-
BMC Ecology and Evolution Jun 202118S rRNA is a major component of the small subunit of the eukaryotic ribosome and an important phylogenetic marker for many groups, often to the point of being the only...
BACKGROUND
18S rRNA is a major component of the small subunit of the eukaryotic ribosome and an important phylogenetic marker for many groups, often to the point of being the only marker available for some. A core structure across eukaryotes exists for this molecule that can help to inform about its evolution in different groups. Using an alignment of 18S rDNA for Rotifera as traditionally recognized (=Bdelloidea, Monogononta, and Seisonacea, but not Acanthocephala), I fitted sequences for three exemplar species (Adineta vaga, Brachionus plicatilis, and Seison nebaliae, respectively) to the core structure and used these maps to reveal patterns of evolution for the remainder of this diverse group of microscopic animals.
RESULTS
The obtained variability maps of the 18S rRNA molecule revealed a pattern of high diversity among the three major rotifer clades coupled with strong conservation within each of bdelloids and monogononts. A majority of individual sites (ca. 60%) were constant even across rotifers as a whole with variable sites showing only intermediate rates of evolution. Although the three structural maps each showed good agreement with the inferred core structure for eukaryotic 18S rRNA and so were highly similar to one another at the secondary and tertiary levels, the overall pattern is of three highly distinct, but conserved motifs within the group at the primary sequence level. A novel finding was that of a variably expressed deletion at the 3' end of the V3 hypervariable region among some bdelloid species that occasionally extended into and included the pseudoknot structure following this region as well as the central "square" of the 18S rRNA molecule. Compared to other groups, levels of variation and rates of evolution for 18S rRNA in Rotifera roughly matched those for Gastropoda and Acanthocephala, despite increasing evidence for the latter being a clade within Rotifera.
CONCLUSIONS
The lack of comparative data for comparable groups makes interpretation of the results (i.e., very low variation within each of the three major rotifer clades, but high variation between them) and their potential novelty difficult. However, these findings in combination with the high morphological diversity within rotifers potentially help to explain why no clear consensus has been reached to date with regard to the phylogenetic relationships among the major groups.
Topics: Acanthocephala; Animals; Evolution, Molecular; Phylogeny; RNA, Ribosomal, 18S; Rotifera
PubMed: 34112085
DOI: 10.1186/s12862-021-01845-2 -
Journal of Helminthology Jan 2023Reptiles, as well as other vertebrate groups, harbour a significant diversity of parasitic organisms, from nematodes and other helminths to viruses and bacteria. The... (Review)
Review
Reptiles, as well as other vertebrate groups, harbour a significant diversity of parasitic organisms, from nematodes and other helminths to viruses and bacteria. The Northeast is one of the richest regions in Brazil in terms of the reptile diversity, number of species and endemism. Parasites are diverse organisms and knowledge about the parasitic fauna of vertebrates is an important factor in understanding the ecological relationships between hosts and the environment. Studies on the parasitic fauna of reptiles in South America have increased in the past few years. The present review is a compilation of 122 studies published from 1924 to 2021. We present information on 101 species of reptiles from five groups (amphisbaenians, crocodile, testudines, snakes and lizards) and 183 parasitic taxa belonging to four phyla: Nematoda; Arthropoda; Platyhelminthes; and Acanthocephala. Nematodes were the most frequently recorded species. Lizards and snakes had more records of parasitism and higher levels of parasite richness and diversity. Ceará was the state with most studies and recorded cases of parasite-host association. The Caatinga and Atlantic Forest were the most investigated environments. The objective of this review was to contribute knowledge on the parasitic biodiversity in reptiles from Northeast Brazil, which may help identify gaps in our knowledge and guide future studies.
Topics: Animals; Parasites; Brazil; Checklist; Nematoda; Lizards; Snakes
PubMed: 36637249
DOI: 10.1017/S0022149X22000785 -
Journal of Clinical Microbiology Oct 2021Acanthocephala is a phylum of parasitic pseudocoelomates that infect a wide range of vertebrate and invertebrate hosts and can cause zoonotic infections in humans. The... (Review)
Review
Acanthocephala is a phylum of parasitic pseudocoelomates that infect a wide range of vertebrate and invertebrate hosts and can cause zoonotic infections in humans. The zoologic literature is quite rich and diverse; however, the human-centric literature is sparse, with sporadic reports over the past 70 years. Causal agents of acanthocephaliasis in humans are reviewed as well as their biology and life cycle. This review provides the first consolidated and summarized report of human cases of acanthocephaliasis based on English language publications, including epidemiology, clinical presentation, treatment, and diagnosis and identification.
Topics: Acanthocephala; Animals; Helminthiasis; Host-Parasite Interactions; Humans; Intestinal Diseases, Parasitic; Parasites
PubMed: 34076470
DOI: 10.1128/JCM.02691-20 -
Journal of Helminthology Jan 2024Acanthocephalans constitute a small taxonomic group related to rotifers and specialized in a parasitic lifestyle. Anurans act as paratenic and definitive hosts and... (Review)
Review
Acanthocephalans constitute a small taxonomic group related to rotifers and specialized in a parasitic lifestyle. Anurans act as paratenic and definitive hosts and infections always occur trophically. Our objective is to describe and summarize the richness of acanthocephalans in Neotropical anurans. We conducted a literature review in the main research databases, compiling data published until August 2021. We identified 66 articles with records of acanthocephalan-anuran association, 53.03% were carried out in Brazil. We detected 108 species of anurans from 11 families parasitized by acanthocephalans. With the exception of Bufonidae, Hylidae and Leptodactylidae, which are relatively well-studied families, interaction with acanthocephalans remains largely unexplored for most anuran species. We found six families of acanthocephalans: Centrorhynchidae, Echinorhynchidae, Oligacanthorhynchidae, Cavisomidae, Neoechinorhynchidae and Plagiorhynchidae. Centrorhynchidae and Echinorhynchidae presented the largest number of taxa associated with anurans. The largest number of records corresponded to acanthocephalans in the larval stage (cystacanths), for which anurans act as paratenic hosts. We observed a lack of specific taxonomic resolution in the identifications of most reports, because a large part of the records in the larval stage make morphological identification difficult. Brazil, Mexico, Paraguay, Argentina, Ecuador and Peru are the countries with the most records, while Costa Rica, Venezuela, Colombia, Chile and Uruguay exhibited the lowest publication numbers, resulting in gaps in the distribution of acanthocephalans. We expanded the known number of anuran species parasitized by acanthocephalans, compared to the last published review. Overall, we aim to contribute to the understanding of diversity within this intriguing but understudied group.
Topics: Animals; Acanthocephala; Parasites; Anura; Bufonidae; Argentina; Larva
PubMed: 38263742
DOI: 10.1017/S0022149X23000986 -
Zootaxa May 2021Of 32 papers including Acanthocephala that were published in Zootaxa from 2001 to 2020, 5, by 11 authors from 5 countries, described 5 new species and redescribed 1...
Of 32 papers including Acanthocephala that were published in Zootaxa from 2001 to 2020, 5, by 11 authors from 5 countries, described 5 new species and redescribed 1 known species and 27 checklists from 11 countries and/geographical regions by 72 authors. A bibliographic analysis of these papers, the number of species reported in the checklists, and a list of new species are presented in this paper.
Topics: Acanthocephala; Animals; Anniversaries and Special Events; Periodicals as Topic
PubMed: 34187016
DOI: 10.11646/zootaxa.4979.1.7 -
Zootaxa Jan 2021The nemertean order Monostilifera consists of 594 species in 127 genera and is distributed worldwide. Within the Monostilifera, two suborders have been recognized,...
The nemertean order Monostilifera consists of 594 species in 127 genera and is distributed worldwide. Within the Monostilifera, two suborders have been recognized, Cratenemertea and Eumonostilifera. Within the latter, two, unranked clade names, Oerstediina and Amphiporina, were recently proposed without formal taxonomic definition. In this article, I give morphological circumscriptions and clade definitions for Cratenemertea, Eumonostilifera, Oerstediina, Plectonemertidae, Oerstediidae, and Amphiporina. Oerstediina and Amphiporina are placed on the Linnaean rank of infraorder. Constituent genera and species for each higher taxon are tabulated. The genus Amphiporella Friedrich, 1939 is herein replaced with Germanemertes nom. nov. to avoid homonymy with the Carboniferous fossil bryozoan genus Amphiporella Girty, 1910. Loxorrhochmidae Diesing, 1862 is declared a nomen oblitum relative to Tetrastemmatidae Hubrecht, 1897, a nomen protectum under Article 23.9 of the International Code of Zoological Nomenclature. There remain 308 species of eumonostiliferans whose infraorder affiliation is uncertain due to the lack of information on vascular morphology and molecular sequence data. The suborder affiliation of the two species Cinclidonemertes mooreae Crandall, 2010 and Verrillianemertes schultzei Senz, 2001 is left uncertain.
Topics: Acanthocephala; Animals; Bryozoa; Fossils; Phylogeny
PubMed: 33756663
DOI: 10.11646/zootaxa.4920.2.1 -
Revista Brasileira de Parasitologia... 2020This study evaluated the parasitic fauna of hybrids tambacu (Colossoma macropomum × Piaractus mesopotamicus) and patinga (P. mesopotamicus × Piaractus brachypomus) and...
This study evaluated the parasitic fauna of hybrids tambacu (Colossoma macropomum × Piaractus mesopotamicus) and patinga (P. mesopotamicus × Piaractus brachypomus) and their host-parasite-environment interaction during the warm and cold seasons in two fish farms located in the State of Mato Grosso do Sul, Brazil, South America. A total of 120 fish, being 60 fish for species (30 in the warm season and 30 in the cold season) were examined. Water quality was measured weekly to evaluate the interaction between environmental conditions and parasitism. Fifteen species of parasites were found: Ichthyophthirius multifiliis, Chilodonella hexasticha e Trichodina sp. (Protozoa), Henneguya piaractus, Myxobolus colossomatis and Myxobolus cuneus (Myxozoa); Anacanthorus penilabiatus, Mymarothecium boegeri, Mymarothecium viatorum, and Notozothecium janauachensis (Monogenoidea), Goezia spinulosa and Goezia sp. (Nematoda), Echinorhynchus jucundus (Acanthocephala), and Dolops carvalhoi, Lernaea cyprinacea (Crustacea). The ciliate protozoan I. multifiliis and monogenoids were the most prevalent parasites in the cold and warm seasons for both hybrids in the different culture systems intensive production and sportive fishing. It was observed that the serrasalmid hybrids are more susceptible to parasites and harbor high diversity of parasites in relation to the parental species C. macropomum, P. mesopotamicus and P. brachypomus, with a predominance of ectoparasites.
Topics: Animals; Aquaculture; Brazil; Characiformes; Fish Diseases; Parasites
PubMed: 33084783
DOI: 10.1590/S1984-29612020084 -
Parasitology Dec 2022Most individual fish in wild and farmed populations can be infected with parasites. Fish intestines can harbour protozoans, myxozoans and helminths, which include... (Review)
Review
Most individual fish in wild and farmed populations can be infected with parasites. Fish intestines can harbour protozoans, myxozoans and helminths, which include several species of digeneans, cestodes, nematodes and acanthocephalans. Enteric parasites often induce inflammation of the intestine; the pathogen provokes changes in the host physiology, which will be genetically selected for if they benefit the parasite. The host response to intestinal parasites involves neural, endocrine and immune systems and interaction among these systems is coordinated by hormones, chemokines, cytokines and neurotransmitters including peptides. Intestinal fish parasites have effects on the components of the enteric nervous and endocrine systems; mechanical/chemical changes impair the activity of these systems, including gut motility and digestion. Investigations on the role of the neuroendocrine system in response to fish intestinal parasites are very few. This paper provides immunohistochemical and ultrastructural data on effects of parasites on the enteric nervous system and the enteric endocrine system in several fish–parasite systems. Emphasis is on the occurrence of 21 molecules including cholecystokinin-8, neuropeptide Y, enkephalins, galanin, vasoactive intestinal peptide and serotonin in infected tissues.
Topics: Animals; Parasites; Fish Diseases; Acanthocephala; Fishes; Intestinal Diseases, Parasitic; Neurosecretory Systems
PubMed: 36076315
DOI: 10.1017/S0031182022001160 -
Parasitology Apr 2021Identifying the factors that structure host–parasite interactions is fundamental to understand the drivers of species distributions and to predict novel cross-species...
Identifying the factors that structure host–parasite interactions is fundamental to understand the drivers of species distributions and to predict novel cross-species transmission events. More phylogenetically related host species tend to have more similar parasite associations, but parasite specificity may vary as a function of transmission mode, parasite taxonomy or life history. Accordingly, analyses that attempt to infer host−parasite associations using combined data on different parasite groups may perform quite differently relative to analyses on each parasite subset. In essence, are more data always better when predicting host−parasite associations, or does parasite taxonomic resolution matter? Here, we explore how taxonomic resolution affects predictive models of host−parasite associations using the London Natural History Museum's database of host–helminth interactions. Using boosted regression trees, we demonstrate that taxon-specific models (i.e. of Acanthocephalans, Nematodes and Platyhelminthes) consistently outperform full models in predicting mammal-helminth associations. At finer spatial resolutions, full and taxon-specific model performance does not vary, suggesting tradeoffs between phylogenetic and spatial scales of analysis. Although all models identify similar host and parasite covariates as important to such patterns, our results emphasize the importance of phylogenetic scale in the study of host–parasite interactions and suggest that using taxonomic subsets of data may improve predictions of parasite distributions and cross-species transmission. Predictive models of host–pathogen interactions should thus attempt to encompass the spatial resolution and phylogenetic scale desired for inference and prediction and potentially use model averaging or ensemble models to combine predictions from separately trained models.
Topics: Acanthocephala; Animals; Host-Parasite Interactions; Mammals; Models, Biological; Nematoda; Phylogeny; Platyhelminths; Spatial Analysis
PubMed: 33342442
DOI: 10.1017/S0031182020002371 -
Infectious Disorders Drug Targets 2020Swine species are an important source of meat production worldwide, except in Islamic countries where pig breeding and pork consumption are forbidden. Hence, they are... (Review)
Review
BACKGROUND
Swine species are an important source of meat production worldwide, except in Islamic countries where pig breeding and pork consumption are forbidden. Hence, they are often neglected in these regions. A considerable number of wild boars (Sus scrofa) inhabit Iranian territories, particularly in dense forests of north, west and southwest of the country, but our knowledge regarding their parasites is very limited.
OBJECTIVE
The lack of a comprehensive record in this connection encouraged us to review the whole works of literature in the country.
METHODS
The current review presents all the information about the parasitic diseases of wild boar in Iran extracted from articles available in both Persian and English databases until June 2017.
RESULTS
So far, 8 genera of protozoa (Toxoplasma, Balanthidium, Tritrichomonas, Blastocystis, Entamoeba, Iodamoeba, Chilomastix and Sarcocystis) and 20 helminth species, including four cestode species, two trematode species, thirteen nematode species as well as a single species of Acanthocephala have been described in Iranian wild boars.
CONCLUSION
This review sheds light on the veterinary and public health aspects of the parasitic diseases of wild boars in the country and alerts authorities for future preventive measures.
Topics: Alveolata; Amoebozoa; Animals; Helminthiasis, Animal; Helminths; Iran; Protozoan Infections, Animal; Sus scrofa; Swine; Swine Diseases
PubMed: 31322074
DOI: 10.2174/1871526519666190716121824