scholarly journals The role of phylogeny and ecological opportunity in host-parasite interactions: network metrics, host repertoire, and network link prediction.

Author(s):  
Armando Cruz-Laufer ◽  
Tom Artois ◽  
Stephan Koblmüller ◽  
Antoine Pariselle ◽  
Karen Smeets ◽  
...  

Hosts and parasites have often intimate associations. Therefore, the evolution of their interactions is crucial for understanding species-rich host-parasite communities. Yet relatively few studies investigate eco-evolutionary feedbacks in these systems as large datasets remain scarce. Here, we explore African cichlid fishes and their flatworm gill parasites (Cichlidogyrus spp.) including 9901 reported infections and 473 different host-parasite combinations collected through a survey of peer-reviewed literature. We apply network metrics, estimate host repertoires, and use network link prediction (NLP) algorithms to investigate meta-community structures and their predictors including evolutionary, ecological, and morphological parameters. Host repertoire was mostly determined by the hosts’ evolutionary history. Both ecological and evolutionary parameters predicted host parasite associations but many interactions remain undetected according to NLP. We conclude that ecological opportunity paired with ecological fitting has shaped interactions. The cichlid-Cichlidogyrus network is a suitable study system for eco-evolutionary feedbacks but taxonomic research remains key to finding undetected interactions.

Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1452-1460
Author(s):  
Elvira D'Bastiani ◽  
Karla M. Campião ◽  
Walter A. Boeger ◽  
Sabrina B. L. Araújo

AbstractDespite the great interest to quantify the structure of host–parasite interaction networks, the real influence of some factors such as taxonomy, host body size and ecological opportunity remains poorly understood. In this paper, we investigate the general patterns of organization and structure of interactions in two anuran–parasite networks in the Brazilian Pantanal (seasonally flooded environment) and Atlantic Forest (non-flooded forest). We present theoretical models to test whether the structures of these host–parasite interaction networks are influenced by neutrality, host taxonomy and host body size. Subsequently, we calculated metrics of connectance, nestedness and modularity to characterize the network structure. We demonstrated the structure networks were influenced mainly by body size and taxonomy of the host. Moreover, our results showed that the seasonally flooded environment present networks with higher connectance/nestedness and lower modularity compared to the other environment. The results also suggest that seasonal floods may promote ecological opportunities for new species associations.


2020 ◽  
Author(s):  
Elvira D’Bastiani ◽  
Karla Magalhães Campião ◽  
Walter Antonio Boeger ◽  
Sabrina Borges Lino Araújo

AbstractDespite the great interest to quantify the structure of ecological networks, the influence of morphological, ecological and evolutionary characteristics of the species still remains poorly understood. One of the challenging issues in ecology is how the interaction opportunity influences and provides changes to the associations between species, and which effects these changes have on ecological systems. To explore topological patterns in host-parasite networks, we sampled endoparasites-anurans interactions in South America in order to determine whether the effect of the ecological opportunity affects our understanding of the topological structure of the interaction networks. To identify the effect of the ecological opportunity for interaction, we investigated interactions in environments with and without flood pulse, where presence would promote higher ecological opportunity of interaction. Moreover, we created three theoretical models with filters to test the influence of the ecological opportunity for interaction: random, phylogeny and host body size. We then calculated commonly used binary network metrics (connectance, nestedness and modularity) for the networks generated by the theoretical models. We demonstrated that the interaction ecological opportunity changes the structure of host-parasite networks, and was influenced mainly by phylogeny and body size of the host. Our results indicate that environments that offer greater opportunities for interaction between species present networks with the most connectance/nestedness and less modularity. Networks in environments that do not have such opportunities for interaction depict the opposite pattern. Our results indicate that the ecological opportunity of interaction is reflected in an increase in interaction associations between species and affect/change the organization of these interactive assemblages. From an epidemiological point of view, changes in the composition of parasitic species are associated with risks of invasions and emerging diseases. In part, emerging diseases are the result of processes such as those occurring during the flood pulse, in which climate change, travel, and global trade create opportunities for new species associations. Our results provide insight into the dynamics of incorporating a new resource, considering an evolutionary factor responsible for these changes in species composition.


2020 ◽  
Vol 94 ◽  
Author(s):  
J. Schwelm ◽  
O. Kudlai ◽  
N.J. Smit ◽  
C. Selbach ◽  
B. Sures

Abstract Bithynids snails are a widespread group of molluscs in European freshwater systems. However, not much information is available on trematode communities from molluscs of this family. Here, we investigate the trematode diversity of Bithynia tentaculata, based on molecular and morphological data. A total of 682 snails from the rivers Lippe and Rhine in North Rhine-Westphalia, Germany, and 121 B. tentaculata from Curonian Lagoon, Lithuania were screened for infections with digeneans. In total, B. tentaculata showed a trematode prevalence of 12.9% and 14%, respectively. The phylogenetic analyses based on 55 novel sequences for 36 isolates demonstrated a high diversity of digeneans. Analyses of the molecular and morphological data revealed a species-rich trematode fauna, comprising 20 species, belonging to ten families. Interestingly, the larval trematode community of B. tentaculata shows little overlap with the well-studied trematode fauna of lymnaeids and planorbids, and some of the detected species (Echinochasmus beleocephalus and E. coaxatus) constitute first records for B. tentaculata in Central Europe. Our study revealed an abundant, diverse and distinct trematode fauna in B. tentaculata, which highlights the need for further research on this so far understudied host–parasite system. Therefore, we might currently be underestimating the ecological roles of several parasite communities of non-pulmonate snail host families in European fresh waters.


Parasitology ◽  
1979 ◽  
Vol 78 (1) ◽  
pp. 53-66 ◽  
Author(s):  
J. Riley ◽  
J. L. James ◽  
A. A. Banaja

SUMMARYThe frontal and sub-parietal glands of the pentastomidReighardia sternaeelaborate lamellate secretion which is poured on to the cuticle. The entire surface of the cuticle, including the mouth, hook pits and reproductive apertures, is coated with secretion. Electron microscope studies indicate that the glands are continuously active, which implies a turnover of surface membranes. The postulated function of these membranes is to protect certain vital areas of the host–parasite interface, notably the pores of ion-transporting cells, from the host immune response. The available evidence suggests that pentastomids do evoke a strong immune response but since most are long-lived they must circumvent it. We believe the surface membrane system to be instrumental in this. Studies on another pentastomid,Porocephalus crotaliin rats have shown that an immune response stimulated by a primary infection will kill subsequent infections and that the surface membranes are strongly immunogenic. Obvious parallels between this situation and that of schistosome infections in mammals are discussed. An alternative explanation of concomitant immunity is proposed.


Parasitology ◽  
2012 ◽  
Vol 139 (11) ◽  
pp. 1478-1491 ◽  
Author(s):  
JOB DE ROIJ ◽  
ANDREW D. C. MacCOLL

SUMMARYParasite ecologists are often interested in the repeatability of patterns in parasite communities in space and/or time, because of implications for the dynamics of host-parasite interactions. Field studies usually examine temporal and spatial variation in isolation or limit themselves to a small number of host populations. Here, we studied the macroparasite communities of 12 populations of three-spined stickleback,Gasterosteus aculeatusL., on North Uist, Scotland, separated by small geographical distances, during the breeding season in 2 consecutive years (2007 and 2008) to determine: (1) the extent of spatial variation in macroparasite communities, (2) whether this variation is consistent across years, and (3) whether habitat characteristics can explain differences in macroparasite community composition among populations. We found substantial variation in parasite communities among populations. Generally, measures of parasite community composition were higher in 2008 than in 2007, but this effect of year was consistent across populations, such that the relative differences in these measures among populations changed little between years. These data suggest that there is short-term stability in the spatial variation in macroparasite communities of North Uist sticklebacks. However, none of the 5 habitat characteristics measured explained spatial variation in any measure of parasite community composition.


2021 ◽  
Vol 8 (3) ◽  
pp. 189-200
Author(s):  
Adel Razek

In this assessment, we have made an effort of synthesis on the role of theoretical and observational investigations in the analysis of the concepts and functioning of different natural biological and artificial phenomena. In this context, we pursued the objective of examining published works relating to the behavioral prediction of phenomena associated with its observation. We have examined examples from the literature concerning phenomena with known behaviors that associated to knowledge uncertainty as well as cases concerning phenomena with unknown and changing random behaviors linked to random uncertainty. The concerned cases are relative to brain functioning in neuroscience, modern smart industrial devices, and health care predictive endemic protocols. As predictive modeling is very concerned by the problematics relative to uncertainties that depend on the degree of matching in the link prediction-observation, we investigated first how to improve the model to match better the observation. Thus, we considered the case when the observed behavior and its model are contrasting, that implies the development of revised or amended models. Then we studied the case concerning the practice of modeling for the prediction of future behaviors of a phenomenon that is well known, and owning identified behavior. For such case, we illustrated the situation of prediction matched to observation operated in two cases. These are the Bayesian Brain theory in neuroscience and the Digital Twins industrial concept. The last investigated circumstance concerns the use of modeling for the prediction of future behaviors of a phenomenon that is not well known, or owning behavior varying arbitrary. For this situation, we studied contagion infections with an unknown mutant virus where the prediction task is very complicated and would be constrained only to adjust the principal clinical observation protocol. Keywords: prediction, observation, Bayesian, neuroscience, brain functioning, mutant virus


Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 487 ◽  
Author(s):  
Mladen Vujošević ◽  
Marija Rajičić ◽  
Jelena Blagojević

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.


2008 ◽  
Vol 57 (4) ◽  
pp. 562-573 ◽  
Author(s):  
Luke J. Harmon ◽  
Jane Melville ◽  
Allan Larson ◽  
Jonathan B. Losos

2018 ◽  
Vol 27 (24) ◽  
pp. 5104-5119 ◽  
Author(s):  
Andrew D. Sweet ◽  
Kevin P. Johnson
Keyword(s):  

2021 ◽  
Author(s):  
Curtis M Lively ◽  
Julie Xu ◽  
Frida Ben-Ami

Parasite-mediated selection is thought to maintain host genetic diversity for resistance. We might thus expect to find a strong positive correlation between host genetic diversity and infection prevalence across natural populations. Here we used computer simulations to examine host-parasite coevolution in 20 simi-isolated clonal populations across a broad range of values for both parasite virulence and parasite fecundity. We found that the correlation between host genetic diversity and infection prevalence can be significantly positive for intermediate values of parasite virulence and fecundity. But the correlation can also be weak and statistically non-significant, even when parasite-mediated frequency-dependent selection is the sole force maintaining host diversity. Hence correlational analyses of field populations, while useful, might underestimate the role of parasites in maintaining host diversity.


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