scholarly journals The yellow perch (Perca flavescens) microbiome revealed resistance to colonisation mostly associated with neutralism driven by rare taxa under cadmium disturbance

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Bachar Cheaib ◽  
Hamza Seghouani ◽  
Martin Llewellyn ◽  
Katherine Vandal-Lenghan ◽  
Pierre-Luc Mercier ◽  
...  

Abstract Background Disentangling the dynamics of microbial interactions within communities improves our comprehension of metacommunity assembly of microbiota during host development and under perturbations. To assess the impact of stochastic variation of neutral processes on microbiota structure and composition under disturbance, two types of microbial habitats, free-living (water), and host-associated (skin and gut) were experimentally exposed to either a constant or gradual selection regime exerted by two sublethal cadmium chloride dosages (CdCl2). Yellow Perch (Perca flavescens) was used as a piscivorous ecotoxicological model. Using 16S rDNA gene based metataxonomics, quantitative diversity metrics of water, skin and gut microbial communities were characterized along with development and across experimental conditions. Results After 30 days, constant and gradual selection regimes drove a significant alpha diversity increase for both skin and gut microbiota. In the skin, pervasive negative correlations between taxa in both selection regimes in addition to the taxonomic convergence with the environmental bacterial community, suggest a loss of colonisation resistance resulting in the dysbiosis of yellow perch microbiota. Furthermore, the network connectivity in gut microbiome was exclusively maintained by rare (low abundance) OTUs, while most abundant OTUs were mainly composed of opportunistic invaders such as Mycoplasma and other genera related to fish pathogens such as Flavobacterium. Finally, the mathematical modelling of community assembly using both non-linear least squares models (NLS) based estimates of migration rates and normalized stochasticity ratios (NST) based beta-diversity distances suggested neutral processes drove by taxonomic drift in host and water communities for almost all treatments. The NLS models predicted higher demographic stochasticity in the cadmium-free host and water microbiomes, however, NST models suggested higher ecological stochasticity under perturbations. Conclusions Neutral models agree that water and host-microbiota assembly promoted by rare taxa have evolved predominantly under neutral processes with potential involvement of deterministic forces sourced from host filtering and cadmium selection. The early signals of perturbations in the skin microbiome revealed antagonistic interactions by a preponderance of negative correlations in the co-abundance networks. Our findings enhance our understanding of community assembly host-associated and free-living under anthropogenic selective pressure.

2020 ◽  
Author(s):  
Bachar Cheaib ◽  
Hamza Seghouani ◽  
Martin Stephen Llewellyn ◽  
Katherine Vandal-Lenghan ◽  
Pierre-Luc Mercier ◽  
...  

Abstract Background: Disentangling the dynamics of microbial interactions within communities improves our comprehension of metacommunity assembly of microbiota during host development and under perturbations. To assess the impact of stochastic variation of neutral processes on microbiota structure and composition under disturbance, two types of microbial habitats, free-living (water), and host-associated (skin and gut) were experimentally exposed to either a constant or gradual selection regime exerted by two sublethal cadmium chloride dosages (CdCl2). Yellow Perch (Perca flavescens) was used as a piscivorous ecotoxicological model. Using 16S rDNA gene based metataxonomics, quantitative metrics of water, skin and gut microbial communities were characterized along with development and across experimental conditions. Results: After 30 days, constant and gradual selection regimes drove a significant alpha diversity increase for both skin and gut microbiota. In the skin, pervasive negative correlations between taxa in both selection regimes in addition to the taxonomic convergence with the environmental bacterial community, suggest a loss of colonisation resistance resulting in the dysbiosis of yellow perch microbiota. Furthermore, the network connectivity in gut microbiome was exclusively maintained by rare (low abundance) OTUs, while most abundant OTUs were mainly composed of opportunistic invaders such as Mycoplasma and other genera related to fish pathogens such as Flavobacterium. Finally, the mathematical modelling of community assembly using both non-linear least squares models (NLS) and normalized stochasticity ratios (NST) based beta-diversity distances suggested neutral processes drove by taxonomic drift in host and water communities for almost all treatments. The NLS models predicted higher stochasticity in the cadmium-free host and water communities, however, NST models suggested higher stochasticity ratios under disturbance. Conclusions: Neutral models agree that water and host-microbiota assembly promoted by the occurrence frequence of rare taxa have evolved predominantly under neutral processes with potential involvement of deterministic forces sourced from host filtering and cadmium selection. The early signals of perturbations in the skin microbiome revealed antagonistic interactions by preponderance of negative correlations in the co-abundace networks. Our findings enhance our understanding of community assembly host-associated and free-living under anthropogenic selective pressure.


2020 ◽  
Author(s):  
Bachar Cheaib ◽  
Hamza Seghouani ◽  
Martin Stephen Llewellyn ◽  
Katherine Vandal-Lenghan ◽  
Pierre-Luc Mercier ◽  
...  

Abstract Background: Disentangling the dynamics of microbial interactions within communities improves our comprehension of metacommunity assembly of microbiota during host development and under perturbations. To assess the impact of stochastic variation of neutral processes on microbiota structure and composition under disturbance, two types of microbial habitats, free-living (water), and host-associated (skin and gut) were experimentally exposed to either a constant or gradual selection regime exerted by two sublethal cadmium chloride dosages (CdCl2). Yellow Perch (Perca flavescens) was used as a piscivorous ecotoxicological model. Using 16S rDNA gene based metataxonomics, quantitative diversity metrics of water, skin and gut microbial communities were characterized along with development and across experimental conditions. Results: After 30 days, constant and gradual selection regimes drove a significant alpha diversity increase for both skin and gut microbiota. In the skin, pervasive negative correlations between taxa in both selection regimes in addition to the taxonomic convergence with the environmental bacterial community, suggest a loss of colonisation resistance resulting in the dysbiosis of yellow perch microbiota. Furthermore, the network connectivity in gut microbiome was exclusively maintained by rare (low abundance) OTUs, while most abundant OTUs were mainly composed of opportunistic invaders such as Mycoplasma and other genera related to fish pathogens such as Flavobacterium. Finally, the mathematical modelling of community assembly using both non-linear least squares models (NLS) based estimates of migration rates and normalized stochasticity ratios (NST) based beta-diversity distances suggested neutral processes drove by taxonomic drift in host and water communities for almost all treatments. The NLS models predicted higher demographic stochasticity in the cadmium-free host and water microbiomes, however, NST models suggested higher ecological stochasticity under perturbations. Conclusions: Neutral models agree that water and host-microbiota assembly promoted by rare taxa have evolved predominantly under neutral processes with potential involvement of deterministic forces sourced from host filtering and cadmium selection. The early signals of perturbations in the skin microbiome revealed antagonistic interactions by a preponderance of negative correlations in the co-abundance networks. Our findings enhance our understanding of community assembly host-associated and free-living under anthropogenic selective pressure.


1991 ◽  
Vol 69 (1) ◽  
pp. 258-262 ◽  
Author(s):  
Dawn H. Sephton ◽  
William R. Driedzic

White perch (Morone americana), yellow perch (Perca flavescens), and smallmouth bass (Micropterus dolomieui) were acclimated to 5 and 20 °C. There was an increase in ventricle mass relative to body mass in smallmouth bass only following acclimation to 5° C. Maximal in vitro activities of hexokinase, citrate synthase, carnitine acyl CoA transferase (with palmitoyl CoA, palmitoleoyl CoA, and oleoyl CoA as substrates), and total ATPase were assessed in crude heart homogenates. Tissues removed from warm-acclimated animals were tested at 20 and 5 °C; tissues removed from cold-acclimated animals were assessed at 5 °C. Acute temperature transitions were associated with decreases in the activities of hexokinase (Q10 ≈ 1.8), citrate synthase (Q10 ≈ 1.4), and ATPase (Q10 ≈ 1.7). The impact of temperature on carnitine acyl CoA transferases was generally less severe. This suggests that maximal fatty acid oxidation is conserved better than glucose oxidation during a warm to cold transition. Maximal enzyme activities were generally unaffected by the acclimation regime, with the exception of that of carnitine acyl CoA transferase in white perch heart. The substantial increase in carnitine acyl CoA transferase activity when unsaturated CoA derivatives were provided as substrate suggests an increased capacity to oxidize unsaturated fatty acids at low temperature following an acclimation period. Attempts to sustantiate this contention by offering labelled oleic acid to ventricle sheets were thwarted by a high rate of incorporation into the total lipid pool.


1995 ◽  
Vol 52 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Todd M. Koel ◽  
John J. Peterka

Laboratory-based bioassays were conducted to determine concentrations of sodium-sulfate type salinities that limit the hatching success of several fish species. Survival to hatching (SH) was significantly lower (P < 0.05) in sodium-sulfate type waters from Devils Lake, North Dakota, of ≥ 2400 mg/L total dissolved solids (TDS) than in fresh water of 200 mg/L. In waters of 200, 1150, 2400, 4250, and 6350 mg/L TDS, walleye (Stizostedion vitreum) SH was 41, 38, 7, 1, and 0%; northern pike (Esox lucius) SH was 92, 68, 33, 2, and 0%; yellow perch (Perca flavescens) SH was 88, 70, 73, 0, and 0%; white sucker (Catostomus commersoni) SH was 87, 95, 66, 0, and 0%; common carp (Cyprinus carpio) SH was 71, 69, 49, 63, and 25%.


1992 ◽  
Vol 49 (12) ◽  
pp. 2474-2482 ◽  
Author(s):  
Jay A. Nelson ◽  
John J. Magnuson

Little is known about the animals that occupy naturally acidic habitats. To better understand the physiological state of animals from temperate, naturally acidic systems, we compared metabolite stores and meristics of two yellow perch (Perca flavescens) populations in northern Wisconsin. One population originated from a naturally acidic, dystrophic lake (Acid-Lake-Perch, ALP) and had previously been shown to have enhanced tolerance to low pH. The second population came from two nearby interconnected circumneutral, mesotrophic lakes (Neutral-Lake-Perch, NLP). Perch were collected throughout the year to account for seasonal effects and to discern whether patterns of metabolite utilization differed between populations. ALP had smaller livers containing less glycogen and greater muscle glycogen content than NLP. The ALP also had significantly greater liver and visceral lipid contents, and females from this population committed a greater fraction of their body mass to egg production. We interpret these results as indicative of physiological divergence at the population level in yellow perch. These results are discussed as possible products of H+ -driven changes in metabolism and as possible products of different life history strategies between populations. Our results also show that perch living in acidic, dystrophic Wharton Lake are not acid stressed.


1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield


1997 ◽  
Vol 54 (8) ◽  
pp. 1903-1915 ◽  
Author(s):  
S A Thayer ◽  
R C Haas ◽  
R D Hunter ◽  
R H Kushler

Zebra mussels (Dreissena polymorpha) in enclosures located in an experimental pond adjacent to Lake St. Clair, Michigan, increased sedimentation rate but had relatively minor effects on percent organic matter and percent nitrogen content of sediment. In contrast, sediment from Lake St. Clair adjacent to zebra mussels was significantly higher in carbon than that 0.5 m away. Zebra mussels increase the nutritional value of surficial sediment and provide greater structural heterogeneity, which is probably more important in causing change among zoobenthos. Zoobenthos and yellow perch (Perca flavescens) diet were dominated by dipteran larvae and leeches. Zoobenthos was significantly different between enclosures with and without zebra mussels. Treatments with zebra mussels had significantly more oligochaetes and tended to have more crustaceans (isopods and amphipods). In June, yellow perch without zebra mussels consumed significantly more zooplankton, and those with mussels had more crustaceans in their diet. Zooplankton density was greater in treatments without zebra mussels. Yellow perch with zebra mussels grew significantly more than those without mussels. Zebra mussels in the enclosures neither reproduced nor were eaten by yellow perch; hence. the observed growth differences were due to indirect effects involving zebra mussel induced changes in benthic structure and biota.


2021 ◽  
Author(s):  
Wisely Chua ◽  
Si En Poh ◽  
Hao Li

The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.


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