Ingestion and digestion studies in Tetrahymena pyriformis based on chemically modified microparticles

Dürichen, Hendrike; Siegmund, Lisa; Burmester, Anke; Fischer, Martin S.; Wöstemeyer, Johannes

doi:10.1016/j.ejop.2015.11.004

Cited by 15 publications

(16 citation statements)

References 44 publications

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“…Furthermore, the freshwater environment is one that is subject to more frequent and pronounced variation in physical and chemical conditions than the marine environment in which Tetrahymena ’s ancestors originated. Therefore, it seems reasonable to propose that Tetrahymena has evolved many different genes to specifically adjust to frequent environmental change, including the sensing of different bacterial foods and their digestion products [80–82]. Most Tetrahymena LRR genes do not include transmembrane domains, and many LRR proteins may be restricted to the cytoplasmic cell domain.…”

Section: Discussionmentioning

confidence: 99%

Hidden genomic evolution in a morphospecies—The landscape of rapidly evolving genes in Tetrahymena

et al. 2019

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A morphospecies is defined as a taxonomic species based wholly on morphology, but often morphospecies consist of clusters of cryptic species that can be identified genetically or molecularly. The nature of the evolutionary novelty that accompanies speciation in a morphospecies is an intriguing question. Morphospecies are particularly common among ciliates, a group of unicellular eukaryotes that separates 2 kinds of nuclei—the silenced germline nucleus (micronucleus [MIC]) and the actively expressed somatic nucleus (macronucleus [MAC])—within a common cytoplasm. Because of their very similar morphologies, members of the Tetrahymena genus are considered a morphospecies. We explored the hidden genomic evolution within this genus by performing a comprehensive comparative analysis of the somatic genomes of 10 species and the germline genomes of 2 species of Tetrahymena . These species show high genetic divergence; phylogenomic analysis suggests that the genus originated about 300 million years ago (Mya). Seven universal protein domains are preferentially included among the species-specific (i.e., the youngest) Tetrahymena genes. In particular, leucine-rich repeat (LRR) genes make the largest contribution to the high level of genome divergence of the 10 species. LRR genes can be sorted into 3 different age groups. Parallel evolutionary trajectories have independently occurred among LRR genes in the different Tetrahymena species. Thousands of young LRR genes contain tandem arrays of exactly 90-bp exons. The introns separating these exons show a unique, extreme phase 2 bias, suggesting a clonal origin and successive expansions of 90-bp–exon LRR genes. Identifying LRR gene age groups allowed us to document a Tetrahymena intron length cycle. The youngest 90-bp exon LRR genes in T . thermophila are concentrated in pericentromeric and subtelomeric regions of the 5 micronuclear chromosomes, suggesting that these regions act as genome innovation centers. Copies of a Tetrahymena Long interspersed element (LINE)-like retrotransposon are very frequently found physically adjacent to 90-bp exon/intron repeat units of the youngest LRR genes. We propose that Tetrahymena species have used a massive exon-shuffling mechanism, involving unequal crossing over possibly in concert with retrotransposition, to create the unique 90-bp exon array LRR genes.

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Section: Discussionmentioning

confidence: 99%

Hidden genomic evolution in a morphospecies—The landscape of rapidly evolving genes in Tetrahymena

et al. 2019

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“…The literature presents much data on the uptake of nano-and microparticles by protozoans, based on the particle size [10,19,23] and based on whether the particles are edible or inedible [20,21,24]. In most of the studies, specially prepared particles, mainly spherical microspheres, were used for analyses [10,19,22,23,[25][26][27]. However, in the natural environment, secondary microparticles of different shapes can be detected [28][29][30], and their uptake by protozoans may differ from that of primary microparticles.…”

Section: Introductionmentioning

confidence: 99%

Influence of Nano- and Small Microplastics on Ciliated Protozoan Spirostomum ambiguum (Müller, 1786) Ehrenberg, 1835

Nałęcz-Jawecki

Chojnacka

Wawryniuk

et al. 2021

Water

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This study evaluated the uptake of secondary nano- and small microparticles by the protozoan Spirostomum ambiguum, comparing edible (baker’s yeasts) and inedible (red latex) particles. Secondary nano- and microplastic particles were prepared from household materials made of four different polymers and served to the protozoans separately and as two-component mixtures in different proportions. The number and content of food vacuoles formed by the protozoan were analyzed using a digital microscope. The microscopic results showed that the protozoans ingested the secondary microplastic particles to a similar degree as the latex microspheres but to a lesser extent compared to the nutritional food—baker’s yeasts. At the microplastic concentrations of 1000 and 10,000 particles mL–1, no food vacuoles were observed inside the cells, which may be a finding of great ecological importance. In the protozoans served two-component mixtures, both microplastics and yeasts were found in the vacuoles formed by the organisms. The egestion of two-component vacuoles by the protozoans was slower than that of vacuoles containing a single component.

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“…M6A modification of linc1281 regulates mESC differentiation through ceRNA mechanisms [ 12 ]. H19 knockdown actives S-adenosyl homocysteine hydrolase, then increases DNMT3b-mediated methylation of lncRNA-coding gene Nctc1 within the lgf2-H19-Nctc1 locus [ 22 ]. LncRNAs play different roles while located in the cytoplasm or nucleus [ 16 ].…”

Section: Discussionmentioning

confidence: 99%

Downregulated lncRNA RCPCD promotes differentiation of embryonic stem cells into cardiac pacemaker-like cells by suppressing HCN4 promoter methylation

Zhu

You²,

Wei

et al. 2021

Cell Death Dis

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Long non-coding RNA (lncRNA) is receiving increasing attention in embryonic stem cells (ESCs) research. However, the roles of lncRNA in the differentiation of ESCs into pacemaker-like cells are still unclear. Therefore, the present study aims to explore the roles and mechanisms of lncRNA in the differentiation of ESCs into pacemaker-like cells. ESCs were cultured and induced differentiation to pacemaker-like cells. RNA sequencing was used to identify the differential expression lncRNAs during the differentiation of ESCs into pacemaker-like cells. Cell morphology observation, flow cytometry, quantitative real-time polymerase chain reaction, western blot, and immunofluorescence were used to detect the differentiation of ESCs into pacemaker-like cells. LncRNA and genes overexpression or knockdown through transfected adenovirus in the differentiation process. The fluorescence in situ hybridization (FISH) detected the lncRNA location in the differentiated ESCs. Luciferase reporter gene assay, methylation-specific PCR, chromatin immunoprecipitation assay, and RNA immunoprecipitation assay were performed to reveal the mechanism of lncRNA-regulating HCN4 expression. Rescue experiments were used to confirm that lncRNA regulates the differentiation of ESCs into pacemaker-like cells through HCN4. We cultured the ESCs and induced the differentiation of ESCs into pacemaker-like cells successfully. The expression of lncRNA RCPCD was significantly decreased in the differentiation of ESCs into pacemaker-like cells. Overexpression of RCPCD inhibited the differentiation of ESCs into pacemaker-like cells. RCPCD inhibited the expression of HCN4 by increasing HCN4 methylation at the promoter region through DNMT1, DNMT2, and DNMT3. RCPCD inhibited the differentiation of ESCs into pacemaker-like cells by inhibiting the expression of HCN4. Our results confirm the roles and mechanism of lncRNA RCPCD in the differentiation of ESCs into pacemaker-like cells, which could pave the path for the development of a cell-based biological pacemaker.

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Ingestion and digestion studies in Tetrahymena pyriformis based on chemically modified microparticles

Cited by 15 publications

References 44 publications

Hidden genomic evolution in a morphospecies—The landscape of rapidly evolving genes in Tetrahymena

Hidden genomic evolution in a morphospecies—The landscape of rapidly evolving genes in Tetrahymena

Influence of Nano- and Small Microplastics on Ciliated Protozoan Spirostomum ambiguum (Müller, 1786) Ehrenberg, 1835

Downregulated lncRNA RCPCD promotes differentiation of embryonic stem cells into cardiac pacemaker-like cells by suppressing HCN4 promoter methylation

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