The myxozoans and modulate rainbow trout immune responses: quantitative shotgun proteomics at the portals of entry after single and co-infections.

Introduction: Little is known about the proteomic changes at the portals of entry in rainbow trout after infection with the myxozoan parasites, , and . Whirling disease (WD) is a severe disease of salmonids, caused by the myxosporean , while, proliferative kidney disease (PKD) is caused by , which instead belongs to the class Malacosporea. Climate change is providing more suitable conditions for myxozoan parasites lifecycle, posing a high risk to salmonid aquaculture and contributing to the decline of wild trout populations in North America and Europe.

Evolution of myxozoan mitochondrial genomes: insights from myxobolids.

Background: Myxozoa is a class of cnidarian parasites that encompasses over 2,400 species. Phylogenetic relationships among myxozoans remain highly debated, owing to both a lack of informative morphological characters and a shortage of molecular markers. Mitochondrial (mt) genomes are a common marker in phylogeny and biogeography.

Morphological and genetic analysis of Zhao . 2015 and sp. nov. (Myxozoa: Ceratomyxidae) from the East China Sea.

We describe Zhao . 2015 and sp. nov.

Identification of induced antigens of the malacosporean parasite (Cnidaria) using induced antigen technology.

is a malacosporean endoparasite that causes proliferative kidney disease (PKD) in wild and farmed salmonids in Europe and North America. The life cycle of completes between invertebrate bryozoan and vertebrate fish hosts. Inside the fish, virulence factors of are induced during infection or interactions with host cells.

: a cnidarian parasite of annelids and salmonids.

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.

Using a mechanistic framework to model the density of an aquatic parasite .

is a myxozoan parasite endemic to the Pacific Northwest of North America that is linked to low survival rates of juvenile salmonids in some watersheds such as the Klamath River basin. The density of actinospores in the water column is typically highest in the spring (March-June), and directly influences infection rates for outmigrating juvenile salmonids. Current management approaches require quantities of density to assess disease risk and estimate survival of juvenile salmonids.

A myxozoan genome reveals mosaic evolution in a parasitic cnidarian.

Background: Parasite evolution has been conceptualized as a process of genetic loss and simplification. Contrary to this model, there is evidence of expansion and conservation of gene families related to essential functions of parasitism in some parasite genomes, reminiscent of widespread mosaic evolution-where subregions of a genome have different rates of evolutionary change. We found evidence of mosaic genome evolution in the cnidarian Myxobolus honghuensis, a myxozoan parasite of fish, with extremely simple morphology.

Proteases as Therapeutic Targets Against the Parasitic Cnidarian : Characterization of Molecules Key to Parasite Virulence In Salmonid Hosts.

Proteases and their inhibitors play critical roles in host-parasite interactions and in the outcomes of infections. is a myxozoan pathogen that causes enteronecrosis in economically important salmonids from the Pacific Northwest of North America. This cnidarian parasite has host-specific genotypes with varying virulence, making it a powerful system to decipher virulence mechanisms in myxozoans.

The cnidarian parasite utilizes inherited and recruited venom-like compounds during infection.

Background: Cnidarians are the most ancient venomous organisms. They store a cocktail of venom proteins inside unique stinging organelles called nematocysts. When a cnidarian encounters chemical and physical cues from a potential threat or prey animal, the nematocyst is triggered and fires a harpoon-like tubule to penetrate and inject venom into the prey.

To React or Not to React: The Dilemma of Fish Immune Systems Facing Myxozoan Infections.

Myxozoans are microscopic, metazoan, obligate parasites, belonging to the phylum Cnidaria. In contrast to the free-living lifestyle of most members of this taxon, myxozoans have complex life cycles alternating between vertebrate and invertebrate hosts. Vertebrate hosts are primarily fish, although they are also reported from amphibians, reptiles, trematodes, mollusks, birds and mammals.

Intestinal Transcriptomic and Histologic Profiling Reveals Tissue Repair Mechanisms Underlying Resistance to the Parasite .

Background: Myxozoan parasites infect fish worldwide causing significant disease or death in many economically important fish species, including rainbow trout and steelhead trout (). The myxozoan is a parasite of salmon and trout that causes ceratomyxosis, a disease characterized by severe inflammation in the intestine resulting in hemorrhaging and necrosis. Populations of that are genetically fixed for resistance or susceptibility to ceratomyxosis exist naturally, offering a tractable system for studying the immune response to myxozoans.

Data of de novo transcriptome assembly of the myxozoan parasite .

a myxozoan endoparasite, causes proliferative kidney disease in salmonids. The life cycle of occurs between invertebrate bryozoan and vertebrate fish hosts. develops in the body cavity of colonial bryozoan and spores are released from mature spore sacs into the water likely through the vestibular pore and infect fish by attaching to their gills.

A tale of two fish: Comparative transcriptomics of resistant and susceptible steelhead following exposure to Ceratonova shasta highlights differences in parasite recognition.

Diseases caused by myxozoan parasites represent a significant threat to the health of salmonids in both the wild and aquaculture setting, and there are no effective therapeutants for their control. The myxozoan Ceratonova shasta is an intestinal parasite of salmonids that causes severe enteronecrosis and mortality. Most fish populations appear genetically fixed as resistant or susceptible to the parasite, offering an attractive model system for studying the immune response to myxozoans.

Myxobolus cerebralis Causes Presporogonic Mortality in Juvenile Mountain Whitefish.

Recent range expansions of whirling disease impelled us to understand the impacts of its causative agent, the myxozoan parasite Myxobolus cerebralis, on lesser-studied fish hosts. Mountain Whitefish Prosopium williamsoni overlap broadly with M. cerebralis across the western United States and Canada, and populations have experienced widespread declines since the 1990s.

Evolutionary Analysis of Cystatins of Early-Emerging Metazoans Reveals a Novel Subtype in Parasitic Cnidarians.

The evolutionary aspects of cystatins are greatly underexplored in early-emerging metazoans. Thus, we surveyed the gene organization, protein architecture, and phylogeny of cystatin homologues mined from 110 genomes and the transcriptomes of 58 basal metazoan species, encompassing free-living and parasite taxa of Porifera, Placozoa, Cnidaria (including Myxozoa), and Ctenophora. We found that the cystatin gene repertoire significantly differs among phyla, with stefins present in most of the investigated lineages but with type 2 cystatins missing in several basal metazoan groups.

Myxosporea (Myxozoa, Cnidaria) Lack DNA Cytosine Methylation.

DNA cytosine methylation is central to many biological processes, including regulation of gene expression, cellular differentiation, and development. This DNA modification is conserved across animals, having been found in representatives of sponges, ctenophores, cnidarians, and bilaterians, and with very few known instances of secondary loss in animals. Myxozoans are a group of microscopic, obligate endoparasitic cnidarians that have lost many genes over the course of their evolution from free-living ancestors.

Transcriptome Analysis Elucidates the Key Responses of Bryozoan during the Development of (Myxozoa).

Bryozoans are sessile, filter-feeding, and colony-building invertebrate organisms. is a well known primary host of the myxozoan parasite . There have been no attempts to identify the cellular responses induced in during the development.

A comparison of the structure and function of nematocysts in free-living and parasitic cnidarians (Myxozoa).

Myxozoans are obligate parasites that have complex life cycles requiring alternate vertebrate and invertebrate hosts, with transmission via microscopic waterborne spores. Unusually for parasites, they belong to the phylum Cnidaria, alongside thousands of free-living corals, sea anemones, jellyfish and hydrozoans. Their cnidarian affinity is affirmed by genetic relatedness and the presence of nematocysts, historically called "polar capsules" in myxozoan research.

and assays reveal that cations affect nematocyst discharge in (Cnidaria: Myxozoa).

Myxozoans are parasitic, microscopic cnidarians that have retained the phylum-characteristic stinging capsules called nematocysts. Free-living cnidarians, like jellyfish and corals, utilize nematocysts for feeding and defence, with discharge powered by osmotic energy. Myxozoans use nematocysts to anchor to their fish hosts in the first step of infection, however, the discharge mechanism is poorly understood.

Transcriptome-Wide Comparisons and Virulence Gene Polymorphisms of Host-Associated Genotypes of the Cnidarian Parasite Ceratonova shasta in Salmonids.

Ceratonova shasta is an important myxozoan pathogen affecting the health of salmonid fishes in the Pacific Northwest of North America. Ceratonova shasta exists as a complex of host-specific genotypes, some with low to moderate virulence, and one that causes a profound, lethal infection in susceptible hosts. High throughput sequencing methods are powerful tools for discovering the genetic basis of these host/virulence differences, but deep sequencing of myxozoans has been challenging due to extremely fast molecular evolution of this group, yielding strongly divergent sequences that are difficult to identify, and unavoidable host contamination.

First transcriptome analysis of bryozoan , the primary host of myxozoan parasite .

Bryozoans are aquatic invertebrate moss animals that are found worldwide. is a freshwater bryozoan and is the most common primary host of myxozoan parasite, . However, limited genomic resources are available for this bryozoan, which hampers investigations into the molecular mechanisms of host-parasite interactions.

The invertebrate host of salmonid fish parasites Ceratonova shasta and Parvicapsula minibicornis (Cnidaria: Myxozoa), is a novel fabriciid annelid, Manayunkia occidentalis sp. nov. (Sabellida: Fabriciidae).

Myxosporea (Cnidaria: Myxozoa) are common fish parasites with complex life cycles that involve annelid hosts. Two economically important salmonid-infecting myxosporeans from rivers of the northwestern United States, Ceratonova shasta (Noble, 1950) and Parvicapsula minibicornis Kent et al., 1997, have life cycles that require a freshwater annelid host, identified previously as Manayunkia speciosa Leidy, 1859.

Development and application of a qPCR assay targeting Ichthyophthirius multifiliis in environmental water samples.

Ichthyophthirius multifiliis (Ich) is a globally distributed, freshwater parasitic ciliate that infects wild and cultured fishes. It has a direct, temperature-dependent life cycle that enables rapid multiplication when hosts are plentiful and environmental conditions are favorable. Accurate detection is central to the control of Ich infections and prevention of host mortality, particularly in wild systems where chemical treatments are not feasible.

A cnidarian parasite of salmon (Myxozoa: ) lacks a mitochondrial genome.

Although aerobic respiration is a hallmark of eukaryotes, a few unicellular lineages, growing in hypoxic environments, have secondarily lost this ability. In the absence of oxygen, the mitochondria of these organisms have lost all or parts of their genomes and evolved into mitochondria-related organelles (MROs). There has been debate regarding the presence of MROs in animals.

Validation of environmental DNA sampling for determination of Ceratonova shasta (Cnidaria: Myxozoa) distribution in Plumas National Forest, CA.

Ceratonova shasta is the etiological agent of myxozoan-associated enteronecrosis in North American salmonids. The parasite's life cycle involves waterborne spores and requires both a salmonid fish and a freshwater fabriciid annelid. The success and survival of annelids can be enhanced by flow moderation by dams, and through the erosion of fine sediments into stream channels following wildfires.