| morphology and molecular phylogeny of three cyrtophorid ciliates (protozoa, ciliophora) from china, including two new species, chilodonella parauncinata sp. n. and chlamydonella irregularis sp. n. | this study investigated the morphology and molecular characteristics of three interesting free-living cyrtophorid ciliates, including two new species, isolated from china: chilodonella parauncinata sp. n. can be identified by its elongated body shape, with a sharp protrusion in the left anterior part, cell size ca. 60 × 25 μm in vivo, five right and 6-7 left kineties with kinetosomes densely arranged, and a curved cyrtos. chlamydonella irregularis sp. n. differs from its congeners by the oval bo ... | 2015 | 25227732 |
| heterogeneous rates of molecular evolution among cryptic species of the ciliate morphospecies chilodonella uncinata. | while molecular analyses have provided insight into the phylogeny of ciliates, the few studies assessing intraspecific variation have largely relied on just a single locus [e.g., nuclear small subunit rdna (nssu-rdna) or mitochondrial cytochrome oxidase i]. in this study, we characterize the diversity of several nuclear protein-coding genes plus both nssu-rdna and mitochondrial small subunit rdna (mtssu-rdna) of five isolates of the ciliate morphospecies chilodonella uncinata. although these iso ... | 2012 | 22258433 |
| alternative processing of scrambled genes generates protein diversity in the ciliate chilodonella uncinata. | in ciliates, chromosomal rearrangements occur during the development of the somatic macronuclear genome from the germline micronuclear genome. these rearrangements are extensive in three ciliate classes-armophorea, spirotrichea, and phyllopharyngea-generating a macronucleus with up to 20,000,000 gene-sized chromosomes. earlier, we have shown that these three classes also share elevated rates of protein evolution relative to other ciliates. to assess the evolution of germline-limited sequences in ... | 2010 | 20700892 |
| non-mendelian inheritance of paralogs of 2 cytoskeletal genes in the ciliate chilodonella uncinata. | recognition of the role of non-mendelian inheritance is on the rise, particularly as epigenetic phenomena are shown to shape the transformation of genomes into phenotypes. ciliates provide a model system in which to explore the role of epigenetics because ciliates have both a germ line (micronuclear) and somatic (macronuclear) genome within every cell. in the ciliate chilodonella uncinata, the macronucleus is extensively fragmented such that many genes end up on their own chromosomes. hence, it ... | 2007 | 17890762 |
| variation in macronuclear genome content of three ciliates with extensive chromosomal fragmentation: a preliminary analysis. | the genome architecture of ciliates, including features such as nuclear dualism and large-scale genome rearrangements, impacts gene and genome evolution in these organisms. to better understand the structure of macronuclear chromosomes in ciliates with extensively processed chromosomes, a sample of complete macronuclear chromosomes was sequenced from three ciliate species: metopus es (class [cl]: armophorea), nyctotherus ovalis (cl: armophorea), and chilodonella uncinata (cl: phyllopharyngea). b ... | 2007 | 17552979 |
| benthic ciliates in adriatic sea lagoons. | sediment samples were collected from four sandy and muddy bottom sites at both sacca di goro lagoon (northern adriatic sea) and lesina lagoon (southern adriatic sea) on one occasion in may and one occasion in july in order to make a comparative study of ciliate abundance and diversity. the temperature, ph, dissolved oxygen, and redox potential were measured at the time of collection, the water content of the sediments was determined, and samples subjected to granulometric analysis. the ciliated ... | 2006 | 17070761 |
| short-term harmful effects of ammonia nitrogen on activated sludge microfauna. | the response of activated sludge microfauna in terms of abundance and diversity has been analysed to evaluate both the toxic effect of ammonia nitrogen and the acclimatisation capacity of these microorganisms to its toxicity. the harmful effect of ammonia nitrogen was studied by means of two toxicological tests. the ammonia concentrations tested were: 9, 20, 30 and 50mg nh4+-n/l in the first toxicological test and 30, 40, 50 and 80 mg nh4+-n/l in the second. the results suggest that ammonia nitr ... | 2005 | 16213541 |
| structure of the micronuclear alpha-tubulin gene in the phyllopharyngean ciliate chilodonella uncinata: implications for the evolution of chromosomal processing. | ciliates are a group of microbial eukaryotes defined by the presence of dimorphic nuclei-each cell contains both a transcriptionally active macronucleus and a germline micronucleus. during the development of the macronucleus, germline chromosomes are rearranged through extensive fragmentation, removal of internally excised sequences (iess) and dna amplification. we have characterized three iess in the gene that encodes alpha-tubulin in the phyllopharyngean ciliate chilodonella uncinata. the iess ... | 2003 | 14557060 |
| evolution of duplicated alpha-tubulin genes in ciliates. | ciliates provide a powerful system to analyze the evolution of duplicated alpha-tubulin genes in the context of single-celled organisms. genealogical analyses of ciliate alpha-tubulin sequences reveal five apparently recent gene duplications. comparisons of paralogs in different ciliates implicate differing patterns of substitutions (e.g., ratios of replacement/synonymous nucleotides and radical/conservative amino acids) following duplication. most substitutions between paralogs in euplotes cras ... | 2002 | 12144013 |
| chilodonella uncinata is not pathogenic to culex pipiens mosquitoes. | chilodonella uncinata was previously reported to be pathogenic to culex and other mosquitoes based on the observation of high densities of ciliates inside of dead mosquito larvae. here, we tested whether co-culturing cx. pipiens with ch. uncinata resulted in decreased survival of the mosquito larvae. we find no evidence that ch. uncinata is pathogenic to cx. pipiens. we suggest that ch. uncinata may instead feed on already deceased larvae. | 2013 | 23413784 |
| protists with different feeding modes change biofilm morphology. | the effect of dexiostoma (filter feeder), vannella, chilodonella (raptorial feeders), spumella, and neobodo (direct interception feeders) on the morphology of multispecies bacterial biofilms was investigated in small flow cells. the filter feeder dexiostoma campylum did not alter biofilm volume and porosity but stimulated the formation of larger microcolonies compared with ungrazed biofilms. in contrast, the raptorial feeder vannella sp. efficiently grazed bacteria from the biofilm surface, lead ... | 2009 | 19519785 |
| electron microscopic studies on the macronuclear development in the ciliate chilodonella uncinata. | the development of macronuclear anlage in the ciliate chilodonella uncinata has been studied through electron microscopy. the ultrastructure of macro- and micronuclei is described for comparison. during the first stage of development, when the dna content of the macronuclear anage increases from 2 c to 32 c, chromosomes are visible as distinct osmiophilic bodies inside the anlage. at the end of the initial polyploidization phase, the chromosomes despiralize, giving rise to long filamentous struc ... | 1978 | 101400 |
| genome structure drives patterns of gene family evolution in ciliates, a case study using chilodonella uncinata (protista, ciliophora, phyllopharyngea). | in most lineages, diversity among gene family members results from gene duplication followed by sequence divergence. because of the genome rearrangements during the development of somatic nuclei, gene family evolution in ciliates involves more complex processes. previous work on the ciliate chilodonella uncinata revealed that macronuclear β-tubulin gene family members are generated by alternative processing, in which germline regions are alternatively used in multiple macronuclear chromosomes. t ... | 2014 | 24749903 |
| microfauna community during pulp and paper wastewater treatment in a unox system. | this study characterized the microfauna community during treatment of pulp and paper wastewater in a unox system aerated with pure oxygen, and with a high organic loading rate (0.4±0.06kg bod/kg mlssday), low sludge retention time (3.73±0.33 day), and high oxygen concentration (≤20mg o2/l) in comparison to municipal treatment systems. in the aeration tank, temperatures were high, averaging 35.7°c (march-may), then 38.9°c (june-august). effluent quality was acceptable: 180±22mg cod/l, 7.2±2.1mg b ... | 2017 | 28314218 |
| morphological and molecular characterization of parafurgasonia zhangi spec. nov. and chilodonella acuta kahl, 1931 (protozoa, ciliophora), from a soil habitat of saudi arabia. | the morphology and infraciliature of two soil ciliates, parafurgasonia zhangi spec. nov. and chilodonella acuta kahl, 1931, collected from saudi arabia, were investigated by observations of both living cells and specimens after standard staining methods. p. zhangi differs from its congeners by the combination of the following features: excretory pore quite near posterior end of paroral membrane, 16 or 17 somatic kineties with about 11 kinetids in each one on dorsal side, paroral membrane gently ... | 2014 | 24760797 |
| micronuclear and macronuclear forms of beta-tubulin genes in the ciliate chilodonella uncinata reveal insights into genome processing and protein evolution. | chilodonella uncinata, like all ciliates, contains two distinct nuclei in every cell: a germline micronucleus and a somatic macronucleus. during development of the macronucleus from a zygotic nucleus, the genome is processed in several ways, including elimination of internal sequences. in this study, we analyze micronuclear and macronuclear copies of beta-tubulin in c. uncinata and find at least four divergent paralogs of beta-tubulin in the macronucleus. we characterize the micronuclear version ... | 2007 | 17552983 |
| analyses of chromosome copy number and expression level of four genes in the ciliate chilodonella uncinata reveal a complex pattern that suggests epigenetic regulation. | chilodonella uncinata, like all ciliates, contains two distinct nuclei in every cell: a germline micronucleus and a somatic macronucleus. the macronucleus develops from the zygotic nucleus through a series of chromosomal rearrangements. macronuclear development in c. uncinata yields a nucleus with highly amplified gene-sized chromosomes. the macronucleus is transcriptionally active during vegetative growth while there is no expression in the micronucleus except during a brief period following co ... | 2012 | 22588027 |
| chromosome copy number variation and control in the ciliate chilodonella uncinata. | copy number variations are widespread in eukaryotes. the unusual genome architecture of ciliates, in particular, with its process of amitosis in macronuclear division, provides a valuable model in which to study copy number variation. the current model of amitosis envisions stochastic distribution of macronuclear chromosomes during asexual reproduction. this suggests that amitosis is likely to result in high levels of copy number variation in ciliates, as dividing daughter cells can have variabl ... | 2013 | 23437129 |
| nanochromosome copy number does not correlate with rna levels though patterns are conserved between strains of the ciliate morphospecies chilodonella uncinata. | in some ciliates, extensive genome fragmentation leads to a macronucleus (i.e. somatic nucleus) containing gene-sized chromosomes that vary in copy number. yet the relationship between copy number and expression level is not well understood as previous work has shown a variety of patterns. for example, nanochromosome copy numbers are positively correlated to mrna levels in spirotrichous ciliates, while one study of chilodonella uncinata suggested that they were inversely correlated. to study fur ... | 2014 | 24907652 |
| colonization dynamics of ciliate morphotypes modified by shifting sandy sediments. | sandy stream-bed sediments colonized by a diverse ciliate community are subject to various disturbance regimes. in microcosms, we investigated the effect of sediment shifting on the colonization dynamics of 3 ciliate morphotypes differing in morphology, behavior and feeding strategy. the dynamics of the ciliate morphotypes inhabiting sediment pore water and overlying water were observed at 3 sediment shifting frequencies: (1) stable sediments, (2) periodically shifting sediments such as migratin ... | 2014 | 25129834 |
| analyses of alternatively processed genes in ciliates provide insights into the origins of scrambled genomes and may provide a mechanism for speciation. | chromosome rearrangements occur in a variety of eukaryotic life cycles, including during the development of the somatic macronuclear genome in ciliates. previous work on the phyllopharyngean ciliate chilodonella uncinata revealed that macronuclear β-tubulin and protein kinase gene families share alternatively processed germ line segments nested within divergent regions. to study genome evolution in this ciliate further, we characterized two additional alternatively processed gene families from t ... | 2015 | 25650397 |
| nuclear architecture and patterns of molecular evolution are correlated in the ciliate chilodonella uncinata. | the relationship between nuclear architecture and patterns of molecular evolution in lineages across the eukaryotic tree of life is not well understood, partly because molecular evolution is traditionally explored as changes in base pairs along a linear sequence without considering the context of nuclear position of chromosomes. the ciliate chilodonella uncinata is an ideal system to address the relationship between nuclear architecture and patterns of molecular evolution as the somatic macronuc ... | 2016 | 27189988 |
| exploration of the germline genome of the ciliate chilodonella uncinata through single-cell omics (transcriptomics and genomics). | separate germline and somatic genomes are found in numerous lineages across the eukaryotic tree of life, often separated into distinct tissues (e.g., in plants, animals, and fungi) or distinct nuclei sharing a common cytoplasm (e.g., in ciliates and some foraminifera). in ciliates, germline-limited (i.e., micronuclear-specific) dna is eliminated during the development of a new somatic (i.e., macronuclear) genome in a process that is tightly linked to large-scale genome rearrangements, such as de ... | 2018 | 29317511 |
| evolution of germline-limited sequences in two populations of the ciliate chilodonella uncinata. | ciliates are microbial eukaryotes that separate their nuclear functions into a germline micronucleus and a somatic macronucleus. during development of the macronucleus the genome undergoes a series of reorganization events that includes the precise excision of intervening dna. here, we determine the architecture of four loci in the micronuclear and macronuclear genomes of the ciliate chilodonella uncinata and compare the levels of variation in micronuclear-limited sequences to macronuclear desti ... | 2012 | 22411695 |
| characterization of the life cycle and heteromeric nature of the macronucleus of the ciliate chilodonella uncinata using fluorescence microscopy. | only a limited number of studies exist on the life cycles of nonmodel ciliates such as chilodonella uncinata (cl: phyllopharyngea). the handful of papers on this taxon indicate the presence of a heteromeric macronucleus, marked by separate dna-rich and dna-poor regions. here, we study the life cycle of c. uncinata using confocal laser scanning microscopy with 4',6-diamidino-2-phenylindole staining, which allows us to differentiate nuclear dynamics of the micronucleus and the macronucleus during ... | 2017 | 24547950 |