubiquitination Proteins Using Evolutionary Profiles and Functional Domain Annotation

2019 ◽  
Vol 20 (5) ◽  
pp. 389-399
Author(s):  
Wangren Qiu ◽  
Chunhui Xu ◽  
Xuan Xiao ◽  
Dong Xu
Keyword(s):  
Correlation Coefficient ◽  
Computational Methods ◽  
Molecular Mechanisms ◽  
Experimental Studies ◽  
Model Organisms ◽  
Functional Domain ◽  
Site Prediction ◽  
Domain Annotation ◽  
Ubiquitination Site ◽  
Matthew’S Correlation Coefficient

Background: Ubiquitination, as a post-translational modification, is a crucial biological process in cell signaling, apoptosis, and localization. Identification of ubiquitination proteins is of fundamental importance for understanding the molecular mechanisms in biological systems and diseases. Although high-throughput experimental studies using mass spectrometry have identified many ubiquitination proteins and ubiquitination sites, the vast majority of ubiquitination proteins remain undiscovered, even in well-studied model organisms. Objective: To reduce experimental costs, computational methods have been introduced to predict ubiquitination sites, but the accuracy is unsatisfactory. If it can be predicted whether a protein can be ubiquitinated or not, it will help in predicting ubiquitination sites. However, all the computational methods so far can only predict ubiquitination sites. Methods: In this study, the first computational method for predicting ubiquitination proteins without relying on ubiquitination site prediction has been developed. The method extracts features from sequence conservation information through a grey system model, as well as functional domain annotation and subcellular localization. Results: Together with the feature analysis and application of the relief feature selection algorithm, the results of 5-fold cross-validation on three datasets achieved a high accuracy of 90.13%, with Matthew’s correlation coefficient of 80.34%. The predicted results on an independent test data achieved 87.71% as accuracy and 75.43% of Matthew’s correlation coefficient, better than the prediction from the best ubiquitination site prediction tool available. Conclusion: Our study may guide experimental design and provide useful insights for studying the mechanisms and modulation of ubiquitination pathways. The code is available at: https://github.com/Chunhuixu/UBIPredic_QWRCHX.

Thermal conditions predict intraspecific variation in senescence rate in frogs and toads

2021 ◽  
Vol 118 (49) ◽  
pp. e2112235118
Author(s):  
Hugo Cayuela ◽  
Jean-François Lemaître ◽  
Erin Muths ◽  
Rebecca M. McCaffery ◽  
Thierry Frétey ◽  
...  
Keyword(s):  
Rana Temporaria ◽  
Experimental Studies ◽  
Thermal Conditions ◽  
Model Organisms ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Climate Change Scenarios ◽  
Intergovernmental Panel ◽  
Anuran Species ◽  
Senescence Rate

Variation in temperature is known to influence mortality patterns in ectotherms. Even though a few experimental studies on model organisms have reported a positive relationship between temperature and actuarial senescence (i.e., the increase in mortality risk with age), how variation in climate influences the senescence rate across the range of a species is still poorly understood in free-ranging animals. We filled this knowledge gap by investigating the relationships linking senescence rate, adult lifespan, and climatic conditions using long-term capture–recapture data from multiple amphibian populations. We considered two pairs of related anuran species from the Ranidae (Rana luteiventris and Rana temporaria) and Bufonidae (Anaxyrus boreas and Bufo bufo) families, which diverged more than 100 Mya and are broadly distributed in North America and Europe. Senescence rates were positively associated with mean annual temperature in all species. In addition, lifespan was negatively correlated with mean annual temperature in all species except A. boreas. In both R. luteiventris and A. boreas, mean annual precipitation and human environmental footprint both had negligible effects on senescence rates or lifespans. Overall, our findings demonstrate the critical influence of thermal conditions on mortality patterns across anuran species from temperate regions. In the current context of further global temperature increases predicted by Intergovernmental Panel on Climate Change scenarios, a widespread acceleration of aging in amphibians is expected to occur in the decades to come, which might threaten even more seriously the viability of populations and exacerbate global decline.

scholarly journals Beneficial and Detrimental Effects of Reactive Oxygen Species on Lifespan: A Comprehensive Review of Comparative and Experimental Studies

2021 ◽  
Vol 9 ◽  
Author(s):  
Hazel J. Shields ◽  
Annika Traa ◽  
Jeremy M. Van Raamsdonk
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Damage ◽  
Comparative Studies ◽  
Experimental Studies ◽  
Reactive Oxygen ◽  
Model Organisms ◽  
Oxygen Species ◽  
Free Radical Theory ◽  
Radical Theory ◽  
The Relationship

Aging is the greatest risk factor for a multitude of diseases including cardiovascular disease, neurodegeneration and cancer. Despite decades of research dedicated to understanding aging, the mechanisms underlying the aging process remain incompletely understood. The widely-accepted free radical theory of aging (FRTA) proposes that the accumulation of oxidative damage caused by reactive oxygen species (ROS) is one of the primary causes of aging. To define the relationship between ROS and aging, there have been two main approaches: comparative studies that measure outcomes related to ROS across species with different lifespans, and experimental studies that modulate ROS levels within a single species using either a genetic or pharmacologic approach. Comparative studies have shown that levels of ROS and oxidative damage are inversely correlated with lifespan. While these studies in general support the FRTA, this type of experiment can only demonstrate correlation, not causation. Experimental studies involving the manipulation of ROS levels in model organisms have generally shown that interventions that increase ROS tend to decrease lifespan, while interventions that decrease ROS tend to increase lifespan. However, there are also multiple examples in which the opposite is observed: increasing ROS levels results in extended longevity, and decreasing ROS levels results in shortened lifespan. While these studies contradict the predictions of the FRTA, these experiments have been performed in a very limited number of species, all of which have a relatively short lifespan. Overall, the data suggest that the relationship between ROS and lifespan is complex, and that ROS can have both beneficial or detrimental effects on longevity depending on the species and conditions. Accordingly, the relationship between ROS and aging is difficult to generalize across the tree of life.

scholarly journals Solid Circulating Velocity Measurement in a Liquid–Solid Micro-Circulating Fluidised Bed

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1159
Author(s):  
Orlando L. do Nascimento ◽  
David A. Reay ◽  
Vladimir Zivkovic
Keyword(s):  
Cross Section ◽  
Velocity Measurement ◽  
Tap Water ◽  
Experimental Studies ◽  
Soda Lime Glass ◽  
Fluidised Bed ◽  
Transition Velocity ◽  
Micro Particles ◽  
Fluidised Beds ◽  
Circulating Fluidised Bed

Liquid–solid circulating fluidised beds (CFB) possess many qualities which makes them useful for industrial operations where particle–liquid contact is vital, e.g., improved heat transfer performance, and consequent uniform temperature, limited back mixing, exceptional solid–liquid contact. Despite this, circulating fluidised beds have seen no application in the micro-technology context. Liquid–solid micro circulating fluidised bed (µCFBs), which basically involves micro-particles fluidisation in fluidised beds within the bed of cross-section or inner diameter at the millimetre scale, could find potential applications in the area of micro-process and microfluidics technology. From an engineering standpoint, it is vital to know the solid circulating velocity, since that dictates the bed capability and operability as processing equipment. Albeit there are several studies on solid circulating velocity measurement in CFBs, this article is introducing the first experimental study on solid circulating velocity measurement in a CFB at micro-scale. The experimental studies were done in a novel micro-CFB which was fabricated by micro milling machining 1 mm2 cross-section channels in Perspex and in a 4 mm2 cross-section micro-CFB made by additive manufacturing technology. Soda-lime glass and polymethyl methacrylate (PMMA) micro-particles were employed as solid materials and tap water as the liquid medium. The digital particle image velocimetry (PIV) method was used as a measurement technique to determine the particle velocity in the micro-CFB system and validated by the valve accumulation technique using a novel magnetic micro-valve. The measured critical transition velocity, Ucr, is comparable to the particle terminal velocity, i.e., the normalised transition velocity is approximately 1 in line with macroscopic systems results and our previous study using simple visual observation. As in macroscopic CFB systems, Ucr decreased with solid inventory (1–9%) and finally becomes stable when the solid inventory is high enough (10–25%) and it increases with a reduction in particle size and density.

scholarly journals Efecto de la espirulina (Arthrospira platensis) (Oscillatoriales: Cyanobacteria) en la cría experimental de Pseudosuccinea columella (Basommatophora: Lymnaeidae)

2015 ◽  
Vol 63 (2) ◽  
pp. 479
Author(s):  
Lucila Prepelitchi ◽  
Julieta M. Pujadas ◽  
Cristina Wisnivesky-Colli
Keyword(s):  
Fasciola Hepatica ◽  
Continuous Production ◽  
Food Resource ◽  
Experimental Studies ◽  
Arthrospira Platensis ◽  
Hatching Rate ◽  
Intermediate Hosts ◽  
Growth Increments ◽  
Artificial Breeding ◽  
Positive Effect

<p>Snails of the family Lymnaeidae, as <em>Pseudosuccinea columella</em>, are the intermediate hosts of <em>Fasciola hepatica</em>, the causative agent of fasciolosis in human and livestock all over the world. A thorough knowledge of snail biology is essential for describing the transmission dynamics and for controlling this disease. Since food quality has had a significant effect on snail growth, fecundity and fertility, in this study we evaluated the use of spirulina (<em>Arthrospira platensis</em>) as a food resource for the artificial breeding of <em>P. columella</em>, an invasive snail and the main intermediate host of <em>F. hepatica</em> in Northeastern Argentina. The main purpose was to measure the effect of spirulina on fitness parameters such as survival rate, growth rate, size at first reproduction, lifetime fecundity and viable offspring. A total of 20 676 newly-laid F<sub>2</sub> eggs were used; half of them were fed with lettuce (treatment L) and the other half with lettuce plus spirulina (treatment L+S). In comparison with <em>P. columella</em> snails fed only with lettuce, we found that <em>P. columella</em> fed with lettuce plus spirulina: <strong>1)</strong> showed higher survival rates, <strong>2)</strong> grew faster and showed higher growth increments, <strong>3)</strong> attained sexual maturity earlier in time (L+S:60 days vs. L:120 days) and at a smaller size (L+S:4.8mm vs. L:8.2mm), <strong>4)</strong> had a longer reproductive period (L+S:150 days vs. L:90 days), <strong>5)</strong> produced a higher number of eggs/snail (L+S:29.6 vs. L:13.3), and <strong>6)</strong> showed a higher offspring hatching rate (L+S:70% vs. L:40%). The supplementation of <em>P. columella</em> diet with commercial spirulina enhances it fitness and improved the artificial breeding of this species. Spirulina may have a direct positive effect on <em>P. columella</em> development by consuming it, along with an indirect positive effect by improving the water quality. This rearing technique provided large number of reproducing adults and a continuous production of offspring, which are essential for developing future experimental studies in order to improve our knowledge on <em>P. columella</em> biology.</p>

scholarly journals Gene network module changes associated with the vertebrate fin to limb transition

2021 ◽  
Author(s):  
Pasan C Fernando ◽  
Paula M Mabee ◽  
Erliang Zeng
Keyword(s):  
Gene Networks ◽  
Gene Network ◽  
Experimental Studies ◽  
Model Organisms ◽  
Biological Knowledge ◽  
Anatomical Structures ◽  
Terrestrial Vertebrate ◽  
General Network ◽  
Gene Modules ◽  
Computational Workflow

AbstractEvolutionary phenotypic transitions, such as the fin to limb transition in vertebrate evolution, result from changes in associated genes and their interactions, often in response to changing environment. Identifying the associated changes in gene networks is vital to achieve a better understanding of these transitions. Previous experimental studies have been typically limited to manipulating a small number of genes. To expand the number of analyzed genes and hence, biological knowledge, we computationally isolated and compared the gene modules for paired fins (pectoral fin, pelvic fin) of fishes (zebrafish) to those of the paired limbs (forelimb, hindlimb) of mammals (mouse) using quality-enhanced gene networks from zebrafish and mouse. We ranked module genes according to their weighted-degrees and identified the highest-ranking hub genes, which were important for the module stability. Further, we identified genes conserved during the fin to limb transition and investigated the fates of zebrafish-specific and mouse-specific module genes in relation to their involvements in newly emerged or lost anatomical structures during the aquatic to terrestrial vertebrate transition. This paper presents the results of our investigations and demonstrates a general network-based computational workflow to study evolutionary phenotypic transitions involving diverse model organisms and anatomical entities.

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