SEARCH · Search PubMed

Results for “Tetrahymenina”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMed1977

[Ultrastructural characteristics of the cortex and of the membranelles of the ciliate Espejoia mucicola (Oligohymenophora, Hymenostomata, Tetrahymenina)].

It was shown in a detailed study of the cortex and buccal organelles of Espejoia that, at the ultrastructural level, the general plan of organization of this ciliate conforms to that of Tetrahymenina. Specific variations seen in the cortex and membranelles bring out the very pronounced affinities of Espejoia to the genus Glaucoma and other related ciliates. In view of the foregoing and on the basis of reccent findings on morphogenesis, we confirm the taxonomic position of Espejoia mucicola among Tetrahymenina in the family Glaucomidae.

Animals↗

PubMed1985

5S and 5.8S ribosomal RNA evolution in the suborder Tetrahymenina (Ciliophora: Hymenostomatida).

The nucleotide sequences of the 5S and 5.8S rRNAs of eight strains of tetrahymenine ciliates have been determined. The sequences indicate a clear distinction between Tetrahymena paravorax and its suggested conspecific T. vorax, but leave the taxonomic distinction between T. vorax and T. leucophrys in doubt. The rRNA sequences of six Tetrahymena species and of three other species of the suborder Tetrahymenina have been used to deduce evolutionary schemes in which ancestral rRNA sequences and changes are proposed. These schemes suggest the predominant acceptance of G----A and C----T transitions in the 5S rDNA during the evolution of the suborder.

Animals↗

PubMed2002

Phylogenetic relationships amongst tetrahymenine ciliates inferred by a comparison of telomerase RNAs.

The phylogenetic relationships between ciliate species in the suborder Tetrahymenina, order Hymenostomata, was investigated by comparing their telomerase RNA (TER) sequences. This relatively small RNA is an integral part of telomerase, the ribonucleoprotein enzyme that catalyses the synthesis of telomeric DNA. Despite a relatively rapid rate of primary sequence divergence, conserved functional and structural elements within TERs facilitate the accurate alignment of truly homologous nucleotides. The tetrahymenine phylogeny derived from distance analysis of TER sequences is largely consistent with those based on rRNA and histone sequences.

Animals↗

PubMed2000

Characterization of histone H3/H4 gene region and phylogenetic affinity of Ichthyophthirius multifiliis based on H4 DNA sequence variation.

We sequenced the amino-terminal third of the histone H3 and H4 genes and the intergenic region from Ichthyophthirius multifiliis. Fourteen recombinant clones of 646 bp were sequenced and the level of sequence variation detected among these clones was similar to that reported among closely related species of Tetrahymena and to levels of sequence variation detected within other ciliates. The intergenic region is 417 bp and approximately 92% AT rich, making it the longest and most AT-rich ciliate H3/H4 intergenic region yet identified. Similar to Tetrahymena, the intergenic region of Ichthyophthirius contains two CCAAT regions arranged in a complementary orientation. A neighbor-joining tree was constructed based on nucleotide sequence variation among H4 genes to evaluate evolutionary relationships within and among six classes of Ciliophora. The single shortest neighbor-joining tree depicted a sister-group relationship of Ichthyophthirius with taxa of Tetrahymenina, thereby supporting monophyly of Oligohymenophorea.

Amino Acid Sequence↗

PubMed1986

Conservation of sequences adjacent to the telomeric C4A2 repeats of ciliate macronuclear ribosomal RNA gene molecules.

We sequenced and compared the telomeric regions of linear rDNAs from vegetative macronuclei of several ciliates in the suborder Tetrahymenina. All telomeres consisted of tandemly repeated C4A2 sequences, including the 5' telomere of the 11 kb rDNA from developing macronuclei of Tetrahymena thermophila. Our sequence of the 11 kb 5' telomeric region shows that each one of a previously described pair of inverted repeats flanking the micronuclear rDNA (Yao et al., Mol. Cell. Biol. 5: 1260-1267, 1985) is 29 bp away from the positions to which telomeric C4A2 repeats are joined to the ends of excised 11 kb rDNA. In general we found that the macronuclear rDNA sequences adjacent to C4A2 repeats are not highly conserved. However, in the non-palindromic rDNA of Glaucoma, we identified a single copy of a conserved sequence, repeated in inverted orientation in Tetrahymena spp., which all form palindromic rDNAs. We propose that this sequence is required for a step in rDNA excision common to both Tetrahymena and Glaucoma.

Animals↗

PubMedDate not supplied

[Protist plankton from the Khanka lake].

We present data on studies of protists in Lake Khanka in late August-early September. A total of 99 species of protists have been found, of them 14 phytoflagellates, 14 zooflagellates, five sarcodins, two heliozoans, 62 infusoria, and two suctorians. Small infusoria from the class of Kinetophragminophora, order Oligotrichida, as well as suborder Tetrahymenina were most numerous. The density of many protist species in Lake Khanka exceeds markedly that in several other high-productivity water reservoirs. Most of the protists belong to bacteriovores (bacteriophages). Many of the found species have high density. This is evidence of the production of bacterial plankton in the lake. In view of very high water turbidity in the lake, we assume that the total production of phytoplankton is not that high. In this connection, an abundance of protists (protist plankton) indicates is an indication for the existence of an additional source of organic matter in Lake Khanka.

Animals↗

PubMed1949