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Open Biology Jun 2022MicroRNAs (miRNAs) are a group of small non-coding RNAs present in a wide diversity of organisms. MiRNAs regulate gene expression at a post-transcriptional level through... (Review)
Review
MicroRNAs (miRNAs) are a group of small non-coding RNAs present in a wide diversity of organisms. MiRNAs regulate gene expression at a post-transcriptional level through their interaction with the 3' untranslated regions of target mRNAs, inducing translational inhibition or mRNA destabilization and degradation. Thus, miRNAs regulate key biological processes, such as cell death, signal transduction, development, cellular proliferation and differentiation. The dysregulation of miRNAs biogenesis and function is related to the pathogenesis of diseases, including parasite infection. Moreover, during host-parasite interactions, parasites and host miRNAs determine the probability of infection and progression of the disease. The present review is focused on the possible role of miRNAs in the pathogenesis of diseases of clinical interest caused by parasitic protists. In addition, the potential role of miRNAs as targets for the design of drugs and diagnostic and prognostic markers of parasitic diseases is also discussed.
Topics: 3' Untranslated Regions; Animals; Gene Expression Regulation; Host-Parasite Interactions; MicroRNAs; Parasites
PubMed: 35702995
DOI: 10.1098/rsob.210395 -
Journal of Helminthology Mar 2023Next generation sequencing technologies have facilitated a shift from a few targeted loci in population genetic studies to whole genome approaches. Here, we review the... (Review)
Review
Next generation sequencing technologies have facilitated a shift from a few targeted loci in population genetic studies to whole genome approaches. Here, we review the types of questions and inferences regarding the population biology and evolution of parasitic helminths being addressed within the field of population genomics. Topics include parabiome, hybridization, population structure, loci under selection and linkage mapping. We highlight various advances, and note the current trends in the field, particularly a focus on human-related parasites despite the inherent biodiversity of helminth species. We conclude by advocating for a broader application of population genomics to reflect the taxonomic and life history breadth displayed by helminth parasites. As such, our basic knowledge about helminth population biology and evolution would be enhanced while the diversity of helminths in itself would facilitate population genomic comparative studies to address broader ecological and evolutionary concepts.
Topics: Metagenomics; Host-Parasite Interactions; Helminths; Hybridization, Genetic; Genetic Variation; Chromosome Mapping; Drug Resistance; Biological Evolution; Parasitology
PubMed: 36927601
DOI: 10.1017/S0022149X23000123 -
Parasitology Dec 2022Finfish aquaculture in freshwater and marine environments is continuously expanding globally, and the potential for a substantial further increase is well documented.... (Review)
Review
Finfish aquaculture in freshwater and marine environments is continuously expanding globally, and the potential for a substantial further increase is well documented. The industry is supplying fish products for human consumption to the same extent as capture fisheries, and new fish species for domestication are still being selected by the industry. The challenge faced by all aquacultured species, classical and novel, is the range of pathogens associated with each new fish type. A fish host in its natural environment carries a series of more or less specific parasites (specialists and generalists). Some of these show a marked ability to propagate in aquaculture settings. They may then elicit disease when infection intensities in the confined aquaculture environment reach high levels. In addition, the risk of transmission of parasites from aquaculture enterprises to wild fish stocks adds to the parasitic challenge. Control programmes of various kinds are needed and these may include chemotherapeutants and medicines as the farmer's first and convenient choice, but mechanical, biological, immunological and genetic control methods are available solutions. New methods are still to be developed by scrutinizing the life cycle of each particular parasite species and pin-pointing the vulnerable stage to be targeted. As parasites exhibit a huge potential for adaptation to environmental changes, one must realize that only one approach rarely is sufficient. The present work therefore elaborates on and advocates for implementation of integrated control strategies for diseases caused by protozoan and metazoan parasites.
Topics: Animals; Humans; Fish Diseases; Aquaculture; Fisheries; Fishes; Parasites; Parasitic Diseases
PubMed: 35950444
DOI: 10.1017/S0031182022001093 -
The Journal of Experimental Biology Sep 2021Obligate brood-parasitic birds never build nests, incubate eggs or supply nestlings with food or protection. Instead, they leave their eggs in nests of other species and... (Review)
Review
Obligate brood-parasitic birds never build nests, incubate eggs or supply nestlings with food or protection. Instead, they leave their eggs in nests of other species and rely on host parents to raise their offspring, which allows the parasite to continue reproducing throughout the breeding season. Although this may be a clever fitness strategy, it is loaded with a set of dynamic challenges for brood parasites, including recognizing individuals from their own species while growing up constantly surrounded by unrelated individuals, remembering the location of potential host nests for successful reproduction and learning the song of their species while spending time being entirely surrounded by another species during a critical developmental period, a predicament that has been likened to being 'raised by wolves'. Here, I will describe what we currently know about the neurobiology associated with the challenges of being a brood parasite and what is known about the proximate mechanisms of brood parasite evolution. The neuroethology of five behaviors (mostly social) in brood parasites is discussed, including: (1) parental care (or the lack thereof), (2) species recognition, (3) song learning, (4) spatial memory and (5) pair-bonding and mate choice. This Review highlights how studies of brood parasites can lend a unique perspective to enduring neuroethological questions and describes the ways in which studying brood-parasitic species enhances our understanding of ecologically relevant behaviors.
Topics: Animals; Birds; Host-Parasite Interactions; Nesting Behavior; Parasites; Reproduction
PubMed: 34486660
DOI: 10.1242/jeb.222307 -
Journal of Helminthology Feb 2023The evolution of helminth parasites has long been seen as an interplay between host resistance to infection and the parasite's capacity to bypass such resistance.... (Review)
Review
The evolution of helminth parasites has long been seen as an interplay between host resistance to infection and the parasite's capacity to bypass such resistance. However, there has recently been an increasing appreciation of the role of symbiotic microbes in the interaction of helminth parasites and their hosts. It is now clear that helminths have a different microbiome from the organisms they parasitize, and sometimes amid large variability, components of the microbiome are shared among different life stages or among populations of the parasite. Helminths have been shown to acquire microbes from their parent generations (vertical transmission) and from their surroundings (horizontal transmission). In this latter case, natural selection has been strongly linked to the fact that helminth-associated microbiota is not simply a random assemblage of the pool of microbes available from their organismal hosts or environments. Indeed, some helminth parasites and specific microbial taxa have evolved complex ecological relationships, ranging from obligate mutualism to reproductive manipulation of the helminth by associated microbes. However, our understanding is still very elementary regarding the net effect of all microbiome components in the eco-evolution of helminths and their interaction with hosts. In this non-exhaustible review, we focus on the bacterial microbiome associated with helminths (as opposed to the microbiome of their hosts) and highlight relevant concepts and key findings in bacterial transmission, ecological associations, and taxonomic and functional diversity of the bacteriome. We integrate the microbiome dimension in a discussion of the evolution of helminth parasites and identify fundamental knowledge gaps, finally suggesting research avenues for understanding the eco-evolutionary impacts of the microbiome in host-parasite interactions in light of new technological developments.
Topics: Animals; Helminths; Microbiota; Parasites; Host-Parasite Interactions; Symbiosis
PubMed: 36790127
DOI: 10.1017/S0022149X23000056 -
Evolution; International Journal of... Dec 2023Hyperparasites (species which parasitize other parasites) are common in natural populations, affecting many parasitic taxa, including: eukaryotic parasites; bacterial...
Hyperparasites (species which parasitize other parasites) are common in natural populations, affecting many parasitic taxa, including: eukaryotic parasites; bacterial and fungal pathogens. Hyperparasitism is therefore likely to shape the ecology and evolution of many host-parasite systems, representing a promising method for biocontrol (e.g., treating antimicrobial resistant infections). However, the eco-evolutionary consequences of hyperparasitism have received little attention. We use a host-parasite-hyperparasite model to explore how introducing a hyperparasite drives the evolution of parasite virulence, and what impact this has on the host population. We show when the introduction of a hyperparasite selects for higher or lower parasite virulence, and the changes in virulence experienced by the host population. Crucially, we show that variation in the direct effects of hyperparasites on virulence and transmission, and the probability of cotransmission, can lead to a previously unseen hysteresis effect, whereby small shifts in hyperparasite characteristics can lead to sudden shifts in parasite virulence. We also show that hyperparasites can induce diversification in parasite virulence, leading to the coexistence of high and low virulence strains. Our results show hyperparasites can have dramatic effects on the evolution of parasite virulence, and that the use of hyperparasites in biocontrol should be approached with caution.
Topics: Animals; Parasites; Virulence; Ecology; Biological Evolution; Host-Parasite Interactions
PubMed: 37778003
DOI: 10.1093/evolut/qpad178 -
Philosophical Transactions of the Royal... Nov 2021Species are shifting their distributions in response to climate change. This geographic reshuffling may result in novel co-occurrences among species, which could lead to...
Species are shifting their distributions in response to climate change. This geographic reshuffling may result in novel co-occurrences among species, which could lead to unseen biotic interactions, including the exchange of parasites between previously isolated hosts. Identifying potential new host-parasite interactions would improve forecasting of disease emergence and inform proactive disease surveillance. However, accurate predictions of future cross-species disease transmission have been hampered by the lack of a generalized approach and data availability. Here, we propose a framework to predict novel host-parasite interactions based on a combination of niche modelling of future host distributions and parasite sharing models. Using the North American ungulates as a proof of concept, we show this approach has high cross-validation accuracy in over 85% of modelled parasites and find that more than 34% of the host-parasite associations forecasted by our models have already been recorded in the literature. We discuss potential sources of uncertainty and bias that may affect our results and similar forecasting approaches, and propose pathways to generate increasingly accurate predictions. Our results indicate that forecasting parasite sharing in response to shifts in host geographic distributions allow for the identification of regions and taxa most susceptible to emergent pathogens under climate change. This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.
Topics: Animals; Artiodactyla; Climate Change; Forecasting; Host-Parasite Interactions; Models, Biological; North America; Parasitology; Perissodactyla
PubMed: 34538143
DOI: 10.1098/rstb.2020.0360 -
Parasitology Dec 2022The myxozoan was described from hatchery rainbow trout over 70 years ago. The parasite continues to cause severe disease in salmon and trout, and is recognized as a... (Review)
Review
The myxozoan was described from hatchery rainbow trout over 70 years ago. The parasite continues to cause severe disease in salmon and trout, and is recognized as a barrier to salmon recovery in some rivers. This review incorporates changes in our knowledge of the parasite's life cycle, taxonomy and biology and examines how this information has expanded our understanding of the interactions between and its salmonid and annelid hosts, and how overarching environmental factors affect this host–parasite system. Development of molecular diagnostic techniques has allowed discrimination of differences in parasite genotypes, which have differing host affinities, and enabled the measurement of the spatio-temporal abundance of these different genotypes. Establishment of the life cycle in the laboratory has enabled studies on host–parasite interactions and the availability of transcriptomic data has informed our understanding of parasite virulence factors and host defences. Together, these advances have informed the development of models and management actions to mitigate disease.
Topics: Animals; Parasites; Cnidaria; Parasitic Diseases, Animal; Fish Diseases; Myxozoa; Oncorhynchus mykiss
PubMed: 36081219
DOI: 10.1017/S0031182022001275 -
PLoS Pathogens Nov 2019The shape and number of mitochondria respond to the metabolic needs during the cell cycle of the eukaryotic cell. In the best-studied model systems of animals and fungi,... (Review)
Review
The shape and number of mitochondria respond to the metabolic needs during the cell cycle of the eukaryotic cell. In the best-studied model systems of animals and fungi, the cells contain many mitochondria, each carrying its own nucleoid. The organelles, however, mostly exist as a dynamic network, which undergoes constant cycles of division and fusion. These mitochondrial dynamics are driven by intricate protein machineries centered around dynamin-related proteins (DRPs). Here, we review recent advances on the dynamics of mitochondria and mitochondrion-related organelles (MROs) of parasitic protists. In contrast to animals and fungi, many parasitic protists from groups of Apicomplexa or Kinetoplastida carry only a single mitochondrion with a single nucleoid. In these groups, mitochondrial division is strictly coupled to the cell cycle, and the morphology of the organelle responds to the cell differentiation during the parasite life cycle. On the other hand, anaerobic parasitic protists such as Giardia, Entamoeba, and Trichomonas contain multiple MROs that have lost their organellar genomes. We discuss the function of DRPs, the occurrence of mitochondrial fusion, and mitophagy in the parasitic protists from the perspective of eukaryote evolution.
Topics: Animals; Mitochondrial Dynamics; Parasites; Parasitic Diseases
PubMed: 31751405
DOI: 10.1371/journal.ppat.1008008 -
Parasites & Vectors Sep 2023
Topics: Animals; Parasites; Artificial Intelligence; Parasitic Diseases
PubMed: 37770977
DOI: 10.1186/s13071-023-05972-1