scholarly journals Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

2009 ◽  
Vol 75 (16) ◽  
pp. 5261-5272 ◽  
Author(s):  
Andrew Dopheide ◽  
Gavin Lear ◽  
Rebecca Stott ◽  
Gillian Lewis
Keyword(s):  
Rflp Analysis ◽  
Molecular Techniques ◽  
Trophic Levels ◽  
Urban Stream ◽  
Macroinvertebrate Communities ◽  
Morphological Examination ◽  
Stream Biofilms ◽  
Sequences Analysis ◽  
Rrna Sequences

ABSTRACT Ciliates are an important component of aquatic ecosystems, acting as predators of bacteria and protozoa and providing nutrition for organisms at higher trophic levels. Understanding of the diversity and ecological role of ciliates in stream biofilms is limited, however. Ciliate diversity in biofilm samples from four streams subject to different impacts by human activity was assessed using microscopy and terminal restriction fragment length polymorphism (T-RFLP) analysis of 18S rRNA sequences. Analysis of 3′ and 5′ terminal fragments yielded very similar estimates of ciliate diversity. The diversity detected using microscopy was consistently lower than that suggested by T-RFLP analysis, indicating the existence of genetic diversity not apparent by morphological examination. Microscopy and T-RFLP analyses revealed similar relative trends in diversity between different streams, with the lowest level of biofilm-associated ciliate diversity found in samples from the least-impacted stream and the highest diversity in samples from moderately to highly impacted streams. Multivariate analysis provided evidence of significantly different ciliate communities in biofilm samples from different streams and seasons, particularly between a highly degraded urban stream and less impacted streams. Microscopy and T-RFLP data both suggested the existence of widely distributed, resilient biofilm-associated ciliates as well as ciliate taxa restricted to sites with particular environmental conditions, with cosmopolitan taxa being more abundant than those with restricted distributions. Differences between ciliate assemblages were associated with water quality characteristics typical of urban stream degradation and may be related to factors such as nutrient availability and macroinvertebrate communities. Microscopic and molecular techniques were considered to be useful complementary approaches for investigation of biofilm ciliate communities.

scholarly journals Is landscape of fear of macroinvertebrate communities a major determinant of mesopredator and prey activity?

2020 ◽  
pp. 8
Author(s):  
Raoul Manenti ◽  
Benedetta Barzaghi
Keyword(s):  
Macroinvertebrate Community ◽  
Trophic Levels ◽  
Macroinvertebrate Communities ◽  
Freshwater Macroinvertebrates ◽  
Landscape Of Fear ◽  
Broad Implication ◽  
Top Predators ◽  
Freshwater Environments ◽  
Scientific Hypotheses

Macroinvertebrate foragers play an important role on the trophic structures of freshwater environments, and multiple trophic levels occur among macroinvertebrate communities providing very interesting scenarios for testing scientific hypotheses. One of the most intriguing aspect to understand is the role played by the landscape of fear (LOF) on macrobenthos density and activity. With this pilot study we wanted to test if LOF at the macrobenthos community levels plays a role in determining the density of both prey and mesopredators. During two consecutive years, we evaluated, with both day and night surveys, the density of two mesopredator triclad species and of one detritivore prey crustacean species, and we compared them to the number of respective predators occurring in the macroinvertebrate community. LOF levels at the macroinvertebrate community did not reduce the abundance of the target taxa. One of the triclad species was instead positively related to the levels of LOF assessed for it on the basis of the available knowledge. The broad implication of the research is that the abundance of freshwater macroinvertebrates is not mainly linked to the predation risk at the community level, suggesting that also for researches on macrobenthos LOF analyses should take in consideration the role of top predators.

The Influence of Benthic Biota on Copper Speciation and Distribution in Freshwater-Sediment Systems

1981 ◽  
Vol 16 (1) ◽  
pp. 45-58 ◽  
Author(s):  
G. Krantzberg ◽  
P.M. Stokes
Keyword(s):  
Freshwater Sediment ◽  
Benthic Macroinvertebrate ◽  
Macroinvertebrate Communities ◽  
Copper Species ◽  
Copper Speciation ◽  
Physico Chemical ◽  
Macro Benthos

Abstract An investigation was made of the effects exerted by benthic macroinvertebrate communities on copper speciation in sediments from a lake which is becoming acidified. In laboratory microcosms, benthic macroinvertebrate communities stimulated the flux of copper from sediment to water. The presence of the macro-benthos resulted in a redistribution of physico-chemical copper species within the sediment with a transfer from more strongly complexed forms (HC1 extractable) to adsorbed and cation exchangeable forms (MgCl2 extractable). The role of bio-turbation in copper transformations is discussed.

scholarly journals Molecular detection of cattle Sarcocystis spp. in North-West Italy highlights their association with bovine eosinophilic myositis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Selene Rubiola ◽  
Tiziana Civera ◽  
Felice Panebianco ◽  
Davide Vercellino ◽  
Francesco Chiesa
Keyword(s):  
18S Rdna ◽  
Inflammatory Myopathy ◽  
Molecular Techniques ◽  
Diaphragm Muscle ◽  
Economic Losses ◽  
Intermediate Hosts ◽  
Slaughter Cattle ◽  
Significant Difference ◽  
Pcr Targeting

Abstract Background Cattle are intermediate hosts of six Sarcocystis species, among which Sarcocystis hominis and Sarcocystis heydorni can infect humans through the consumption of raw or undercooked meat. In addition to the zoonotic potential, there is increasing interest in these protozoa because of the evidence supporting the role of Sarcocystis spp. in the occurrence of bovine eosinophilic myositis (BEM), a specific inflammatory myopathy which leads to carcass condemnation and considerable economic losses. Actually, all the prevalence studies carried out on cattle in Italy have been based on either morphological or 18S rDNA-based molecular techniques, most likely leading to misidentification of closely related species. Therefore, there is a strong need for new data on the prevalence of the different Sarcocystis spp. in cattle in Italy and their association with bovine eosinophilic myositis. Methods To reach our aim, individual striated muscle samples from BEM condemned carcasses (N = 54) and diaphragm muscle samples from randomly sampled carcasses (N = 59) were obtained from Northwest Italy slaughterhouses. Genomic DNA was extracted and analyzed by multiplex-PCR targeting 18S rDNA and cox1 genes. PCR products amplified using the genus-specific primer set in absence of the specific fragment for S. hirsuta, S. cruzi, S. hominis or S. bovifelis were sequenced to achieve species identification. Results Sarcocystis DNA was detected in 67.8% of the samples from slaughter cattle and in 90.7% of the samples from BEM condemned carcasses. S. cruzi was identified as the most prevalent species in slaughter cattle (61%), followed by S. bovifelis (10.2%), S. hominis (8.5%) and S. hirsuta (1.7%). Notably, among the different Sarcocystis spp. detected, the presence of S. bovifelis and S. hominis was significantly higher in samples isolated from BEM condemned carcasses (46.3% and 40.7% respectively), while there was no statistically significant difference between the presence of S. cruzi or S. hirsuta in BEM condemned carcasses (42.6% and 1.8%, respectively) and randomly sampled carcasses. Furthermore, DNA sequence analysis revealed the presence of a putative new species in two carcasses. Conclusions Our study contributes to updating the data on the prevalence of the different Sarcocystis spp. in cattle in Italy, highlighting the presence of three Sarcocystis spp., S. cruzi, S. hominis and S. bovifelis, in BEM lesions and allowing us to speculate on the possible role of S. hominis and S. bovifelis as the major sarcosporidian species involved in bovine eosinophilic myositis. Graphic Abstract

scholarly journals Calcium Signaling in Vertebrate Development and Its Role in Disease

2018 ◽  
Vol 19 (11) ◽  
pp. 3390 ◽  
Author(s):  
Sudip Paudel ◽  
Regan Sindelar ◽  
Margaret Saha
Keyword(s):  
Calcium Signaling ◽  
Critical Role ◽  
Molecular Techniques ◽  
Model Organisms ◽  
Vertebrate Development ◽  
Developmental Defects ◽  
Calcium Activity ◽  
Human Genes ◽  
Underlying Mechanisms

Accumulating evidence over the past three decades suggests that altered calcium signaling during development may be a major driving force for adult pathophysiological events. Well over a hundred human genes encode proteins that are specifically dedicated to calcium homeostasis and calcium signaling, and the majority of these are expressed during embryonic development. Recent advances in molecular techniques have identified impaired calcium signaling during development due to either mutations or dysregulation of these proteins. This impaired signaling has been implicated in various human diseases ranging from cardiac malformations to epilepsy. Although the molecular basis of these and other diseases have been well studied in adult systems, the potential developmental origins of such diseases are less well characterized. In this review, we will discuss the recent evidence that examines different patterns of calcium activity during early development, as well as potential medical conditions associated with its dysregulation. Studies performed using various model organisms, including zebrafish, Xenopus, and mouse, have underscored the critical role of calcium activity in infertility, abortive pregnancy, developmental defects, and a range of diseases which manifest later in life. Understanding the underlying mechanisms by which calcium regulates these diverse developmental processes remains a challenge; however, this knowledge will potentially enable calcium signaling to be used as a therapeutic target in regenerative and personalized medicine.

scholarly journals B Chromosomes in Populations of Mammals Revisited

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 487 ◽  
Author(s):  
Mladen Vujošević ◽  
Marija Rajičić ◽  
Jelena Blagojević
Keyword(s):  
Mammalian Species ◽  
B Chromosome ◽  
Molecular Techniques ◽  
B Chromosomes ◽  
General View ◽  
Protein Coding ◽  
Host Parasite Interactions ◽  
Quantitative Characteristics ◽  
Host Parasite

The study of B chromosomes (Bs) started more than a century ago, while their presence in mammals dates since 1965. As the past two decades have seen huge progress in application of molecular techniques, we decided to throw a glance on new data on Bs in mammals and to review them. We listed 85 mammals with Bs that make 1.94% of karyotypically studied species. Contrary to general view, a typical B chromosome in mammals appears both as sub- or metacentric that is the same size as small chromosomes of standard complement. Both karyotypically stable and unstable species possess Bs. The presence of Bs in certain species influences the cell division, the degree of recombination, the development, a number of quantitative characteristics, the host-parasite interactions and their behaviour. There is at least some data on molecular structure of Bs recorded in nearly a quarter of species. Nevertheless, a more detailed molecular composition of Bs presently known for six mammalian species, confirms the presence of protein coding genes, and the transcriptional activity for some of them. Therefore, the idea that Bs are inert is outdated, but the role of Bs is yet to be determined. The maintenance of Bs is obviously not the same for all species, so the current models must be adapted while bearing in mind that Bs are not inactive as it was once thought.

scholarly journals A review on macrobenthic trophic relationships along subtropical sandy shores in southernmost Brazil

2014 ◽  
Vol 14 (3) ◽  
Author(s):  
Raphael Mathias Pinotti ◽  
Diogo Marroni Minasi ◽  
Leonir André Colling ◽  
Carlos Emílio Bemvenuti
Keyword(s):  
Surf Zone ◽  
Fish Assemblages ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
Intermediate Type ◽  
Sandy Shores ◽  
Macrobenthic Assemblages ◽  
High Species Richness ◽  
Asterionellopsis Glacialis

Main trophic relationships that occur along the exposed sandy shores in southernmost Brazil (∼33° S) are established taking into account several biological compartments operating at morphodynamically distinct environments. Beaches are predominantly of the intermediate type but some stretches of coastline are truly dissipative (Cassino Beach) or tending-to-reflective (Concheiros Beach), presenting thus diverse biological compartments and inhabitant macrobenthic assemblages. Dense concentrations of the surf-zone diatom Asterionellopsis glacialis are responsible - at least for the intermediate shorelines - for the most year-round primary production, sustaining several consumers up to tertiary level. Among them, bivalves Amarilladesma mactroides, Donax hanleyanus and the hippid crabEmerita brasiliensis can account for more than 95% of all the surf-zone secondary production, in addition to the elevated biomass of the suspension-feeder polychaete Spio gaucha and the scavenger isopod Excirolana armata. Crabs, whelks, carnivorous polychaetes, seabirds and surf-zone fishes may also be present and occupy superior trophic levels depending on the beach morphodynamics. Based on the high species richness, abundance and the role of macrobenthic fauna in transferring matter and energy to seabirds and the surf-zone fish assemblages, we address this important issue on the Southwestern Atlantic ecology. Conservation efforts should be implemented for the southernmost Brazilian sandy shores, at least for those non urbanized areas.

scholarly journals Metabarcoding reveals different zooplankton communities in northern and southern areas of the North Sea

2020 ◽  
Author(s):  
Jan Niklas Macher ◽  
Berry B. van der Hoorn ◽  
Katja T. C. A. Peijnenburg ◽  
Lodewijk van Walraven ◽  
Willem Renema
Keyword(s):  
North Sea ◽  
Zooplankton Community ◽  
Taxonomic Diversity ◽  
Molecular Techniques ◽  
Trophic Levels ◽  
List Type ◽  
The North ◽  
Shelf Sea ◽  
The North Sea ◽  
Zooplankton Communities

AbstractZooplankton are key players in marine ecosystems, linking primary production to higher trophic levels. The high abundance and high taxonomic diversity renders zooplankton ideal for biodiversity monitoring. However, taxonomic identification of the zooplankton assemblage is challenging due to its high diversity, subtle morphological differences and the presence of many meroplanktonic species, especially in coastal seas. Molecular techniques such as metabarcoding can help with rapid processing and identification of taxa in complex samples, and are therefore promising tools for identifying zooplankton communities. In this study, we applied metabarcoding of the mitochondrial cytochrome c oxidase I gene to zooplankton samples collected along a latitudinal transect in the North Sea, a shelf sea of the Atlantic Ocean. Northern regions of the North Sea are influenced by inflow of oceanic Atlantic waters, whereas the southern parts are characterised by more coastal waters. Our metabarcoding results indicated strong differences in zooplankton community composition between northern and southern areas of the North Sea, particularly in the classes Copepoda, Actinopterygii (ray-finned fishes) and Polychaeta. We compared these results to the known distributions of species reported in previous studies, and by comparing the abundance of copepods to data obtained from the Continuous Plankton Recorder (CPR). We found that our metabarcoding results are mostly congruent with the reported distribution and abundance patterns of zooplankton species in the North Sea. Our results highlight the power of metabarcoding to rapidly assess complex zooplankton samples, and we suggest that the technique could be used in future monitoring campaigns and biodiversity assessments.HighlightsZooplankton communities are different in northern and southern areas of the North SeaMetabarcoding results are consistent with known species distributions and abundanceMetabarcoding allows for fast identification of meroplanktonic species

scholarly journals Molecular characterization of Cronobacter sakazakii isolated from different herbal teas and mixtures in Serbia

Genetika ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 921-934
Author(s):  
Dragana Josic ◽  
Marija Stojanovic ◽  
Zorica Lepsanovic ◽  
Vera Katic
Keyword(s):  
Molecular Characterization ◽  
Infant Formula ◽  
Powdered Infant Formula ◽  
Cronobacter Sakazakii ◽  
Safety Risks ◽  
High Prevalence ◽  
Sequences Analysis ◽  
Human Infections ◽  
Rrna Sequences

Cronobacter sakazakii is an important cause of human infections that can be serious and even fatal among premature neonates and immunocompromised adults or infants. Because of its high tolerance to osmotic stress, C. sakazakii is frequently isolated from dried foods, such as powdered infant formula and herbal teas. The aim of investigation was detection, identification and molecular characterization of Cronobacter sakazakii isolates from infant formula and various herbal teas collected from Serbian market and tested for import control. C. sakazakii was not detected in any of the 360 analysed samples of powdered infant formula. However, 192 out of 520 samples of herbal teas tested were positive for C. sakazakii (37.1%). The high prevalence was observed in teas for children (51.6%) and in ?baby? teas (44.1%), followed by medicinal teas (38%). The largest one-herb-teas group (221 samples) contained 72 C. sakazakii-positive samples (32.6%) and involved Sennae folium, Althaeae radix, Menthae piperitae folium, Chamomilae flos and Urticae folium teas. Molecular characterization of isolated C. sakazakii from different herbal teas by rep-PCR, RAPD and 16S rRNA sequences analysis showed the high similarity to C. sakazakii NCTC 8155. Knowing this strain as one of the most pathogenic clinical strains, our results raise concern about the safety risks these foods pose to immunocompromised and healthy consumers, especially for babies and children.

scholarly journals Bioconcentration of glyphosate in wetland biofilms

2020 ◽  
Author(s):  
Laura Beecraft ◽  
Rebecca Rooney
Keyword(s):  
Trophic Levels ◽  
Breakdown Product ◽  
Exposure Risk ◽  
Surrounding Water ◽  
Wetland Water ◽  
Pesticides Exposure ◽  
Wetland Water Quality ◽  
Herbicide Glyphosate

AbstractWetland biofilms were exposed to the herbicide glyphosate via in situ field exposures and controlled microcosm experiments to measure bioconcentration and metabolism of glyphosate by biofilm organisms. Glyphosate concentrations in biofilms were orders of magnitude higher than the surrounding water, bioconcentration factors averaged 835 and 199 in field- and lab-exposed biofilms, respectively. Glyphosate in water where it had been detected in biofilms at field-exposed sites ranged from below detection (<0.001 ppm) up to 0.13 ppm. Glyphosate bioconcentration in biofilms was inversely proportional to levels in the surrounding water, and the retention kinetics were similar to both adsorption and enzymatic models. Microorganisms present in both the water and biofilms metabolized glyphosate to its primary breakdown product aminomethyl phosphonic acid (AMPA), with increased rates of breakdown in and around the biofilms. Photosynthetic efficiency of the algae within the biofilms was not affected by 24 h glyphosate controlled exposures. Our results demonstrate the role of biofilms in improving wetland water quality by removing contaminants like glyphosate, but also as a potential exposure route to higher trophic levels via consumption. Due to bioconcentration of pesticides, exposure risk to organisms consuming or living in biofilms may be much higher than indicated by concentrations in ambient water samples.

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