Haemogregarines from western Palaearctic freshwater turtles (generaEmys, Mauremys) are conspecific withHaemogregarina stepanowiDanilewsky, 1885

SUMMARYThe majority ofHaemogregarinaspecies have been based on the morphology of their erythrocytic stages and supposed strict host specificity. The quantity of species with a limited number of overlapping diagnostic traits has led to a considerable mess in haemogregarine taxonomy and significant synonymy. We analysed host specificity, intra- and interspecific variability, evolutionary relationships, and the distribution of the type species of the genusHaemogregarina–H. stepanowi.The morphology of blood stages and 18S rDNA sequences of this haemogregarine from four western Palaearctic hard-shelled freshwater turtles (Emys orbicularis, Mauremys caspica, Mauremys leprosaandMauremys rivulata) were compared withHaemogregarina balli. Additional sequences of 18S rDNA ofHaemogregarina-like isolates collected from three species of African hinged terrapins (genusPelusios) were used to enlarge the dataset for phylogenetic analyses. Thirteen sequences (1085 bp) ofHaemogregarinarepresenting all four western Palaearctic turtle species were identical, corresponding toH. stepanowi, which is closely related to the Nearctic speciesH. balli. In our analyses,Haemogregarinaspp. constituted a monophyletic clade sister to the genusHepatozoon. Haemogregarina stepanowipossesses a wide distribution range from the Maghreb, through Europe, Turkey and the Middle East to Iran. We consider that the genusHaemogregarinahas a low host specificity crossing the family level of its vertebrate hosts and that its distribution is likely to be linked to the vector and definitive host – the leech.

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Sarcocystis Attenuati N. Sp. (Apicomplexa: Sarcocystidae) Infecting the Asian Gray Shrew, Crocidura Attenuata (Insectivora: Soricidae), in China

10.21203/rs.3.rs-907878/v1 ◽

2021 ◽

Author(s):

junjie hu ◽

Jun Sun ◽

Yanmei Guo ◽

Hongxia Zeng ◽

Yunzhi Zhang ◽

...

Keyword(s):

Host Specificity ◽

Definitive Host ◽

18S Rdna ◽

Common Species ◽

Molecular Characteristics ◽

Intermediate Hosts ◽

Parasite Life Cycle ◽

Rdna Sequences ◽

Transmission Electron ◽

18S Rdna Sequences

Abstract Background: There are limited data on Sarcocystis in insectivores. The Asian gray shrew, Crocidura attenuata, is one of the most common species of insectivores in the family Soricidae distributed in South Asia and Southeast Asia. To date, Sarcocystis has never been recorded in this host.Methods: Tissues from 42 Asian gray shrews were collected in China in 2017 and 2018. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). To complete the parasite life cycle, muscle tissues of the host infected with sarcocysts were force-fed to two beauty rat snakes, Elaphe taeniura. Individual sarcocysts from different Asian gray shrews and oocysts/sporocysts isolated from the small intestines and feces of the experimental snakes were selected for DNA extraction, and seven genetic markers, including two nuclear loci (18S rDNA and ITS1), three mitochondrial genes (cox1, cox3 and cytb), and two apicoplastic genes (rpoB and clpC), were amplified, sequenced and analyzed.Results: Sarcocysts were found in 17 of 42 (40.5%) Asian gray shrews. Under LM, the microscopic sarcocysts were exhibited saw-tooth-like protrusions measuring 3.3–4.5 μm. Ultrastructurally, the sarcocyst wall contained numerous lancet- or leaf-like villous protrusions, similar to type 9h. The experimental beauty rat snakes shed oocysts/sporcysts measuring 11.9–16.7 × 9.2–10.6 μm with a prepatent period of 10 to 11 days. Comparing these sequences with those previously deposited in GenBank revealed that the 18S rDNA sequences and cox1 sequences shared the highest similarity with those of S. scandentiborneensis recorded in tree shrews, Tuaia minor and T. tana (i.e., 97.6–98.3% and 100% identity, respectively). Phylogenetic analysis based on 18S rDNA, ITS1 or cox1 sequences revealed that this parasite formed an independent clade with Sarcocystis spp. that utilize small animals as intermediate hosts and snakes as the known or presumed definitive host. On the basis of morphological and molecular characteristics and host specificity, the parasite was proposed as a new species, named S. attenuati.Conclusions: Sarcocysts were recorded in Asian gray shrews for the first time. The sarcocysts were characterized morphologically and molecularly. The 18S rDNA and cox1 sequences of S. attenuati, named in the present study, shared the highest identities with those of S. scandentiborneensis. However, the sarcocysts of the two species of Sarcocystis were quite different under LM and TEM. Based on experimental infection, beauty rat snakes have been proven to be a definitive host of S. attenuati. As more species of Sarcocystis from insectivores and other small mammals are properly morphologically and molecularly characterized, we may gain a better understanding of the biodiversity, host specificity and evolution of Sarcocystis in the future.

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Unexplored diversity of microscopic myxomycetes: evidence from environmental DNA

Plant Ecology and Evolution ◽

10.5091/plecevo.2019.1621 ◽

2019 ◽

Vol 152 (3) ◽

pp. 499-506 ◽

Cited By ~ 2

Author(s):

Oleg N. Shchepin ◽

Martin Schnittler ◽

Nikki H.A. Dagamac ◽

Dmitry V. Leontyev ◽

Yuri K. Novozhilov

Keyword(s):

New Species ◽

18S Rdna ◽

Sequence Similarity ◽

Phylogenetic Analyses ◽

Environmental Dna ◽

Full Length ◽

Detection Techniques ◽

Rdna Sequences ◽

18S Rdna Sequences ◽

Environmental Sequences

Background and aims – Recent studies showed the position of two slime mould species with microscopic sporocarps, Echinosteliopsis oligospora and Echinostelium bisporum, within the class Myxomycetes. These minute species are seldom seen in studies based on detection of sporocarps and can easily be confused with protosteloid amoebozoans.Methods – We searched all published ePCR data sets that targeted myxomycete 18S rDNA for the presence of environmental sequences similar to E. oligospora and Echinosteliales in traditional circumscription, and performed phylogenetic analyses that included short environmental sequences and full-length 18S rDNA sequences representing all the major groups of myxomycetes.Key results – We report 19 unique sequences which are closely related to E. bisporum or E. oligospora based on sequence similarity (73.1–95.2% similarity) and which form well-supported monophyletic clades with these species in phylogenetic analyses. They may represent new species that are not yet described. Our phylogeny based on full-length 18S rDNA sequences further confirms the position of E. bisporum and E. oligospora within myxomycetes and the paraphyly of the order Echinosteliales in its traditional circumscription.Conclusions – Our results show that ePCR-based studies can reveal myxomycete taxa that often escape detection by traditional approaches, including potentially new species, and thus provide valuable new data on diversity and ecology of myxomycetes. As such, strategies for studying myxomycetes biodiversity should be revised, focusing also on molecular detection techniques in addition to the sporocarp-based ones.

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Molecular data implicate bryozoans as hosts for PKX (Phylum Myxozoa) and identify a clade of bryozoan parasites within the Myxozoa

Parasitology ◽

10.1017/s003118209900520x ◽

1999 ◽

Vol 119 (6) ◽

pp. 555-561 ◽

Cited By ~ 60

Author(s):

C. L. ANDERSON ◽

E. U. CANNING ◽

B. OKAMURA

Keyword(s):

18S Rdna ◽

Phylogenetic Analyses ◽

Molecular Data ◽

Salmonid Fish ◽

Abnormal Immune Response ◽

Rdna Sequences ◽

Pectinatella Magnifica ◽

18S Rdna Sequences ◽

Cristatella Mucedo ◽

Distinct Taxon

Proliferative kidney disease (PKD), a condition associated with high mortality in salmonid fish, represents an abnormal immune response to the presence of an enigmatic myxozoan, which has been designated simply as PKX organism because its generic and specific status are obscure. Phylogenetic analyses of partial sequences of the 18S rDNA of PKX and of myxozoan parasites infecting the bryozoans Cristatella mucedo, Pectinatella magnifica and Plumatella rugosa, including the previously named Tetracapsula bryozoides from C. mucedo, showed that these taxa represent a distinct clade that diverged early in the evolution of the Myxozoa before the radiation of the other known myxozoan genera. A common feature of the myxozoans in this clade may be the electron-dense sporoplasmosomes with a lucent bar-like structure, which occur in T. bryozoides and PKX but not in the myxozoans belonging to the established orders Bivalvulida and Multivalvulida. Variation of 0·5–1·1% was found among the PKX 18S rDNA sequences obtained from fish from North America and Europe. The 18S rDNA sequence for T. bryozoides showed that it is a distinct taxon, not closely related to PKX but some sequences from myxozoans infecting 2 of the bryozoan species were so similar to those of PKX as to be indistinguishable. Other sequences from the new myxozoans in bryozoans at first appeared distinct from PKX in a maximum likelihood tree but, when analysed further, were also found to be phylogenetically indistinguishable from PKX. We propose that at least some variants of these new myxozoans from bryozoans are able to infect and multiply in salmonid fish, in which they stimulate the immune reaction and cause PKD but are unable to form mature spores to complete their development.

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Molecular Evidence for the Wide Distribution of Two Lineages of Terrestrial Green Algae (Chlorophyta) over Tropics to Temperate Zone

ISRN Ecology ◽

10.5402/2012/795924 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 7

Author(s):

Ladislav Hodač ◽

Christine Hallmann ◽

Helen Rosenkranz ◽

Fabian Faßhauer ◽

Thomas Friedl

Keyword(s):

Phylogenetic Analyses ◽

Wide Distribution ◽

Tree Bark ◽

Close Relative ◽

Molecular Evidence ◽

European Origin ◽

Rdna Sequences ◽

Green Algal ◽

18S Rdna Sequences ◽

A New Species

Phylogenetic analyses of 18S rDNA sequences from environmental clones and culture strains revealed a widespread distribution of two subaerial green algal lineages, Jenufa and Xylochloris, recently described from rainforests in southeast Asia. A new lineage of Jenufa (Chlorophyceae), most closely related to or even conspecific with J. minuta, was formed by sequences of European origin. Two more lineages of Jenufa were formed by three additional sequences from Ecuador and Panama. The other lineage was a close relative of Xylochloris irregularis (Trebouxiophyceae), probably representing a new species of the genus and distinct from the only so far described species, X. irregularis. It comprised two distinct clades each containing almost identical sequences from Germany and Ecuador. Analyses of the new sequences for both genera allowed to presume a preference of J. minuta to subaerial growth on rock or artificial hard substrates combined with a remarkable adaptation to extended periods of darkness, whereas Xylochloris may preferably occur on tree bark or in the soil.

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Phylogenetic analyses of the polycystine Radiolaria based on the 18s rDNA sequences of the Spumellarida and the Nassellarida

European Journal of Protistology ◽

10.1016/j.ejop.2005.06.001 ◽

2005 ◽

Vol 41 (4) ◽

pp. 287-298 ◽

Cited By ~ 21

Author(s):

Tomoko Yuasa ◽

Osamu Takahashi ◽

Daisuke Honda ◽

Shigeki Mayama

Keyword(s):

18S Rdna ◽

Phylogenetic Analyses ◽

Rdna Sequences ◽

18S Rdna Sequences

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Molecular phylogenetic analyses of tissue coccidia (sarcocystidae; apicomplexa) based on nuclear 18s RDNA and mitochondrial COI sequences confirms the paraphyly of the genus Hammondia

Parasitology Open ◽

10.1017/pao.2015.7 ◽

2016 ◽

Vol 2 ◽

Cited By ~ 10

Author(s):

MOSUN E. OGEDENGBE ◽

JOSEPH D. OGEDENGBE ◽

JULIA C. WHALE ◽

KRISTIN ELLIOT ◽

MARCO A. JUÁREZ-ESTRADA ◽

...

Keyword(s):

18S Rdna ◽

Neospora Caninum ◽

Phylogenetic Analyses ◽

Mitochondrial Coi ◽

Rdna Sequences ◽

Molecular Phylogenetic ◽

18S Rdna Sequences ◽

Phylogenetic Hypotheses ◽

Coi Sequences ◽

Sarcocystis Rileyi

SUMMARYPartial mitochondrial cytochromecoxidase subunit I (mt COI) sequences were generated from:Toxoplasma gondii(strains CTG, GTI, MAS, ME49, PTG, TgCatBr5, TgCat, Br64, TgCgCal, TgToucan);Neospora caninum(Strain NC1);Hammondia hammondi(Strain H.H–20);H. heydorni; H. cf.triffittae; Cystoisospora felis; C. suis; C. canis; C. rivolta; C. cf.ohioensis; Caryospora bigenetica; Sarcocystis rileyi; andS. neurona. Nuclear 18S rDNA sequences were generated forH. heydorni, H. hammondi, C. suis, C. canis, C. felis, C. rivolta, C. cf.ohioensis, S. neurona, andS. rileyi. Aligned, concatenated 18S rDNA and COI sequences were Bayesian analysed using partitioned nucleotide substitution models [HKY + I + G for 18S; GTR + I + G codon (code = metmt) for COI]. Phylogenetic hypotheses supported a monophyletic Sarcocystidae and its subfamilie with two major clades within the Toxoplasmatinae: (1) a monophyletic clade ofCystoisosporaspp. withNephroisospora eptesici; and (2) a clade ofToxoplasma, NeosporaandHammondia. Within the latter,Hammondiawas shown to be paraphyletic;H. heydorniandH. triffittaewere monophyletic withN. caninum[canine definitive hosts (DHs)], whereasH. hammondiwas monophyletic withT. gondii(feline DHs). A new genus is erected to resolve the paraphyly of the genusHammondiaconfirmed using mt COI and combined 18S/COI sequence datasets.

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