Decay of similarity with host phylogenetic distance in parasite faunas

Parasitology ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 733-741 ◽  
Author(s):  
R. POULIN
Keyword(s):  
Exponential Decay ◽  
Dna Sequences ◽  
Host Species ◽  
Environmental Gradients ◽  
Meta Analysis ◽  
Host Switching ◽  
Phylogenetic Distance ◽  
Pairwise Similarity ◽  
Metazoan Parasites ◽  
Geographical Space

SUMMARYExponential decay in community similarity as a function of distance is a ubiquitous phenomenon in biogeography. Thus, for parasite communities, pairwise similarity decreases with increasing geographical distance between host populations. This biogeographical rule should also apply along other dimensions characterizing the separation between communities. Since host-switching and phylogenetic affinities among host species affect the evolution of parasite faunas across host phylogenetic space the same way as dispersal and environmental gradients affect the assembly of local communities in geographical space, an exponential decay in similarity of parasite faunas with increasing host phylogenetic distance should be observed. This prediction is tested using data on metazoan parasites of 45 species of Canadian freshwater fishes belonging to 5 families. Across all host species, pairwise similarity in the composition of parasite faunas decayed exponentially, though not strongly, with increasing phylogenetic distance between hosts (measured as the number of substitutions per site along DNA sequences). A meta-analysis of correlations computed for separate fish families indicates only a very weak overall relationship. Data distribution indicates that phylogenetically close host species tend to share many of their parasites, while phylogenetically distant hosts have roughly equal chances of harbouring very similar or very dissimilar parasite faunas. The same pattern was seen when monogenean and trematode parasites were analysed separately, whereas no significant decay was observed for cestodes or nematodes, suggesting different patterns of host-switching and parasite colonization among these taxa. The results show that similarity in species composition decreases, though weakly, with increasing distance in the same manner in phylogenetic space as it does in geographical space.

scholarly journals The dynamics of preferential host switching: host phylogeny as a key predictor of parasite prevalence and distribution

2017 ◽  
Author(s):  
Jan Engelstädter ◽  
Nicole Z. Fortuna
Keyword(s):  
Host Species ◽  
Species Turnover ◽  
Death Process ◽  
Major Influence ◽  
Host Switching ◽  
Infection Frequency ◽  
Phylogenetic Distance ◽  
Host Shifts ◽  
Host Trees ◽  
Wide Range

AbstractThis preprint has been reviewed and recommended byPeer Community In Evolutionary Biology(https://doi.org/10.24072/pci.evolbiol.100049).New parasites commonly arise through host-shifts, where parasites from one host species jump to and become established in a new host species. There is much evidence that the probability of host-shifts decreases with increasing phylogenetic distance between donor and recipient hosts, but the consequences of such preferential host switching remain little explored. We develop a mathematical model to investigate the dynamics of parasite host-shifts in the presence of this phylogenetic distance effect. Host trees evolve under a stochastic birth-death process and parasites co-evolve concurrently on those trees, undergoing host-shifts, co-speciation and extinction. Our model indicates that host trees have a major influence on these dynamics. This applies both to individual trees that evolved under the same stochastic process and to sets of trees that evolved with different macroevolutionary parameters. We predict that trees consisting of a few large clades of host species and those with fast species turnover should harbour more parasites than trees with many small clades and those that diversify more slowly. Within trees, large clades should exhibit a higher infection frequency than small clades. We discuss our results in the light of recent cophylogenetic studies in a wide range of host-parasite systems, including the intracellular bacteriumWolbachia.

An updated look at the uneven distribution of cryptic diversity among parasitic helminths

2017 ◽  
Vol 92 (2) ◽  
pp. 197-202 ◽  
Author(s):  
G. Pérez-Ponce de León ◽  
R. Poulin
Keyword(s):  
Cryptic Species ◽  
Dna Sequences ◽  
Meta Analysis ◽  
Parasitic Nematodes ◽  
Trematode Species ◽  
Sampling Effort ◽  
Separate Analysis ◽  
Cryptic Diversity ◽  
Parasite Diversity ◽  
Parasitic Helminths

AbstractCryptic parasite diversity is a major issue for taxonomy and systematics, and for attempts to control diseases of humans, domestic animals and wildlife. Here, we re-examine an earlier report that, after correcting for sampling effort, more cryptic species of trematodes are found per published study than for other helminth taxa. We performed a meta-analysis of 110 studies that used DNA sequences to search for cryptic species in parasitic helminth taxa. After correcting for study effort and accounting for the biogeographical region of origins, we found that more cryptic species tend to be uncovered among trematodes, and fewer among cestodes and animal-parasitic nematodes, than in other helminth groups. However, this pattern was only apparent when we included only studies using nuclear markers in the analysis; it was not seen in a separate analysis based only on mitochondrial markers. We propose that the greater occurrence of cryptic diversity among trematodes may be due to some of their unique features, such as their mode of reproduction or frequent lack of hard morphological structures, or to the way in which trematode species are described. Whatever the reason, the high frequency of cryptic species among trematodes has huge implications for estimates of parasite diversity and for future taxonomic research.

Specificity

2021 ◽  
pp. 159-182
Author(s):  
Paul Schmid-Hempel
Keyword(s):  
Host Range ◽  
Host Species ◽  
Cross Reactivity ◽  
Geographical Range ◽  
Immune Memory ◽  
Phylogenetic Distance ◽  
Immune Priming ◽  
Number Of Factors ◽  
Ecological Filter ◽  
Immune Defences

infect a number of host species. This host range is given by an ecological filter (the possibility of encounter) and a physiological one (the capacity of establishing an infection). Host ranges typically are right-skewed, with most parasites infecting only a few, but few infecting very many hosts. There is no universally valid hypothesis that explains host range. However, a number of factors contribute to host range, such as geographical range, phylogenetic distance, host predictability, and parasite virulence. Specificity and cross-reactivity of immune defences are important mechanisms. Moreover, immune memory is based on specificity; transgenerational immune priming protects offspring when parents have already been exposed to the same or similar parasites.

scholarly journals Meta-Analysis of Microbial Communities in Hot Springs: Recurrent Taxa and Complex Shaping Factors beyond pH and Temperature

2020 ◽  
Vol 8 (6) ◽  
pp. 906 ◽  
Author(s):  
Francisco L. Massello ◽  
Chia Sing Chan ◽  
Kok-Gan Chan ◽  
Kian Mau Goh ◽  
Edgardo Donati ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Metabolic Profile ◽  
Hot Springs ◽  
Meta Analysis ◽  
Extreme Environments ◽  
Alpha Diversity ◽  
Amplicon Sequencing ◽  
Phylogenetic Distance ◽  
Microbial Profile ◽  
The World

The study of microbial communities from extreme environments is a fascinating topic. With every study, biologists and ecologists reveal interesting facts and questions that dispel the old belief that these are inhospitable environments. In this work, we assess the microbial diversity of three hot springs from Neuquén, Argentina, using high-throughput amplicon sequencing. We predicted a distinct metabolic profile in the acidic and the circumneutral samples, with the first ones being dominated by chemolithotrophs and the second ones by chemoheterotrophs. Then, we collected data of the microbial communities of hot springs around the world in an effort to comprehend the roles of pH and temperature as shaping factors. Interestingly, there was a covariation between both parameters and the phylogenetic distance between communities; however, neither of them could explain much of the microbial profile in an ordination model. Moreover, there was no correlation between alpha diversity and these parameters. Therefore, the microbial communities’ profile seemed to have complex shaping factors beyond pH and temperature. Lastly, we looked for taxa associated with different environmental conditions. Several such taxa were found. For example, Hydrogenobaculum was frequently present in acidic springs, as was the Sulfolobaceae family; on the other hand, Candidatus Hydrothermae phylum was strongly associated with circumneutral conditions. Interestingly, some singularities related to sites featuring certain taxa were also observed.

Analysis of parasite host-switching: limitations on the use of phylogenies

Parasitology ◽  
1999 ◽  
Vol 119 (S1) ◽  
pp. S111-S123 ◽  
Author(s):  
J. A. Jackson
Keyword(s):  
Host Species ◽  
Host Tree ◽  
Host Switching ◽  
Environmental Constraints ◽  
Important Process ◽  
Potential Host ◽  
Historical Reconstructions ◽  
History Of ◽  
Host Parasite ◽  
Parasite Assemblages

SUMMARYEven the most generalist parasites usually occur in only a subset of potential host species, a tendency which reflects overriding environmental constraints on their distributions in nature. The periodic shifting of these limitations represented by host-switches may have been an important process in the evolution of many host-parasite assemblages. To study such events, however, it must first be established where and when they have occurred. Past host-switches within a group of parasites are usually inferred from a comparison of the parasite phylogeny with that of the hosts. Congruence between the phylogenies is often attributed to a history of association by descent with cospeciation, and incongruence to host-switching or extinction in ‘duplicated’ parasite lineages (which diverged without a corresponding branching of the host tree). The inference of host-switching from incongrucnt patterns is discussed. Difficulties arise because incongruence can frequently be explained by different combinations of biologically distinct events whose relative probabilities are uncertain. Also, the models of host parasite relationships implicit in historical reconstructions may often not allow for plausible sources of incongruence other than host-switching or duplication/extinction, or for the possibility that colonization could, in some circumstances, be disguised by ‘false’ congruence.

scholarly journals Co-infection does not predict disease signs in Gopherus tortoises

2017 ◽  
Vol 4 (10) ◽  
pp. 171003 ◽  
Author(s):  
Chava L. Weitzman ◽  
Ryan Gov ◽  
Franziska C. Sandmeier ◽  
Sarah J. Snyder ◽  
C. Richard Tracy
Keyword(s):  
Dna Sequences ◽  
Host Species ◽  
Disease Ecology ◽  
Clinical Signs ◽  
Infection Intensity ◽  
The United States ◽  
Host Immune System ◽  
Disease Dynamics ◽  
Upper Respiratory Tract ◽  
The Impact

In disease ecology, the host immune system interacts with environmental conditions and pathogen properties to affect the impact of disease on the host. Within the host, pathogens may interact to facilitate or inhibit each other's growth, and pathogens interact with different hosts differently. We investigated co-infection of two Mycoplasma and the association of infection with clinical signs of upper respiratory tract disease in four congeneric tortoise host species ( Gopherus ) in the United States to detect differences in infection risk and disease dynamics in these hosts. Mojave Desert tortoises had greater prevalence of Mycoplasma agassizii than Texas tortoises and gopher tortoises, while there were no differences in Mycoplasma testudineum prevalence among host species. In some host species, the presence of each pathogen influenced the infection intensity of the other; hence, these two mycoplasmas interact differently within different hosts, and our results may indicate facilitation of these bacteria. Neither infection nor co-infection was associated with clinical signs of disease, which tend to fluctuate across time. From M. agassizii DNA sequences, we detected no meaningful differentiation of haplotypes among hosts. Experimental inoculation studies and recurrent resampling of wild individuals could help to decipher the underlying mechanisms of disease dynamics in this system.

Metazoan parasites of three species of scoter (Anatidae)

1982 ◽  
Vol 60 (10) ◽  
pp. 2253-2257 ◽  
Author(s):  
Charles E. Bourgeois ◽  
William Threlfall
Keyword(s):  
New Brunswick ◽  
Host Species ◽  
Quantitative Data ◽  
Marine Ecosystem ◽  
Life Cycles ◽  
Individual Species ◽  
Intensity Of Infection ◽  
New Host ◽  
Metazoan Parasites ◽  
New Host Records

One hundred and seventy-five (94 surf, 36 white-winged, and 45 black) scoters obtained from four localities (New Brunswick, British Columbia, Labrador, and Norway) in 1973–1978 were examined for metazoan parasites, with 91% (159 birds: 86 surf, 33 white-winged, and 40 black scoters) being infected. Approximately 45 species of parasites, excluding cestodes, were found (36 from the surf, 25 from the white-winged, and 27 from the black), including 39 which were new host records. Quantitative data, including prevalence and intensity of infection, are given for each helminth and host. Comparisons between different ages and sexes are made, and between different host species. Individual species of parasites are discussed with regard to topics such as location within host. Comments are made on the geographical distribution of the parasites found and their life cycles, where known (seven cycle through the marine ecosystem, seven through freshwater, four through either system, and one through a dipteran).

A checklist of metazoan parasites recorded in freshwater fish from Turkey

Zootaxa ◽  
2003 ◽  
Vol 394 (1) ◽  
pp. 1 ◽  
Author(s):  
AHMET ÖKTENER
Keyword(s):  
Freshwater Fish ◽  
Host Species ◽  
Parasite Species ◽  
Host Fish ◽  
Species List ◽  
Metazoan Parasites ◽  
Host List

A checklist of the metazoon parasites of freshwater fish in Turkey has been compiled from parasitological studies done in Turkey between 1964 and 2003. The parasite species list is arranged by phylum and class, providing parasite species name and author, host fish, location of host fish capture and author and date of published record. The host list consists of all parasite species listed by host species. One hundred and thirteen parasite species are listed from 41 host species belonging to 26 genera.

Sign in / Sign up

Export Citation Format

Share Document