LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 44

Search options

  1. Article ; Online: Selfing mutants link Ku proteins to mating type determination in Tetrahymena.

    Lin, I-Ting / Yao, Meng-Chao

    PLoS biology

    2020  Volume 18, Issue 8, Page(s) e3000756

    Abstract: Recognition of self and nonself is important for outcrossing organisms, and different mating types establish the barrier against self-mating. In the unicellular ciliate T. thermophila, mating type determination requires complex DNA rearrangements at a ... ...

    Abstract Recognition of self and nonself is important for outcrossing organisms, and different mating types establish the barrier against self-mating. In the unicellular ciliate T. thermophila, mating type determination requires complex DNA rearrangements at a single mat locus during conjugation to produce a type-specific gene pair (MTA and MTB) for 1 of 7 possible mating types. Surprisingly, we found that decreased expression of the DNA breakage-repair protein Ku80 at late stages of conjugation generated persistent selfing phenotype in the progeny. DNA analysis revealed multiple mating-type gene pairs as well as a variety of mis-paired, unusually arranged mating-type genes in these selfers that resemble some proposed rearrangement intermediates. They are found also in normal cells during conjugation and are lost after 10 fissions but are retained in Ku mutants. Silencing of TKU80 or TKU70-2 immediately after conjugation also generated selfing phenotype, revealing a hidden DNA rearrangement process beyond conjugation. Mating reactions between the mutant and normal cells suggest a 2-component system for self-nonself-recognition through MTA and MTB genes.
    MeSH term(s) Conjugation, Genetic ; Crosses, Genetic ; DNA, Protozoan/genetics ; DNA, Protozoan/metabolism ; Gene Expression ; Gene Rearrangement ; Gene Silencing ; Ku Autoantigen/genetics ; Ku Autoantigen/metabolism ; Phenotype ; Protozoan Proteins/genetics ; Protozoan Proteins/metabolism ; Reproduction ; Tetrahymena thermophila/genetics ; Tetrahymena thermophila/metabolism
    Chemical Substances DNA, Protozoan ; Protozoan Proteins ; Ku Autoantigen (EC 4.2.99.-)
    Language English
    Publishing date 2020-08-03
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2126776-5
    ISSN 1545-7885 ; 1544-9173
    ISSN (online) 1545-7885
    ISSN 1544-9173
    DOI 10.1371/journal.pbio.3000756
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Structure and dynamics of the contractile vacuole complex in Tetrahymena thermophila.

    Cheng, Chao-Yin / Romero, Daniel P / Zoltner, Martin / Yao, Meng-Chao / Turkewitz, Aaron P

    Journal of cell science

    2023  Volume 136, Issue 22

    Abstract: The contractile vacuole complex (CVC) is a dynamic and morphologically complex membrane organelle, comprising a large vesicle (bladder) linked with a tubular reticulum (spongiome). CVCs provide key osmoregulatory roles across diverse eukaryotic lineages, ...

    Abstract The contractile vacuole complex (CVC) is a dynamic and morphologically complex membrane organelle, comprising a large vesicle (bladder) linked with a tubular reticulum (spongiome). CVCs provide key osmoregulatory roles across diverse eukaryotic lineages, but probing the mechanisms underlying their structure and function is hampered by the limited tools available for in vivo analysis. In the experimentally tractable ciliate Tetrahymena thermophila, we describe four proteins that, as endogenously tagged constructs, localize specifically to distinct CVC zones. The DOPEY homolog Dop1p and the CORVET subunit Vps8Dp localize both to the bladder and spongiome but with different local distributions that are sensitive to osmotic perturbation, whereas the lipid scramblase Scr7p colocalizes with Vps8Dp. The H+-ATPase subunit Vma4 is spongiome specific. The live imaging permitted by these probes revealed dynamics at multiple scales including rapid exchange of CVC-localized and soluble protein pools versus lateral diffusion in the spongiome, spongiome extension and branching, and CVC formation during mitosis. Although the association with DOP1 and VPS8D implicate the CVC in endosomal trafficking, both the bladder and spongiome might be isolated from bulk endocytic input.
    MeSH term(s) Vacuoles/metabolism ; Tetrahymena thermophila ; Endosomes ; Proteins/metabolism ; Mitosis
    Chemical Substances Proteins
    Language English
    Publishing date 2023-11-27
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2993-2
    ISSN 1477-9137 ; 0021-9533
    ISSN (online) 1477-9137
    ISSN 0021-9533
    DOI 10.1242/jcs.261511
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Modulating somatic DNA copy number through maternal RNA.

    Yao, Meng-Chao

    Proceedings of the National Academy of Sciences of the United States of America

    2010  Volume 107, Issue 51, Page(s) 21951–21952

    MeSH term(s) Animals ; Chromosomes/genetics ; Chromosomes/metabolism ; Ciliophora/genetics ; Ciliophora/metabolism ; DNA Copy Number Variations/physiology ; DNA, Protozoan/genetics ; DNA, Protozoan/metabolism ; Epigenesis, Genetic/physiology ; Gene Amplification/physiology ; Gene Dosage/physiology ; Genes, Protozoan/physiology ; Genome, Protozoan/physiology ; Macronucleus/genetics ; Macronucleus/metabolism ; Micronucleus, Germline/genetics ; Micronucleus, Germline/metabolism ; Models, Genetic ; RNA, Protozoan/genetics ; RNA, Protozoan/metabolism ; RNA, Small Nuclear/genetics ; RNA, Small Nuclear/metabolism
    Chemical Substances DNA, Protozoan ; RNA, Protozoan ; RNA, Small Nuclear
    Language English
    Publishing date 2010-12-13
    Publishing country United States
    Document type Comment ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.1017135108
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Abundant and diverse Tetrahymena species living in the bladder traps of aquatic carnivorous Utricularia plants.

    Cheng, Chao-Yin / Chang, Shang-Lin / Lin, I-Ting / Yao, Meng-Chao

    Scientific reports

    2019  Volume 9, Issue 1, Page(s) 13669

    Abstract: Ciliates are unicellular eukaryotes known for their cellular complexity and wide range of natural habitats. How they adapt to their niches and what roles they play in ecology remain largely unknown. The genus Tetrahymena is among the best-studied groups ... ...

    Abstract Ciliates are unicellular eukaryotes known for their cellular complexity and wide range of natural habitats. How they adapt to their niches and what roles they play in ecology remain largely unknown. The genus Tetrahymena is among the best-studied groups of ciliates and one particular species, Tetrahymena thermophila, is a well-known laboratory model organism in cell and molecular biology, making it an excellent candidate for study in protist ecology. Here, based on cytochrome c oxidase subunit I (COX1) gene barcoding, we identify a total of 19 different putative Tetrahymena species and two closely related Glaucoma lineages isolated from distinct natural habitats, of which 13 are new species. These latter include 11 Tetrahymena species found in the bladder traps of Utricularia plants, the most species-rich and widely distributed aquatic carnivorous plant, thus revealing a previously unknown but significant symbiosis of Tetrahymena species living among the microbial community of Utricularia bladder traps. Additional species were collected using an artificial trap method we have developed. We show that diverse Tetrahymena species may live even within the same habitat and that their populations are highly dynamic, suggesting that the diversity and biomass of species worldwide is far greater than currently appreciated.
    MeSH term(s) Aquatic Organisms/parasitology ; Carnivory ; Cyclooxygenase 1/genetics ; DNA Barcoding, Taxonomic ; Lamiales/parasitology ; Phylogeny ; Phylogeography ; Protozoan Proteins/genetics ; Sequence Analysis, DNA/methods ; Symbiosis ; Taiwan ; Tetrahymena/classification ; Tetrahymena/genetics ; Tetrahymena/isolation & purification
    Chemical Substances Protozoan Proteins ; Cyclooxygenase 1 (EC 1.14.99.1)
    Language English
    Publishing date 2019-09-20
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-019-50123-1
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Molecular biology. RNA rules.

    Yao, Meng-Chao

    Nature

    2008  Volume 451, Issue 7175, Page(s) 131–132

    MeSH term(s) Animals ; DNA, Protozoan/genetics ; DNA, Protozoan/metabolism ; Epistasis, Genetic ; Gene Expression Regulation, Developmental/genetics ; Gene Rearrangement/genetics ; Genome, Protozoan/genetics ; Macronucleus/genetics ; Oxytricha/cytology ; Oxytricha/genetics ; Oxytricha/growth & development ; RNA, Protozoan/genetics ; RNA, Protozoan/metabolism ; Templates, Genetic
    Chemical Substances DNA, Protozoan ; RNA, Protozoan
    Language English
    Publishing date 2008-01-10
    Publishing country England
    Document type Comment ; News
    ZDB-ID 120714-3
    ISSN 1476-4687 ; 0028-0836
    ISSN (online) 1476-4687
    ISSN 0028-0836
    DOI 10.1038/451131a
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Programmed Minichromosome Elimination as a Mechanism for Somatic Genome Reduction in Tetrahymena thermophila.

    Lin, Chih-Yi Gabriela / Lin, I-Ting / Yao, Meng-Chao

    PLoS genetics

    2016  Volume 12, Issue 11, Page(s) e1006403

    Abstract: The maintenance of chromosome integrity is crucial for genetic stability. However, programmed chromosome fragmentations are known to occur in many organisms, and in the ciliate Tetrahymena the five germline chromosomes are fragmented into hundreds of ... ...

    Abstract The maintenance of chromosome integrity is crucial for genetic stability. However, programmed chromosome fragmentations are known to occur in many organisms, and in the ciliate Tetrahymena the five germline chromosomes are fragmented into hundreds of minichromosomes during somatic nuclear differentiation. Here, we showed that there are different fates of these minichromosomes after chromosome breakage. Among the 326 somatic minichromosomes identified using genomic data, 50 are selectively eliminated from the mature somatic genome. Interestingly, many and probably most of these minichromosomes are eliminated during the growth period between 6 and 20 doublings right after conjugation. Genes with potential conjugation-specific functions are found in these minichromosomes. This study revealed a new mode of programmed DNA elimination in ciliates similar to those observed in parasitic nematodes, which could play a role in developmental gene regulation.
    MeSH term(s) Animals ; Cell Nucleus/genetics ; Chromosomal Instability/genetics ; Chromosome Breakage ; Chromosomes/genetics ; Databases, Genetic ; Gene Expression/genetics ; Genomic Library ; Germ Cells/growth & development ; Telomere/genetics ; Tetrahymena thermophila/genetics ; Tetrahymena thermophila/growth & development
    Language English
    Publishing date 2016-11-02
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2186725-2
    ISSN 1553-7404 ; 1553-7390
    ISSN (online) 1553-7404
    ISSN 1553-7390
    DOI 10.1371/journal.pgen.1006403
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Dynamic distributions of long double-stranded RNA in Tetrahymena during nuclear development and genome rearrangements.

    Woo, Tai-Ting / Chao, Ju-Lan / Yao, Meng-Chao

    Journal of cell science

    2016  Volume 129, Issue 5, Page(s) 1046–1058

    Abstract: Bi-directional non-coding transcripts and their ∼29-nt small RNA products are known to guide DNA deletion in Tetrahymena, leading to the removal of one-third of the genome from developing somatic nuclei. Using an antibody specific for long double- ... ...

    Abstract Bi-directional non-coding transcripts and their ∼29-nt small RNA products are known to guide DNA deletion in Tetrahymena, leading to the removal of one-third of the genome from developing somatic nuclei. Using an antibody specific for long double-stranded RNAs (dsRNAs), we determined the dynamic subcellular distributions of these RNAs. Conjugation-specific dsRNAs were found and show sequential appearances in parental germline, parental somatic nuclei and finally in new somatic nuclei of progeny. The dsRNAs in germline nuclei and new somatic nuclei are likely transcribed from the sequences destined for deletion; however, the dsRNAs in parental somatic nuclei are unexpected, and PCR analyses suggested that they were transcribed in this nucleus. Deficiency in the RNA interference (RNAi) pathway led to abnormal aggregations of dsRNA in both the parental and new somatic nuclei, whereas accumulation of dsRNAs in the germline nuclei was only seen in the Dicer-like gene mutant. In addition, RNAi mutants displayed an early loss of dsRNAs from developing somatic nuclei. Thus, long dsRNAs are made in multiple nuclear compartments and some are linked to small RNA production whereas others might participate in their regulations.
    MeSH term(s) Cell Nucleus/physiology ; Gene Rearrangement ; Genome, Protozoan ; Heterochromatin/metabolism ; Protozoan Proteins/genetics ; Protozoan Proteins/metabolism ; RNA Transport ; RNA, Double-Stranded/genetics ; RNA, Double-Stranded/metabolism ; RNA, Protozoan/genetics ; RNA, Protozoan/metabolism ; Tetrahymena
    Chemical Substances Heterochromatin ; Protozoan Proteins ; RNA, Double-Stranded ; RNA, Protozoan
    Language English
    Publishing date 2016-03-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2993-2
    ISSN 1477-9137 ; 0021-9533
    ISSN (online) 1477-9137
    ISSN 0021-9533
    DOI 10.1242/jcs.178236
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Setting boundaries for genome-wide heterochromatic DNA deletions through flanking inverted repeats in Tetrahymena thermophila.

    Lin, Chih-Yi Gabriela / Chao, Ju-Lan / Tsai, Huai-Kuang / Chalker, Douglas / Yao, Meng-Chao

    Nucleic acids research

    2019  Volume 47, Issue 10, Page(s) 5181–5192

    Abstract: Eukaryotic cells pack their genomic DNA into euchromatin and heterochromatin. Boundaries between these domains have been shown to be set by boundary elements. In Tetrahymena, heterochromatin domains are targeted for deletion from the somatic nuclei ... ...

    Abstract Eukaryotic cells pack their genomic DNA into euchromatin and heterochromatin. Boundaries between these domains have been shown to be set by boundary elements. In Tetrahymena, heterochromatin domains are targeted for deletion from the somatic nuclei through a sophisticated programmed DNA rearrangement mechanism, resulting in the elimination of 34% of the germline genome in ∼10,000 dispersed segments. Here we showed that most of these deletions occur consistently with very limited variations in their boundaries among inbred lines. We identified several potential flanking regulatory sequences, each associated with a subset of deletions, using a genome-wide motif finding approach. These flanking sequences are inverted repeats with the copies located at nearly identical distances from the opposite ends of the deleted regions, suggesting potential roles in boundary determination. By removing and testing two such inverted repeats in vivo, we found that the ability for boundary maintenance of the associated deletion were lost. Furthermore, we analyzed the deletion boundaries in mutants of a known boundary-determining protein, Lia3p and found that the subset of deletions that are affected by LIA3 knockout contained common features of flanking regulatory sequences. This study suggests a common mechanism for setting deletion boundaries by flanking inverted repeats in Tetrahymena thermophila.
    MeSH term(s) Amino Acid Motifs ; Cell Nucleus/metabolism ; DNA, Protozoan/genetics ; DNA, Protozoan/metabolism ; Euchromatin/chemistry ; Gene Deletion ; Gene Expression Regulation ; Gene Rearrangement ; Genome, Protozoan ; Heterochromatin/chemistry ; Protein Domains ; Protozoan Proteins/genetics ; Tetrahymena thermophila/genetics
    Chemical Substances DNA, Protozoan ; Euchromatin ; Heterochromatin ; Protozoan Proteins
    Language English
    Publishing date 2019-05-29
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkz209
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Setting boundaries for genome-wide heterochromatic DNA deletions through flanking inverted repeats in Tetrahymena thermophile.

    Lin, Chih-Yi Gabriela / Chao, Ju-Lan / Tsai, Huai-Kuang / Chalker, Douglas / Yao, Meng-Chao

    Nucleic acids research

    2019  Volume 47, Issue 13, Page(s) 7143–7144

    Language English
    Publishing date 2019-06-05
    Publishing country England
    Document type Journal Article ; Published Erratum
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkz481
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Tetrahymena thermophila JMJD3 homolog regulates H3K27 methylation and nuclear differentiation.

    Chung, Pei-Han / Yao, Meng-Chao

    Eukaryotic cell

    2012  Volume 11, Issue 5, Page(s) 601–614

    Abstract: Histone H3K27me3 modification is an important regulator for development and gene expression. In Tetrahymena thermophila, the complex chromatin dynamics of H3K27me3 marks during nuclear development suggested that an H3K27me3 demethylase might exist. Here, ...

    Abstract Histone H3K27me3 modification is an important regulator for development and gene expression. In Tetrahymena thermophila, the complex chromatin dynamics of H3K27me3 marks during nuclear development suggested that an H3K27me3 demethylase might exist. Here, we report an H3K27me3 demethylase homolog, JMJ1, in Tetrahymena. During conjugation, JMJ1 expression is upregulated and the protein is localized first in the parental macronucleus and then in the new macronucleus. In conjugating cells, knockdown of JMJ1 expression resulted in a severe reduction in the production of progeny, suggesting that JMJ1 is essential for Tetrahymena conjugation. Furthermore, knockdown of JMJ1 resulted in increased H3K27 trimethylation in the new macronucleus and reduced transcription of genes related to DNA elimination, while the DNA elimination process was also partially blocked. Knockdown of the H3K27 methyltransferase EZL2 but not that of EZL1 partially restored progeny production in JMJ1-knockdown cells and reduced abnormal H3K27me3 accumulation in the new macronucleus. Taken together, these results demonstrate a critical role for JMJ1 in regulating H3K27me3 during conjugation and the importance of JMJ1 in regulating gene expression in the new macronucleus but not in regulating the formation of heterochromatin associated with programmed DNA deletion.
    MeSH term(s) Amino Acid Sequence ; Blotting, Western ; Cadmium Chloride/pharmacology ; Chromatin Immunoprecipitation ; Chromosome Breakage ; Computational Biology ; Conjugation, Genetic ; DNA, Protozoan/genetics ; DNA, Protozoan/metabolism ; Gene Knockdown Techniques ; Heterochromatin/genetics ; Heterochromatin/metabolism ; Histone Methyltransferases ; Histone-Lysine N-Methyltransferase/genetics ; Histone-Lysine N-Methyltransferase/metabolism ; Histones/metabolism ; Jumonji Domain-Containing Histone Demethylases/metabolism ; Macronucleus/enzymology ; Macronucleus/genetics ; Macronucleus/metabolism ; Methylation ; Molecular Sequence Data ; Nuclear Proteins/genetics ; Nuclear Proteins/metabolism ; Phosphoproteins/genetics ; Phosphoproteins/metabolism ; Phylogeny ; Protozoan Proteins/genetics ; Protozoan Proteins/metabolism ; RNA Interference ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; RNA, Protozoan/genetics ; Sequence Alignment ; Sequence Homology, Amino Acid ; Tetrahymena thermophila/enzymology ; Tetrahymena thermophila/genetics ; Tetrahymena thermophila/metabolism ; Transcription, Genetic ; Transcriptional Activation
    Chemical Substances DNA, Protozoan ; Heterochromatin ; Histones ; Nuclear Proteins ; Pdd1 protein, Tetrahymena ; Phosphoproteins ; Protozoan Proteins ; RNA, Messenger ; RNA, Protozoan ; Jumonji Domain-Containing Histone Demethylases (EC 1.14.11.-) ; Histone Methyltransferases (EC 2.1.1.-) ; Histone-Lysine N-Methyltransferase (EC 2.1.1.43) ; Cadmium Chloride (J6K4F9V3BA)
    Language English
    Publishing date 2012-03-16
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2077635-4
    ISSN 1535-9786 ; 1535-9778
    ISSN (online) 1535-9786
    ISSN 1535-9778
    DOI 10.1128/EC.05290-11
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top