Search

Start Over Creator Dvořáková, Helena

2. Didymium-like myxogastrids (class Mycetozoa) as endocommensals of sea urchins (Sphaerechinus granularis)

Creator:
Dyková, Iva, Lom, Jiří, Dvořáková, Helena, Pecková, Hana, and Fiala, Ivan
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Didymium-like myxogastrids, Myxogastrea, sea-urchin amoeba strains, SSU rDNA, flagellar apparatus, and phylogeny
Language:
English
Description:
This paper sums up the results of light microscopical, ultrastructural and molecular studies of five strains of amoeboid organisms isolated as endocommensals from coelomic fluid of sea urchins, Sphaerechinus granularis (Lamarck), collected in the Adriatic Sea. The organisms are reported as Didymium-like myxogastrids. Of the life-cycle stages, the attached amoeboids, flagellated trophozoites, cysts and biflagellated swarmers are described. Formation of fruiting bodies was not observed. Although phylogenetic analyses of SSU rDNA sequences indicated a close relationship with Hyperamoeba dachnaya, our sea-urchin strains have not been assigned to the genus Hyperamoeba Alexeieff, 1923. The presence of either one or two flagella reported in phylogenetically closely related organisms and mutually distant phylogenetic positions of strains declared as representatives of the genus Hyperamoeba justify our approach. Data obtained in this study may be useful in future analyses of relationships of the genera Didymium, Hyperamoeba, Physarum and Pseudodidymium as well as in higher-order phylogeny of Myxogastrea.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Fish-isolated Naegleria strains and their phylogeny inferred from ITS and SSU rDNA sequences

Creator:
Dyková, Iva, Pecková, Hana, Fiala, Ivan, and Dvořáková, Helena
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Naegleria, fish-isolated strains, SSU rDNA, ITS, phylogeny, and taxonomy
Language:
English
Description:
Effort was made to identify Naegleria strains isolated from organs of fish, using phylogenetic analyses of SSU rDNA and ITS sequences. Eighteen fish-isolated strains studied enlarged substantially the so far available set of Naegleria strains characterized by both molecular markers. The phylogenetic analyses of separate and concatenated SSU rDNA and ITS sequences revealed phylogenetic relationships of strains under study; however, they failed to solve classification of fish-isolated strains into species. The sequence similarity of strain-representatives of Naegleria species as well as data obtained on intragenomic variation of ITS sequences discouraged the authors from the definition of new species. The results of the present study provide evidence of a need to re-evaluate the current practice of setting boundaries between species of the genus Naegleria. Sequences obtained in this study have been deposited in GenBank with accession numbers DQ768714-DQ768743.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Fish-isolated strains of Hartmannella vermiformis Page, 1967: morphology, phylogeny and molecular diagnosis of the species in tissue lesions

Creator:
Dyková, Iva, Pindová, Zuzana, Fiala, Ivan, Dvořáková, Helena, and Macháčková, Blanka
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
amphizoic amoebae, Hartmannella vermiformis, morphology, phylogeny, and in situ hybridisation
Language:
English
Description:
Based on morphological and molecular characterisation, four amoeba strains isolated from organs of freshwater fish were identified as Hartmannella vermiformis Page, 1967. Small subunit rRNA gene sequences of these strains expand the set of corresponding complete and almost complete sequences of this species to twelve. A new species-specific oligonucleotide probe inferred from recently available SSU rRNA gene sequences was designed and successfully tested in tissue lesions produced by one strain of H. vermiformis in experimentally infected fish.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Phylogeny of Flabellulidae (Amoebozoa: Leptomyxida) inferred from SSU rDNA sequences of the type strain of Flabellula citata Schaeffer, 1926 and newly isolated strains of marine amoebae

Creator:
Dyková, Iva, Fiala, Ivan, Pecková, Hana, and Dvořáková, Helena
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Amoebozoa, Leptomyxida, Flabellulidae, Flabellula citata, and SSU rDNA phylogeny
Language:
English
Description:
New strains of non-vannellid flattened amoebae isolated from fish, an invertebrate and the marine environment were studied together with Flabellula citata Schaeffer, 1926 selected by morphology as a reference strain. The study revealed a paucity of features distinguishing individual strains at the generic level, but clearly evidenced mutual phylogenetic relationships within the assemblage of strains as well as their affiliation to the Leptomyxida. In this study, the SSU rDNA dataset of leptomyxids was expanded and a new branching pattern was presented within this lineage of Amoebozoa. Sequences of three newly introduced strains clustered in close relationship with the type strain of F. citata, the type species of the genus. Three strains, including one resembling Flamella sp., were positioned within a sister-group containing Paraflabellula spp. Results of phylogenetic analysis confirmed doubts of previous authors regarding generic assignment of several Rhizamoeba and Ripidomyxa strains.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public